diff options
| author | Jakub Jelinek <jakub@redhat.com> | 2006-03-31 02:30:28 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-31 12:18:52 -0800 |
| commit | da2e9e1ff40c863a12803c32209baaded3512433 (patch) | |
| tree | 7770ed3904d312850e745cca175a7322b63785ab /arch/x86_64 | |
| parent | 97db7fbfc7712bc403330c81c04ddfa82b335bce (diff) | |
[PATCH] Mark unwind info for signal trampolines in vDSOs
Mark 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).
Signed-off-by: Jakub Jelinek <jakub@redhat.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/x86_64')
| -rw-r--r-- | arch/x86_64/ia32/vsyscall-sigreturn.S | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/arch/x86_64/ia32/vsyscall-sigreturn.S b/arch/x86_64/ia32/vsyscall-sigreturn.S index d90321fe9bb..1384367cdbe 100644 --- a/arch/x86_64/ia32/vsyscall-sigreturn.S +++ b/arch/x86_64/ia32/vsyscall-sigreturn.S @@ -32,9 +32,28 @@ __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 presumed call instruction. Since we didn't get here via @@ -97,7 +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 |