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ea73179e |
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13-Feb-2024 |
Naveen N Rao <naveen@kernel.org> |
powerpc/ftrace: Ignore ftrace locations in exit text sections Michael reported that we are seeing an ftrace bug on bootup when KASAN is enabled and we are using -fpatchable-function-entry: ftrace: allocating 47780 entries in 18 pages ftrace-powerpc: 0xc0000000020b3d5c: No module provided for non-kernel address ------------[ ftrace bug ]------------ ftrace faulted on modifying [<c0000000020b3d5c>] 0xc0000000020b3d5c Initializing ftrace call sites ftrace record flags: 0 (0) expected tramp: c00000000008cef4 ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at kernel/trace/ftrace.c:2180 ftrace_bug+0x3c0/0x424 Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0-rc3-00120-g0f71dcfb4aef #860 Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries NIP: c0000000003aa81c LR: c0000000003aa818 CTR: 0000000000000000 REGS: c0000000033cfab0 TRAP: 0700 Not tainted (6.5.0-rc3-00120-g0f71dcfb4aef) MSR: 8000000002021033 <SF,VEC,ME,IR,DR,RI,LE> CR: 28028240 XER: 00000000 CFAR: c0000000002781a8 IRQMASK: 3 ... NIP [c0000000003aa81c] ftrace_bug+0x3c0/0x424 LR [c0000000003aa818] ftrace_bug+0x3bc/0x424 Call Trace: ftrace_bug+0x3bc/0x424 (unreliable) ftrace_process_locs+0x5f4/0x8a0 ftrace_init+0xc0/0x1d0 start_kernel+0x1d8/0x484 With CONFIG_FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY=y and CONFIG_KASAN=y, compiler emits nops in functions that it generates for registering and unregistering global variables (unlike with -pg and -mprofile-kernel where calls to _mcount() are not generated in those functions). Those functions then end up in INIT_TEXT and EXIT_TEXT respectively. We don't expect to see any profiled functions in EXIT_TEXT, so ftrace_init_nop() assumes that all addresses that aren't in the core kernel text belongs to a module. Since these functions do not match that criteria, we see the above bug. Address this by having ftrace ignore all locations in the text exit sections of vmlinux. Fixes: 0f71dcfb4aef ("powerpc/ftrace: Add support for -fpatchable-function-entry") Cc: stable@vger.kernel.org # v6.6+ Reported-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Naveen N Rao <naveen@kernel.org> Reviewed-by: Benjamin Gray <bgray@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20240213175410.1091313-1-naveen@kernel.org
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0f71dcfb |
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19-Jun-2023 |
Naveen N Rao <naveen@kernel.org> |
powerpc/ftrace: Add support for -fpatchable-function-entry GCC v13.1 updated support for -fpatchable-function-entry on ppc64le to emit nops after the local entry point, rather than before it. This allows us to use this in the kernel for ftrace purposes. A new script is added under arch/powerpc/tools/ to help detect if nops are emitted after the function local entry point, or before the global entry point. With -fpatchable-function-entry, we no longer have the profiling instructions generated at function entry, so we only need to validate the presence of two nops at the ftrace location in ftrace_init_nop(). We patch the preceding instruction with 'mflr r0' to match the -mprofile-kernel ABI for subsequent ftrace use. This changes the profiling instructions used on ppc32. The default -pg option emits an additional 'stw' instruction after 'mflr r0' and before the branch to _mcount 'bl _mcount'. This is very similar to the original -mprofile-kernel implementation on ppc64le, where an additional 'std' instruction was used to save LR to its save location in the caller's stackframe. Subsequently, this additional store was removed in later compiler versions for performance reasons. The same reasons apply for ppc32 so we only patch in a 'mflr r0'. Signed-off-by: Naveen N Rao <naveen@kernel.org> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/68586d22981a2c3bb45f27a2b621173d10a7d092.1687166935.git.naveen@kernel.org
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c91c5a82 |
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19-Jun-2023 |
Naveen N Rao <naveen@kernel.org> |
powerpc/ftrace: Implement ftrace_replace_code() Implement ftrace_replace_code() to consolidate logic from the different ftrace patching routines: ftrace_make_nop(), ftrace_make_call() and ftrace_modify_call(). Note that ftrace_make_call() is still required primarily to handle patching modules during their load time. The other two routines should no longer be called. This lays the groundwork to enable better control in patching ftrace locations, including the ability to nop-out preceding profiling instructions when ftrace is disabled. Signed-off-by: Naveen N Rao <naveen@kernel.org> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/c28f852225646b0561bbf3c1d22d03f041ace8e0.1687166935.git.naveen@kernel.org
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a26ce427 |
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19-Jun-2023 |
Naveen N Rao <naveen@kernel.org> |
powerpc/ftrace: Replace use of ftrace_call_replace() with ftrace_create_branch_inst() ftrace_create_branch_inst() is clearer about its intent than ftrace_call_replace(). Signed-off-by: Naveen N Rao <naveen@kernel.org> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/953513b88fa922ba7a66d772dc1310710efe9177.1687166935.git.naveen@kernel.org
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67385738 |
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19-Jun-2023 |
Naveen N Rao <naveen@kernel.org> |
powerpc/ftrace: Simplify ftrace_modify_call() Now that we validate the ftrace location during initialization in ftrace_init_nop(), we can simplify ftrace_modify_call() to patch-in the updated branch instruction without worrying about the instructions surrounding the ftrace location. Note that we continue to ensure we have the expected branch instruction at the ftrace location before patching it with the updated branch destination. Signed-off-by: Naveen N Rao <naveen@kernel.org> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/06275720939f8ee4c2f61c9e9a3e89b1fa3c441d.1687166935.git.naveen@kernel.org
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9365e23b |
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19-Jun-2023 |
Naveen N Rao <naveen@kernel.org> |
