Messages in this thread Patch in this message | | | Date | Mon, 27 Feb 2006 16:43:54 -0500 | From | Jakub Jelinek <> | Subject | [PATCH] Mark unwind info for signal trampolines in vDSOs |
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Hi!
The following patch marks unwind info for signal trampolines using the new S augmentation flag introduced in: http://gcc.gnu.org/PR26208 GCC 4.2 (or patched earlier GCC) will be able to special case unwinding through frames right above signal trampolines. As the augmentations start with z flag and S is at the very end of the augmentation string, older GCCs will just skip the S flag as unknown (that's why an augmentation flag was chosen over say a new CFA opcode).
Please apply.
Signed-off-by: Jakub Jelinek <jakub@redhat.com>
--- linux-2.6.15/arch/i386/kernel/vsyscall-sigreturn.S.jj 2006-01-02 22:21:10.000000000 -0500 +++ linux-2.6.15/arch/i386/kernel/vsyscall-sigreturn.S 2006-02-21 05:10:31.000000000 -0500 @@ -44,7 +44,7 @@ __kernel_rt_sigreturn: .LSTARTCIEDLSI1: .long 0 /* CIE ID */ .byte 1 /* Version number */ - .string "zR" /* NUL-terminated augmentation string */ + .string "zRS" /* NUL-terminated augmentation string */ .uleb128 1 /* Code alignment factor */ .sleb128 -4 /* Data alignment factor */ .byte 8 /* Return address register column */ --- linux-2.6.15/arch/x86_64/ia32/vsyscall-sigreturn.S.jj 2006-01-02 22:21:10.000000000 -0500 +++ linux-2.6.15/arch/x86_64/ia32/vsyscall-sigreturn.S 2006-02-21 05:17:41.000000000 -0500 @@ -31,8 +31,27 @@ __kernel_rt_sigreturn: .size __kernel_rt_sigreturn,.-.LSTART_rt_sigreturn .section .eh_frame,"a",@progbits +.LSTARTFRAMES: + .long .LENDCIES-.LSTARTCIES +.LSTARTCIES: + .long 0 /* CIE ID */ + .byte 1 /* Version number */ + .string "zRS" /* NUL-terminated augmentation string */ + .uleb128 1 /* Code alignment factor */ + .sleb128 -4 /* Data alignment factor */ + .byte 8 /* Return address register column */ + .uleb128 1 /* Augmentation value length */ + .byte 0x1b /* DW_EH_PE_pcrel|DW_EH_PE_sdata4. */ + .byte 0x0c /* DW_CFA_def_cfa */ + .uleb128 4 + .uleb128 4 + .byte 0x88 /* DW_CFA_offset, column 0x8 */ + .uleb128 1 + .align 4 +.LENDCIES: + .long .LENDFDE2-.LSTARTFDE2 /* Length FDE */ .LSTARTFDE2: - .long .LSTARTFDE2-.LSTARTFRAME /* CIE pointer */ + .long .LSTARTFDE2-.LSTARTFRAMES /* CIE pointer */ /* HACK: The dwarf2 unwind routines will subtract 1 from the return address to get an address in the middle of the @@ -96,7 +116,7 @@ __kernel_rt_sigreturn: .long .LENDFDE3-.LSTARTFDE3 /* Length FDE */ .LSTARTFDE3: - .long .LSTARTFDE3-.LSTARTFRAME /* CIE pointer */ + .long .LSTARTFDE3-.LSTARTFRAMES /* CIE pointer */ /* HACK: See above wrt unwind library assumptions. */ .long .LSTART_rt_sigreturn-1-. /* PC-relative start address */ .long .LEND_rt_sigreturn-.LSTART_rt_sigreturn+1 --- linux-2.6.15/arch/powerpc/kernel/vdso32/sigtramp.S.jj 2006-01-02 22:21:10.000000000 -0500 +++ linux-2.6.15/arch/powerpc/kernel/vdso32/sigtramp.S 2006-02-21 05:24:12.000000000 -0500 @@ -261,7 +261,7 @@ V_FUNCTION_END(__kernel_sigtramp_rt32) .Lcie_start: .long 0 /* CIE ID */ .byte 1 /* Version number */ - .string "zR" /* NUL-terminated augmentation string */ + .string "zRS" /* NUL-terminated augmentation string */ .uleb128 4 /* Code alignment factor */ .sleb128 -4 /* Data alignment factor */ .byte 67 /* Return address register column, ap */ --- linux-2.6.15/arch/powerpc/kernel/vdso64/sigtramp.S.jj 2006-01-02 22:21:10.000000000 -0500 +++ linux-2.6.15/arch/powerpc/kernel/vdso64/sigtramp.S 2006-02-21 05:28:28.000000000 -0500 @@ -263,7 +263,7 @@ V_FUNCTION_END(__kernel_sigtramp_rt64) .Lcie_start: .long 0 /* CIE ID */ .byte 1 /* Version number */ - .string "zR" /* NUL-terminated augmentation string */ + .string "zRS" /* NUL-terminated augmentation string */ .uleb128 4 /* Code alignment factor */ .sleb128 -8 /* Data alignment factor */ .byte 67 /* Return address register column, ap */ Jakub - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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