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24b8a236 |
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18-Oct-2023 |
Linus Torvalds <torvalds@linux-foundation.org> |
x86/fpu: Clean up FPU switching in the middle of task switching It happens to work, but it's very very wrong, because our 'current' macro is magic that is supposedly loading a stable value. It just happens to be not quite stable enough and the compilers re-load the value enough for this code to work. But it's wrong. The whole struct fpu *prev_fpu = &prev->fpu; thing in __switch_to() is pretty ugly. There's no reason why we should look at that 'prev_fpu' pointer there, or pass it down. And it only generates worse code, in how it loads 'current' when __switch_to() has the right task pointers. The attached patch not only cleans this up, it actually generates better code too: (a) it removes one push/pop pair at entry/exit because there's one less register used (no 'current') (b) it removes that pointless load of 'current' because it just uses the right argument: - movq %gs:pcpu_hot(%rip), %r12 - testq $16384, (%r12) + testq $16384, (%rdi) Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20231018184227.446318-1-ubizjak@gmail.com
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#
7fef0997 |
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07-Mar-2023 |
Linus Torvalds <torvalds@linux-foundation.org> |
x86/resctl: fix scheduler confusion with 'current' The implementation of 'current' on x86 is very intentionally special: it is a very common thing to look up, and it uses 'this_cpu_read_stable()' to get the current thread pointer efficiently from per-cpu storage. And the keyword in there is 'stable': the current thread pointer never changes as far as a single thread is concerned. Even if when a thread is preempted, or moved to another CPU, or even across an explicit call 'schedule()' that thread will still have the same value for 'current'. It is, after all, the kernel base pointer to thread-local storage. That's why it's stable to begin with, but it's also why it's important enough that we have that special 'this_cpu_read_stable()' access for it. So this is all done very intentionally to allow the compiler to treat 'current' as a value that never visibly changes, so that the compiler can do CSE and combine multiple different 'current' accesses into one. However, there is obviously one very special situation when the currently running thread does actually change: inside the scheduler itself. So the scheduler code paths are special, and do not have a 'current' thread at all. Instead there are _two_ threads: the previous and the next thread - typically called 'prev' and 'next' (or prev_p/next_p) internally. So this is all actually quite straightforward and simple, and not all that complicated. Except for when you then have special code that is run in scheduler context, that code then has to be aware that 'current' isn't really a valid thing. Did you mean 'prev'? Did you mean 'next'? In fact, even if then look at the code, and you use 'current' after the new value has been assigned to the percpu variable, we have explicitly told the compiler that 'current' is magical and always stable. So the compiler is quite free to use an older (or newer) value of 'current', and the actual assignment to the percpu storage is not relevant even if it might look that way. Which is exactly what happened in the resctl code, that blithely used 'current' in '__resctrl_sched_in()' when it really wanted the new process state (as implied by the name: we're scheduling 'into' that new resctl state). And clang would end up just using the old thread pointer value at least in some configurations. This could have happened with gcc too, and purely depends on random compiler details. Clang just seems to have been more aggressive about moving the read of the per-cpu current_task pointer around. The fix is trivial: just make the resctl code adhere to the scheduler rules of using the prev/next thread pointer explicitly, instead of using 'current' in a situation where it just wasn't valid. That same code is then also used outside of the scheduler context (when a thread resctl state is explicitly changed), and then we will just pass in 'current' as that pointer, of course. There is no ambiguity in that case. The fix may be trivial, but noticing and figuring out what went wrong was not. The credit for that goes to Stephane Eranian. Reported-by: Stephane Eranian <eranian@google.com> Link: https://lore.kernel.org/lkml/20230303231133.1486085-1-eranian@google.com/ Link: https://lore.kernel.org/lkml/alpine.LFD.2.01.0908011214330.3304@localhost.localdomain/ Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Tony Luck <tony.luck@intel.com> Tested-by: Stephane Eranian <eranian@google.com> Tested-by: Babu Moger <babu.moger@amd.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
c063a217 |
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15-Sep-2022 |
Thomas Gleixner <tglx@linutronix.de> |
x86/percpu: Move current_top_of_stack next to current_task Extend the struct pcpu_hot cacheline with current_top_of_stack; another very frequently used value. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220915111145.493038635@infradead.org
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#
e57ef2ed |
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15-Sep-2022 |
Thomas Gleixner <tglx@linutronix.de> |
x86: Put hot per CPU variables into a struct The layout of per-cpu variables is at the mercy of the compiler. This can lead to random performance fluctuations from build to build. Create a structure to hold some of the hottest per-cpu variables, starting with current_task. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220915111145.179707194@infradead.org
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#
f5c0b4f3 |
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12-May-2022 |
Thomas Gleixner <tglx@linutronix.de> |
x86/prctl: Remove pointless task argument The functions invoked via do_arch_prctl_common() can only operate on the current task and none of these function uses the task argument. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/87lev7vtxj.ffs@tglx
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3a24a608 |
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25-Mar-2022 |
Brian Gerst <brgerst@gmail.com> |
x86/32: Remove lazy GS macros GS is always a user segment now. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lore.kernel.org/r/20220325153953.162643-4-brgerst@gmail.com
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63e81807 |
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14-Oct-2021 |
Thomas Gleixner <tglx@linutronix.de> |
x86/fpu: Move context switch and exit to user inlines into sched.h internal.h is a kitchen sink which needs to get out of the way to prepare for the upcoming changes. Move the context switch and exit to user inlines into a separate header, which is all that code needs. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20211015011539.349132461@linutronix.de
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9568bfb4 |
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14-Oct-2021 |
Thomas Gleixner <tglx@linutronix.de> |
x86/fpu: Remove pointless argument from switch_fpu_finish() Unused since the FPU switching rework. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20211015011538.433135710@linutronix.de
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44e21535 |
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29-Jun-2020 |
Dmitry Safonov <0x7f454c46@gmail.com> |
x86/dumpstack: Add log_lvl to __show_regs() show_trace_log_lvl() provides x86 platform-specific way to unwind backtrace with a given log level. Unfortunately, registers dump(s) are not printed with the same log level - instead, KERN_DEFAULT is always used. Arista's switches uses quite common setup with rsyslog, where only urgent messages goes to console (console_log_level=KERN_ERR), everything else goes into /var/log/ as the console baud-rate often is indecently slow (9600 bps). Backtrace dumps without registers printed have proven to be as useful as morning standups. Furthermore, in order to introduce KERN_UNSUPPRESSED (which I believe is still the most elegant way to fix raciness of sysrq[1]) the log level should be passed down the stack to register dumping functions. Besides, there is a potential use-case for printing traces with KERN_DEBUG level [2] (where registers dump shouldn't appear with higher log level). Add log_lvl parameter to __show_regs(). Keep the used log level intact to separate visible change. [1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/ [2]: https://lore.kernel.org/linux-doc/20190724170249.9644-1-dima@arista.com/ Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Petr Mladek <pmladek@suse.com> Link: https://lkml.kernel.org/r/20200629144847.492794-3-dima@arista.com
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#
e31cf2f4 |
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08-Jun-2020 |
Mike Rapoport <rppt@kernel.org> |
mm: don't include asm/pgtable.h if linux/mm.h is already included Patch series "mm: consolidate definitions of page table accessors", v2. The low level page table accessors (pXY_index(), pXY_offset()) are duplicated across all architectures and sometimes more than once. For instance, we have 31 definition of pgd_offset() for 25 supported architectures. Most of these definitions are actually identical and typically it boils down to, e.g. static inline unsigned long pmd_index(unsigned long address) { return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1); } static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address) { return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address); } These definitions can be shared among 90% of the arches provided XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined. For architectures that really need a custom version there is always possibility to override the generic version with the usual ifdefs magic. These patches introduce include/linux/pgtable.h that replaces include/asm-generic/pgtable.h and add the definitions of the page table accessors to the new header. This patch (of 12): The linux/mm.h header includes <asm/pgtable.h> to allow inlining of the functions involving page table manipulations, e.g. pte_alloc() and pmd_alloc(). So, there is no point to explicitly include <asm/pgtable.h> in the files that include <linux/mm.h>. The include statements in such cases are remove with a simple loop: for f in $(git grep -l "include <linux/mm.h>") ; do sed -i -e '/include <asm\/pgtable.h>/ d' $f done Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nick Hu <nickhu@andestech.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
8dd97c65 |
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05-May-2020 |
Reinette Chatre <reinette.chatre@intel.com> |
x86/resctrl: Rename asm/resctrl_sched.h to asm/resctrl.h asm/resctrl_sched.h is dedicated to the code used for configuration of the CPU resource control state when a task is scheduled. Rename resctrl_sched.h to resctrl.h in preparation of additions that will no longer make this file dedicated to work done during scheduling. No functional change. Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/6914e0ef880b539a82a6d889f9423496d471ad1d.1588715690.git.reinette.chatre@intel.com
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#
ffd75b37 |
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13-Mar-2020 |
Brian Gerst <brgerst@gmail.com> |
x86: Remove unneeded includes Clean up includes of and in <asm/syscalls.h> Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200313195144.164260-19-brgerst@gmail.com
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2b10906f |
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19-Dec-2019 |
Brian Gerst <brgerst@gmail.com> |
x86: Remove force_iret() force_iret() was originally intended to prevent the return to user mode with the SYSRET or SYSEXIT instructions, in cases where the register state could have been changed to be incompatible with those instructions. The entry code has been significantly reworked since then, and register state is validated before SYSRET or SYSEXIT are used. force_iret() no longer serves its original purpose and can be eliminated. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Oleg Nesterov <oleg@redhat.com> Link: https://lkml.kernel.org/r/20191219115812.102620-1-brgerst@gmail.com
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#
a24ca997 |
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11-Nov-2019 |
Thomas Gleixner <tglx@linutronix.de> |
x86/iopl: Remove legacy IOPL option The IOPL emulation via the I/O bitmap is sufficient. Remove the legacy cruft dealing with the (e)flags based IOPL mechanism. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Juergen Gross <jgross@suse.com> (Paravirt and Xen parts) Acked-by: Andy Lutomirski <luto@kernel.org>
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#
2fff071d |
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11-Nov-2019 |
Thomas Gleixner <tglx@linutronix.de> |
x86/process: Unify copy_thread_tls() While looking at the TSS io bitmap it turned out that any change in that area would require identical changes to copy_thread_tls(). The 32 and 64 bit variants share sufficient code to consolidate them into a common function to avoid duplication of upcoming modifications. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Andy Lutomirski <luto@kernel.org>
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#
3c88c692 |
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07-May-2019 |
Peter Zijlstra <peterz@infradead.org> |
x86/stackframe/32: Provide consistent pt_regs Currently pt_regs on x86_32 has an oddity in that kernel regs (!user_mode(regs)) are short two entries (esp/ss). This means that any code trying to use them (typically: regs->sp) needs to jump through some unfortunate hoops. Change the entry code to fix this up and create a full pt_regs frame. This then simplifies various trampolines in ftrace and kprobes, the stack unwinder, ptrace, kdump and kgdb. Much thanks to Josh for help with the cleanups! Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
5f409e20 |
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03-Apr-2019 |
Rik van Riel <riel@surriel.com> |
x86/fpu: Defer FPU state load until return to userspace Defer loading of FPU state until return to userspace. This gives the kernel the potential to skip loading FPU state for tasks that stay in kernel mode, or for tasks that end up with repeated invocations of kernel_fpu_begin() & kernel_fpu_end(). The fpregs_lock/unlock() section ensures that the registers remain unchanged. Otherwise a context switch or a bottom half could save the registers to its FPU context and the processor's FPU registers would became random if modified at the same time. KVM swaps the host/guest registers on entry/exit path. This flow has been kept as is. First it ensures that the registers are loaded and then saves the current (host) state before it loads the guest's registers. The swap is done at the very end with disabled interrupts so it should not change anymore before theg guest is entered. The read/save version seems to be cheaper compared to memcpy() in a micro benchmark. Each thread gets TIF_NEED_FPU_LOAD set as part of fork() / fpu__copy(). For kernel threads, this flag gets never cleared which avoids saving / restoring the FPU state for kernel threads and during in-kernel usage of the FPU registers. [ bp: Correct and update commit message and fix checkpatch warnings. s/register/registers/ where it is used in plural. minor comment corrections. remove unused trace_x86_fpu_activate_state() TP. ] Signed-off-by: Rik van Riel <riel@surriel.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Aubrey Li <aubrey.li@intel.com> Cc: Babu Moger <Babu.Moger@amd.com> Cc: "Chang S. Bae" <chang.seok.bae@intel.com> Cc: Dmitry Safonov <dima@arista.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: kvm ML <kvm@vger.kernel.org> Cc: Nicolai Stange <nstange@suse.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Waiman Long <longman@redhat.com> Cc: x86-ml <x86@kernel.org> Cc: Yi Wang <wang.yi59@zte.com.cn> Link: https://lkml.kernel.org/r/20190403164156.19645-24-bigeasy@linutronix.de
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2722146e |
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03-Apr-2019 |
Sebastian Andrzej Siewior <bigeasy@linutronix.de> |
x86/fpu: Remove fpu->initialized The struct fpu.initialized member is always set to one for user tasks and zero for kernel tasks. This avoids saving/restoring the FPU registers for kernel threads. The ->initialized = 0 case for user tasks has been removed in previous changes, for instance, by doing an explicit unconditional init at fork() time for FPU-less systems which was otherwise delayed until the emulated opcode. The context switch code (switch_fpu_prepare() + switch_fpu_finish()) can't unconditionally save/restore registers for kernel threads. Not only would it slow down the switch but also load a zeroed xcomp_bv for XSAVES. For kernel_fpu_begin() (+end) the situation is similar: EFI with runtime services uses this before alternatives_patched is true. Which means that this function is used too early and it wasn't the case before. For those two cases, use current->mm to distinguish between user and kernel thread. For kernel_fpu_begin() skip save/restore of the FPU registers. During the context switch into a kernel thread don't do anything. There is no reason to save the FPU state of a kernel thread. The reordering in __switch_to() is important because the current() pointer needs to be valid before switch_fpu_finish() is invoked so ->mm is seen of the new task instead the old one. N.B.: fpu__save() doesn't need to check ->mm because it is called by user tasks only. [ bp: Massage. ] Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Aubrey Li <aubrey.li@intel.com> Cc: Babu Moger <Babu.Moger@amd.com> Cc: "Chang S. Bae" <chang.seok.bae@intel.com> Cc: Dmitry Safonov <dima@arista.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: kvm ML <kvm@vger.kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Nicolai Stange <nstange@suse.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Will Deacon <will.deacon@arm.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190403164156.19645-8-bigeasy@linutronix.de
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6dd677a0 |
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03-Apr-2019 |
Sebastian Andrzej Siewior <bigeasy@linutronix.de> |
x86/fpu: Remove fpu__restore() There are no users of fpu__restore() so it is time to remove it. The comment regarding fpu__restore() and TS bit is stale since commit b3b0870ef3ffe ("i387: do not preload FPU state at task switch time") and has no meaning since. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Aubrey Li <aubrey.li@intel.com> Cc: Babu Moger <Babu.Moger@amd.com> Cc: "Chang S. Bae" <chang.seok.bae@intel.com> Cc: Dmitry Safonov <dima@arista.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: kvm ML <kvm@vger.kernel.org> Cc: linux-doc@vger.kernel.org Cc: Nicolai Stange <nstange@suse.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190403164156.19645-3-bigeasy@linutronix.de
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6690e86b |
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14-Feb-2019 |
Peter Zijlstra <peterz@infradead.org> |
sched/x86: Save [ER]FLAGS on context switch Effectively reverts commit: 2c7577a75837 ("sched/x86_64: Don't save flags on context switch") Specifically because SMAP uses FLAGS.AC which invalidates the claim that the kernel has clean flags. In particular; while preemption from interrupt return is fine (the IRET frame on the exception stack contains FLAGS) it breaks any code that does synchonous scheduling, including preempt_enable(). This has become a significant issue ever since commit: 5b24a7a2aa20 ("Add 'unsafe' user access functions for batched accesses") provided for means of having 'normal' C code between STAC / CLAC, exposing the FLAGS.AC state. So far this hasn't led to trouble, however fix it before it comes apart. Reported-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org Fixes: 5b24a7a2aa20 ("Add 'unsafe' user access functions for batched accesses") Signed-off-by: Ingo Molnar <mingo@kernel.org>