powerpc/ftrace: Simplify ftrace_make_call() Now that we validate the ftrace location during initialization in ftrace_init_nop(), we can simplify ftrace_make_call() to replace the nop without worrying about the instructions surrounding the ftrace location. Note that we continue to ensure that we have a nop at the ftrace location before patching it. Signed-off-by: Naveen N Rao <naveen@kernel.org> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/2d28866d2f556488a663981abe5621511efb207b.1687166935.git.naveen@kernel.org
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562bde0b |
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19-Jun-2023 |
Naveen N Rao <naveen@kernel.org> |
powerpc/ftrace: Simplify ftrace_make_nop() Now that we validate the ftrace location during initialization in ftrace_init_nop(), we can simplify ftrace_make_nop() to patch-in the nop without worrying about the instructions surrounding the ftrace location. Note that we continue to ensure that we have a bl to ftrace_[regs_]caller at the ftrace location before nop-ing it out. Signed-off-by: Naveen N Rao <naveen@kernel.org> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/e12ccbf28c50c3a07fb614f4d392e55f7098a729.1687166935.git.naveen@kernel.org
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cc93b923 |
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19-Jun-2023 |
Naveen N Rao <naveen@kernel.org> |
powerpc/ftrace: Add separate ftrace_init_nop() with additional validation Currently, we validate instructions around the ftrace location every time we have to enable/disable ftrace. Introduce ftrace_init_nop() to instead perform all the validation during ftrace initialization. This allows us to simply patch the necessary instructions during enabling/disabling ftrace. Signed-off-by: Naveen N Rao <naveen@kernel.org> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/f373684081e8e98be09b7f44d2d93069768324dc.1687166935.git.naveen@kernel.org
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33bb8a0b |
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19-Jun-2023 |
Naveen N Rao <naveen@kernel.org> |
powerpc/ftrace: Stop re-purposing linker generated long branches for ftrace Commit 67361cf8071286 ("powerpc/ftrace: Handle large kernel configs") added ftrace support for ppc64 kernel images with a text section larger than 32MB. The patch did two things: 1. Add stubs at the end of .text to branch into ftrace_[regs_]caller for functions that were out of branch range. 2. Re-purpose linker-generated long branches to _mcount to instead branch to ftrace_[regs_]caller. Before that, we only supported kernel .text up to ~32MB. With the above, we now support up to ~96MB: - The first 32MB of kernel text can branch directly into ftrace_[regs_]caller since that symbol is usually at the beginning. - The modified long_branch from (2) above is used by the next 32MB of kernel text. - The next 32MB of kernel text can use the stub at the end of text to branch back to ftrace_[regs_]caller. While re-purposing the long branch works in practice, it still restricts ftrace to kernel text up to ~96MB. The stub at the end of kernel text from (1) already enables us to extend ftrace support for kernel text up to 64MB, which fulfils the original requirement. Further, once we switch to -fpatchable-function-entry, there will not be a long branch that we can use. Stop re-purposing the linker-generated long branches for ftrace to simplify the code. If there are good reasons to support ftrace on kernels beyond 64MB, we can consider adding support by using -fpatchable-function-entry. Signed-off-by: Naveen N Rao <naveen@kernel.org> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/33fa3be97f8e1f2171254ef2e1b0d5c8836c11fd.1687166935.git.naveen@kernel.org
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f4fcbf2e |
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19-Jun-2023 |
Naveen N Rao <naveen@kernel.org> |
powerpc/ftrace: Refactor ftrace_modify_code() Split up ftrace_modify_code() into a few helpers for future use. Also update error messages accordingly. Signed-off-by: Naveen N Rao <naveen@kernel.org> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/a8daa49712b44ff539e6c22a2ea649a540386798.1687166935.git.naveen@kernel.org
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f3993a03 |
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19-Jun-2023 |
Naveen N Rao <naveen@kernel.org> |
powerpc/ftrace: Extend ftrace support for large kernels to ppc32 Commit 67361cf8071286 ("powerpc/ftrace: Handle large kernel configs") added ftrace support for ppc64 kernel images with a text section larger than 32MB. The approach itself isn't specific to ppc64, so extend the same to also work on ppc32. While at it, reduce the space reserved for the stub from 64 bytes to 32 bytes since the different stub variants are all less than 8 instructions. To reduce use of #ifdef, a stub implementation is provided for kernel_toc_address() and -SZ_2G is cast to 'long long' to prevent errors on ppc32. Signed-off-by: Naveen N Rao <naveen@kernel.org> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/9fa3258cbb9105cf8a0a8135214d44ffbc75fe84.1687166935.git.naveen@kernel.org
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b5efb61c |
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19-Jun-2023 |
Naveen N Rao <naveen@kernel.org> |
powerpc/ftrace: Use FTRACE_REGS_ADDR to identify the correct ftrace trampoline Instead of keying off DYNAMIC_FTRACE_WITH_REGS, use FTRACE_REGS_ADDR to identify the proper ftrace trampoline address to use. Signed-off-by: Naveen N Rao <naveen@kernel.org> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/6045a280a57a7ea937a5bb13ccac747026dbfb07.1687166935.git.naveen@kernel.org
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96d7a136 |
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19-Jun-2023 |
Naveen N Rao <naveen@kernel.org> |
powerpc/ftrace: Simplify function_graph support in ftrace.c Since we now support DYNAMIC_FTRACE_WITH_ARGS across ppc32 and ppc64 ELFv2, we can simplify function_graph tracer support code in ftrace.c Signed-off-by: Naveen N Rao <naveen@kernel.org> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/4dc92c4b1ed444dc62b748ae7327acdb9e096864.1687166935.git.naveen@kernel.org
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7f7797b3 |
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19-Jun-2023 |
Naveen N Rao <naveen@kernel.org> |
