From 9e565292270a2d55524be38835104c564ac8f795 Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Thu, 13 May 2010 21:43:03 -0700 Subject: 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 LKML-Reference: <20100514044303.A6FE7400BE@magilla.sf.frob.com> Signed-off-by: H. Peter Anvin --- arch/x86/Makefile | 5 +++-- 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 /* -- cgit v1.2.2