diff options
| author | Naveen N Rao <naveen@kernel.org> | 2023-06-09 09:15:01 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2023-06-19 17:37:13 +1000 |
| commit | d24da1f85530a5b47590c0febd1395dd8fc73124 (patch) | |
| tree | 2efce4d53f32b514e477bd550681a6bdaeca98ef /arch/powerpc/Kconfig | |
| parent | f4f913c980bc6abe0ccfe88fe3909c125afe4a2d (diff) | |
powerpc/ftrace: Disable ftrace on ppc32 if using clang
Ftrace on ppc32 expects a three instruction sequence at the beginning of
each function when specifying -pg:
mflr r0
stw r0,4(r1)
bl _mcount
This is the case with all supported versions of gcc. Clang however emits
a branch to _mcount after the function prologue, similar to the pre
-mprofile-kernel ABI on ppc64. This is not supported.
Disable ftrace on ppc32 if using clang for now. This can be re-enabled
later if clang picks up support for -fpatchable-function-entry on ppc32.
Signed-off-by: Naveen N Rao <naveen@kernel.org>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://github.com/llvm/llvm-project/issues/63220
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230609034501.407971-1-naveen@kernel.org
Diffstat (limited to 'arch/powerpc/Kconfig')
| -rw-r--r-- | arch/powerpc/Kconfig | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index dea8e0c7f7e3..8b955bc7b59f 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -236,7 +236,7 @@ config PPC select HAVE_FUNCTION_DESCRIPTORS if PPC64_ELF_ABI_V1 select HAVE_FUNCTION_ERROR_INJECTION select HAVE_FUNCTION_GRAPH_TRACER - select HAVE_FUNCTION_TRACER + select HAVE_FUNCTION_TRACER if PPC64 || (PPC32 && CC_IS_GCC) select HAVE_GCC_PLUGINS if GCC_VERSION >= 50200 # plugin support on gcc <= 5.1 is buggy on PPC select HAVE_GENERIC_VDSO select HAVE_HARDLOCKUP_DETECTOR_ARCH if PPC_BOOK3S_64 && SMP |