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e08e3211 |
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28-Nov-2018 |
Sebastian Andrzej Siewior <bigeasy@linutronix.de> |
x86/process/32: Remove asm/math_emu.h include The math_emu.h header files contains the definition of struct math_emu_info which is not used in this file. Remove the asm/math_emu.h include. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Rik van Riel <riel@surriel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm ML <kvm@vger.kernel.org> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20181128222035.2996-3-bigeasy@linutronix.de
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#
ff16701a |
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25-Nov-2018 |
Thomas Gleixner <tglx@linutronix.de> |
x86/process: Consolidate and simplify switch_to_xtra() code Move the conditional invocation of __switch_to_xtra() into an inline function so the logic can be shared between 32 and 64 bit. Remove the handthrough of the TSS pointer and retrieve the pointer directly in the bitmap handling function. Use this_cpu_ptr() instead of the per_cpu() indirection. This is a preparatory change so integration of conditional indirect branch speculation optimization happens only in one place. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Casey Schaufler <casey.schaufler@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jon Masters <jcm@redhat.com> Cc: Waiman Long <longman9394@gmail.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Dave Stewart <david.c.stewart@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181125185005.280855518@linutronix.de
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#
352940ec |
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21-Nov-2018 |
Babu Moger <Babu.Moger@amd.com> |
x86/resctrl: Rename the RDT functions and definitions As AMD is starting to support RESCTRL features, rename the RDT functions and definitions to more generic names. Replace "intel_rdt" with "resctrl" where applicable. Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: "Chang S. Bae" <chang.seok.bae@intel.com> Cc: David Miller <davem@davemloft.net> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Dmitry Safonov <dima@arista.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: <linux-doc@vger.kernel.org> Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Pu Wen <puwen@hygon.cn> Cc: <qianyue.zj@alibaba-inc.com> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Reinette Chatre <reinette.chatre@intel.com> Cc: Rian Hunter <rian@alum.mit.edu> Cc: Sherry Hurwitz <sherry.hurwitz@amd.com> Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Lendacky <Thomas.Lendacky@amd.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: <xiaochen.shen@intel.com> Link: https://lkml.kernel.org/r/20181121202811.4492-3-babu.moger@amd.com
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#
fa7d9493 |
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21-Nov-2018 |
Babu Moger <Babu.Moger@amd.com> |
x86/resctrl: Rename and move rdt files to a separate directory New generation of AMD processors add support for RDT (or QOS) features. Together, these features will be called RESCTRL. With more than one vendors supporting these features, it seems more appropriate to rename these files. Create a new directory with the name 'resctrl' and move all the intel_rdt files to the new directory. This way all the resctrl related code resides inside one directory. [ bp: Add SPDX identifier to the Makefile ] Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: "Chang S. Bae" <chang.seok.bae@intel.com> Cc: David Miller <davem@davemloft.net> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Dmitry Safonov <dima@arista.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: <linux-doc@vger.kernel.org> Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Pu Wen <puwen@hygon.cn> Cc: <qianyue.zj@alibaba-inc.com> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Reinette Chatre <reinette.chatre@intel.com> Cc: Rian Hunter <rian@alum.mit.edu> Cc: Sherry Hurwitz <sherry.hurwitz@amd.com> Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Lendacky <Thomas.Lendacky@amd.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: <xiaochen.shen@intel.com> Link: https://lkml.kernel.org/r/20181121202811.4492-2-babu.moger@amd.com
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#
9fe6299d |
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31-Aug-2018 |
Jann Horn <jannh@google.com> |
x86/process: Don't mix user/kernel regs in 64bit __show_regs() When the kernel.print-fatal-signals sysctl has been enabled, a simple userspace crash will cause the kernel to write a crash dump that contains, among other things, the kernel gsbase into dmesg. As suggested by Andy, limit output to pt_regs, FS_BASE and KERNEL_GS_BASE in this case. This also moves the bitness-specific logic from show_regs() into process_{32,64}.c. Fixes: 45807a1df9f5 ("vdso: print fatal signals") Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20180831194151.123586-1-jannh@google.com
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#
252e1a05 |
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18-Jul-2018 |
Joerg Roedel <jroedel@suse.de> |
x86/entry: Rename update_sp0 to update_task_stack The function does not update sp0 anymore but updates makes the task-stack visible for entry code. This is by either writing it to sp1 or by doing a hypercall. Rename the function to get rid of the misleading name. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Pavel Machek <pavel@ucw.cz> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: linux-mm@kvack.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Waiman Long <llong@redhat.com> Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca> Cc: joro@8bytes.org Link: https://lkml.kernel.org/r/1531906876-13451-15-git-send-email-joro@8bytes.org
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#
45d7b255 |
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18-Jul-2018 |
Joerg Roedel <jroedel@suse.de> |
x86/entry/32: Enter the kernel via trampoline stack Use the entry-stack as a trampoline to enter the kernel. The entry-stack is already in the cpu_entry_area and will be mapped to userspace when PTI is enabled. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Pavel Machek <pavel@ucw.cz> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: linux-mm@kvack.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Waiman Long <llong@redhat.com> Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca> Cc: joro@8bytes.org Link: https://lkml.kernel.org/r/1531906876-13451-8-git-send-email-joro@8bytes.org
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#
a6b744f3 |
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18-Jul-2018 |
Joerg Roedel <jroedel@suse.de> |
x86/entry/32: Load task stack from x86_tss.sp1 in SYSENTER handler x86_tss.sp0 will be used to point to the entry stack later to use it as a trampoline stack for other kernel entry points besides SYSENTER. So store the real task stack pointer in x86_tss.sp1, which is otherwise unused by the hardware, as Linux doesn't make use of Ring 1. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Pavel Machek <pavel@ucw.cz> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: linux-mm@kvack.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Waiman Long <llong@redhat.com> Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca> Cc: joro@8bytes.org Link: https://lkml.kernel.org/r/1531906876-13451-4-git-send-email-joro@8bytes.org
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#
7cccf072 |
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17-Apr-2018 |
Borislav Petkov <bp@suse.de> |
x86/dumpstack: Add a show_ip() function ... which shows the Instruction Pointer along with the insn bytes around it. Use it whenever rIP is printed. Drop the rIP < PAGE_OFFSET check since probe_kernel_read() can handle any address properly. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Link: https://lkml.kernel.org/r/20180417161124.5294-8-bp@alien8.de
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#
c482feef |
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04-Dec-2017 |
Andy Lutomirski <luto@kernel.org> |
x86/entry/64: Make cpu_entry_area.tss read-only The TSS is a fairly juicy target for exploits, and, now that the TSS is in the cpu_entry_area, it's no longer protected by kASLR. Make it read-only on x86_64. On x86_32, it can't be RO because it's written by the CPU during task switches, and we use a task gate for double faults. I'd also be nervous about errata if we tried to make it RO even on configurations without double fault handling. [ tglx: AMD confirmed that there is no problem on 64-bit with TSS RO. So it's probably safe to assume that it's a non issue, though Intel might have been creative in that area. Still waiting for confirmation. ] Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bpetkov@suse.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Link: https://lkml.kernel.org/r/20171204150606.733700132@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
46f5a10a |
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02-Nov-2017 |
Andy Lutomirski <luto@kernel.org> |
x86/entry/64: Remove all remaining direct thread_struct::sp0 reads The only remaining readers in context switch code or vm86(), and they all just want to update TSS.sp0 to match the current task. Replace them all with a new helper update_sp0(). Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/2d231687f4ff288c9d9e98d7861b7df374246ac3.1509609304.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
da51da18 |
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02-Nov-2017 |
Andy Lutomirski <luto@kernel.org> |
x86/entry/64: Pass SP0 directly to load_sp0() load_sp0() had an odd signature: void load_sp0(struct tss_struct *tss, struct thread_struct *thread); Simplify it to: void load_sp0(unsigned long sp0); Also simplify a few get_cpu()/put_cpu() sequences to preempt_disable()/preempt_enable(). Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/2655d8b42ed940aa384fe18ee1129bbbcf730a08.1509609304.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
bd7dc5a6 |
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02-Nov-2017 |
Andy Lutomirski <luto@kernel.org> |
x86/entry/32: Pull the MSR_IA32_SYSENTER_CS update code out of native_load_sp0() This causes the MSR_IA32_SYSENTER_CS write to move out of the paravirt callback. This shouldn't affect Xen PV: Xen already ignores MSR_IA32_SYSENTER_ESP writes. In any event, Xen doesn't support vm86() in a useful way. Note to any potential backporters: This patch won't break lguest, as lguest didn't have any SYSENTER support at all. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/75cf09fe03ae778532d0ca6c65aa58e66bc2f90c.1509609304.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
05830204 |
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25-Jul-2017 |
Vikas Shivappa <vikas.shivappa@linux.intel.com> |
x86/intel_rdt: Change file names to accommodate RDT monitor code Because the "perf cqm" and resctrl code were separately added and indivdually configurable, there seem to be separate context switch code and also things on global .h which are not really needed. Move only the scheduling specific code and definitions to <asm/intel_rdt_sched.h> and the put all the other declarations to a local intel_rdt.h. h/t to Reinette Chatre for pointing out that we should separate the public interfaces used by other parts of the kernel from private objects shared between the various files comprising RDT. No functional change. Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: tony.luck@intel.com Cc: fenghua.yu@intel.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: davidcc@google.com Cc: reinette.chatre@intel.com Link: http://lkml.kernel.org/r/1501017287-28083-5-git-send-email-vikas.shivappa@linux.intel.com
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#
99504819 |
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28-Jul-2017 |
Andy Lutomirski <luto@kernel.org> |
x86/asm/32: Remove a bunch of '& 0xffff' from pt_regs segment reads Now that pt_regs properly defines segment fields as 16-bit on 32-bit CPUs, there's no need to mask off the high word. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
6c690ee1 |
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12-Jun-2017 |
Andy Lutomirski <luto@kernel.org> |
x86/mm: Split read_cr3() into read_cr3_pa() and __read_cr3() The kernel has several code paths that read CR3. Most of them assume that CR3 contains the PGD's physical address, whereas some of them awkwardly use PHYSICAL_PAGE_MASK to mask off low bits. Add explicit mask macros for CR3 and convert all of the CR3 readers. This will keep them from breaking when PCID is enabled. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: xen-devel <xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/883f8fb121f4616c1c1427ad87350bb2f5ffeca1.1497288170.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
5d9070b1 |
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28-May-2017 |
Borislav Petkov <bp@suse.de> |
x86/debug/32: Convert a smp_processor_id() call to raw to avoid DEBUG_PREEMPT warning ... to raw_smp_processor_id() to not trip the BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1 check. The reasoning behind it is that __warn() already uses the raw_ variants but the show_regs() path on 32-bit doesn't. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170528092212.fiod7kygpjm23m3o@pd.tnic Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
79170fda |
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20-Mar-2017 |
Kyle Huey <me@kylehuey.com> |
x86/syscalls/32: Wire up arch_prctl on x86-32 Hook up arch_prctl to call do_arch_prctl() on x86-32, and in 32 bit compat mode on x86-64. This allows to have arch_prctls that are not specific to 64 bits. On UML, simply stub out this syscall. Signed-off-by: Kyle Huey <khuey@kylehuey.com> Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com> Cc: kvm@vger.kernel.org Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: linux-kselftest@vger.kernel.org Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Robert O'Callahan <robert@ocallahan.org> Cc: Richard Weinberger <richard@nod.at> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Len Brown <len.brown@intel.com> Cc: Shuah Khan <shuah@kernel.org> Cc: user-mode-linux-devel@lists.sourceforge.net Cc: Jeff Dike <jdike@addtoit.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: user-mode-linux-user@lists.sourceforge.net Cc: David Matlack <dmatlack@google.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Dmitry Safonov <dsafonov@virtuozzo.com> Cc: linux-fsdevel@vger.kernel.org Cc: Paolo Bonzini <pbonzini@redhat.com> Link: http://lkml.kernel.org/r/20170320081628.18952-7-khuey@kylehuey.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
68db0cf1 |
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08-Feb-2017 |
Ingo Molnar <mingo@kernel.org> |
sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/task_stack.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
29930025 |
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08-Feb-2017 |
Ingo Molnar <mingo@kernel.org> |
sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h> We are going to split <linux/sched/task.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/task.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
34bc3560 |
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09-Dec-2016 |
Thomas Gleixner <tglx@linutronix.de> |
x86: Remove empty idle.h header One include less is always a good thing(tm). Good riddance. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Jiri Olsa <jolsa@redhat.com> Link: http://lkml.kernel.org/r/20161209182912.2726-6-bp@alien8.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
4f341a5e |
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28-Oct-2016 |
Fenghua Yu <fenghua.yu@intel.com> |
x86/intel_rdt: Add scheduler hook Hook the x86 scheduler code to update closid based on whether the current task is assigned to a specific closid or running on a CPU assigned to a specific closid. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com> Cc: "Tony Luck" <tony.luck@intel.com> Cc: "Shaohua Li" <shli@fb.com> Cc: "Sai Prakhya" <sai.praneeth.prakhya@intel.com> Cc: "Peter Zijlstra" <peterz@infradead.org> Cc: "Stephane Eranian" <eranian@google.com> Cc: "Dave Hansen" <dave.hansen@intel.com> Cc: "David Carrillo-Cisneros" <davidcc@google.com> Cc: "Nilay Vaish" <nilayvaish@gmail.com> Cc: "Vikas Shivappa" <vikas.shivappa@linux.intel.com> Cc: "Ingo Molnar" <mingo@elte.hu> Cc: "Borislav Petkov" <bp@suse.de> Cc: "H. Peter Anvin" <h.peter.anvin@intel.com> Link: http://lkml.kernel.org/r/1477692289-37412-10-git-send-email-fenghua.yu@intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
bb5e5ce5 |
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25-Oct-2016 |
Josh Poimboeuf <jpoimboe@redhat.com> |
x86/dumpstack: Remove kernel text addresses from stack dump Printing kernel text addresses in stack dumps is of questionable value, especially now that address randomization is becoming common. It can be a security issue because it leaks kernel addresses. It also affects the usefulness of the stack dump. Linus says: "I actually spend time cleaning up commit messages in logs, because useless data that isn't actually information (random hex numbers) is actively detrimental. It makes commit logs less legible. It also makes it harder to parse dumps. It's not useful. That makes it actively bad. I probably look at more oops reports than most people. I have not found the hex numbers useful for the last five years, because they are just randomized crap. The stack content thing just makes code scroll off the screen etc, for example." The only real downside to removing these addresses is that they can be used to disambiguate duplicate symbol names. However such cases are rare, and the context of the stack dump should be enough to be able to figure it out. There's now a 'faddr2line' script which can be used to convert a function address to a file name and line: $ ./scripts/faddr2line ~/k/vmlinux write_sysrq_trigger+0x51/0x60 write_sysrq_trigger+0x51/0x60: write_sysrq_trigger at drivers/tty/sysrq.c:1098 Or gdb can be used: $ echo "list *write_sysrq_trigger+0x51" |gdb ~/k/vmlinux |grep "is in" (gdb) 0xffffffff815b5d83 is in driver_probe_device (/home/jpoimboe/git/linux/drivers/base/dd.c:378). (But note that when there are duplicate symbol names, gdb will only show the first symbol it finds. faddr2line is recommended over gdb because it handles duplicates and it also does function size checking.) Here's an example of what a stack dump looks like after this change: BUG: unable to handle kernel NULL pointer dereference at (null) IP: sysrq_handle_crash+0x45/0x80 PGD 36bfa067 [ 29.650644] PUD 7aca3067 Oops: 0002 [#1] PREEMPT SMP Modules linked in: ... CPU: 1 PID: 786 Comm: bash Tainted: G E 4.9.0-rc1+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014 task: ffff880078582a40 task.stack: ffffc90000ba8000 RIP: 0010:sysrq_handle_crash+0x45/0x80 RSP: 0018:ffffc90000babdc8 EFLAGS: 00010296 RAX: ffff880078582a40 RBX: 0000000000000063 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000292 RBP: ffffc90000babdc8 R08: 0000000b31866061 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000007 R14: ffffffff81ee8680 R15: 0000000000000000 FS: 00007ffb43869700(0000) GS:ffff88007d400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000007a3e9000 CR4: 00000000001406e0 Stack: ffffc90000babe00 ffffffff81572d08 ffffffff81572bd5 0000000000000002 0000000000000000 ffff880079606600 00007ffb4386e000 ffffc90000babe20 ffffffff81573201 ffff880036a3fd00 fffffffffffffffb ffffc90000babe40 Call Trace: __handle_sysrq+0x138/0x220 ? __handle_sysrq+0x5/0x220 write_sysrq_trigger+0x51/0x60 proc_reg_write+0x42/0x70 __vfs_write+0x37/0x140 ? preempt_count_sub+0xa1/0x100 ? __sb_start_write+0xf5/0x210 ? vfs_write+0x183/0x1a0 vfs_write+0xb8/0x1a0 SyS_write+0x58/0xc0 entry_SYSCALL_64_fastpath+0x1f/0xc2 RIP: 0033:0x7ffb42f55940 RSP: 002b:00007ffd33bb6b18 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000046 RCX: 00007ffb42f55940 RDX: 0000000000000002 RSI: 00007ffb4386e000 RDI: 0000000000000001 RBP: 0000000000000011 R08: 00007ffb4321ea40 R09: 00007ffb43869700 R10: 00007ffb43869700 R11: 0000000000000246 R12: 0000000000778a10 R13: 00007ffd33bb5c00 R14: 0000000000000007 R15: 0000000000000010 Code: 34 e8 d0 34 bc ff 48 c7 c2 3b 2b 57 81 be 01 00 00 00 48 c7 c7 e0 dd e5 81 e8 a8 55 ba ff c7 05 0e 3f de 00 01 00 00 00 0f ae f8 <c6> 04 25 00 00 00 00 01 5d c3 e8 4c 49 bc ff 84 c0 75 c3 48 c7 RIP: sysrq_handle_crash+0x45/0x80 RSP: ffffc90000babdc8 CR2: 0000000000000000 Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/69329cb29b8f324bb5fcea14d61d224807fb6488.1477405374.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