powerpc64/ftrace: Move ELFv1 and -pg support code into a separate file ELFv1 support is deprecated and on the way out. Pre -mprofile-kernel ftrace support (-pg only) is very limited and is retained primarily for clang builds. It won't be necessary once clang lands support for -fpatchable-function-entry. Copy the existing ftrace code supporting these into ftrace_pg.c. ftrace.c can then be refactored and enhanced with a focus on ppc32 and ppc64 ELFv2. Signed-off-by: Naveen N Rao <naveen@kernel.org> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/1eb6cc6c3141ddb77a2a25f8a9e83d83ff312b02.1687166935.git.naveen@kernel.org
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7e3a68be |
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07-Apr-2023 |
Nicholas Piggin <npiggin@gmail.com> |
powerpc/64: vmlinux support building with PCREL addresing PC-Relative or PCREL addressing is an extension to the ELF ABI which uses Power ISA v3.1 PC-relative instructions to calculate addresses, rather than the traditional TOC scheme. Add an option to build vmlinux using pcrel addressing. Modules continue to use TOC addressing. - TOC address helpers and r2 are poisoned with -1 when running vmlinux. r2 could be used for something useful once things are ironed out. - Assembly must call C functions with @notoc annotation, or the linker complains aobut a missing nop after the call. This is done with the CFUNC macro introduced earlier. - Boot: with the exception of prom_init, the execution branches to the kernel virtual address early in boot, before any addresses are generated, which ensures 34-bit pcrel addressing does not miss the high PAGE_OFFSET bits. TOC relative addressing has a similar requirement. prom_init does not go to the virtual address and its addresses should not carry over to the post-prom kernel. - Ftrace trampolines are converted from TOC addressing to pcrel addressing, including module ftrace trampolines that currently use the kernel TOC to find ftrace target functions. - BPF function prologue and function calling generation are converted from TOC to pcrel. - copypage_64.S has an interesting problem, prefixed instructions have alignment restrictions so the linker can add padding, which makes the assembler treat the difference between two local labels as non-constant even if alignment is arranged so padding is not required. This may need toolchain help to solve nicely, for now move the prefix instruction out of the alternate patch section to work around it. This reduces kernel text size by about 6%. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230408021752.862660-6-npiggin@gmail.com
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dc5dac74 |
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07-Apr-2023 |
Nicholas Piggin <npiggin@gmail.com> |
powerpc/64: Add support to build with prefixed instructions Add an option to build kernel and module with prefixed instructions if the CPU and toolchain support it. This is not related to kernel support for userspace execution of prefixed instructions. Building with prefixed instructions breaks some extended inline asm memory addressing, for example it will provide immediates that exceed the range of simple load/store displacement. Whether this is a toolchain or a kernel asm problem remains to be seen. For now, these are replaced with simpler and less efficient direct register addressing when compiling with prefixed. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230408021752.862660-4-npiggin@gmail.com
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cb928ac1 |
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09-Aug-2022 |
Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> |
powerpc64/ftrace: Fix ftrace for clang builds Clang doesn't support -mprofile-kernel ABI, so guard the checks against CONFIG_DYNAMIC_FTRACE_WITH_REGS, rather than the elf ABI version. Fixes: 23b44fc248f4 ("powerpc/ftrace: Make __ftrace_make_{nop/call}() common to PPC32 and PPC64") Cc: stable@vger.kernel.org # v5.19+ Reported-by: Nick Desaulniers <ndesaulniers@google.com> Reported-by: Ondrej Mosnacek <omosnacek@gmail.com> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Tested-by: Ondrej Mosnacek <omosnacek@gmail.com> Acked-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://github.com/llvm/llvm-project/issues/57031 Link: https://github.com/ClangBuiltLinux/linux/issues/1682 Link: https://lore.kernel.org/r/20220809095907.418764-1-naveen.n.rao@linux.vnet.ibm.com
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2b461880 |
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18-Jul-2022 |
Michael Ellerman <mpe@ellerman.id.au> |
powerpc: Fix all occurences of duplicate words Since commit 87c78b612f4f ("powerpc: Fix all occurences of "the the"") fixed "the the", there's now a steady stream of patches fixing other duplicate words. Just fix them all at once, to save the overhead of dealing with individual patches for each case. This leaves a few cases of "that that", which in some contexts is correct. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220718095158.326606-1-mpe@ellerman.id.au
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2a83afe7 |
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31-May-2022 |
Michael Ellerman <mpe@ellerman.id.au> |
powerpc/64: Drop ppc_inst_as_str() The ppc_inst_as_str() macro tries to make printing variable length, aka "prefixed", instructions convenient. It mostly succeeds, but it does hide an on-stack buffer, which triggers stack protector. More problematically it doesn't compile at all with GCC 12, with -Wdangling-pointer, due to the fact that it returns the char buffer declared inside the macro: arch/powerpc/kernel/trace/ftrace.c: In function '__ftrace_modify_call': ./include/linux/printk.h:475:44: error: using a dangling pointer to '__str' [-Werror=dangling-pointer=] 475 | #define printk(fmt, ...) printk_index_wrap(_printk, fmt, ##__VA_ARGS__) ... arch/powerpc/kernel/trace/ftrace.c:567:17: note: in expansion of macro 'pr_err' 567 | pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(op)); | ^~~~~~ ./arch/powerpc/include/asm/inst.h:156:14: note: '__str' declared here 156 | char __str[PPC_INST_STR_LEN]; \ | ^~~~~ This could be fixed by having the caller declare the buffer, but in some places there'd need to be two buffers. In all cases where ppc_inst_as_str() is used the output is not really meant for user consumption, it's almost always indicative of a kernel bug. A simpler solution is to just print the value as an unsigned long. For normal instructions the output is identical. For prefixed instructions the value is printed as a single 64-bit quantity, whereas previously the low half was printed first. But that is good enough for debug output, especially as prefixed instructions will be rare in kernel code in practice. Old: c000000000111170 60420000 ori r2,r2,0 c000000000111174 04100001 e580fb00 .long 0xe580fb0004100001 New: c00000000010f90c 60420000 ori r2,r2,0 c00000000010f910 e580fb0004100001 .long 0xe580fb0004100001 Reported-by: Bagas Sanjaya <bagasdotme@gmail.com> Reported-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Tested-by: Bagas Sanjaya <bagasdotme@gmail.com> Link: https://lore.kernel.org/r/20220531065936.3674348-1-mpe@ellerman.id.au
