diff options
| author | Conor Dooley | 2023-03-03 14:37:55 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2023-03-17 08:50:29 +0100 |
| commit | 0a6321657eb82d6090391aa96804e4f712acb87d (patch) | |
| tree | 31c856b9dc94c65915734b6650a0507045fc9dd1 /arch/riscv/include | |
| parent | 324912d6c0c4006711054d389faa2239c1655e1e (diff) | |
RISC-V: Don't check text_mutex during stop_machine
[ Upstream commit 2a8db5ec4a28a0fce822d10224db9471a44b6925 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch/riscv/include')
| -rw-r--r-- | arch/riscv/include/asm/ftrace.h | 2 | ||||
| -rw-r--r-- | arch/riscv/include/asm/patch.h | 2 |
2 files changed, 3 insertions, 1 deletions
diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h index 9e73922e1e2e..d47d87c2d7e3 100644 --- a/arch/riscv/include/asm/ftrace.h +++ b/arch/riscv/include/asm/ftrace.h @@ -109,6 +109,6 @@ int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec); #define ftrace_init_nop ftrace_init_nop #endif -#endif +#endif /* CONFIG_DYNAMIC_FTRACE */ #endif /* _ASM_RISCV_FTRACE_H */ diff --git a/arch/riscv/include/asm/patch.h b/arch/riscv/include/asm/patch.h index 9a7d7346001e..98d9de07cba1 100644 --- a/arch/riscv/include/asm/patch.h +++ b/arch/riscv/include/asm/patch.h @@ -9,4 +9,6 @@ int patch_text_nosync(void *addr, const void *insns, size_t len); int patch_text(void *addr, u32 insn); +extern int riscv_patch_in_stop_machine; + #endif /* _ASM_RISCV_PATCH_H */ |