c474e507 |
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14-Oct-2016 |
Rik van Riel <riel@redhat.com> |
x86/fpu: Split old_fpu & new_fpu handling into separate functions By moving all of the new_fpu state handling into switch_fpu_finish(), the code can be simplified some more. This gets rid of the prefetch, but given the size of the FPU register state on modern CPUs, and the amount of work done by __switch_to() inbetween both functions, the value of a single cache line prefetch seems somewhat dubious anyway. Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1476447331-21566-3-git-send-email-riel@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
1ef55be1 |
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29-Sep-2016 |
Andy Lutomirski <luto@kernel.org> |
x86/asm: Get rid of __read_cr4_safe() We use __read_cr4() vs __read_cr4_safe() inconsistently. On CR4-less CPUs, all CR4 bits are effectively clear, so we can make the code simpler and more robust by making __read_cr4() always fix up faults on 32-bit kernels. This may fix some bugs on old 486-like CPUs, but I don't have any easy way to test that. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: david@saggiorato.net Link: http://lkml.kernel.org/r/ea647033d357d9ce2ad2bbde5a631045f5052fb6.1475178370.git.luto@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
ffcb043b |
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12-Aug-2016 |
Brian Gerst <brgerst@gmail.com> |
sched/x86: Fix thread_saved_pc() thread_saved_pc() was using a completely bogus method to get the return address. Since switch_to() was previously inlined, there was no sane way to know where on the stack the return address was stored. Now with the frame of a sleeping thread well defined, this can be implemented correctly. Signed-off-by: Brian Gerst <brgerst@gmail.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1471106302-10159-7-git-send-email-brgerst@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
616d2483 |
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12-Aug-2016 |
Brian Gerst <brgerst@gmail.com> |
sched/x86: Pass kernel thread parameters in 'struct fork_frame' Instead of setting up a fake pt_regs context, put the kernel thread function pointer and arg into the unused callee-restored registers of 'struct fork_frame'. Signed-off-by: Brian Gerst <brgerst@gmail.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1471106302-10159-6-git-send-email-brgerst@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
0100301b |
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12-Aug-2016 |
Brian Gerst <brgerst@gmail.com> |
sched/x86: Rewrite the switch_to() code Move the low-level context switch code to an out-of-line asm stub instead of using complex inline asm. This allows constructing a new stack frame for the child process to make it seamlessly flow to ret_from_fork without an extra test and branch in __switch_to(). It also improves code generation for __schedule() by using the C calling convention instead of clobbering all registers. Signed-off-by: Brian Gerst <brgerst@gmail.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1471106302-10159-5-git-send-email-brgerst@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
186f4360 |
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13-Jul-2016 |
Paul Gortmaker <paul.gortmaker@windriver.com> |
x86/kernel: Audit and remove any unnecessary uses of module.h Historically a lot of these existed because we did not have a distinction between what was modular code and what was providing support to modules via EXPORT_SYMBOL and friends. That changed when we forked out support for the latter into the export.h file. This means we should be able to reduce the usage of module.h in code that is obj-y Makefile or bool Kconfig. The advantage in doing so is that module.h itself sources about 15 other headers; adding significantly to what we feed cpp, and it can obscure what headers we are effectively using. Since module.h was the source for init.h (for __init) and for export.h (for EXPORT_SYMBOL) we consider each obj-y/bool instance for the presence of either and replace as needed. Build testing revealed some implicit header usage that was fixed up accordingly. Note that some bool/obj-y instances remain since module.h is the header for some exception table entry stuff, and for things like __init_or_module (code that is tossed when MODULES=n). Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160714001901.31603-4-paul.gortmaker@windriver.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
d87b7a33 |
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28-Sep-2015 |
Peter Zijlstra <peterz@infradead.org> |
sched/core, sched/x86: Kill thread_info::saved_preempt_count With the introduction of the context switch preempt_count invariant, and the demise of PREEMPT_ACTIVE, its pointless to save/restore the per-cpu preemption count, it must always be 2. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
7ba78053 |
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30-Sep-2015 |
Thomas Gleixner <tglx@linutronix.de> |
x86/process: Unify 32bit and 64bit implementations of get_wchan() The stack layout and the functionality is identical. Use the 64bit version for all of x86. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@alien8.de> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: kasan-dev <kasan-dev@googlegroups.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Wolfram Gloger <wmglo@dent.med.uni-muenchen.de> Link: http://lkml.kernel.org/r/20150930083302.779694618@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
ba3e127e |
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28-Jul-2015 |
Brian Gerst <brgerst@gmail.com> |
x86/vm86: Clean up vm86.h includes vm86.h was being implicitly included in alot of places via processor.h, which in turn got it from math_emu.h. Break that chain and explicitly include vm86.h in all files that need it. Also remove unused vm86 field from math_emu_info. Signed-off-by: Brian Gerst <brgerst@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1438148483-11932-7-git-send-email-brgerst@gmail.com [ Fixed build failure. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
c1bd55f9 |
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30-Jun-2015 |
Josh Triplett <josh@joshtriplett.org> |
x86: opt into HAVE_COPY_THREAD_TLS, for both 32-bit and 64-bit For 32-bit userspace on a 64-bit kernel, this requires modifying stub32_clone to actually swap the appropriate arguments to match CONFIG_CLONE_BACKWARDS, rather than just leaving the C argument for tls broken. Patch co-authored by Josh Triplett and Thiago Macieira. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thiago Macieira <thiago.macieira@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
78f7f1e5 |
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23-Apr-2015 |
Ingo Molnar <mingo@kernel.org> |
x86/fpu: Rename fpu-internal.h to fpu/internal.h This unifies all the FPU related header files under a unified, hiearchical naming scheme: - asm/fpu/types.h: FPU related data types, needed for 'struct task_struct', widely included in almost all kernel code, and hence kept as small as possible. - asm/fpu/api.h: FPU related 'public' methods exported to other subsystems. - asm/fpu/internal.h: FPU subsystem internal methods - asm/fpu/xsave.h: XSAVE support internal methods (Also standardize the header guard in asm/fpu/internal.h.) Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
384a23f9 |
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23-Apr-2015 |
Ingo Molnar <mingo@kernel.org> |
x86/fpu: Use 'struct fpu' in switch_fpu_finish() Migrate this function to pure 'struct fpu' usage. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
cb8818b6 |
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23-Apr-2015 |
Ingo Molnar <mingo@kernel.org> |
x86/fpu: Use 'struct fpu' in switch_fpu_prepare() Migrate this function to pure 'struct fpu' usage. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
3a0aee48 |
|
22-Apr-2015 |
Ingo Molnar <mingo@kernel.org> |
x86/fpu: Rename math_state_restore() to fpu__restore() Move to the new fpu__*() namespace. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
f89e32e0 |
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22-Apr-2015 |
Ingo Molnar <mingo@kernel.org> |
x86/fpu: Fix header file dependencies of fpu-internal.h Fix a minor header file dependency bug in asm/fpu-internal.h: it relies on i387.h but does not include it. All users of fpu-internal.h included it explicitly. Also remove unnecessary includes, to reduce compilation time. This also makes it easier to use it as a standalone header file for FPU internals, such as an upcoming C module in arch/x86/kernel/fpu/. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
fed7c3f0 |
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24-Apr-2015 |
Denys Vlasenko <dvlasenk@redhat.com> |
x86/entry: Remove unused 'kernel_stack' per-cpu variable Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/1429889495-27850-2-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
ef593260 |
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19-Mar-2015 |
Denys Vlasenko <dvlasenk@redhat.com> |
x86/asm/entry: Get rid of KERNEL_STACK_OFFSET PER_CPU_VAR(kernel_stack) was set up in a way where it points five stack slots below the top of stack. Presumably, it was done to avoid one "sub $5*8,%rsp" in syscall/sysenter code paths, where iret frame needs to be created by hand. Ironically, none of them benefits from this optimization, since all of them need to allocate additional data on stack (struct pt_regs), so they still have to perform subtraction. This patch eliminates KERNEL_STACK_OFFSET. PER_CPU_VAR(kernel_stack) now points directly to top of stack. pt_regs allocations are adjusted to allocate iret frame as well. Hopefully we can merge it later with 32-bit specific PER_CPU_VAR(cpu_current_top_of_stack) variable... Net result in generated code is that constants in several insns are changed. This change is necessary for changing struct pt_regs creation in SYSCALL64 code path from MOV to PUSH instructions. Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Acked-by: Borislav Petkov <bp@suse.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/1426785469-15125-2-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
f39b6f0e |
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18-Mar-2015 |
Andy Lutomirski <luto@kernel.org> |
x86/asm/entry: Change all 'user_mode_vm()' calls to 'user_mode()' user_mode_vm() and user_mode() are now the same. Change all callers of user_mode_vm() to user_mode(). The next patch will remove the definition of user_mode_vm. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brad Spengler <spender@grsecurity.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/43b1f57f3df70df5a08b0925897c660725015554.1426728647.git.luto@kernel.org [ Merged to a more recent kernel. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
1daeaa31 |
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21-Mar-2015 |
Brian Gerst <brgerst@gmail.com> |
x86/asm/entry: Fix execve() and sigreturn() syscalls to always return via IRET Both the execve() and sigreturn() family of syscalls have the ability to change registers in ways that may not be compatabile with the syscall path they were called from. In particular, SYSRET and SYSEXIT can't handle non-default %cs and %ss, and some bits in eflags. These syscalls have stubs that are hardcoded to jump to the IRET path, and not return to the original syscall path. The following commit: 76f5df43cab5e76 ("Always allocate a complete "struct pt_regs" on the kernel stack") recently changed this for some 32-bit compat syscalls, but introduced a bug where execve from a 32-bit program to a 64-bit program would fail because it still returned via SYSRETL. This caused Wine to fail when built for both 32-bit and 64-bit. This patch sets TIF_NOTIFY_RESUME for execve() and sigreturn() so that the IRET path is always taken on exit to userspace. Signed-off-by: Brian Gerst <brgerst@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1426978461-32089-1-git-send-email-brgerst@gmail.com [ Improved the changelog and comments. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
a7fcf28d |
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06-Mar-2015 |
Andy Lutomirski <luto@amacapital.net> |
x86/asm/entry: Replace this_cpu_sp0() with current_top_of_stack() and fix it on x86_32 I broke 32-bit kernels. The implementation of sp0 was correct as far as I can tell, but sp0 was much weirder on x86_32 than I realized. It has the following issues: - Init's sp0 is inconsistent with everything else's: non-init tasks are offset by 8 bytes. (I have no idea why, and the comment is unhelpful.) - vm86 does crazy things to sp0. Fix it up by replacing this_cpu_sp0() with current_top_of_stack() and using a new percpu variable to track the top of the stack on x86_32. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 75182b1632a8 ("x86/asm/entry: Switch all C consumers of kernel_stack to this_cpu_sp0()") Link: http://lkml.kernel.org/r/d09dbe270883433776e0cbee3c7079433349e96d.1425692936.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
b27559a4 |
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06-Mar-2015 |
Andy Lutomirski <luto@amacapital.net> |
x86/asm/entry: Delay loading sp0 slightly on task switch The change: 75182b1632a8 ("x86/asm/entry: Switch all C consumers of kernel_stack to this_cpu_sp0()") had the unintended side effect of changing the return value of current_thread_info() during part of the context switch process. Change it back. This has no effect as far as I can tell -- it's just for consistency. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/9fcaa47dd8487db59eed7a3911b6ae409476763e.1425692936.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
24933b82 |
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05-Mar-2015 |
Andy Lutomirski <luto@amacapital.net> |
x86/asm/entry: Rename 'init_tss' to 'cpu_tss' It has nothing to do with init -- there's only one TSS per cpu. Other names considered include: - current_tss: Confusing because we never switch the tss. - singleton_tss: Too long. This patch was generated with 's/init_tss/cpu_tss/g'. Followup patches will fix INIT_TSS and INIT_TSS_IST by hand. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/da29fb2a793e4f649d93ce2d1ed320ebe8516262.1425611534.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
1e02ce4c |
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24-Oct-2014 |
Andy Lutomirski <luto@amacapital.net> |
x86: Store a per-cpu shadow copy of CR4 Context switches and TLB flushes can change individual bits of CR4. CR4 reads take several cycles, so store a shadow copy of CR4 in a per-cpu variable. To avoid wasting a cache line, I added the CR4 shadow to cpu_tlbstate, which is already touched in switch_mm. The heaviest users of the cr4 shadow will be switch_mm and __switch_to_xtra, and __switch_to_xtra is called shortly after switch_mm during context switch, so the cacheline is likely to be hot. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Kees Cook <keescook@chromium.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Vince Weaver <vince@deater.net> Cc: "hillf.zj" <hillf.zj@alibaba-inc.com> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/3a54dd3353fffbf84804398e00dfdc5b7c1afd7d.1414190806.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
6f46b3ae |
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02-Sep-2014 |
Oleg Nesterov <oleg@redhat.com> |
x86: copy_thread: Don't nullify ->ptrace_bps twice Both 32bit and 64bit versions of copy_thread() do memset(ptrace_bps) twice for no reason, kill the 2nd memset(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Link: http://lkml.kernel.org/r/20140902175733.GA21676@redhat.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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#
dc56c0f9 |
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02-Sep-2014 |
Oleg Nesterov <oleg@redhat.com> |
x86, fpu: Shift "fpu_counter = 0" from copy_thread() to arch_dup_task_struct() Cosmetic, but I think thread.fpu_counter should be initialized in arch_dup_task_struct() too, along with other "fpu" variables. And probably it make sense to turn it into thread.fpu->counter. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Link: http://lkml.kernel.org/r/20140902175730.GA21669@redhat.com Reviewed-by: Suresh Siddha <sbsiddha@gmail.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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#
198d208d |
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06-Feb-2014 |
Steven Rostedt <srostedt@redhat.com> |
x86: Keep thread_info on thread stack in x86_32 x86_64 uses a per_cpu variable kernel_stack to always point to the thread stack of current. This is where the thread_info is stored and is accessed from this location even when the irq or exception stack is in use. This removes the complexity of having to maintain the thread info on the stack when interrupts are running and having to copy the preempt_count and other fields to the interrupt stack. x86_32 uses the old method of copying the thread_info from the thread stack to the exception stack just before executing the exception. Having the two different requires #ifdefs and also the x86_32 way is a bit of a pain to maintain. By converting x86_32 to the same method of x86_64, we can remove #ifdefs, clean up the x86_32 code a little, and remove the overhead of the copy. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Brian Gerst <brgerst@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20110806012354.263834829@goodmis.org Link: http://lkml.kernel.org/r/20140206144321.852942014@goodmis.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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#
663b55b9 |
|
06-Jan-2014 |
Paul Gortmaker <paul.gortmaker@windriver.com> |
x86: Delete non-required instances of include <linux/init.h> None of these files are actually using any __init type directives and hence don't need to include <linux/init.h>. Most are just a left over from __devinit and __cpuinit removal, or simply due to code getting copied from one driver to the next. [ hpa: undid incorrect removal from arch/x86/kernel/head_32.S ] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Link: http://lkml.kernel.org/r/1389054026-12947-1-git-send-email-paul.gortmaker@windriver.com Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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#
c375f15a |
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12-Nov-2013 |
Vineet Gupta <Vineet.Gupta1@synopsys.com> |
x86: move fpu_counter into ARCH specific thread_struct Only a couple of arches (sh/x86) use fpu_counter in task_struct so it can be moved out into ARCH specific thread_struct, reducing the size of task_struct for other arches. Compile tested i386_defconfig + gcc 4.7.3 Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Paul Mundt <paul.mundt@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
c2daa3be |
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14-Aug-2013 |
Peter Zijlstra <peterz@infradead.org> |