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84ade0a6 |
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15-May-2022 |
Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> |
powerpc/ftrace: Remove ftrace init tramp once kernel init is complete Stop using the ftrace trampoline for init section once kernel init is complete. Fixes: 67361cf8071286 ("powerpc/ftrace: Handle large kernel configs") Cc: stable@vger.kernel.org # v4.20+ Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220516071422.463738-1-naveen.n.rao@linux.vnet.ibm.com
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af8b9f35 |
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08-May-2022 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/ftrace: Minimise number of #ifdefs A lot of #ifdefs can be replaced by IS_ENABLED() Do so. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Fold in changes suggested by Naveen and Christophe on list] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/18ce6708d6f8c71d87436f9c6019f04df4125128.1652074503.git.christophe.leroy@csgroup.eu
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b97d0e3d |
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08-May-2022 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/ftrace: Simplify expected_nop_sequence() Avoid ifdefs around expected_nop_sequence(). While at it make it a bool. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/305d22472f1f92127fba09692df6bb5d079a8cd0.1652074503.git.christophe.leroy@csgroup.eu
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c8deb280 |
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08-May-2022 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/ftrace: Use size macro instead of opencoding 0x80000000 is SZ_2G. Use it. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Fix comparison against unsigned -SZ_2G] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/bb6626e884acffe87b58736291df57db3deaa9b9.1652074503.git.christophe.leroy@csgroup.eu
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e89aa642 |
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08-May-2022 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/ftrace: Use PPC_RAW_xxx() macros instead of opencoding. PPC_RAW_xxx() macros are self explanatory and less error prone than open coding. Use them in ftrace.c Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/9292094c9a69cef6d29ee83f435a557b59c45065.1652074503.git.christophe.leroy@csgroup.eu
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cf9df92a |
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08-May-2022 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/ftrace: Use BRANCH_SET_LINK instead of value 1 To make it explicit, use BRANCH_SET_LINK instead of value 1 when calling create_branch(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d57847063ac93660a5af620d4df1847f10edf61a.1652074503.git.christophe.leroy@csgroup.eu
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ccf6607e |
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08-May-2022 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/ftrace: Remove ftrace_plt_tramps[] ftrace_plt_tramps table is never filled so it is useless. Remove it. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/daeeb618a6619e3a7e3f82f1bd83ca7c25af6330.1652074503.git.christophe.leroy@csgroup.eu
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c2cba93d |
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08-May-2022 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/ftrace: Use CONFIG_FUNCTION_TRACER instead of CONFIG_DYNAMIC_FTRACE Since commit 0c0c52306f47 ("powerpc: Only support DYNAMIC_FTRACE not static"), CONFIG_DYNAMIC_FTRACE is always selected when CONFIG_FUNCTION_TRACER is selected. To avoid confusion and have the reader wonder what's happen when CONFIG_FUNCTION_TRACER is selected and CONFIG_DYNAMIC_FTRACE is not, use CONFIG_FUNCTION_TRACER in ifdefs instead of CONFIG_DYNAMIC_FTRACE. As CONFIG_FUNCTION_GRAPH_TRACER depends on CONFIG_FUNCTION_TRACER, ftrace.o doesn't need to appear for both symbols in Makefile. Then as ftrace.o is built only when CONFIG_FUNCTION_TRACER is selected ifdef CONFIG_FUNCTION_TRACER is not needed in ftrace.c, and since it implies CONFIG_DYNAMIC_FTRACE, CONFIG_DYNAMIC_FTRACE is not needed in ftrace.c Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/628d357503eb90b4a034f99b7df516caaff4d279.1652074503.git.christophe.leroy@csgroup.eu
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23b44fc2 |
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08-May-2022 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/ftrace: Make __ftrace_make_{nop/call}() common to PPC32 and PPC64 Since c93d4f6ecf4b ("powerpc/ftrace: Add module_trampoline_target() for PPC32"), __ftrace_make_nop() for PPC32 is very similar to the one for PPC64. Same for __ftrace_make_call(). Make them common. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/96f53c237316dab4b1b8c682685266faa92da816.1652074503.git.christophe.leroy@csgroup.eu
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7d40aff8 |
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08-May-2022 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc: Replace PPC64_ELF_ABI_v{1/2} by CONFIG_PPC64_ELF_ABI_V{1/2} Replace all uses of PPC64_ELF_ABI_v1 and PPC64_ELF_ABI_v2 by resp CONFIG_PPC64_ELF_ABI_V1 and CONFIG_PPC64_ELF_ABI_V2. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/ba13d59e8c50bc9aa6328f1c7f0c0d0278e0a3a7.1652074503.git.christophe.leroy@csgroup.eu
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bbffdd2f |
