diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/Makefile | 35 | ||||
| -rw-r--r-- | arch/x86/Makefile_32.cpu | 18 | ||||
| -rw-r--r-- | arch/x86/kernel/ftrace.c | 6 |
3 files changed, 37 insertions, 22 deletions
diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 2d449337a360..a94a4d10f2df 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -120,10 +120,6 @@ else # -funit-at-a-time shrinks the kernel .text considerably # unfortunately it makes reading oopses harder. KBUILD_CFLAGS += $(call cc-option,-funit-at-a-time) - - # this works around some issues with generating unwind tables in older gccs - # newer gccs do it by default - KBUILD_CFLAGS += $(call cc-option,-maccumulate-outgoing-args) endif ifdef CONFIG_X86_X32 @@ -147,6 +143,37 @@ ifeq ($(CONFIG_KMEMCHECK),y) KBUILD_CFLAGS += $(call cc-option,-fno-builtin-memcpy) endif +# +# If the function graph tracer is used with mcount instead of fentry, +# '-maccumulate-outgoing-args' is needed to prevent a GCC bug +# (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42109) +# +ifdef CONFIG_FUNCTION_GRAPH_TRACER + ifndef CONFIG_HAVE_FENTRY + ACCUMULATE_OUTGOING_ARGS := 1 + else + ifeq ($(call cc-option-yn, -mfentry), n) + ACCUMULATE_OUTGOING_ARGS := 1 + endif + endif +endif + +# +# Jump labels need '-maccumulate-outgoing-args' for gcc < 4.5.2 to prevent a +# GCC bug (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=46226). There's no way +# to test for this bug at compile-time because the test case needs to execute, +# which is a no-go for cross compilers. So check the GCC version instead. +# +ifdef CONFIG_JUMP_LABEL + ifneq ($(ACCUMULATE_OUTGOING_ARGS), 1) + ACCUMULATE_OUTGOING_ARGS = $(call cc-if-fullversion, -lt, 040502, 1) + endif +endif + +ifeq ($(ACCUMULATE_OUTGOING_ARGS), 1) + KBUILD_CFLAGS += -maccumulate-outgoing-args +endif + # Stackpointer is addressed different for 32 bit and 64 bit x86 sp-$(CONFIG_X86_32) := esp sp-$(CONFIG_X86_64) := rsp diff --git a/arch/x86/Makefile_32.cpu b/arch/x86/Makefile_32.cpu index 6647ed49c66c..a45eb15b7cf2 100644 --- a/arch/x86/Makefile_32.cpu +++ b/arch/x86/Makefile_32.cpu @@ -45,24 +45,6 @@ cflags-$(CONFIG_MGEODE_LX) += $(call cc-option,-march=geode,-march=pentium-mmx) # cpu entries cflags-$(CONFIG_X86_GENERIC) += $(call tune,generic,$(call tune,i686)) -# Work around the pentium-mmx code generator madness of gcc4.4.x which -# does stack alignment by generating horrible code _before_ the mcount -# prologue (push %ebp, mov %esp, %ebp) which breaks the function graph -# tracer assumptions. For i686, generic, core2 this is set by the -# compiler anyway -ifeq ($(CONFIG_FUNCTION_GRAPH_TRACER), y) -ADD_ACCUMULATE_OUTGOING_ARGS := y -endif - -# Work around to a bug with asm goto with first implementations of it -# in gcc causing gcc to mess up the push and pop of the stack in some -# uses of asm goto. -ifeq ($(CONFIG_JUMP_LABEL), y) -ADD_ACCUMULATE_OUTGOING_ARGS := y -endif - -cflags-$(ADD_ACCUMULATE_OUTGOING_ARGS) += $(call cc-option,-maccumulate-outgoing-args) - # Bug fix for binutils: this option is required in order to keep # binutils from generating NOPL instructions against our will. ifneq ($(CONFIG_X86_P6_NOP),y) diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 8f3d9cf26ff9..cbd73eb42170 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -29,6 +29,12 @@ #include <asm/ftrace.h> #include <asm/nops.h> +#if defined(CONFIG_FUNCTION_GRAPH_TRACER) && \ + !defined(CC_USING_FENTRY) && \ + !defined(CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE) +# error The following combination is not supported: ((compiler missing -mfentry) || (CONFIG_X86_32 and !CONFIG_DYNAMIC_FTRACE)) && CONFIG_FUNCTION_GRAPH_TRACER && CONFIG_CC_OPTIMIZE_FOR_SIZE +#endif + #ifdef CONFIG_DYNAMIC_FTRACE int ftrace_arch_code_modify_prepare(void) |