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| author | Naveen N Rao <naveen@kernel.org> | 2023-06-14 14:29:26 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2023-10-20 17:55:56 +1100 |
| commit | f01b0edd562ef5a05bae31fe3a296721f89af7d9 (patch) | |
| tree | 0a18a9123d358c510b3ab1efb231cdf3c04c37e5 /arch/powerpc | |
| parent | d42f55e8ae741540d0d2ebab8ff02f68fb0c802f (diff) | |
| download | linux-f01b0edd562ef5a05bae31fe3a296721f89af7d9.tar.gz linux-f01b0edd562ef5a05bae31fe3a296721f89af7d9.tar.bz2 linux-f01b0edd562ef5a05bae31fe3a296721f89af7d9.zip | |
powerpc/trace: Add support for HAVE_FUNCTION_ARG_ACCESS_API
When creating a kprobe on function entry through tracefs, enable
arguments to be recorded to be specified using $argN syntax.
Signed-off-by: Naveen N Rao <naveen@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230614085926.2176641-1-naveen@kernel.org
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/Kconfig | 1 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/ptrace.h | 17 |
2 files changed, 18 insertions, 0 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index d5d5388973ac..6f105ee4f3cf 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -237,6 +237,7 @@ config PPC select HAVE_EFFICIENT_UNALIGNED_ACCESS select HAVE_FAST_GUP select HAVE_FTRACE_MCOUNT_RECORD + select HAVE_FUNCTION_ARG_ACCESS_API select HAVE_FUNCTION_DESCRIPTORS if PPC64_ELF_ABI_V1 select HAVE_FUNCTION_ERROR_INJECTION select HAVE_FUNCTION_GRAPH_TRACER diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h index 9db8b16567e2..ea8f91fbc62f 100644 --- a/arch/powerpc/include/asm/ptrace.h +++ b/arch/powerpc/include/asm/ptrace.h @@ -397,6 +397,23 @@ static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, return 0; } +/** + * regs_get_kernel_argument() - get Nth function argument in kernel + * @regs: pt_regs of that context + * @n: function argument number (start from 0) + * + * We support up to 8 arguments and assume they are sent in through the GPRs. + * This will fail for fp/vector arguments, but those aren't usually found in + * kernel code. This is expected to be called from kprobes or ftrace with regs. + */ +static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs, unsigned int n) +{ +#define NR_REG_ARGUMENTS 8 + if (n < NR_REG_ARGUMENTS) + return regs_get_register(regs, offsetof(struct pt_regs, gpr[3 + n])); + return 0; +} + #endif /* __ASSEMBLY__ */ #ifndef __powerpc64__ |