linux/arch/x86/vdso/vdso32/int80.S
Roland McGrath cadd516422 x86 vDSO: canonicalize sysenter .eh_frame
Some assembler versions automagically optimize .eh_frame contents,
changing their size.  The CFI in sysenter.S was not using optimal
formatting, so it would be changed by newer/smarter assemblers.
This ran afoul of the wired constant for padding out the other vDSO
images to match its size.  This changes the original hand-coded
source to use the optimal format encoding for its operations.  That
leaves nothing more for a fancy assembler to do, so the sizes will
match the wired-in expected size regardless of the assembler version.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:44 +01:00

57 lines
1.4 KiB
ArmAsm

/*
* Code for the vDSO. This version uses the old int $0x80 method.
*
* First get the common code for the sigreturn entry points.
* This must come first.
*/
#include "sigreturn.S"
.text
.globl __kernel_vsyscall
.type __kernel_vsyscall,@function
ALIGN
__kernel_vsyscall:
.LSTART_vsyscall:
int $0x80
ret
.LEND_vsyscall:
.size __kernel_vsyscall,.-.LSTART_vsyscall
.previous
.section .eh_frame,"a",@progbits
.LSTARTFRAMEDLSI:
.long .LENDCIEDLSI-.LSTARTCIEDLSI
.LSTARTCIEDLSI:
.long 0 /* CIE ID */
.byte 1 /* Version number */
.string "zR" /* 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
.LENDCIEDLSI:
.long .LENDFDEDLSI-.LSTARTFDEDLSI /* Length FDE */
.LSTARTFDEDLSI:
.long .LSTARTFDEDLSI-.LSTARTFRAMEDLSI /* CIE pointer */
.long .LSTART_vsyscall-. /* PC-relative start address */
.long .LEND_vsyscall-.LSTART_vsyscall
.uleb128 0
.align 4
.LENDFDEDLSI:
.previous
/*
* Pad out the segment to match the size of the sysenter.S version.
*/
VDSO32_vsyscall_eh_frame_size = 0x40
.section .data,"aw",@progbits
.space VDSO32_vsyscall_eh_frame_size-(.LENDFDEDLSI-.LSTARTFRAMEDLSI), 0
.previous