#
a370c241 |
|
26-Mar-2024 |
Alexandre Ghiti <alexghiti@rivosinc.com> |
riscv: Disable preemption when using patch_map() patch_map() uses fixmap mappings to circumvent the non-writability of the kernel text mapping. The __set_fixmap() function only flushes the current cpu tlb, it does not emit an IPI so we must make sure that while we use a fixmap mapping, the current task is not migrated on another cpu which could miss the newly introduced fixmap mapping. So in order to avoid any task migration, disable the preemption. Reported-by: Andrea Parri <andrea@rivosinc.com> Closes: https://lore.kernel.org/all/ZcS+GAaM25LXsBOl@andrea/ Reported-by: Andy Chiu <andy.chiu@sifive.com> Closes: https://lore.kernel.org/linux-riscv/CABgGipUMz3Sffu-CkmeUB1dKVwVQ73+7=sgC45-m0AE9RCjOZg@mail.gmail.com/ Fixes: cad539baa48f ("riscv: implement a memset like function for text") Fixes: 0ff7c3b33127 ("riscv: Use text_mutex instead of patch_lock") Co-developed-by: Andy Chiu <andy.chiu@sifive.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Acked-by: Puranjay Mohan <puranjay12@gmail.com> Link: https://lore.kernel.org/r/20240326203017.310422-3-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
|
#
420370f3 |
|
14-Dec-2023 |
Alexandre Ghiti <alexghiti@rivosinc.com> |
riscv: Check if the code to patch lies in the exit section Otherwise we fall through to vmalloc_to_page() which panics since the address does not lie in the vmalloc region. Fixes: 043cb41a85de ("riscv: introduce interfaces to patch kernel code") Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20231214091926.203439-1-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
|
#
cad539ba |
|
31-Aug-2023 |
Puranjay Mohan <puranjay12@gmail.com> |
riscv: implement a memset like function for text The BPF JIT needs to write invalid instructions to RX regions of memory to invalidate removed BPF programs. This needs a function like memset() that can work with RX memory. Implement patch_text_set_nosync() which is similar to text_poke_set() of x86. Signed-off-by: Puranjay Mohan <puranjay12@gmail.com> Reviewed-by: Pu Lehui <pulehui@huawei.com> Acked-by: Björn Töpel <bjorn@kernel.org> Tested-by: Björn Töpel <bjorn@rivosinc.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/r/20230831131229.497941-4-puranjay12@gmail.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
|
#
9721873c |
|
31-Aug-2023 |
Puranjay Mohan <puranjay12@gmail.com> |
riscv: extend patch_text_nosync() for multiple pages The patch_insn_write() function currently doesn't work for multiple pages of instructions, therefore patch_text_nosync() will fail with a page fault if called with lengths spanning multiple pages. This commit extends the patch_insn_write() function to support multiple pages by copying at max 2 pages at a time in a loop. This implementation is similar to text_poke_copy() function of x86. Signed-off-by: Puranjay Mohan <puranjay12@gmail.com> Reviewed-by: Pu Lehui <pulehui@huawei.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/r/20230831131229.497941-3-puranjay12@gmail.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
|
#
2a8db5ec |
|
03-Mar-2023 |
Conor Dooley <conor.dooley@microchip.com> |
RISC-V: Don't check text_mutex during stop_machine We're currently using stop_machine() to update ftrace & kprobes, which means that the thread that takes text_mutex during may not be the same as the thread that eventually patches the code. This isn't actually a race because the lock is still held (preventing any other concurrent accesses) and there is only one thread running during stop_machine(), but it does trigger a lockdep failure. This patch just elides the lockdep check during stop_machine. Fixes: c15ac4fd60d5 ("riscv/ftrace: Add dynamic function tracer support") Suggested-by: Steven Rostedt <rostedt@goodmis.org> Reported-by: Changbin Du <changbin.du@gmail.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230303143754.4005217-1-conor.dooley@microchip.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
|
#
5e57fb7b |
|
15-Feb-2023 |
Pu Lehui <pulehui@huawei.com> |
riscv: Extend patch_text for multiple instructions Extend patch_text for multiple instructions. This is the preparaiton for multiple instructions text patching in riscv BPF trampoline, and may be useful for other scenario. Signed-off-by: Pu Lehui <pulehui@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Acked-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/bpf/20230215135205.1411105-2-pulehui@huaweicloud.com
|
#
8ec14429 |
|
06-Apr-2022 |
Guo Ren <guoren@kernel.org> |
riscv: patch_text: Fixup last cpu should be master These patch_text implementations are using stop_machine_cpuslocked infrastructure with atomic cpu_count. The original idea: When the master CPU patch_text, the others should wait for it. But current implementation is using the first CPU as master, which couldn't guarantee the remaining CPUs are waiting. This patch changes the last CPU as the master to solve the potential risk. Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@kernel.org> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Fixes: 043cb41a85de ("riscv: introduce interfaces to patch kernel code") Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