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08-May-2022 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/ftrace: Use patch_instruction() return directly Instead of returning -EPERM when patch_instruction() fails, just return what patch_instruction returns. That simplifies ftrace_modify_code(): 0: 94 21 ff c0 stwu r1,-64(r1) 4: 93 e1 00 3c stw r31,60(r1) 8: 7c 7f 1b 79 mr. r31,r3 c: 40 80 00 30 bge 3c <ftrace_modify_code+0x3c> 10: 93 c1 00 38 stw r30,56(r1) 14: 7c 9e 23 78 mr r30,r4 18: 7c a4 2b 78 mr r4,r5 1c: 80 bf 00 00 lwz r5,0(r31) 20: 7c 1e 28 40 cmplw r30,r5 24: 40 82 00 34 bne 58 <ftrace_modify_code+0x58> 28: 83 c1 00 38 lwz r30,56(r1) 2c: 7f e3 fb 78 mr r3,r31 30: 83 e1 00 3c lwz r31,60(r1) 34: 38 21 00 40 addi r1,r1,64 38: 48 00 00 00 b 38 <ftrace_modify_code+0x38> 38: R_PPC_REL24 patch_instruction Before: 0: 94 21 ff c0 stwu r1,-64(r1) 4: 93 e1 00 3c stw r31,60(r1) 8: 7c 7f 1b 79 mr. r31,r3 c: 40 80 00 4c bge 58 <ftrace_modify_code+0x58> 10: 93 c1 00 38 stw r30,56(r1) 14: 7c 9e 23 78 mr r30,r4 18: 7c a4 2b 78 mr r4,r5 1c: 80 bf 00 00 lwz r5,0(r31) 20: 7c 08 02 a6 mflr r0 24: 90 01 00 44 stw r0,68(r1) 28: 7c 1e 28 40 cmplw r30,r5 2c: 40 82 00 48 bne 74 <ftrace_modify_code+0x74> 30: 7f e3 fb 78 mr r3,r31 34: 48 00 00 01 bl 34 <ftrace_modify_code+0x34> 34: R_PPC_REL24 patch_instruction 38: 80 01 00 44 lwz r0,68(r1) 3c: 20 63 00 00 subfic r3,r3,0 40: 83 c1 00 38 lwz r30,56(r1) 44: 7c 63 19 10 subfe r3,r3,r3 48: 7c 08 03 a6 mtlr r0 4c: 83 e1 00 3c lwz r31,60(r1) 50: 38 21 00 40 addi r1,r1,64 54: 4e 80 00 20 blr It improves ftrace activation/deactivation duration by about 3%. Modify patch_instruction() return on failure to -EPERM in order to match with ftrace expectations. Other users of patch_instruction() do not care about the exact error value returned. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/49a8597230713e2633e7d9d7b56140787c4a7e20.1652074503.git.christophe.leroy@csgroup.eu
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2c920fca |
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08-May-2022 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/ftrace: Inline ftrace_modify_code() Inlining ftrace_modify_code(), it increases a bit the size of ftrace code but brings 5% improvment on ftrace activation. Usually in C files we let gcc decide what to do but here it really help to 'help' gcc to decide to inline, thought we don't want to force it with an __always_inline that would be too much for CONFIG_CC_OPTIMIZE_FOR_SIZE. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1597a06d57cfc80e6853838c4066e799bf6c7977.1652074503.git.christophe.leroy@csgroup.eu
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a1facd25 |
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08-May-2022 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/ftrace: Use is_offset_in_branch_range() Use is_offset_in_branch_range() instead of create_branch() to check if a target is within branch range. This patch together with the previous one improves ftrace activation time by 7% Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/912ae51782f5a53c44e435497c8c3fb5cc632387.1652074503.git.christophe.leroy@csgroup.eu
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ae3a2a21 |
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08-May-2022 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/ftrace: Remove redundant create_branch() calls Since commit d5937db114e4 ("powerpc/code-patching: Fix patch_branch() return on out-of-range failure") patch_branch() fails with -ERANGE when trying to branch out of range. No need to perform the test twice. Remove redundant create_branch() calls. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/aa45fbad0b4b7493080835d8276c0cb4ce146503.1652074503.git.christophe.leroy@csgroup.eu
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d996d505 |
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08-May-2022 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/ftrace: Refactor prepare_ftrace_return() When we have CONFIG_DYNAMIC_FTRACE_WITH_ARGS, prepare_ftrace_return() is called by ftrace_graph_func() otherwise prepare_ftrace_return() is called from assembly. Refactor prepare_ftrace_return() into a static __prepare_ftrace_return() that will be called by both prepare_ftrace_return() and ftrace_graph_func(). It will allow GCC to fold __prepare_ftrace_return() inside ftrace_graph_func(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/0d42deafe353980c66cf19d3132638c05ba9f4a9.1652074503.git.christophe.leroy@csgroup.eu
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76222808 |
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04-Mar-2022 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc: Move C prototypes out of asm-prototypes.h We originally added asm-prototypes.h in commit 42f5b4cacd78 ("powerpc: Introduce asm-prototypes.h"). It's purpose was for prototypes of C functions that are only called from asm, in order to fix sparse warnings about missing prototypes. A few months later Nick added a different use case in commit 4efca4ed05cb ("kbuild: modversions for EXPORT_SYMBOL() for asm") for C prototypes for exported asm functions. This is basically the inverse of our original usage. Since then we've added various prototypes to asm-prototypes.h for both reasons, meaning we now need to unstitch it all. Dispatch prototypes of C functions into relevant headers and keep only the prototypes for functions defined in assembly. For the time being, leave prom_init() there because moving it into asm/prom.h or asm/setup.h conflicts with drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowrom.o This will be fixed later by untaggling asm/pci.h and asm/prom.h or by renaming the function in shadowrom.c Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/62d46904eca74042097acf4cb12c175e3067f3d1.1646413435.git.christophe.leroy@csgroup.eu
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df45a557 |
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15-Feb-2022 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/ftrace: Add recursion protection in prepare_ftrace_return() The function_graph_enter() does not provide any recursion protection. Add a protection in prepare_ftrace_return() in case function_graph_enter() calls something that gets function graph traced. Fixes: 830213786c49 ("powerpc/ftrace: directly call of function graph tracer by ftrace caller") Reported-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/74edf2ff0a60e66b0d9225a137100a86a0557032.1644949750.git.christophe.leroy@csgroup.eu
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83021378 |