sched, x86: Provide a per-cpu preempt_count implementation Convert x86 to use a per-cpu preemption count. The reason for doing so is that accessing per-cpu variables is a lot cheaper than accessing thread_info variables. We still need to save/restore the actual preemption count due to PREEMPT_ACTIVE so we place the per-cpu __preempt_count variable in the same cache-line as the other hot __switch_to() variables such as current_task. NOTE: this save/restore is required even for !PREEMPT kernels as cond_resched() also relies on preempt_count's PREEMPT_ACTIVE to ignore task_struct::state. Also rename thread_info::preempt_count to ensure nobody is 'accidentally' still poking at it. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-gzn5rfsf8trgjoqx8hyayy3q@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
35ea7903 |
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05-Aug-2013 |
Andi Kleen <ak@linux.intel.com> |
x86, asmlinkage: Make 32bit/64bit __switch_to visible This function is called from inline assembler, so has to be visible. Signed-off-by: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1375740170-7446-6-git-send-email-andi@firstfloor.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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#
1adfa76a |
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27-Apr-2013 |
H. Peter Anvin <hpa@linux.intel.com> |
x86, flags: Rename X86_EFLAGS_BIT1 to X86_EFLAGS_FIXED Bit 1 in the x86 EFLAGS is always set. Name the macro something that actually tries to explain what it is all about, rather than being a tautology. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Gleb Natapov <gleb@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Link: http://lkml.kernel.org/n/tip-f10rx5vjjm6tfnt8o1wseb3v@git.kernel.org
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#
4338774c |
|
17-Jun-2013 |
Dave Jones <davej@redhat.com> |
x86/debug: Only print out DR registers if they are not power-on defaults The DR registers are rarely useful when decoding oopses. With screen real estate during oopses at a premium, we can save two lines by only printing out these registers when they are set to something other than they power-on state. Signed-off-by: Dave Jones <davej@redhat.com> Acked-by: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20130618160911.GA24487@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
a43cb95d |
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30-Apr-2013 |
Tejun Heo <tj@kernel.org> |
dump_stack: unify debug information printed by show_regs() show_regs() is inherently arch-dependent but it does make sense to print generic debug information and some archs already do albeit in slightly different forms. This patch introduces a generic function to print debug information from show_regs() so that different archs print out the same information and it's much easier to modify what's printed. show_regs_print_info() prints out the same debug info as dump_stack() does plus task and thread_info pointers. * Archs which didn't print debug info now do. alpha, arc, blackfin, c6x, cris, frv, h8300, hexagon, ia64, m32r, metag, microblaze, mn10300, openrisc, parisc, score, sh64, sparc, um, xtensa * Already prints debug info. Replaced with show_regs_print_info(). The printed information is superset of what used to be there. arm, arm64, avr32, mips, powerpc, sh32, tile, unicore32, x86 * s390 is special in that it used to print arch-specific information along with generic debug info. Heiko and Martin think that the arch-specific extra isn't worth keeping s390 specfic implementation. Converted to use the generic version. Note that now all archs print the debug info before actual register dumps. An example BUG() dump follows. kernel BUG at /work/os/work/kernel/workqueue.c:4841! invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #7 Hardware name: empty empty/S3992, BIOS 080011 10/26/2007 task: ffff88007c85e040 ti: ffff88007c860000 task.ti: ffff88007c860000 RIP: 0010:[<ffffffff8234a07e>] [<ffffffff8234a07e>] init_workqueues+0x4/0x6 RSP: 0000:ffff88007c861ec8 EFLAGS: 00010246 RAX: ffff88007c861fd8 RBX: ffffffff824466a8 RCX: 0000000000000001 RDX: 0000000000000046 RSI: 0000000000000001 RDI: ffffffff8234a07a RBP: ffff88007c861ec8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8234a07a R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: ffff88015f7ff000 CR3: 00000000021f1000 CR4: 00000000000007f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Stack: ffff88007c861ef8 ffffffff81000312 ffffffff824466a8 ffff88007c85e650 0000000000000003 0000000000000000 ffff88007c861f38 ffffffff82335e5d ffff88007c862080 ffffffff8223d8c0 ffff88007c862080 ffffffff81c47760 Call Trace: [<ffffffff81000312>] do_one_initcall+0x122/0x170 [<ffffffff82335e5d>] kernel_init_freeable+0x9b/0x1c8 [<ffffffff81c47760>] ? rest_init+0x140/0x140 [<ffffffff81c4776e>] kernel_init+0xe/0xf0 [<ffffffff81c6be9c>] ret_from_fork+0x7c/0xb0 [<ffffffff81c47760>] ? rest_init+0x140/0x140 ... v2: Typo fix in x86-32. v3: CPU number dropped from show_regs_print_info() as dump_stack_print_info() has been updated to print it. s390 specific implementation dropped as requested by s390 maintainers. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Sam Ravnborg <sam@ravnborg.org> Acked-by: Chris Metcalf <cmetcalf@tilera.com> [tile bits] Acked-by: Richard Kuo <rkuo@codeaurora.org> [hexagon bits] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
afa86fc4 |
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22-Oct-2012 |
Al Viro <viro@zeniv.linux.org.uk> |
flagday: don't pass regs to copy_thread() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
1d4b4b29 |
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22-Oct-2012 |
Al Viro <viro@zeniv.linux.org.uk> |
x86, um: switch to generic fork/vfork/clone Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
6783eaa2 |
|
02-Aug-2012 |
Al Viro <viro@zeniv.linux.org.uk> |
x86, um/x86: switch to generic sys_execve and kernel_execve 32bit wrapper is lost on that; 64bit one is *not*, since we need to arrange for full pt_regs on stack when we call sys_execve() and we need to load callee-saved ones from there afterwards. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
7076aada |
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10-Sep-2012 |
Al Viro <viro@zeniv.linux.org.uk> |
x86: split ret_from_fork Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
e76623d6 |
|
02-Aug-2012 |
Al Viro <viro@zeniv.linux.org.uk> |
x86: get rid of TIF_IRET hackery TIF_NOTIFY_RESUME will work in precisely the same way; all that is achieved by TIF_IRET is appearing that there's some work to be done, so we end up on the iret exit path. Just use NOTIFY_RESUME. And for execve() do that in 32bit start_thread(), not sys_execve() itself. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
304bceda |
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24-Aug-2012 |
Suresh Siddha <suresh.b.siddha@intel.com> |
x86, fpu: use non-lazy fpu restore for processors supporting xsave Fundamental model of the current Linux kernel is to lazily init and restore FPU instead of restoring the task state during context switch. This changes that fundamental lazy model to the non-lazy model for the processors supporting xsave feature. Reasons driving this model change are: i. Newer processors support optimized state save/restore using xsaveopt and xrstor by tracking the INIT state and MODIFIED state during context-switch. This is faster than modifying the cr0.TS bit which has serializing semantics. ii. Newer glibc versions use SSE for some of the optimized copy/clear routines. With certain workloads (like boot, kernel-compilation etc), application completes its work with in the first 5 task switches, thus taking upto 5 #DNA traps with the kernel not getting a chance to apply the above mentioned pre-load heuristic. iii. Some xstate features (like AMD's LWP feature) don't honor the cr0.TS bit and thus will not work correctly in the presence of lazy restore. Non-lazy state restore is needed for enabling such features. Some data on a two socket SNB system: * Saved 20K DNA exceptions during boot on a two socket SNB system. * Saved 50K DNA exceptions during kernel-compilation workload. * Improved throughput of the AVX based checksumming function inside the kernel by ~15% as xsave/xrstor is faster than the serializing clts/stts pair. Also now kernel_fpu_begin/end() relies on the patched alternative instructions. So move check_fpu() which uses the kernel_fpu_begin/end() after alternative_instructions(). Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/1345842782-24175-7-git-send-email-suresh.b.siddha@intel.com Merge 32-bit boot fix from, Link: http://lkml.kernel.org/r/1347300665-6209-4-git-send-email-suresh.b.siddha@intel.com Cc: Jim Kukunas <james.t.kukunas@linux.intel.com> Cc: NeilBrown <neilb@suse.de> Cc: Avi Kivity <avi@redhat.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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55ccf3fe |
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16-May-2012 |
Suresh Siddha <suresh.b.siddha@intel.com> |
fork: move the real prepare_to_copy() users to arch_dup_task_struct() Historical prepare_to_copy() is mostly a no-op, duplicated for majority of the architectures and the rest following the x86 model of flushing the extended register state like fpu there. Remove it and use the arch_dup_task_struct() instead. Suggested-by: Oleg Nesterov <oleg@redhat.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/1336692811-30576-1-git-send-email-suresh.b.siddha@intel.com Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Howells <dhowells@redhat.com> Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Chris Zankel <chris@zankel.net> Cc: Richard Henderson <rth@twiddle.net> Cc: Russell King <linux@arm.linux.org.uk> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Mark Salter <msalter@redhat.com> Cc: Aurelien Jacquiot <a-jacquiot@ti.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: James E.J. Bottomley <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Chen Liqin <liqin.chen@sunplusct.com> Cc: Lennox Wu <lennox.wu@gmail.com> Cc: David S. Miller <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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c6ae41e7 |
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11-May-2012 |
Alex Shi <alex.shi@linux.alibaba.com> |
x86: replace percpu_xxx funcs with this_cpu_xxx Since percpu_xxx() serial functions are duplicated with this_cpu_xxx(). Removing percpu_xxx() definition and replacing them by this_cpu_xxx() in code. There is no function change in this patch, just preparation for later percpu_xxx serial function removing. On x86 machine the this_cpu_xxx() serial functions are same as __this_cpu_xxx() without no unnecessary premmpt enable/disable. Thanks for Stephen Rothwell, he found and fixed a i386 build error in the patch. Also thanks for Andrew Morton, he kept updating the patchset in Linus' tree. Signed-off-by: Alex Shi <alex.shi@intel.com> Acked-by: Christoph Lameter <cl@gentwo.org> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Tejun Heo <tj@kernel.org>
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f05e798a |
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28-Mar-2012 |
David Howells <dhowells@redhat.com> |
Disintegrate asm/system.h for X86 Disintegrate asm/system.h for X86. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: H. Peter Anvin <hpa@zytor.com> cc: x86@kernel.org
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90e24014 |
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25-Mar-2012 |
Richard Weinberger <richard@nod.at> |
x86: Merge the x86_32 and x86_64 cpu_idle() functions Both functions are mostly identical. The differences are: - x86_32's cpu_idle() makes use of check_pgt_cache(), which is a nop on both x86_32 and x86_64. - x86_64's cpu_idle() uses enter/__exit_idle/(), on x86_32 these function are a nop. - In contrast to x86_32, x86_64 calls rcu_idle_enter/exit() in the innermost loop because idle notifications need RCU. Calling these function on x86_32 also in the innermost loop does not hurt. So we can merge both functions. Signed-off-by: Richard Weinberger <richard@nod.at> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: paulmck@linux.vnet.ibm.com Cc: josh@joshtriplett.org Cc: tj@kernel.org Link: http://lkml.kernel.org/r/1332709204-22496-1-git-send-email-richard@nod.at Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
bd2f5536 |
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20-Mar-2011 |
Thomas Gleixner <tglx@linutronix.de> |
sched/rt: Use schedule_preempt_disabled() Coccinelle based conversion. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-24swm5zut3h9c4a6s46x8rws@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
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1361b83a |
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21-Feb-2012 |
Linus Torvalds <torvalds@linux-foundation.org> |
i387: Split up <asm/i387.h> into exported and internal interfaces While various modules include <asm/i387.h> to get access to things we actually *intend* for them to use, most of that header file was really pretty low-level internal stuff that we really don't want to expose to others. So split the header file into two: the small exported interfaces remain in <asm/i387.h>, while the internal definitions that are only used by core architecture code are now in <asm/fpu-internal.h>. The guiding principle for this was to expose functions that we export to modules, and leave them in <asm/i387.h>, while stuff that is used by task switching or was marked GPL-only is in <asm/fpu-internal.h>. The fpu-internal.h file could be further split up too, especially since arch/x86/kvm/ uses some of the remaining stuff for its module. But that kvm usage should probably be abstracted out a bit, and at least now the internal FPU accessor functions are much more contained. Even if it isn't perhaps as contained as it _could_ be. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1202211340330.5354@i5.linux-foundation.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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#
7e16838d |
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19-Feb-2012 |
Linus Torvalds <torvalds@linux-foundation.org> |
i387: support lazy restore of FPU state This makes us recognize when we try to restore FPU state that matches what we already have in the FPU on this CPU, and avoids the restore entirely if so. To do this, we add two new data fields: - a percpu 'fpu_owner_task' variable that gets written any time we update the "has_fpu" field, and thus acts as a kind of back-pointer to the task that owns the CPU. The exception is when we save the FPU state as part of a context switch - if the save can keep the FPU state around, we leave the 'fpu_owner_task' variable pointing at the task whose FP state still remains on the CPU. - a per-thread 'last_cpu' field, that indicates which CPU that thread used its FPU on last. We update this on every context switch (writing an invalid CPU number if the last context switch didn't leave the FPU in a lazily usable state), so we know that *that* thread has done nothing else with the FPU since. These two fields together can be used when next switching back to the task to see if the CPU still matches: if 'fpu_owner_task' matches the task we are switching to, we know that no other task (or kernel FPU usage) touched the FPU on this CPU in the meantime, and if the current CPU number matches the 'last_cpu' field, we know that this thread did no other FP work on any other CPU, so the FPU state on the CPU must match what was saved on last context switch. In that case, we can avoid the 'f[x]rstor' entirely, and just clear the CR0.TS bit. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
cea20ca3 |
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20-Feb-2012 |
Linus Torvalds <torvalds@linux-foundation.org> |
i387: fix up some fpu_counter confusion This makes sure we clear the FPU usage counter for newly created tasks, just so that we start off in a known state (for example, don't try to preload the FPU state on the first task switch etc). It also fixes a thinko in when we increment the fpu_counter at task switch time, introduced by commit 34ddc81a230b ("i387: re-introduce FPU state preloading at context switch time"). We should increment the *new* task fpu_counter, not the old task, and only if we decide to use that state (whether lazily or preloaded). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
34ddc81a |
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18-Feb-2012 |
Linus Torvalds <torvalds@linux-foundation.org> |
i387: re-introduce FPU state preloading at context switch time After all the FPU state cleanups and finally finding the problem that caused all our FPU save/restore problems, this re-introduces the preloading of FPU state that was removed in commit b3b0870ef3ff ("i387: do not preload FPU state at task switch time"). However, instead of simply reverting the removal, this reimplements preloading with several fixes, most notably - properly abstracted as a true FPU state switch, rather than as open-coded save and restore with various hacks. In particular, implementing it as a proper FPU state switch allows us to optimize the CR0.TS flag accesses: there is no reason to set the TS bit only to then almost immediately clear it again. CR0 accesses are quite slow and expensive, don't flip the bit back and forth for no good reason. - Make sure that the same model works for both x86-32 and x86-64, so that there are no gratuitous differences between the two due to the way they save and restore segment state differently due to architectural differences that really don't matter to the FPU state. - Avoid exposing the "preload" state to the context switch routines, and in particular allow the concept of lazy state restore: if nothing else has used the FPU in the meantime, and the process is still on the same CPU, we can avoid restoring state from memory entirely, just re-expose the state that is still in the FPU unit. That optimized lazy restore isn't actually implemented here, but the infrastructure is set up for it. Of course, older CPU's that use 'fnsave' to save the state cannot take advantage of this, since the state saving also trashes the state. In other words, there is now an actual _design_ to the FPU state saving, rather than just random historical baggage. Hopefully it's easier to follow as a result. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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b3b0870e |
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16-Feb-2012 |
Linus Torvalds <torvalds@linux-foundation.org> |
i387: do not preload FPU state at task switch time Yes, taking the trap to re-load the FPU/MMX state is expensive, but so is spending several days looking for a bug in the state save/restore code. And the preload code has some rather subtle interactions with both paravirtualization support and segment state restore, so it's not nearly as simple as it should be. Also, now that we no longer necessarily depend on a single bit (ie TS_USEDFPU) for keeping track of the state of the FPU, we migth be able to do better. If we are really switching between two processes that keep touching the FP state, save/restore is inevitable, but in the case of having one process that does most of the FPU usage, we may actually be able to do much better than the preloading. In particular, we may be able to keep track of which CPU the process ran on last, and also per CPU keep track of which process' FP state that CPU has. For modern CPU's that don't destroy the FPU contents on save time, that would allow us to do a lazy restore by just re-enabling the existing FPU state - with no restore cost at all! Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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1268fbc7 |
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17-Nov-2011 |
Frederic Weisbecker <fweisbec@gmail.com> |
nohz: Remove tick_nohz_idle_enter_norcu() / tick_nohz_idle_exit_norcu() Those two APIs were provided to optimize the calls of tick_nohz_idle_enter() and rcu_idle_enter() into a single irq disabled section. This way no interrupt happening in-between would needlessly process any RCU job. Now we are talking about an optimization for which benefits have yet to be measured. Let's start simple and completely decouple idle rcu and dyntick idle logics to simplify. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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#