|
#
edfcf91f |
|
17-Dec-2020 |
Guo Ren <guoren@linux.alibaba.com> |
riscv: Fixup compile error BUILD_BUG_ON failed Unfortunately, the current code couldn't be compiled: CC arch/riscv/kernel/patch.o In file included from ./include/linux/kernel.h:11, from ./include/linux/list.h:9, from ./include/linux/preempt.h:11, from ./include/linux/spinlock.h:51, from arch/riscv/kernel/patch.c:6: In function ‘fix_to_virt’, inlined from ‘patch_map’ at arch/riscv/kernel/patch.c:37:17: ./include/linux/compiler.h:392:38: error: call to ‘__compiletime_assert_205’ declared with attribute error: BUILD_BUG_ON failed: idx >= __end_of_fixed_addresses _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) ^ ./include/linux/compiler.h:373:4: note: in definition of macro ‘__compiletime_assert’ prefix ## suffix(); \ ^~~~~~ ./include/linux/compiler.h:392:2: note: in expansion of macro ‘_compiletime_assert’ _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) ^~~~~~~~~~~~~~~~~~~ ./include/linux/build_bug.h:39:37: note: in expansion of macro ‘compiletime_assert’ #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) ^~~~~~~~~~~~~~~~~~ ./include/linux/build_bug.h:50:2: note: in expansion of macro ‘BUILD_BUG_ON_MSG’ BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition) ^~~~~~~~~~~~~~~~ ./include/asm-generic/fixmap.h:32:2: note: in expansion of macro ‘BUILD_BUG_ON’ BUILD_BUG_ON(idx >= __end_of_fixed_addresses); ^~~~~~~~~~~~ Because fix_to_virt(, idx) needs a const value, not a dynamic variable of reg-a0 or BUILD_BUG_ON failed with "idx >= __end_of_fixed_addresses". Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Pekka Enberg <penberg@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
|
#
fe557319 |
|
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>
|
#
05589dde |
|
01-Jun-2020 |
Zong Li <zong.li@sifive.com> |
riscv: fix build warning of missing prototypes Add the missing header in file, it was lost in original implementation. The warning message as follows: - no previous prototype for 'patch_text_nosync' [-Wmissing-prototypes] - no previous prototype for 'patch_text' [-Wmissing-prototypes] Changed in v2: - Correct the typo of commit message. Signed-off-by: Zong Li <zong.li@sifive.com> Reported-by: kbuild test robot <lkp@intel.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
|
#
0ff7c3b3 |
|
21-Apr-2020 |
Zong Li <zong.li@sifive.com> |
riscv: Use text_mutex instead of patch_lock We don't need the additional lock protection when patching the text. There are two patching interfaces here: - patch_text: patch code and always synchronize with stop_machine() - patch_text_nosync: patch code without synchronization, it's caller's responsibility to synchronize all CPUs if needed. For the first one, stop_machine() is protected by its own mutex, and also the irq is already disabled here. For the second one, in risc-v real case now, it would be used to ftrace patching the mcount function, since it already running under kstop_machine(), no other thread will run, so we could use text_mutex on ftrace side. Signed-off-by: Zong Li <zong.li@sifive.com> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
|
#
5303df24 |
|
21-Apr-2020 |
Zong Li <zong.li@sifive.com> |
riscv: Use NOKPROBE_SYMBOL() instead of __krpobes annotation The __kprobes annotation is old style, so change it to NOKPROBE_SYMBOL(). Signed-off-by: Zong Li <zong.li@sifive.com> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
|
#
b80b3d58 |
|
21-Apr-2020 |
Zong Li <zong.li@sifive.com> |
riscv: Remove the 'riscv_' prefix of function name Refactor the function name by removing the 'riscv_' prefix, it would be better unless it could mix up with arch-independent functions. Signed-off-by: Zong Li <zong.li@sifive.com> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
|
#
043cb41a |
|
09-Mar-2020 |
Zong Li <zong.li@sifive.com> |
riscv: introduce interfaces to patch kernel code On strict kernel memory permission, we couldn't patch code without writable permission. Preserve two holes in fixmap area, so we can map the kernel code temporarily to fixmap area, then patch the instructions. We need two pages here because we support the compressed instruction, so the instruction might be align to 2 bytes. When patching the 32-bit length instruction which is 2 bytes alignment, it will across two pages. Introduce two interfaces to patch kernel code: riscv_patch_text_nosync: - patch code without synchronization, it's caller's responsibility to synchronize all CPUs if needed. riscv_patch_text: - patch code and always synchronize with stop_machine() Signed-off-by: Zong Li <zong.li@sifive.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
|