From: Stephen Boyd swboyd@chromium.org
[ Upstream commit a743f26d03a96593c0f3d05dc26b388f45de67c9 ]
Per commit b3f11af9b2ce ("arm64: ftrace: forbid CALL_OPS with CC_OPTIMIZE_FOR_SIZE"), GCC is silently ignoring `-falign-functions=N` when passed `-Os`, causing functions to be improperly aligned. This doesn't seem to be a problem with Clang though, where enabling CALL_OPS with CC_OPTIMIZE_FOR_SIZE doesn't spit out any warnings at boot about misaligned patch-sites. Only forbid CALL_OPS if GCC is used and we're optimizing for size so that CALL_OPS can be used with clang optimizing for size.
Cc: Jason Ling jasonling@chromium.org Cc: Florian Fainelli f.fainelli@gmail.com Cc: Mark Rutland mark.rutland@arm.com Cc: Nathan Chancellor nathan@kernel.org Cc: Nick Desaulniers ndesaulniers@google.com Cc: Bill Wendling morbo@google.com Cc: Justin Stitt justinstitt@google.com Cc: llvm@lists.linux.dev Fixes: b3f11af9b2ce ("arm64: ftrace: forbid CALL_OPS with CC_OPTIMIZE_FOR_SIZE") Signed-off-by: Stephen Boyd swboyd@chromium.org Reviewed-by: Nathan Chancellor nathan@kernel.org Link: https://lore.kernel.org/r/20240223064032.3463229-1-swboyd@chromium.org Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm64/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 456e8680e16ea..77dfbc8ab2d3b 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -196,7 +196,7 @@ config ARM64 if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \ - !CC_OPTIMIZE_FOR_SIZE) + (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE)) select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ if DYNAMIC_FTRACE_WITH_ARGS select HAVE_SAMPLE_FTRACE_DIRECT