The -ftracer optimization was disabled in __noclone as a workaround to GCC duplicating a blob of inline assembly that happened to define a global variable. It has been pointed out that no amount of workarounds can guarantee the compiler won't duplicate inline assembly[1], and that disabling the -ftracer optimization has several unintended and nasty side effects[2][3]. Now that the offending KVM code which required the workaround has been properly fixed and no longer uses __noclone, remove the -ftracer optimization tweak from __noclone. [1] https://lore.kernel.org/lkml/ri6y38lo23g.fsf@xxxxxxx/T/#u [2] https://lore.kernel.org/lkml/20181218140105.ajuiglkpvstt3qxs@treble/T/#u [3] https://patchwork.kernel.org/patch/8707981/#21817015 This reverts commit 95272c29378ee7dc15f43fa2758cb28a5913a06d. Suggested-by: Andi Kleen <ak@xxxxxxxxxxxxxxx> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx> Cc: Nadav Amit <namit@xxxxxxxxxx> Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx> Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Cc: Martin Jambor <mjambor@xxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> Cc: Miroslav Benes <mbenes@xxxxxxx> Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> --- include/linux/compiler_attributes.h | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h index f8c400ba1929..f3e16fc9a5df 100644 --- a/include/linux/compiler_attributes.h +++ b/include/linux/compiler_attributes.h @@ -163,17 +163,11 @@ /* * Optional: not supported by clang - * Note: icc does not recognize gcc's no-tracer * * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-noclone-function-attribute - * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-optimize-function-attribute */ #if __has_attribute(__noclone__) -# if __has_attribute(__optimize__) -# define __noclone __attribute__((__noclone__, __optimize__("no-tracer"))) -# else -# define __noclone __attribute__((__noclone__)) -# endif +# define __noclone __attribute__((__noclone__)) #else # define __noclone #endif -- 2.19.2