2bbb6817 |
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08-Oct-2011 |
Frederic Weisbecker <fweisbec@gmail.com> |
nohz: Allow rcu extended quiescent state handling seperately from tick stop It is assumed that rcu won't be used once we switch to tickless mode and until we restart the tick. However this is not always true, as in x86-64 where we dereference the idle notifiers after the tick is stopped. To prepare for fixing this, add two new APIs: tick_nohz_idle_enter_norcu() and tick_nohz_idle_exit_norcu(). If no use of RCU is made in the idle loop between tick_nohz_enter_idle() and tick_nohz_exit_idle() calls, the arch must instead call the new *_norcu() version such that the arch doesn't need to call rcu_idle_enter() and rcu_idle_exit(). Otherwise the arch must call tick_nohz_enter_idle() and tick_nohz_exit_idle() and also call explicitly: - rcu_idle_enter() after its last use of RCU before the CPU is put to sleep. - rcu_idle_exit() before the first use of RCU after the CPU is woken up. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: David Miller <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Paul Mackerras <paulus@samba.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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280f0677 |
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07-Oct-2011 |
Frederic Weisbecker <fweisbec@gmail.com> |
nohz: Separate out irq exit and idle loop dyntick logic The tick_nohz_stop_sched_tick() function, which tries to delay the next timer tick as long as possible, can be called from two places: - From the idle loop to start the dytick idle mode - From interrupt exit if we have interrupted the dyntick idle mode, so that we reprogram the next tick event in case the irq changed some internal state that requires this action. There are only few minor differences between both that are handled by that function, driven by the ts->inidle cpu variable and the inidle parameter. The whole guarantees that we only update the dyntick mode on irq exit if we actually interrupted the dyntick idle mode, and that we enter in RCU extended quiescent state from idle loop entry only. Split this function into: - tick_nohz_idle_enter(), which sets ts->inidle to 1, enters dynticks idle mode unconditionally if it can, and enters into RCU extended quiescent state. - tick_nohz_irq_exit() which only updates the dynticks idle mode when ts->inidle is set (ie: if tick_nohz_idle_enter() has been called). To maintain symmetry, tick_nohz_restart_sched_tick() has been renamed into tick_nohz_idle_exit(). This simplifies the code and micro-optimize the irq exit path (no need for local_irq_save there). This also prepares for the split between dynticks and rcu extended quiescent state logics. We'll need this split to further fix illegal uses of RCU in extended quiescent states in the idle loop. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: David Miller <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Paul Mackerras <paulus@samba.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
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b227e233 |
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30-Sep-2011 |
Don Zickus <dzickus@redhat.com> |
x86, nmi: Add in logic to handle multiple events and unknown NMIs Previous patches allow the NMI subsystem to process multipe NMI events in one NMI. As previously discussed this can cause issues when an event triggered another NMI but is processed in the current NMI. This causes the next NMI to go unprocessed and become an 'unknown' NMI. To handle this, we first have to flag whether or not the NMI handler handled more than one event or not. If it did, then there exists a chance that the next NMI might be already processed. Once the NMI is flagged as a candidate to be swallowed, we next look for a back-to-back NMI condition. This is determined by looking at the %rip from pt_regs. If it is the same as the previous NMI, it is assumed the cpu did not have a chance to jump back into a non-NMI context and execute code and instead handled another NMI. If both of those conditions are true then we will swallow any unknown NMI. There still exists a chance that we accidentally swallow a real unknown NMI, but for now things seem better. An optimization has also been added to the nmi notifier rountine. Because x86 can latch up to one NMI while currently processing an NMI, we don't have to worry about executing _all_ the handlers in a standalone NMI. The idea is if multiple NMIs come in, the second NMI will represent them. For those back-to-back NMI cases, we have the potentail to drop NMIs. Therefore only execute all the handlers in the second half of a detected back-to-back NMI. Signed-off-by: Don Zickus <dzickus@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1317409584-23662-5-git-send-email-dzickus@redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
ea70ef3d |
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28-Apr-2011 |
Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> |
sched: x86_32 Fix typo in switch_to() description This patch fixes the typo in parameters passed to x86_32 switch_to() description. Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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#
a0bfa137 |
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01-Apr-2011 |
Len Brown <len.brown@intel.com> |
cpuidle: stop depending on pm_idle cpuidle users should call cpuidle_call_idle() directly rather than via (pm_idle)() function pointer. Architecture may choose to continue using (pm_idle)(), but cpuidle need not depend on it: my_arch_cpu_idle() ... if(cpuidle_call_idle()) pm_idle(); cc: Kevin Hilman <khilman@deeprootsystems.com> cc: Paul Mundt <lethal@linux-sh.org> cc: x86@kernel.org Acked-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
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#
dac853ae |
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09-Jun-2011 |
Mathias Krause <minipli@googlemail.com> |
exec: delay address limit change until point of no return Unconditionally changing the address limit to USER_DS and not restoring it to its old value in the error path is wrong because it prevents us using kernel memory on repeated calls to this function. This, in fact, breaks the fallback of hard coded paths to the init program from being ever successful if the first candidate fails to load. With this patch applied switching to USER_DS is delayed until the point of no return is reached which makes it possible to have a multi-arch rootfs with one arch specific init binary for each of the (hard coded) probed paths. Since the address limit is already set to USER_DS when start_thread() will be invoked, this redundancy can be safely removed. Signed-off-by: Mathias Krause <minipli@googlemail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
f77cfe4e |
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07-Jan-2011 |
Thomas Renninger <trenn@suse.de> |
cpuidle/x86/perf: fix power:cpu_idle double end events and throw cpu_idle events from the cpuidle layer Currently intel_idle and acpi_idle driver show double cpu_idle "exit idle" events -> this patch fixes it and makes cpu_idle events throwing less complex. It also introduces cpu_idle events for all architectures which use the cpuidle subsystem, namely: - arch/arm/mach-at91/cpuidle.c - arch/arm/mach-davinci/cpuidle.c - arch/arm/mach-kirkwood/cpuidle.c - arch/arm/mach-omap2/cpuidle34xx.c - arch/drivers/acpi/processor_idle.c (for all cases, not only mwait) - arch/x86/kernel/process.c (did throw events before, but was a mess) - drivers/idle/intel_idle.c (did throw events before) Convention should be: Fire cpu_idle events inside the current pm_idle function (not somewhere down the the callee tree) to keep things easy. Current possible pm_idle functions in X86: c1e_idle, poll_idle, cpuidle_idle_call, mwait_idle, default_idle -> this is really easy is now. This affects userspace: The type field of the cpu_idle power event can now direclty get mapped to: /sys/devices/system/cpu/cpuX/cpuidle/stateX/{name,desc,usage,time,...} instead of throwing very CPU/mwait specific values. This change is not visible for the intel_idle driver. For the acpi_idle driver it should only be visible if the vendor misses out C-states in his BIOS. Another (perf timechart) patch reads out cpuidle info of cpu_idle events from: /sys/.../cpuidle/stateX/*, then the cpuidle events are mapped to the correct C-/cpuidle state again, even if e.g. vendors miss out C-states in their BIOS and for example only export C1 and C3. -> everything is fine. Signed-off-by: Thomas Renninger <trenn@suse.de> CC: Robert Schoene <robert.schoene@tu-dresden.de> CC: Jean Pihet <j-pihet@ti.com> CC: Arjan van de Ven <arjan@linux.intel.com> CC: Ingo Molnar <mingo@elte.hu> CC: Frederic Weisbecker <fweisbec@gmail.com> CC: linux-pm@lists.linux-foundation.org CC: linux-acpi@vger.kernel.org CC: linux-kernel@vger.kernel.org CC: linux-perf-users@vger.kernel.org CC: linux-omap@vger.kernel.org Signed-off-by: Len Brown <len.brown@intel.com>
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#
25e41933 |
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03-Jan-2011 |
Thomas Renninger <trenn@suse.de> |
perf: Clean up power events by introducing new, more generic ones Add these new power trace events: power:cpu_idle power:cpu_frequency power:machine_suspend The old C-state/idle accounting events: power:power_start power:power_end Have now a replacement (but we are still keeping the old tracepoints for compatibility): power:cpu_idle and power:power_frequency is replaced with: power:cpu_frequency power:machine_suspend is newly introduced. Jean Pihet has a patch integrated into the generic layer (kernel/power/suspend.c) which will make use of it. the type= field got removed from both, it was never used and the type is differed by the event type itself. perf timechart userspace tool gets adjusted in a separate patch. Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Jean Pihet <jean.pihet@newoldbits.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: rjw@sisk.pl LKML-Reference: <1294073445-14812-3-git-send-email-trenn@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1290072314-31155-2-git-send-email-trenn@suse.de>
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#
c882e0fe |
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14-Jun-2010 |
Robert Schöne <robert.schoene@tu-dresden.de> |
x86, perf: Add power_end event to process_*.c cpu_idle routine Systems using the idle thread from process_32.c and process_64.c do not generate power_end events which could be traced using perf. This patch adds the event generation for such systems. Signed-off-by: Robert Schoene <robert.schoene@tu-dresden.de> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <1276515440.5441.45.camel@localhost> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
86603283 |
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06-May-2010 |
Avi Kivity <avi@redhat.com> |
x86: Introduce 'struct fpu' and related API Currently all fpu state access is through tsk->thread.xstate. Since we wish to generalize fpu access to non-task contexts, wrap the state in a new 'struct fpu' and convert existing access to use an fpu API. Signal frame handlers are not converted to the API since they will remain task context only things. Signed-off-by: Avi Kivity <avi@redhat.com> Acked-by: Suresh Siddha <suresh.b.siddha@intel.com> LKML-Reference: <1273135546-29690-3-git-send-email-avi@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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#
faa4602e |
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25-Mar-2010 |
Peter Zijlstra <a.p.zijlstra@chello.nl> |
x86, perf, bts, mm: Delete the never used BTS-ptrace code Support for the PMU's BTS features has been upstreamed in v2.6.32, but we still have the old and disabled ptrace-BTS, as Linus noticed it not so long ago. It's buggy: TIF_DEBUGCTLMSR is trampling all over that MSR without regard for other uses (perf) and doesn't provide the flexibility needed for perf either. Its users are ptrace-block-step and ptrace-bts, since ptrace-bts was never used and ptrace-block-step can be implemented using a much simpler approach. So axe all 3000 lines of it. That includes the *locked_memory*() APIs in mm/mlock.c as well. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Markus Metzger <markus.t.metzger@intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <20100325135413.938004390@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
3bef4447 |
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13-Jan-2010 |
Brian Gerst <brgerst@gmail.com> |
x86: Merge show_regs() Using kernel_stack_pointer() allows 32-bit and 64-bit versions to be merged. This is more correct for 64-bit, since the old %rsp is always saved on the stack. Signed-off-by: Brian Gerst <brgerst@gmail.com> LKML-Reference: <1263397555-27695-1-git-send-email-brgerst@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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#
d015a092 |
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28-Dec-2009 |
Pekka Enberg <penberg@cs.helsinki.fi> |
x86: Use KERN_DEFAULT log-level in __show_regs() Andrew Morton reported a strange looking kmemcheck warning: WARNING: kmemcheck: Caught 32-bit read from uninitialized memory (ffff88004fba6c20) 0000000000000000310000000000000000000000000000002413000000c9ffff u u u u u u u u u u u u u u u u i i i i i i i i u u u u u u u u [<ffffffff810af3aa>] kmemleak_scan+0x25a/0x540 [<ffffffff810afbcb>] kmemleak_scan_thread+0x5b/0xe0 [<ffffffff8104d0fe>] kthread+0x9e/0xb0 [<ffffffff81003074>] kernel_thread_helper+0x4/0x10 [<ffffffffffffffff>] 0xffffffffffffffff The above printout is missing register dump completely. The problem here is that the output comes from syslog which doesn't show KERN_INFO log-level messages. We didn't see this before because both of us were testing on 32-bit kernels which use the _default_ log-level. Fix that up by explicitly using KERN_DEFAULT log-level for __show_regs() printks. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Vegard Nossum <vegard.nossum@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <1261988819.4641.2.camel@penberg-laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
df59e7bf |
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08-Dec-2009 |
Brian Gerst <brgerst@gmail.com> |
x86: Merge kernel_thread() Signed-off-by: Brian Gerst <brgerst@gmail.com> LKML-Reference: <1260380084-3707-6-git-send-email-brgerst@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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#
f443ff42 |
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08-Dec-2009 |
Brian Gerst <brgerst@gmail.com> |
x86: Sync 32/64-bit kernel_thread Signed-off-by: Brian Gerst <brgerst@gmail.com> LKML-Reference: <1260380084-3707-5-git-send-email-brgerst@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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#
e840227c |
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08-Dec-2009 |
Brian Gerst <brgerst@gmail.com> |
x86, 32-bit: Use same regs as 64-bit for kernel_thread_helper The arg should be in %eax, but that is clobbered by the return value of clone. The function pointer can be in any register. Also, don't push args onto the stack, since regparm(3) is the normal calling convention now. Signed-off-by: Brian Gerst <brgerst@gmail.com> LKML-Reference: <1260380084-3707-4-git-send-email-brgerst@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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#
f839bbc5 |
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09-Dec-2009 |
Brian Gerst <brgerst@gmail.com> |
x86: Merge sys_clone Change 32-bit sys_clone to new PTREGSCALL stub, and merge with 64-bit. Signed-off-by: Brian Gerst <brgerst@gmail.com> LKML-Reference: <1260403316-5679-7-git-send-email-brgerst@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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#
11cf88bd |
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09-Dec-2009 |
Brian Gerst <brgerst@gmail.com> |
x86: Merge sys_execve Change 32-bit sys_execve to PTREGSCALL3, and merge with 64-bit. Signed-off-by: Brian Gerst <brgerst@gmail.com> LKML-Reference: <1260403316-5679-4-git-send-email-brgerst@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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#
814e2c84 |
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08-Dec-2009 |
Andy Isaacson <adi@hexapodia.org> |
x86: Factor duplicated code out of __show_regs() into show_regs_common() Unify x86_32 and x86_64 implementations of __show_regs() header, standardizing on the x86_64 format string in the process. Also, 32-bit will now call print_modules. Signed-off-by: Andy Isaacson <adi@hexapodia.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Robert Hancock <hancockrwd@gmail.com> Cc: Richard Zidlicky <rz@linux-m68k.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <20091208082942.GA27174@hexapodia.org> [ v2: resolved conflict ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
24f1e32c |
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09-Sep-2009 |
Frederic Weisbecker <fweisbec@gmail.com> |
hw-breakpoints: Rewrite the hw-breakpoints layer on top of perf events This patch rebase the implementation of the breakpoints API on top of perf events instances. Each breakpoints are now perf events that handle the register scheduling, thread/cpu attachment, etc.. The new layering is now made as follows: ptrace kgdb ftrace perf syscall \ | / / \ | / / / Core breakpoint API / / | / | / Breakpoints perf events | | Breakpoints PMU ---- Debug Register constraints handling (Part of core breakpoint API) | | Hardware debug registers Reasons of this rewrite: - Use the centralized/optimized pmu registers scheduling, implying an easier arch integration - More powerful register handling: perf attributes (pinned/flexible events, exclusive/non-exclusive, tunable period, etc...) Impact: - New perf ABI: the hardware breakpoints counters - Ptrace breakpoints setting remains tricky and still needs some per thread breakpoints references. Todo (in the order): - Support breakpoints perf counter events for perf tools (ie: implement perf_bpcounter_event()) - Support from perf tools Changes in v2: - Follow the perf "event " rename - The ptrace regression have been fixed (ptrace breakpoint perf events weren't released when a task ended) - Drop the struct hw_breakpoint and store generic fields in perf_event_attr. - Separate core and arch specific headers, drop asm-generic/hw_breakpoint.h and create linux/hw_breakpoint.h - Use new generic len/type for breakpoint - Handle off case: when breakpoints api is not supported by an arch Changes in v3: - Fix broken CONFIG_KVM, we need to propagate the breakpoint api changes to kvm when we exit the guest and restore the bp registers to the host. Changes in v4: - Drop the hw_breakpoint_restore() stub as it is only used by KVM - EXPORT_SYMBOL_GPL hw_breakpoint_restore() as KVM can be built as a module - Restore the breakpoints unconditionally on kvm guest exit: TIF_DEBUG_THREAD doesn't anymore cover every cases of running breakpoints and vcpu->arch.switch_db_regs might not always be set when the guest used debug registers. (Waiting for a reliable optimization) Changes in v5: - Split-up the asm-generic/hw-breakpoint.h moving to linux/hw_breakpoint.h into a separate patch - Optimize the breakpoints restoring while switching from kvm guest to host. We only want to restore the state if we have active breakpoints to the host, otherwise we don't care about messed-up address registers. - Add asm/hw_breakpoint.h to Kbuild - Fix bad breakpoint type in trace_selftest.c Changes in v6: - Fix wrong header inclusion in trace.h (triggered a build error with CONFIG_FTRACE_SELFTEST Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jan Kiszka <jan.kiszka@web.de> Cc: Jiri Slaby <jirislaby@gmail.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Avi Kivity <avi@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Paul Mundt <lethal@linux-sh.org>
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#
a489ca35 |
