Commit 894ef530 authored by Alexander Lobakin's avatar Alexander Lobakin Committed by Thomas Bogendoerfer
Browse files

MIPS: properly stop .eh_frame generation 



Commit 866b6a89 ("MIPS: Add DWARF unwinding to assembly") added
-fno-asynchronous-unwind-tables to KBUILD_CFLAGS to prevent compiler
from emitting .eh_frame symbols.
However, as MIPS heavily uses CFI, that's not enough. Use the
approach taken for x86 (as it also uses CFI) and explicitly put CFI
symbols into the .debug_frame section (except for VDSO).
This allows us to drop .eh_frame from DISCARDS as it's no longer
being generated.

Fixes: 866b6a89 ("MIPS: Add DWARF unwinding to assembly")
Suggested-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarAlexander Lobakin <alobakin@pm.me>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Reviewed-by: default avatarNathan Chancellor <natechancellor@gmail.com>
Signed-off-by: default avatarThomas Bogendoerfer <tsbogend@alpha.franken.de>
parent 5629d418

arch/mips/include/asm/asm.h

+18 −0
Original line number Diff line number Diff line
@@ -20,10 +20,27 @@ 
#include <asm/sgidefs.h>

#include <asm/asm-eva.h>



#ifndef __VDSO__

/*

 * Emit CFI data in .debug_frame sections, not .eh_frame sections.

 * We don't do DWARF unwinding at runtime, so only the offline DWARF

 * information is useful to anyone. Note we should change this if we

 * ever decide to enable DWARF unwinding at runtime.

 */

#define CFI_SECTIONS	.cfi_sections .debug_frame

#else

 /*

  * For the vDSO, emit both runtime unwind information and debug

  * symbols for the .dbg file.

  */

#define CFI_SECTIONS

#endif



/*

 * LEAF - declare leaf routine

 */

#define LEAF(symbol)					\

		CFI_SECTIONS;				\

		.globl	symbol;				\

		.align	2;				\

		.type	symbol, @function;		\
@@ -36,6 +53,7 @@ symbol: .frame sp, 0, ra; \ 
 * NESTED - declare nested routine entry point

 */

#define NESTED(symbol, framesize, rpc)			\

		CFI_SECTIONS;				\

		.globl	symbol;				\

		.align	2;				\

		.type	symbol, @function;		\

arch/mips/kernel/vmlinux.lds.S

+0 −1
Original line number Diff line number Diff line
@@ -224,6 +224,5 @@ SECTIONS 
		*(.options)

		*(.pdr)

		*(.reginfo)

		*(.eh_frame)

	}

}