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20-Dec-2021 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/ftrace: directly call of function graph tracer by ftrace caller Modify function graph tracer to be handled directly by the standard ftrace caller. This is made possible as powerpc now supports CONFIG_DYNAMIC_FTRACE_WITH_ARGS. This change simplifies the call of function graph ftrace. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/04d196585ff81bde06a000bd9c633a33a5b21130.1640017960.git.christophe.leroy@csgroup.eu
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0c81ed5e |
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20-Dec-2021 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/ftrace: Refactor ftrace_{en/dis}able_ftrace_graph_caller ftrace_enable_ftrace_graph_caller() and ftrace_disable_ftrace_graph_caller() have common code. They will have even more common code after following patch. Refactor into a single ftrace_modify_ftrace_graph_caller() function. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/f37785a531f1a8f201e1b3da45997a5c77e9d820.1640017960.git.christophe.leroy@csgroup.eu
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c545b9f0 |
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29-Nov-2021 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/inst: Define ppc_inst_t In order to stop using 'struct ppc_inst' on PPC32, define a ppc_inst_t typedef. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/fe5baa2c66fea9db05a8b300b3e8d2880a42596c.1638208156.git.christophe.leroy@csgroup.eu
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7dfbfb87 |
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28-Oct-2021 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/ftrace: Activate HAVE_DYNAMIC_FTRACE_WITH_REGS on PPC32 Unlike PPC64, PPC32 doesn't require any special compiler option to get _mcount() call not clobbering registers. Provide ftrace_regs_caller() and ftrace_regs_call() and activate HAVE_DYNAMIC_FTRACE_WITH_REGS. That's heavily copied from ftrace_64_mprofile.S For the time being leave livepatching aside, it will come with following patch. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1862dc7719855cc2a4eec80920d94c955877557e.1635423081.git.christophe.leroy@csgroup.eu
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c93d4f6e |
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28-Oct-2021 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/ftrace: Add module_trampoline_target() for PPC32 module_trampoline_target() is used by __ftrace_modify_call(). Implement it for PPC32 so that CONFIG_DYNAMIC_FTRACE_WITH_REGS can be activated on PPC32 as well. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/42345f464fb465f0fc76f3090e250be8fc1729f0.1635423081.git.christophe.leroy@csgroup.eu
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69d4d6e5 |
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20-May-2021 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc: Don't use 'struct ppc_inst' to reference instruction location 'struct ppc_inst' is an internal representation of an instruction, but in-memory instructions are and will remain a table of 'u32' forever. Replace all 'struct ppc_inst *' used for locating an instruction in memory by 'u32 *'. This removes a lot of undue casts to 'struct ppc_inst *'. It also helps locating ab-use of 'struct ppc_inst' dereference. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Fix ppc_inst_next(), use u32 instead of unsigned int] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7062722b087228e42cbd896e39bfdf526d6a340a.1621516826.git.christophe.leroy@csgroup.eu
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5a03e1e9 |
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20-May-2021 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/ftrace: Use PPC_RAW_MFLR() and PPC_RAW_NOP() Use PPC_RAW_MFLR() instead of open coding with PPC_INST_MFLR. Same for PPC_INST_NOP. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/98fd4d717810b7c4032a1edf62dd6fe638e64329.1621506159.git.christophe.leroy@csgroup.eu
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8804d5be |
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20-May-2021 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/lib/code-patching: Use PPC_RAW_() macros Instead of open coding with PPC_INST_ defines, use PPC_RAW_() macros. It improves readability. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/8c92f1d9e825ee47c6f88fe43ad42d2a8cc2ab4a.1621506159.git.christophe.leroy@csgroup.eu
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41d6cf68 |
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14-Apr-2021 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc: Rename probe_kernel_read_inst() When probe_kernel_read_inst() was created, it was to mimic probe_kernel_read() function. Since then, probe_kernel_read() has been renamed copy_from_kernel_nofault(). Rename probe_kernel_read_inst() into copy_inst_from_kernel_nofault(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/b783d1f7cdb8914992384a669a2af57051b6bdcf.1618405715.git.christophe.leroy@csgroup.eu
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50428fdc |
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01-Jun-2020 |
Jordan Niethe <jniethe5@gmail.com> |
powerpc: Add a ppc_inst_as_str() helper There are quite a few places where instructions are printed, this is done using a '%x' format specifier. With the introduction of prefixed instructions, this does not work well. Currently in these places, ppc_inst_val() is used for the value for %x so only the first word of prefixed instructions are printed. When the instructions are word instructions, only a single word should be printed. For prefixed instructions both the prefix and suffix should be printed. To accommodate both of these situations, instead of a '%x' specifier use '%s' and introduce a helper, __ppc_inst_as_str() which returns a char *. The char * __ppc_inst_as_str() returns is buffer that is passed to it by the caller. It is cumbersome to require every caller of __ppc_inst_as_str() to now declare a buffer. To make it more convenient to use __ppc_inst_as_str(), wrap it in a macro that uses a compound statement to allocate a buffer on the caller's stack before calling it. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Acked-by: Segher Boessenkool <segher@kernel.crashing.org> [mpe: Drop 0x prefix to match most existings uses, especially xmon] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200602052728.18227-1-jniethe5@gmail.com
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fe557319 |
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17-Jun-2020 |