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02-Nov-2009 |
Arjan van de Ven <arjan@linux.intel.com> |
x86: Make sure we also print a Code: line for show_regs() show_regs() is called as a mini BUG() equivalent in some places, specifically for the "scheduling while atomic" case. Unfortunately right now it does not print a Code: line unlike a real bug/oops. This patch changes the x86 implementation of show_regs() so that it calls the same function as oopses do to print the registers as well as the Code: line. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> LKML-Reference: <20091102165915.4a980fc0@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
def3c5d0 |
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12-Oct-2009 |
H. Peter Anvin <hpa@zytor.com> |
x86: use kernel_stack_pointer() in process_32.c The way to obtain a kernel-mode stack pointer from a struct pt_regs in 32-bit mode is "subtle": the stack doesn't actually contain the stack pointer, but rather the location where it would have been marks the actual previous stack frame. For clarity, use kernel_stack_pointer() instead of coding this weirdness explicitly. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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#
bdf977b3 |
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02-Aug-2009 |
Tejun Heo <tj@kernel.org> |
x86, percpu: Collect hot percpu variables into one cacheline On x86_64, percpu variables current_task and kernel_stack are used for get_current() and current_thread_info() respectively and thus are often used close to each other. Move definition of current_task to kernel/cpu/common.c right above kernel_stack definition and align it to cacheline so that they always fall into the same cacheline. Two percpu variables defined there together - irq_stack_ptr and irq_count - are also pretty hot and will benefit from sharing the cacheline. For consistency, current_task definition for x86_32 is also moved to kernel/cpu/common.c. Putting current_task and kernel_stack into the same cacheline was suggested by Linus Torvalds. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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#
2fcddce1 |
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24-Apr-2009 |
Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> |
x86-32: make sure clts is batched during context switch If we're preloading the fpu state during context switch, make sure the clts happens while we're batching the cpu context update, then do the actual __math_state_restore once the updates are flushed. This allows more efficient context switches when running paravirtualized, as all the hypercalls can be folded together into one. [ Impact: optimise paravirtual FPU context switch ] Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Alok Kataria <akataria@vmware.com> Cc: Rusty Russell <rusty@rustcorp.com.au>
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#
66cb5917 |
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01-Jun-2009 |
K.Prasad <prasad@linux.vnet.ibm.com> |
hw-breakpoints: use the new wrapper routines to access debug registers in process/thread code This patch enables the use of abstract debug registers in process-handling routines, according to the new hardware breakpoint Api. [ Impact: adapt thread breakpoints handling code to the new breakpoint Api ] Original-patch-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com> Reviewed-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
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#
bf78ad69 |
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11-May-2009 |
Amerigo Wang <amwang@redhat.com> |
x86: process.c, remove useless headers <stdarg.h> is not needed by these files, remove them. [ Impact: cleanup ] Signed-off-by: WANG Cong <amwang@redhat.com> Cc: akpm@linux-foundation.org LKML-Reference: <20090512032956.5040.77055.sendpatchset@localhost.localdomain> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
9d62dcdf |
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11-May-2009 |
Amerigo Wang <amwang@redhat.com> |
x86: merge process.c a bit Merge arch_align_stack() and arch_randomize_brk(), since they are the same. Tested on x86_64. [ Impact: cleanup ] Signed-off-by: Amerigo Wang <amwang@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
2311f0de |
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03-Apr-2009 |
Markus Metzger <markus.t.metzger@intel.com> |
x86, ds: add leakage warning Add a warning in case a debug store context is not removed before the task it is attached to is freed. Remove the old warning at thread exit. It is too early. Declare the debug store context field in thread_struct unconditionally. Remove ds_copy_thread() and ds_exit_thread() and do the work directly in process*.c. Signed-off-by: Markus Metzger <markus.t.metzger@intel.com> Cc: roland@redhat.com Cc: eranian@googlemail.com Cc: oleg@redhat.com Cc: juan.villacis@intel.com Cc: ak@linux.jf.intel.com LKML-Reference: <20090403144601.254472000@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
6f2c55b8 |
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02-Apr-2009 |
Alexey Dobriyan <adobriyan@gmail.com> |
Simplify copy_thread() First argument unused since 2.3.11. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
224101ed |
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18-Feb-2009 |
Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> |
x86/paravirt: finish change from lazy cpu to context switch start/end Impact: fix lazy context switch API Pass the previous and next tasks into the context switch start end calls, so that the called functions can properly access the task state (esp in end_context_switch, in which the next task is not yet completely current). Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
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#
7fd7d83d |
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18-Feb-2009 |
Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> |
x86/pvops: replace arch_enter_lazy_cpu_mode with arch_start_context_switch Impact: simplification, prepare for later changes Make lazy cpu mode more specific to context switching, so that it makes sense to do more context-switch specific things in the callbacks. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
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#
389d1fb1 |
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27-Feb-2009 |
Jeremy Fitzhardinge <jeremy@goop.org> |
x86: unify chunks of kernel/process*.c With x86-32 and -64 using the same mechanism for managing the tss io permissions bitmap, large chunks of process*.c are trivially unifyable, including: - exit_thread - flush_thread - __switch_to_xtra (along with tsc enable/disable) and as bonus pickups: - sys_fork - sys_vfork (Note: asmlinkage expands to empty on x86-64) Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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db949bba |
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27-Feb-2009 |
Jeremy Fitzhardinge <jeremy@goop.org> |
x86-32: use non-lazy io bitmap context switching Impact: remove 32-bit optimization to prepare unification x86-32 and -64 differ in the way they context-switch tasks with io permission bitmaps. x86-64 simply copies the next tasks io bitmap into place (if any) on context switch. x86-32 invalidates the bitmap on context switch, so that the next IO instruction will fault; at that point it installs the appropriate IO bitmap. This makes context switching IO-bitmap-using tasks a bit more less expensive, at the cost of making the next IO instruction slower due to the extra fault. This tradeoff only makes sense if IO-bitmap-using processes are relatively common, but they don't actually use IO instructions very often. However, in a typical desktop system, the only process likely to be using IO bitmaps is the X server, and nothing at all on a server. Therefore the lazy context switch doesn't really win all that much, and its just a gratuitious difference from 64-bit code. This patch removes the lazy context switch, with a view to unifying this code in a later change. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
bf51935f |
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17-Feb-2009 |
Paul E. McKenney <paulmck@kernel.org> |
x86, rcu: fix strange load average and ksoftirqd behavior Damien Wyart reported high ksoftirqd CPU usage (20%) on an otherwise idle system. The function-graph trace Damien provided: > 799.521187 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.521371 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.521555 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.521738 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.521934 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.522068 | 1) ksoftir-2324 | | rcu_check_callbacks() { > 799.522208 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.522392 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.522575 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.522759 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.522956 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.523074 | 1) ksoftir-2324 | | rcu_check_callbacks() { > 799.523214 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.523397 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.523579 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.523762 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.523960 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.524079 | 1) ksoftir-2324 | | rcu_check_callbacks() { > 799.524220 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.524403 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.524587 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.524770 | 1) <idle>-0 | | rcu_check_callbacks() { > [ . . . ] Shows rcu_check_callbacks() being invoked way too often. It should be called once per jiffy, and here it is called no less than 22 times in about 3.5 milliseconds, meaning one call every 160 microseconds or so. Why do we need to call rcu_pending() and rcu_check_callbacks() from the idle loop of 32-bit x86, especially given that no other architecture does this? The following patch removes the call to rcu_pending() and rcu_check_callbacks() from the x86 32-bit idle loop in order to reduce the softirq load on idle systems. Reported-by: Damien Wyart <damien.wyart@free.fr> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
b12bdaf1 |
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11-Feb-2009 |
Brian Gerst <brgerst@gmail.com> |
x86: use regparm(3) for passed-in pt_regs pointer Some syscalls need to access the pt_regs structure, either to copy user register state or to modifiy it. This patch adds stubs to load the address of the pt_regs struct into the %eax register, and changes the syscalls to take the pointer as an argument instead of relying on the assumption that the pt_regs structure overlaps the function arguments. Drop the use of regparm(1) due to concern about gcc bugs, and to move in the direction of the eventual removal of regparm(0) for asmlinkage. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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#
253f29a4 |
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10-Feb-2009 |
Brian Gerst <brgerst@gmail.com> |
x86: pass in pt_regs pointer for syscalls that need it Some syscalls need to access the pt_regs structure, either to copy user register state or to modifiy it. This patch adds stubs to load the address of the pt_regs struct into the %eax register, and changes the syscalls to regparm(1) to receive the pt_regs pointer as the first argument. Signed-off-by: Brian Gerst <brgerst@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
5c79d2a5 |
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11-Feb-2009 |
Tejun Heo <tj@kernel.org> |
x86: fix x86_32 stack protector bugs Impact: fix x86_32 stack protector Brian Gerst found out that %gs was being initialized to stack_canary instead of stack_canary - 20, which basically gave the same canary value for all threads. Fixing this also exposed the following bugs. * cpu_idle() didn't call boot_init_stack_canary() * stack canary switching in switch_to() was being done too late making the initial run of a new thread use the old stack canary value. Fix all of them and while at it update comment in cpu_idle() about calling boot_init_stack_canary(). Reported-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
60a5317f |
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09-Feb-2009 |
Tejun Heo <tj@kernel.org> |
x86: implement x86_32 stack protector Impact: stack protector for x86_32 Implement stack protector for x86_32. GDT entry 28 is used for it. It's set to point to stack_canary-20 and have the length of 24 bytes. CONFIG_CC_STACKPROTECTOR turns off CONFIG_X86_32_LAZY_GS and sets %gs to the stack canary segment on entry. As %gs is otherwise unused by the kernel, the canary can be anywhere. It's defined as a percpu variable. x86_32 exception handlers take register frame on stack directly as struct pt_regs. With -fstack-protector turned on, gcc copies the whole structure after the stack canary and (of course) doesn't copy back on return thus losing all changed. For now, -fno-stack-protector is added to all files which contain those functions. We definitely need something better. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
ccbeed3a |
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09-Feb-2009 |
Tejun Heo <tj@kernel.org> |
x86: make lazy %gs optional on x86_32 Impact: pt_regs changed, lazy gs handling made optional, add slight overhead to SAVE_ALL, simplifies error_code path a bit On x86_32, %gs hasn't been used by kernel and handled lazily. pt_regs doesn't have place for it and gs is saved/loaded only when necessary. In preparation for stack protector support, this patch makes lazy %gs handling optional by doing the followings. * Add CONFIG_X86_32_LAZY_GS and place for gs in pt_regs. * Save and restore %gs along with other registers in entry_32.S unless LAZY_GS. Note that this unfortunately adds "pushl $0" on SAVE_ALL even when LAZY_GS. However, it adds no overhead to common exit path and simplifies entry path with error code. * Define different user_gs accessors depending on LAZY_GS and add lazy_save_gs() and lazy_load_gs() which are noop if !LAZY_GS. The lazy_*_gs() ops are used to save, load and clear %gs lazily. * Define ELF_CORE_COPY_KERNEL_REGS() which always read %gs directly. xen and lguest changes need to be verified. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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d9a89a26 |
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09-Feb-2009 |
Tejun Heo <tj@kernel.org> |
x86: add %gs accessors for x86_32 Impact: cleanup On x86_32, %gs is handled lazily. It's not saved and restored on kernel entry/exit but only when necessary which usually is during task switch but there are few other places. Currently, it's done by calling savesegment() and loadsegment() explicitly. Define get_user_gs(), set_user_gs() and task_user_gs() and use them instead. While at it, clean up register access macros in signal.c. This cleans up code a bit and will help future changes. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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03d2989d |
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22-Jan-2009 |
Brian Gerst <brgerst@gmail.com> |
x86: remove idle_timestamp from 32bit irq_cpustat_t Impact: bogus irq_cpustat field removed idle_timestamp is left over from the removed irqbalance code. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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ea927906 |
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18-Jan-2009 |
Brian Gerst <brgerst@gmail.com> |
x86-64: Move cpu number from PDA to per-cpu and consolidate with 32-bit. tj: moved cpu_number definition out of CONFIG_HAVE_SETUP_PER_CPU_AREA for voyager. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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6dbde353 |
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15-Jan-2009 |
Ingo Molnar <mingo@elte.hu> |
percpu: add optimized generic percpu accessors It is an optimization and a cleanup, and adds the following new generic percpu methods: percpu_read() percpu_write() percpu_add() percpu_sub() percpu_and() percpu_or() percpu_xor() and implements support for them on x86. (other architectures will fall back to a default implementation) The advantage is that for example to read a local percpu variable, instead of this sequence: return __get_cpu_var(var); ffffffff8102ca2b: 48 8b 14 fd 80 09 74 mov -0x7e8bf680(,%rdi,8),%rdx ffffffff8102ca32: 81 ffffffff8102ca33: 48 c7 c0 d8 59 00 00 mov $0x59d8,%rax ffffffff8102ca3a: 48 8b 04 10 mov (%rax,%rdx,1),%rax We can get a single instruction by using the optimized variants: return percpu_read(var); ffffffff8102ca3f: 65 48 8b 05 91 8f fd mov %gs:0x7efd8f91(%rip),%rax I also cleaned up the x86-specific APIs and made the x86 code use these new generic percpu primitives. tj: * fixed generic percpu_sub() definition as Roel Kluin pointed out * added percpu_and() for completeness's sake * made generic percpu ops atomic against preemption Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
befa9e78 |
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04-Jan-2009 |
Jaswinder Singh Rajput <jaswinder@infradead.org> |
x86: process_32.c fix style problems Impact: cleanup Fix: WARNING: Use #include <linux/uaccess.h> instead of <asm/uaccess.h> WARNING: Use #include <linux/io.h> instead of <asm/io.h> WARNING: Use #include <linux/kdebug.h> instead of <asm/kdebug.h> WARNING: Use #include <linux/smp.h> instead of <asm/smp.h> ERROR: "foo * bar" should be "foo *bar" ERROR: trailing whitespace ERROR: spaces required around that ':' (ctx:WxO) ERROR: spaces required around that ':' (ctx:OxW) total: 7 errors, 4 warnings Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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bf53de90 |
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19-Dec-2008 |
Markus Metzger <markus.t.metzger@intel.com> |
x86, bts: add fork and exit handling Impact: introduce new ptrace facility Add arch_ptrace_untrace() function that is called when the tracer detaches (either voluntarily or when the tracing task dies); ptrace_disable() is only called on a voluntary detach. Add ptrace_fork() and arch_ptrace_fork(). They are called when a traced task is forked. Clear DS and BTS related fields on fork. Release DS resources and reclaim memory in ptrace_untrace(). This releases resources already when the tracing task dies. We used to do that when the traced task dies. Signed-off-by: Markus Metzger <markus.t.metzger@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
c2724775 |
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11-Dec-2008 |
Markus Metzger <markus.t.metzger@intel.com> |
x86, bts: provide in-kernel branch-trace interface Impact: cleanup Move the BTS bits from ptrace.c into ds.c. Signed-off-by: Markus Metzger <markus.t.metzger@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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8b96f011 |
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05-Dec-2008 |
Frederic Weisbecker <fweisbec@gmail.com> |
tracing/function-graph-tracer: introduce __notrace_funcgraph to filter special functions Impact: trace more functions When the function graph tracer is configured, three more files are not traced to prevent only four functions to be traced. And this impacts the normal function tracer too. arch/x86/kernel/process_64/32.c: I had crashes when I let this file traced. After some debugging, I saw that the "current" task point was changed inside__swtich_to(), ie: "write_pda(pcurrent, next_p);" inside process_64.c Since the tracer store the original return address of the function inside current, we had crashes. Only __switch_to() has to be excluded from tracing. kernel/module.c and kernel/extable.c: Because of a function used internally by the function graph tracer: __kernel_text_address() To let the other functions inside these files to be traced, this patch introduces the __notrace_funcgraph function prefix which is __notrace if function graph tracer is configured and nothing if not. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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e2ce07c8 |
