From cadd516422d9382313144aa58f9e46ee7a2c0a28 Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Wed, 30 Jan 2008 13:30:44 +0100 Subject: 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 Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/vdso/vdso32/int80.S | 2 +- arch/x86/vdso/vdso32/syscall.S | 2 +- arch/x86/vdso/vdso32/sysenter.S | 18 ++++++------------ 3 files changed, 8 insertions(+), 14 deletions(-) (limited to 'arch/x86/vdso') diff --git a/arch/x86/vdso/vdso32/int80.S b/arch/x86/vdso/vdso32/int80.S index be4b7a9a7cd..b15b7c01aed 100644 --- a/arch/x86/vdso/vdso32/int80.S +++ b/arch/x86/vdso/vdso32/int80.S @@ -50,7 +50,7 @@ __kernel_vsyscall: /* * Pad out the segment to match the size of the sysenter.S version. */ -VDSO32_vsyscall_eh_frame_size = 0x44 +VDSO32_vsyscall_eh_frame_size = 0x40 .section .data,"aw",@progbits .space VDSO32_vsyscall_eh_frame_size-(.LENDFDEDLSI-.LSTARTFRAMEDLSI), 0 .previous diff --git a/arch/x86/vdso/vdso32/syscall.S b/arch/x86/vdso/vdso32/syscall.S index fe88d34f822..5415b5613d5 100644 --- a/arch/x86/vdso/vdso32/syscall.S +++ b/arch/x86/vdso/vdso32/syscall.S @@ -71,7 +71,7 @@ __kernel_vsyscall: /* * Pad out the segment to match the size of the sysenter.S version. */ -VDSO32_vsyscall_eh_frame_size = 0x44 +VDSO32_vsyscall_eh_frame_size = 0x40 .section .data,"aw",@progbits .space VDSO32_vsyscall_eh_frame_size-(.LENDFDE1-.LSTARTFRAME), 0 .previous diff --git a/arch/x86/vdso/vdso32/sysenter.S b/arch/x86/vdso/vdso32/sysenter.S index 902d5fc11f1..e2800affa75 100644 --- a/arch/x86/vdso/vdso32/sysenter.S +++ b/arch/x86/vdso/vdso32/sysenter.S @@ -84,31 +84,25 @@ VDSO32_SYSENTER_RETURN: /* Symbol used by sysenter.c via vdso32-syms.h */ .uleb128 0 /* What follows are the instructions for the table generation. We have to record all changes of the stack pointer. */ - .byte 0x04 /* DW_CFA_advance_loc4 */ - .long .Lpush_ecx-.LSTART_vsyscall + .byte 0x40 + (.Lpush_ecx-.LSTART_vsyscall) /* DW_CFA_advance_loc */ .byte 0x0e /* DW_CFA_def_cfa_offset */ .byte 0x08 /* RA at offset 8 now */ - .byte 0x04 /* DW_CFA_advance_loc4 */ - .long .Lpush_edx-.Lpush_ecx + .byte 0x40 + (.Lpush_edx-.Lpush_ecx) /* DW_CFA_advance_loc */ .byte 0x0e /* DW_CFA_def_cfa_offset */ .byte 0x0c /* RA at offset 12 now */ - .byte 0x04 /* DW_CFA_advance_loc4 */ - .long .Lenter_kernel-.Lpush_edx + .byte 0x40 + (.Lenter_kernel-.Lpush_edx) /* DW_CFA_advance_loc */ .byte 0x0e /* DW_CFA_def_cfa_offset */ .byte 0x10 /* RA at offset 16 now */ .byte 0x85, 0x04 /* DW_CFA_offset %ebp -16 */ /* Finally the epilogue. */ - .byte 0x04 /* DW_CFA_advance_loc4 */ - .long .Lpop_ebp-.Lenter_kernel + .byte 0x40 + (.Lpop_ebp-.Lenter_kernel) /* DW_CFA_advance_loc */ .byte 0x0e /* DW_CFA_def_cfa_offset */ .byte 0x0c /* RA at offset 12 now */ .byte 0xc5 /* DW_CFA_restore %ebp */ - .byte 0x04 /* DW_CFA_advance_loc4 */ - .long .Lpop_edx-.Lpop_ebp + .byte 0x40 + (.Lpop_edx-.Lpop_ebp) /* DW_CFA_advance_loc */ .byte 0x0e /* DW_CFA_def_cfa_offset */ .byte 0x08 /* RA at offset 8 now */ - .byte 0x04 /* DW_CFA_advance_loc4 */ - .long .Lpop_ecx-.Lpop_edx + .byte 0x40 + (.Lpop_ecx-.Lpop_edx) /* DW_CFA_advance_loc */ .byte 0x0e /* DW_CFA_def_cfa_offset */ .byte 0x04 /* RA at offset 4 now */ .align 4 -- cgit v1.2.3-70-g09d2