Christoph Hellwig <hch@lst.de> |
maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault Better describe what these functions do. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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95b980a0 |
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05-May-2020 |
Jordan Niethe <jniethe5@gmail.com> |
powerpc: Add a probe_kernel_read_inst() function Introduce a probe_kernel_read_inst() function to use in cases where probe_kernel_read() is used for getting an instruction. This will be more useful for prefixed instructions. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Reviewed-by: Alistair Popple <alistair@popple.id.au> [mpe: Don't write to *inst on error] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200506034050.24806-15-jniethe5@gmail.com
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f8faaffa |
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05-May-2020 |
Jordan Niethe <jniethe5@gmail.com> |
powerpc: Use a function for reading instructions Prefixed instructions will mean there are instructions of different length. As a result dereferencing a pointer to an instruction will not necessarily give the desired result. Introduce a function for reading instructions from memory into the instruction data type. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Alistair Popple <alistair@popple.id.au> Link: https://lore.kernel.org/r/20200506034050.24806-13-jniethe5@gmail.com
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94afd069 |
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05-May-2020 |
Jordan Niethe <jniethe5@gmail.com> |
powerpc: Use a datatype for instructions Currently unsigned ints are used to represent instructions on powerpc. This has worked well as instructions have always been 4 byte words. However, ISA v3.1 introduces some changes to instructions that mean this scheme will no longer work as well. This change is Prefixed Instructions. A prefixed instruction is made up of a word prefix followed by a word suffix to make an 8 byte double word instruction. No matter the endianness of the system the prefix always comes first. Prefixed instructions are only planned for powerpc64. Introduce a ppc_inst type to represent both prefixed and word instructions on powerpc64 while keeping it possible to exclusively have word instructions on powerpc32. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> [mpe: Fix compile error in emulate_spe()] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200506034050.24806-12-jniethe5@gmail.com
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217862d9 |
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05-May-2020 |
Jordan Niethe <jniethe5@gmail.com> |
powerpc: Introduce functions for instruction equality In preparation for an instruction data type that can not be directly used with the '==' operator use functions for checking equality. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Balamuruhan S <bala24@linux.ibm.com> Link: https://lore.kernel.org/r/20200506034050.24806-11-jniethe5@gmail.com
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777e26f0 |
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05-May-2020 |
Jordan Niethe <jniethe5@gmail.com> |
powerpc: Use an accessor for instructions In preparation for introducing a more complicated instruction type to accommodate prefixed instructions use an accessor for getting an instruction as a u32. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200506034050.24806-8-jniethe5@gmail.com
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75346251 |
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05-May-2020 |
Jordan Niethe <jniethe5@gmail.com> |
powerpc: Use a macro for creating instructions from u32s In preparation for instructions having a more complex data type start using a macro, ppc_inst(), for making an instruction out of a u32. A macro is used so that instructions can be used as initializer elements. Currently this does nothing, but it will allow for creating a data type that can represent prefixed instructions. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> [mpe: Change include guard to _ASM_POWERPC_INST_H] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Alistair Popple <alistair@popple.id.au> Link: https://lore.kernel.org/r/20200506034050.24806-7-jniethe5@gmail.com
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7c95d889 |
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05-May-2020 |
Jordan Niethe <jniethe5@gmail.com> |
powerpc: Change calling convention for create_branch() et. al. create_branch(), create_cond_branch() and translate_branch() return the instruction that they create, or return 0 to signal an error. Separate these concerns in preparation for an instruction type that is not just an unsigned int. Fill the created instruction to a pointer passed as the first parameter to the function and use a non-zero return value to signify an error. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Alistair Popple <alistair@popple.id.au> Link: https://lore.kernel.org/r/20200506034050.24806-6-jniethe5@gmail.com
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370011a2 |
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05-Sep-2019 |
Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> |
powerpc/ftrace: Enable HAVE_FUNCTION_GRAPH_RET_ADDR_PTR This associates entries in the ftrace_ret_stack with corresponding stack frames, enabling more robust stack unwinding. Also update the only user of ftrace_graph_ret_addr() to pass the stack pointer. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/0224f2d0971b069c678e2ff678cfc2cd1e114cfe.1567707399.git.naveen.n.rao@linux.vnet.ibm.com
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7f9c929a |
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03-May-2019 |
Christophe Leroy <christophe.leroy@c-s.fr> |
powerpc: Move PPC_HA() PPC_HI() and PPC_LO() to ppc-opcode.h PPC_HA() PPC_HI() and PPC_LO() macros are nice macros. Move them from module64.c to ppc-opcode.h in order to use them in other places. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: Clean up formatting in new code, drop duplicates in ftrace.c] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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7bea7ac0 |
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14-Jan-2019 |
Michael Ellerman <mpe@ellerman.id.au> |
