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| author | Roland McGrath <roland@redhat.com> | 2010-05-14 06:43:03 +0200 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2010-05-14 07:15:18 +0200 |
| commit | 9e565292270a2d55524be38835104c564ac8f795 (patch) | |
| tree | a4a2c6e5b2013e142b866b1f4dcca44a8f7384a4 | |
| parent | x86-64: Reduce SMP locks table size (diff) | |
| download | linux-9e565292270a2d55524be38835104c564ac8f795.tar.xz linux-9e565292270a2d55524be38835104c564ac8f795.zip | |
x86: Use .cfi_sections for assembly code
The newer assemblers support the .cfi_sections directive so we can put
the CFI from .S files into the .debug_frame section that is preserved
in unstripped vmlinux and in separate debuginfo, rather than the
.eh_frame section that is now discarded by vmlinux.lds.S.
Signed-off-by: Roland McGrath <roland@redhat.com>
LKML-Reference: <20100514044303.A6FE7400BE@magilla.sf.frob.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| -rw-r--r-- | arch/x86/Makefile | 5 | ||||
| -rw-r--r-- | arch/x86/include/asm/dwarf2.h | 12 |
2 files changed, 15 insertions, 2 deletions
diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 0a43dc515e4c..8aa1b59b9074 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -95,8 +95,9 @@ sp-$(CONFIG_X86_64) := rsp cfi := $(call as-instr,.cfi_startproc\n.cfi_rel_offset $(sp-y)$(comma)0\n.cfi_endproc,-DCONFIG_AS_CFI=1) # is .cfi_signal_frame supported too? cfi-sigframe := $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1) -KBUILD_AFLAGS += $(cfi) $(cfi-sigframe) -KBUILD_CFLAGS += $(cfi) $(cfi-sigframe) +cfi-sections := $(call as-instr,.cfi_sections .debug_frame,-DCONFIG_AS_CFI_SECTIONS=1) +KBUILD_AFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) +KBUILD_CFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) LDFLAGS := -m elf_$(UTS_MACHINE) diff --git a/arch/x86/include/asm/dwarf2.h b/arch/x86/include/asm/dwarf2.h index ae6253ab9029..733f7e91e7a9 100644 --- a/arch/x86/include/asm/dwarf2.h +++ b/arch/x86/include/asm/dwarf2.h @@ -34,6 +34,18 @@ #define CFI_SIGNAL_FRAME #endif +#if defined(CONFIG_AS_CFI_SECTIONS) && defined(__ASSEMBLY__) + /* + * Emit CFI data in .debug_frame sections, not .eh_frame sections. + * The latter we currently just discard since we don't do DWARF + * unwinding at runtime. So only the offline DWARF information is + * useful to anyone. Note we should not use this directive if this + * file is used in the vDSO assembly, or if vmlinux.lds.S gets + * changed so it doesn't discard .eh_frame. + */ + .cfi_sections .debug_frame +#endif + #else /* |