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| author | Sumit Garg <sumit.garg@linaro.org> | 2021-10-11 14:50:59 +0200 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2021-10-12 10:24:49 +0200 |
| commit | de56379f21c70196ff18c48790e8e43865893869 (patch) | |
| tree | 9d9eb433f2d9932e955442aa2701adcf99fa9e7d | |
| parent | arm64: asm: setup.h: export common variables (diff) | |
| download | linux-de56379f21c70196ff18c48790e8e43865893869.tar.xz linux-de56379f21c70196ff18c48790e8e43865893869.zip | |
arm64: ftrace: use function_nocfi for _mcount as well
Commit 800618f955a9 ("arm64: ftrace: use function_nocfi for ftrace_call")
only fixed address of ftrace_call but address of _mcount needs to be
fixed as well. Use function_nocfi() to get the actual address of _mcount
function as with CONFIG_CFI_CLANG, the compiler replaces function pointers
with jump table addresses which breaks dynamic ftrace as the address of
_mcount is replaced with the address of _mcount.cfi_jt.
With mainline, this won't be a problem since by default
CONFIG_DYNAMIC_FTRACE_WITH_REGS=y with Clang >= 10 as it supports
-fpatchable-function-entry and CFI requires Clang 12 but for consistency
we should add function_nocfi() for _mcount as well.
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lore.kernel.org/r/20211011125059.3378646-1-sumit.garg@linaro.org
Signed-off-by: Will Deacon <will@kernel.org>
| -rw-r--r-- | arch/arm64/include/asm/ftrace.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h index 91fa4baa1a93..347b0cc68f07 100644 --- a/arch/arm64/include/asm/ftrace.h +++ b/arch/arm64/include/asm/ftrace.h @@ -15,7 +15,7 @@ #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS #define ARCH_SUPPORTS_FTRACE_OPS 1 #else -#define MCOUNT_ADDR ((unsigned long)_mcount) +#define MCOUNT_ADDR ((unsigned long)function_nocfi(_mcount)) #endif /* The BL at the callsite's adjusted rec->ip */ |