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03-Apr-2008 |
Pekka Enberg <penberg@cs.helsinki.fi> |
x86: __show_registers() and __show_regs() API unification Currently the low-level function to dump user-passed registers on i386 is called __show_registers() whereas on x86-64 it's called __show_regs(). Unify the API to simplify porting of kmemcheck to x86-64. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Vegard Nossum <vegard.nossum@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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1eda8149 |
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23-Sep-2008 |
Marc Dionne <marc.c.dionne@gmail.com> |
x86: prevent stale state of c1e_mask across CPU offline/online, fix Fix build error introduced by commit 4faac97d44ac27 ("x86: prevent stale state of c1e_mask across CPU offline/online"). process_32.c needs to include idle.h to get the prototype for c1e_remove_cpu() Signed-off-by: Marc Dionne <marc.c.dionne@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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4faac97d |
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22-Sep-2008 |
Thomas Gleixner <tglx@linutronix.de> |
x86: prevent stale state of c1e_mask across CPU offline/online Impact: hang which happens across CPU offline/online on AMD C1E systems. When a CPU goes offline then the corresponding bit in the broadcast mask is cleared. For AMD C1E enabled CPUs we do not reenable the broadcast when the CPU comes online again as we do not clear the corresponding bit in the c1e_mask, which keeps track which CPUs have been switched to broadcast already. So on those !$@#& machines we never switch back to broadcasting after a CPU offline/online cycle. Clear the bit when the CPU plays dead. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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90f7d25c |
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16-Sep-2008 |
Arjan van de Ven <arjan@linux.intel.com> |
x86: print DMI information in the oops trace in order to diagnose hard system specific issues, it's useful to have the system name in the oops (as provided by DMI) Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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913da64b |
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03-Sep-2008 |
Alex Nixon <alex.nixon@citrix.com> |
x86: build fix for !CONFIG_SMP Move reset_lazy_tlbstate into tlb_32.c, and define noop versions of play_dead() in process_{32,64}.c when !CONFIG_SMP. Signed-off-by: Alex Nixon <alex.nixon@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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a21f5d88 |
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22-Aug-2008 |
Alex Nixon <alex.nixon@citrix.com> |
x86: unify x86_32 and x86_64 play_dead into one function Add the new play_dead into smpboot.c, as it fits more cleanly in there alongside other CONFIG_HOTPLUG functions. Separate out the common code into its own function. Signed-off-by: Alex Nixon <alex.nixon@citrix.com> Acked-by: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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37900258 |
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22-Aug-2008 |
Alex Nixon <alex.nixon@citrix.com> |
x86_32: clean up play_dead The removal of the CPU from the various maps was redundant as it already happened in cpu_disable. After cleaning this up, cpu_uninit only resets the tlb state, so rename it and create a noop version for the X86_64 case (so the two play_deads can be unified later). Signed-off-by: Alex Nixon <alex.nixon@citrix.com> Acked-by: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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93be71b6 |
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22-Aug-2008 |
Alex Nixon <alex.nixon@citrix.com> |
x86: add cpu hotplug hooks into smp_ops Signed-off-by: Alex Nixon <alex.nixon@citrix.com> Acked-by: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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394a1505 |
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14-Aug-2008 |
Mark Langsdorf <mark.langsdorf@amd.com> |
x86: invalidate caches before going into suspend When a CPU core is shut down, all of its caches need to be flushed to prevent stale data from causing errors if the core is resumed. Current Linux suspend code performs an assignment after the flush, which can add dirty data back to the cache. On some AMD platforms, additional speculative reads have caused crashes on resume because of this dirty data. Relocate the cache flush to be the very last thing done before halting. Tie into an assembly line so the compile will not reorder it. Add some documentation explaining what is going on and why we're doing this. Signed-off-by: Mark Langsdorf <mark.langsdorf@amd.com> Acked-by: Mark Borden <mark.borden@amd.com> Acked-by: Michael Hohmuth <michael.hohmuth@amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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fb26132b |
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21-Jul-2008 |
Jaswinder Singh <jaswinder@infradead.org> |
x86: process_32.c declare cpu_number before they get used Moved DECLARE_PER_CPU(int, cpu_number) from CONFIG_X86_32_SMP to CONFIG_X86_32 because cpu_number is required for both. And include asm/smp.h in process_32.c Signed-off-by: Jaswinder Singh <jaswinder@infradead.org>
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bbc1f698 |
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21-Jul-2008 |
Jaswinder Singh <jaswinder@infradead.org> |
x86: Introducing asm/syscalls.h Declaring arch-dependent syscalls for x86 architecture Signed-off-by: Jaswinder Singh <jaswinder@infradead.org>
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b8f8c3cf |
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18-Jul-2008 |
Thomas Gleixner <tglx@linutronix.de> |
nohz: prevent tick stop outside of the idle loop Jack Ren and Eric Miao tracked down the following long standing problem in the NOHZ code: scheduler switch to idle task enable interrupts Window starts here ----> interrupt happens (does not set NEED_RESCHED) irq_exit() stops the tick ----> interrupt happens (does set NEED_RESCHED) return from schedule() cpu_idle(): preempt_disable(); Window ends here The interrupts can happen at any point inside the race window. The first interrupt stops the tick, the second one causes the scheduler to rerun and switch away from idle again and we end up with the tick disabled. The fact that it needs two interrupts where the first one does not set NEED_RESCHED and the second one does made the bug obscure and extremly hard to reproduce and analyse. Kudos to Jack and Eric. Solution: Limit the NOHZ functionality to the idle loop to make sure that we can not run into such a situation ever again. cpu_idle() { preempt_disable(); while(1) { tick_nohz_stop_sched_tick(1); <- tell NOHZ code that we are in the idle loop while (!need_resched()) halt(); tick_nohz_restart_sched_tick(); <- disables NOHZ mode preempt_enable_no_resched(); schedule(); preempt_disable(); } } In hindsight we should have done this forever, but ... /me grabs a large brown paperbag. Debugged-by: Jack Ren <jack.ren@marvell.com>, Debugged-by: eric miao <eric.y.miao@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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1481a3dd |
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04-Jun-2008 |
Glauber Costa <gcosta@redhat.com> |
x86: move cpu_exit_clear to process_32.c Take it out of smpboot.c, and move it to process_32.c, closer to its only user. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
75118a82 |
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13-Jun-2008 |
Suresh Siddha <suresh.b.siddha@intel.com> |
x86: fix NULL pointer deref in __switch_to Patrick McHardy reported a crash: > > I get this oops once a day, its apparently triggered by something > > run by cron, but the process is a different one each time. > > > > Kernel is -git from yesterday shortly before the -rc6 release > > (last commit is the usb-2.6 merge, the x86 patches are missing), > > .config is attached. > > > > I'll retry with current -git, but the patches that have gone in > > since I last updated don't look related. > > > > [62060.043009] BUG: unable to handle kernel NULL pointer dereference at > > 000001ff > > [62060.043009] IP: [<c0102a9b>] __switch_to+0x2f/0x118 > > [62060.043009] *pde = 00000000 > > [62060.043009] Oops: 0002 [#1] PREEMPT Vegard Nossum analyzed it: > This decodes to > > 0: 0f ae 00 fxsave (%eax) > > so it's related to the floating-point context. This is the exact > location of the crash: > > $ addr2line -e arch/x86/kernel/process_32.o -i ab0 > include/asm/i387.h:232 > include/asm/i387.h:262 > arch/x86/kernel/process_32.c:595 > > ...so it looks like prev_task->thread.xstate->fxsave has become NULL. > Or maybe it never had any other value. Somehow (as described below) TS_USEDFPU is set but the fpu is not allocated or freed. Another possible FPU pre-emption issue with the sleazy FPU optimization which was benign before but not so anymore, with the dynamic FPU allocation patch. New task is getting exec'd and it is prempted at the below point. flush_thread() { ... /* * Forget coprocessor state.. */ clear_fpu(tsk); <----- Preemption point clear_used_math(); ... } Now when it context switches in again, as the used_math() is still set and fpu_counter can be > 5, we will do a math_state_restore() which sets the task's TS_USEDFPU. After it continues from the above preemption point it does clear_used_math() and much later free_thread_xstate(). Now, at the next context switch, it is quite possible that xstate is null, used_math() is not set and TS_USEDFPU is still set. This will trigger unlazy_fpu() causing kernel oops. Fix this by clearing tsk's fpu_counter before clearing task's fpu. Reported-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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00dba564 |
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09-Jun-2008 |
Thomas Gleixner <tglx@linutronix.de> |
x86: move more common idle functions/variables to process.c more unification. Should cause no change in functionality. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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6ddd2a27 |
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09-Jun-2008 |
Thomas Gleixner <tglx@linutronix.de> |
x86: simplify idle selection default_idle is selected in cpu_idle(), when no other idle routine is selected. Select it in select_idle_routine() when mwait is not selected. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
870568b3 |
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02-Jun-2008 |
Suresh Siddha <suresh.b.siddha@intel.com> |
x86, fpu: fix CONFIG_PREEMPT=y corruption of application's FPU stack Jürgen Mell reported an FPU state corruption bug under CONFIG_PREEMPT, and bisected it to commit v2.6.19-1363-gacc2076, "i386: add sleazy FPU optimization". Add tsk_used_math() checks to prevent calling math_state_restore() which can sleep in the case of !tsk_used_math(). This prevents making a blocking call in __switch_to(). Apparently "fpu_counter > 5" check is not enough, as in some signal handling and fork/exec scenarios, fpu_counter > 5 and !tsk_used_math() is possible. It's a side effect though. This is the failing scenario: process 'A' in save_i387_ia32() just after clear_used_math() Got an interrupt and pre-empted out. At the next context switch to process 'A' again, kernel tries to restore the math state proactively and sees a fpu_counter > 0 and !tsk_used_math() This results in init_fpu() during the __switch_to()'s math_state_restore() And resulting in fpu corruption which will be saved/restored (save_i387_fxsave and restore_i387_fxsave) during the remaining part of the signal handling after the context switch. Bisected-by: Jürgen Mell <j.mell@t-online.de> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Tested-by: Jürgen Mell <j.mell@t-online.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org
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6cd8a4bb |
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12-May-2008 |
Steven Rostedt <srostedt@redhat.com> |
ftrace: trace preempt off critical timings Add preempt off timings. A lot of kernel core code is taken from the RT patch latency trace that was written by Ingo Molnar. This adds "preemptoff" and "preemptirqsoff" to /debugfs/tracing/available_tracers Now instead of just tracing irqs off, preemption off can be selected to be recorded. When this is selected, it shares the same files as irqs off timings. One can either trace preemption off, irqs off, or one or the other off. By echoing "preemptoff" into /debugfs/tracing/current_tracer, recording of preempt off only is performed. "irqsoff" will only record the time irqs are disabled, but "preemptirqsoff" will take the total time irqs or preemption are disabled. Runtime switching of these options is now supported by simpling echoing in the appropriate trace name into /debugfs/tracing/current_tracer. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
970e7250 |
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16-Apr-2008 |
Andrew Morton <akpm@linux-foundation.org> |
x86, ptrace: PEBS support, warning fix arch/x86/kernel/process_32.c:566: warning: unused variable 'ds_next' arch/x86/kernel/process_32.c:566: warning: unused variable 'ds_prev' Cc: Markus Metzger <markus.t.metzger@intel.com> Cc: Andi Kleen <ak@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: Roland McGrath <roland@redhat.com> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Cc: <juan.villacis@intel.com> Cc: stephane eranian <eranian@googlemail.com> Cc: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
93fa7636 |
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08-Apr-2008 |
Markus Metzger <markus.t.metzger@intel.com> |
x86, ptrace: PEBS support Polish the ds.h interface and add support for PEBS. Ds.c is meant to be the resource allocator for per-thread and per-cpu BTS and PEBS recording. It is used by ptrace/utrace to provide execution tracing of debugged tasks. It will be used by profilers (e.g. perfmon2). It may be used by kernel debuggers to provide a kernel execution trace. Changes in detail: - guard DS and ptrace by CONFIG macros - separate DS and BTS more clearly - simplify field accesses - add functions to manage PEBS buffers - add simple protection/allocation mechanism - added support for Atom Opens: - buffer overflow handling Currently, only circular buffers are supported. This is all we need for debugging. Profilers would want an overflow notification. This is planned to be added when perfmon2 is made to use the ds.h interface. - utrace intermediate layer Signed-off-by: Markus Metzger <markus.t.metzger@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
7f424a8b |
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25-Apr-2008 |
Peter Zijlstra <peterz@infradead.org> |
fix idle (arch, acpi and apm) and lockdep OK, so 25-mm1 gave a lockdep error which made me look into this. The first thing that I noticed was the horrible mess; the second thing I saw was hacks like: 71e93d15612c61c2e26a169567becf088e71b8ff The problem is that arch idle routines are somewhat inconsitent with their IRQ state handling and instead of fixing _that_, we go paper over the problem. So the thing I've tried to do is set a standard for idle routines and fix them all up to adhere to that. So the rules are: idle routines are entered with IRQs disabled idle routines will exit with IRQs enabled Nearly all already did this in one form or another. Merge the 32 and 64 bit bits so they no longer have different bugs. As for the actual lockdep warning; __sti_mwait() did a plainly un-annotated irq-enable. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Bob Copeland <me@bobcopeland.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
a4928cff |
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23-Apr-2008 |
Ingo Molnar <mingo@elte.hu> |
"make namespacecheck" fixes Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
aa283f49 |
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10-Mar-2008 |
Suresh Siddha <suresh.b.siddha@intel.com> |
x86, fpu: lazy allocation of FPU area - v5 Only allocate the FPU area when the application actually uses FPU, i.e., in the first lazy FPU trap. This could save memory for non-fpu using apps. for example: on my system after boot, there are around 300 processes, with only 17 using FPU. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
61c4628b |
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10-Mar-2008 |
Suresh Siddha <suresh.b.siddha@intel.com> |
x86, fpu: split FPU state from task struct - v5 Split the FPU save area from the task struct. This allows easy migration of FPU context, and it's generally cleaner. It also allows the following two optimizations: 1) only allocate when the application actually uses FPU, so in the first lazy FPU trap. This could save memory for non-fpu using apps. Next patch does this lazy allocation. 2) allocate the right size for the actual cpu rather than 512 bytes always. Patches enabling xsave/xrstor support (coming shortly) will take advantage of this. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
529e25f6 |
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13-Apr-2008 |
Erik Bosman <ejbosman@cs.vu.nl> |
x86: implement prctl PR_GET_TSC and PR_SET_TSC This patch implements the PR_GET_TSC and PR_SET_TSC prctl() commands on the x86 platform (both 32 and 64 bit.) These commands control the ability to read the timestamp counter from userspace (the RDTSC instruction.) While the RDTSC instuction is a useful profiling tool, it is also the source of some non-determinism in ring-3. For deterministic replay applications it is useful to be able to trap and emulate (and record the outcome of) this instruction. This patch uses code earlier used to disable the timestamp counter for the SECCOMP framework. A side-effect of this patch is that the SECCOMP environment will now also disable the timestamp counter on x86_64 due to the addition of the TIF_NOTSC define on this platform. The code which enables/disables the RDTSC instruction during context switches is in the __switch_to_xtra function, which already handles other unusual conditions, so normal performance should not have to suffer from this change. Signed-off-by: Erik Bosman <ejbosman@cs.vu.nl> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
120d5bf1 |
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09-Apr-2008 |
Jacek Luczak <difrost.kernel@gmail.com> |
x86: remove vm86.h inclusion from process_32.c I've made a small investigation about vm86.h inclusion rules and it looks like everything is more or less ok. Files that rely on asm/vm86.h symbols are: - kprobes.c - process_32.c - signal_32.c - traps_32.c - vm86_32.c File process_32.c includes vm86.h explicitly. We can remove that include and it won't break anything. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
13af4836 |
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02-Apr-2008 |
Ingo Molnar <mingo@elte.hu> |
x86: improve default idle Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
3b22ec7b |
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19-Mar-2008 |
Glauber de Oliveira Costa <gcosta@redhat.com> |
x86: always enable irqs when entering idle This matches x86_64 behaviour, which is a superior one IMHO Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
5b0e5084 |
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10-Mar-2008 |
Jan Beulich <jbeulich@novell.com> |
x86: prevent unconditional writes to DebugCtl MSR Otherwise, enabling (or better, subsequent disabling) of single stepping would cause a kernel oops on CPUs not having this MSR. The patch could have been added a conditional to the MSR write in user_disable_single_step(), but centralizing the updates seems safer and (looking forward) better manageable. Signed-off-by: Jan Beulich <jbeulich@novell.com> Cc: Markus Metzger <markus.t.metzger@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