powerpc/syscalls: Fix syscall tracing Recently in commit fbf508da7440 ("powerpc: split compat syscall table out from native table") we changed the layout of the system call table. Instead of having two entries for each syscall number, one for the regular entry point and one for the compat entry point, we now have separate tables for regular and compat entry points. This inadvertently broke syscall tracing (CONFIG_FTRACE_SYSCALLS), because our implementation of arch_syscall_addr() knew about the layout of the table (it did nr * 2). We can fix it just by dropping our version of arch_syscall_addr() and using the generic version which does: return (unsigned long)sys_call_table[nr]; Fixes: fbf508da7440 ("powerpc: split compat syscall table out from native table") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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fe60522e |
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18-Nov-2018 |
Steven Rostedt (VMware) <rostedt@goodmis.org> |
powerpc/function_graph: Simplify with function_graph_enter() The function_graph_enter() function does the work of calling the function graph hook function and the management of the shadow stack, simplifying the work done in the architecture dependent prepare_ftrace_return(). Have powerpc use the new code, and remove the shadow stack management as well as having to set up the trace structure. This is needed to prepare for a fix of a design bug on how the curr_ret_stack is used. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: linuxppc-dev@lists.ozlabs.org Cc: stable@kernel.org Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback") Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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d64cf54e |
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13-Nov-2018 |
YueHaibing <yuehaibing@huawei.com> |
powerpc64/ftrace: Drop pointless static qualifier in is_b_op() There is no need to have the 'intoffset' variable static since new value always be assigned before use it. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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67361cf8 |
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16-Oct-2018 |
Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> |
powerpc/ftrace: Handle large kernel configs Currently, we expect to be able to reach ftrace_caller() from all ftrace-enabled functions through a single relative branch. With large kernel configs, we see functions outside of 32MB of ftrace_caller() causing ftrace_init() to bail. In such configurations, gcc/ld emits two types of trampolines for mcount(): 1. A long_branch, which has a single branch to mcount() for functions that are one hop away from mcount(): c0000000019e8544 <00031b56.long_branch._mcount>: c0000000019e8544: 4a 69 3f ac b c00000000007c4f0 <._mcount> 2. A plt_branch, for functions that are farther away from mcount(): c0000000051f33f8 <0008ba04.plt_branch._mcount>: c0000000051f33f8: 3d 82 ff a4 addis r12,r2,-92 c0000000051f33fc: e9 8c 04 20 ld r12,1056(r12) c0000000051f3400: 7d 89 03 a6 mtctr r12 c0000000051f3404: 4e 80 04 20 bctr We can reuse those trampolines for ftrace if we can have those trampolines go to ftrace_caller() instead. However, with ABIv2, we cannot depend on r2 being valid. As such, we use only the long_branch trampolines by patching those to instead branch to ftrace_caller or ftrace_regs_caller. In addition, we add additional trampolines around .text and .init.text to catch locations that are covered by the plt branches. This allows ftrace to work with most large kernel configurations. For now, we always patch the trampolines to go to ftrace_regs_caller, which is slightly inefficient. This can be optimized further at a later point. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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abba7597 |
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30-May-2018 |
Nicholas Piggin <npiggin@gmail.com> |
powerpc/kbuild: move -mprofile-kernel check to Kconfig This eliminates the workaround that requires disabling -mprofile-kernel by default in Kconfig. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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0c0c5230 |
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26-Mar-2018 |
Michael Ellerman <mpe@ellerman.id.au> |
powerpc: Only support DYNAMIC_FTRACE not static We've had dynamic ftrace support for over 9 years since Steve first wrote it, all the distros use dynamic, and static is basically untested these days, so drop support for static ftrace. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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ae30cc05 |
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18-Apr-2018 |
Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> |
powerpc64/ftrace: Implement support for ftrace_regs_caller() With -mprofile-kernel, we always save the full register state in ftrace_caller(). While this works, this is inefficient if we're not interested in the register state, such as when we're using the function tracer. Rename the existing ftrace_caller() as ftrace_regs_caller() and provide a simpler implementation for ftrace_caller() that is used when registers are not required to be saved. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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9ef40423 |
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18-Apr-2018 |
Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> |
powerpc64/ftrace: Use the generic version of ftrace_replace_code() Our implementation matches that of the generic version, which also handles FTRACE_UPDATE_MODIFY_CALL. So, remove our implementation in favor of the generic version. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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b2441318 |
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01-Nov-2017 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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7853f9c0 |
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25-Apr-2017 |
Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> |
powerpc: Split ftrace bits into a separate file entry_*.S now includes a lot more than just kernel entry/exit code. As a first step at cleaning this up, let's split out the ftrace bits into separate files. Also move all related tracing code into a new trace/ subdirectory. No functional changes. Suggested-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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