513ad84b |
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20-Feb-2008 |
Ingo Molnar <mingo@elte.hu> |
x86: de-macro start_thread() Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
92bc2056 |
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08-Feb-2008 |
Harvey Harrison <harvey.harrison@gmail.com> |
x86: change most X86_32 pt_regs members to unsigned long Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
783e391b |
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10-Apr-2008 |
Venki Pallipadi <venkatesh.pallipadi@intel.com> |
x86: Simplify cpu_idle_wait This patch also resolves hangs on boot: http://lkml.org/lkml/2008/2/23/263 http://bugzilla.kernel.org/show_bug.cgi?id=10093 The bug was causing once-in-few-reboots 10-15 sec wait during boot on certain laptops. Earlier commit 40d6a146629b98d8e322b6f9332b182c7cbff3df added smp_call_function in cpu_idle_wait() to kick cpus that are in tickless idle. Looking at cpu_idle_wait code at that time, code seemed to be over-engineered for a case which is rarely used (while changing idle handler). Below is a simplified version of cpu_idle_wait, which just makes a dummy smp_call_function to all cpus, to make them come out of old idle handler and start using the new idle handler. It eliminates code in the idle loop to handle cpu_idle_wait. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
b4ef95de |
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26-Feb-2008 |
Ingo Molnar <mingo@elte.hu> |
x86: disable BTS ptrace extensions for now revert the BTS ptrace extension for now. based on general objections from Roland McGrath: http://lkml.org/lkml/2008/2/21/323 we'll let the BTS functionality cook some more and re-enable it in v2.6.26. We'll leave the dead code around to help the development of this code. (X86_BTS is not defined at the moment) Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
1eb11411 |
|
08-Feb-2008 |
David Howells <dhowells@redhat.com> |
aout: remove unnecessary inclusions of {asm, linux}/a.out.h Remove now unnecessary inclusions of {asm,linux}/a.out.h. [akpm@linux-foundation.org: fix alpha build] Signed-off-by: David Howells <dhowells@redhat.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
7fa30315 |
|
08-Feb-2008 |
David Howells <dhowells@redhat.com> |
aout: suppress A.OUT library support if !CONFIG_ARCH_SUPPORTS_AOUT Suppress A.OUT library support if CONFIG_ARCH_SUPPORTS_AOUT is not set. Not all architectures support the A.OUT binfmt, so the ELF binfmt should not be permitted to go looking for A.OUT libraries to load in such a case. Not only that, but under such conditions A.OUT core dumps are not produced either. To make this work, this patch also does the following: (1) Makes the existence of the contents of linux/a.out.h contingent on CONFIG_ARCH_SUPPORTS_AOUT. (2) Renames dump_thread() to aout_dump_thread() as it's only called by A.OUT core dumping code. (3) Moves aout_dump_thread() into asm/a.out-core.h and makes it inline. This is then included only where needed. This means that this bit of arch code will be stored in the appropriate A.OUT binfmt module rather than the core kernel. (4) Drops A.OUT support for Blackfin (according to Mike Frysinger it's not needed) and FRV. This patch depends on the previous patch to move STACK_TOP[_MAX] out of asm/a.out.h and into asm/processor.h as they're required whether or not A.OUT format is available. [jdike@addtoit.com: uml: re-remove accidentally restored code] Signed-off-by: David Howells <dhowells@redhat.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
7bb308a1 |
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04-Feb-2008 |
Harvey Harrison <harvey.harrison@gmail.com> |
x86: small sparse fix in process_32.c arch/x86/kernel/process_32.c:254:43: warning: Using plain integer as NULL pointer Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
4c02ad1e |
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30-Jan-2008 |
Sam Ravnborg <sam@ravnborg.org> |
x86: fix section mismatch warning in process_*.c Fix the following warning: WARNING: arch/x86/kernel/built-in.o(.text+0x3): Section mismatch: reference to .cpuinit.data:force_mwait in 'mwait_usable' [Seen on 64 bit only but similar pattern exist on 32 bit so fix it there too] mwait_usable() were only used by a function annotated __cpuinit so annotate mwait_usable() with __cpuinit to fix the warning. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
27415a4f |
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30-Jan-2008 |
Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> |
x86: move warning message of polling idle and HT enabled The warning message at idle_setup() is never shown because smp_num_sibling hasn't been updated at this point yet. Move this polling idle and HT enabled warning to select_idle_routine(). I also implement this warning on 64-bit kernel. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
0c07ee38 |
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30-Jan-2008 |
Andi Kleen <ak@linux.intel.com> |
x86: use the correct cpuid method to detect MWAIT support for C states Previously there was a AMD specific quirk to handle the case of AMD Fam10h MWAIT not supporting any C states. But it turns out that CPUID already has ways to detectly detect that without using special quirks. The new code simply checks if MWAIT supports at least C1 and doesn't use it if it doesn't. No more vendor specific code. Note this is does not simply clear MWAIT because MWAIT can be still useful even without C states. Credit goes to Ben Serebrin for pointing out the (nearly) obvious. Cc: "Andreas Herrmann" <andreas.herrmann3@amd.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
0723a69a |
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30-Jan-2008 |
Benjamin LaHaise <bcrl@kvack.org> |
x86: fix synchronize_rcu(): high latency on idle system an otherwise idle system takes about 3 ticks per network interface in unregister_netdev() due to multiple calls to synchronize_rcu(), which adds up to quite a few seconds for tearing down thousands of interfaces. By flushing pending rcu callbacks in the idle loop, the system makes progress hundreds of times faster. If this is indeed a sane thing to, it probably needs to be done for other architectures than x86. And yes, the network stack shouldn't call synchronize_rcu() quite so much, but fixing that is a little more involved. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
5bc27dc2 |
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30-Jan-2008 |
Arjan van de Ven <arjan@linux.intel.com> |
x86: pull bp calculation earlier into the backtrace path Right now, we take the stack pointer early during the backtrace path, but only calculate bp several functions deep later, making it hard to reconcile the stack and bp backtraces (as well as showing several internal backtrace functions on the stack with bp based backtracing). This patch moves the bp taking to the same place we take the stack pointer; sadly this ripples through several layers of the back tracing stack, but it's not all that bad in the end I hope. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
60b3b9af |
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30-Jan-2008 |
Roland McGrath <roland@redhat.com> |
x86: x86 user_regset cleanup This removes a bunch of dead code that is no longer needed now that the user_regset interfaces are being used for all these jobs. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
bdb4f156 |
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30-Jan-2008 |
Jan Beulich <jbeulich@novell.com> |
i386: hard_{en,dis}able_TSC can be static Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
75604d7f |
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30-Jan-2008 |
Harvey Harrison <harvey.harrison@gmail.com> |
x86: remove all definitions with fastcall fastcall is always defined to be empty, remove it from arch/x86 Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
eee3af4a |
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30-Jan-2008 |
Markus Metzger <markus.t.metzger@intel.com> |
x86, ptrace: support for branch trace store(BTS) Resend using different mail client Changes to the last version: - split implementation into two layers: ds/bts and ptrace - renamed TIF's - save/restore ds save area msr in __switch_to_xtra() - make block-stepping only look at BTF bit Signed-off-by: Markus Metzger <markus.t.metzger@intel.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
6612538c |
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30-Jan-2008 |
Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> |
x86: clean up process_32/64.c White space and coding style clean up. Make process_32/64.c similar. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
faca6227 |
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30-Jan-2008 |
H. Peter Anvin <hpa@zytor.com> |
x86: use generic register name in the thread and tss structures This changes size-specific register names (eip/rip, esp/rsp, etc.) to generic names in the thread and tss structures. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
0f534093 |
|
30-Jan-2008 |
Roland McGrath <roland@redhat.com> |
x86: x86-32 thread_struct.debugreg This replaces the debugreg[7] member of thread_struct with individual members debugreg0, etc. This saves two words for the dummies 4 and 5, and harmonizes the code between 32 and 64. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
153d5f2e |
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30-Jan-2008 |
H. Peter Anvin <hpa@zytor.com> |
x86: use generic register names in struct user_regs_struct Switch struct user_regs_struct (defined in <asm/user.h>, which is no longer exported to userspace) to using register names without e- or r-prefixes for both 32 and 64 bit x86. This is intended as a preliminary step in unifying this code between architectures. Also, be a bit more strict in truncating 32-bit "extended" segment register values to 16 bits. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
65ea5b03 |
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30-Jan-2008 |
H. Peter Anvin <hpa@zytor.com> |
x86: rename the struct pt_regs members for 32/64-bit consistency We have a lot of code which differs only by the naming of specific members of structures that contain registers. In order to enable additional unifications, this patch drops the e- or r- size prefix from the register names in struct pt_regs, and drops the x- prefixes for segment registers on the 32-bit side. This patch also performs the equivalent renames in some additional places that might be candidates for unification in the future. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
7e991604 |
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30-Jan-2008 |
Roland McGrath <roland@redhat.com> |
x86: debugctlmsr context switch This adds low-level support for a per-thread value of MSR_IA32_DEBUGCTLMSR. The per-thread value is switched in when TIF_DEBUGCTLMSR is set. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
e1f28773 |
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30-Jan-2008 |
Roland McGrath <roland@redhat.com> |
x86 single_step: TIF_FORCED_TF This changes the single-step support to use a new thread_info flag TIF_FORCED_TF instead of the PT_DTRACE flag in task_struct.ptrace. This keeps arch implementation uses out of this non-arch field. This changes the ptrace access to eflags to mask TF and maintain the TIF_FORCED_TF flag directly if userland sets TF, instead of relying on ptrace_signal_deliver. The 64-bit and 32-bit kernels are harmonized on this same behavior. The ptrace_signal_deliver approach works now, but this change makes the low-level register access code reliable when called from different contexts than a ptrace stop, which will be possible in the future. The 64-bit do_debug exception handler is also changed not to clear TF from user-mode registers. This matches the 32-bit kernel's behavior. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
efd1ca52 |
|
30-Jan-2008 |
Roland McGrath <roland@redhat.com> |
x86: TLS cleanup This consolidates the four different places that implemented the same encoding magic for the GDT-slot 32-bit TLS support. The old tls32.c was renamed and is now only slightly modified to be the shared implementation. Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Zachary Amsden <zach@vmware.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
c1d171a0 |
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30-Jan-2008 |
Jiri Kosina <jkosina@suse.cz> |
x86: randomize brk Randomize the location of the heap (brk) for i386 and x86_64. The range is randomized in the range starting at current brk location up to 0x02000000 offset for both architectures. This, together with pie-executable-randomization.patch and pie-executable-randomization-fix.patch, should make the address space randomization on i386 and x86_64 complete. Arjan says: This is known to break older versions of some emacs variants, whose dumper code assumed that the last variable declared in the program is equal to the start of the dynamically allocated memory region. (The dumper is the code where emacs effectively dumps core at the end of it's compilation stage; this coredump is then loaded as the main program during normal use) iirc this was 5 years or so; we found this way back when I was at RH and we first did the security stuff there (including this brk randomization). It wasn't all variants of emacs, and it got fixed as a result (I vaguely remember that emacs already had code to deal with it for other archs/oses, just ifdeffed wrongly). It's a rare and wrong assumption as a general thing, just on x86 it mostly happened to be true (but to be honest, it'll break too if gcc does something fancy or if the linker does a non-standard order). Still its something we should at least document. Note 2: afaik it only broke the emacs *build*. I'm not 100% sure about that (it IS 5 years ago) though. [ akpm@linux-foundation.org: deuglification ] Signed-off-by: Jiri Kosina <jkosina@suse.cz> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Roland McGrath <roland@redhat.com> Cc: Jakub Jelinek <jakub@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
718fc13b |
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30-Jan-2008 |
Thomas Gleixner <tglx@linutronix.de> |
x86: move debug related declarations to kdebug.h Move them and fixup some users. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
5ee613b6 |
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30-Jan-2008 |
Ingo Molnar <mingo@elte.hu> |
x86: idle wakeup event in the HLT loop do a proper idle-wakeup event on HLT as well - some CPUs stop the TSC in HLT too, not just when going through the ACPI methods. (the ACPI idle code already does this.) [ update the 64-bit side too, as noticed by Jiri Slaby. ] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
40d6a146 |
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14-Jan-2008 |
Steven Rostedt <rostedt@goodmis.org> |
Kick CPUS that might be sleeping in cpus_idle_wait Sometimes cpu_idle_wait gets stuck because it might miss CPUS that are already in idle, have no tasks waiting to run and have no interrupts going to them. This is common on bootup when switching cpu idle governors. This patch gives those CPUS that don't check in an IPI kick. Background: ----------- I notice this while developing the mcount patches, that every once in a while the system would hang. Looking deeper, the hang was always at boot up when registering init_menu of the cpu_idle menu governor. Talking with Thomas Gliexner, we discovered that one of the CPUS had no timer events scheduled for it and it was in idle (running with NO_HZ). So the CPU would not set the cpu_idle_state bit. Hitting sysrq-t a few times would eventually route the interrupt to the stuck CPU and the system would continue. Note, I would have used the PDA isidle but that is set after the cpu_idle_state bit is cleared, and would leave a window open where we may miss being kicked. hmm, looking closer at this, we still have a small race window between clearing the cpu_idle_state and disabling interrupts (hence the RFC). CPU0: CPU 1: --------- --------- cpu_idle_wait(): cpu_idle(): | __cpu_cpu_var(is_idle) = 1; | if (__get_cpu_var(cpu_idle_state)) /* == 0 */ per_cpu(cpu_idle_state, 1) = 1; | if (per_cpu(is_idle, 1)) /* == 1 */ | smp_call_function(1) | | receives ipi and runs do_nothing. wait on map == empty idle(); /* waits forever */ So really we need interrupts off for most of this then. One might think that we could simply clear the cpu_idle_state from do_nothing, but I'm assuming that cpu_idle governors can be removed, and this might cause a race that a governor might be used after the module was removed. Venki said: I think your RFC patch is the right solution here. As I see it, there is no race with your RFC patch. As long as you call a dummy smp_call_function on all CPUs, we should be OK. We can get rid of cpu_idle_state and the current wait forever logic altogether with dummy smp_call_function. And so there wont be any wait forever scenario. The whole point of cpu_idle_wait() is to make all CPUs come out of idle loop atleast once. The caller will use cpu_idle_wait something like this. // Want to change idle handler - Switch global idle handler to always present default_idle - call cpu_idle_wait so that all cpus come out of idle for an instant and stop using old idle pointer and start using default idle - Change the idle handler to a new handler - optional cpu_idle_wait if you want all cpus to start using the new handler immediately. Maybe the below 1s patch is safe bet for .24. But for .25, I would say we just replace all complicated logic by simple dummy smp_call_function and remove cpu_idle_state altogether. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andi Kleen <ak@suse.de> Cc: Len Brown <lenb@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
3446fa05 |
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19-Dec-2007 |
Adrian Bunk <bunk@kernel.org> |
x86_32: select_idle_routine() must be __cpuinit CONFIG_HOTPLUG_CPU=y: WARNING: vmlinux.o(.text+0x1199a): Section mismatch: reference to .init.text.5:select_idle_routine (between 'init_intel' and 'init_nexgen') Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
19c5870c |
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19-Oct-2007 |
Alexey Dobriyan <adobriyan@openvz.org> |
Use helpers to obtain task pid in printks (arch code) One of the easiest things to isolate is the pid printed in kernel log. There was a patch, that made this for arch-independent code, this one makes so for arch/xxx files. It took some time to cross-compile it, but hopefully these are all the printks in arch code. Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org> Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
9d975ebd |
|
19-Oct-2007 |
Pavel Emelyanov <xemul@openvz.org> |
i386: consolidate show_regs and show_registers for i386 Both functions printk the same information, except for CRx and debug registers in the show_registers() one and a bit different manner. So move the common code into one place. This is already done for x86_64, so I think it's worth having the same on i386. This saves 100 bytes of .rodata section :) ... but only 8 from .text :( [ tglx: arch/x86 adaptation ] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
835c34a1 |
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12-Oct-2007 |
Dave Jones <davej@redhat.com> |
Delete filenames in comments. Since the x86 merge, lots of files that referenced their own filenames are no longer correct. Rather than keep them up to date, just delete them, as they add no real value. Additionally: - fix up comment formatting in scx200_32.c - Remove a credit from myself in setup_64.c from a time when we had no SCM - remove longwinded history from tsc_32.c which can be figured out from git. Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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9a163ed8 |
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11-Oct-2007 |
Thomas Gleixner <tglx@linutronix.de> |
i386: move kernel Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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