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authorRoland McGrath <roland@redhat.com>2008-01-30 13:30:44 +0100
committerIngo Molnar <mingo@elte.hu>2008-01-30 13:30:44 +0100
commitcadd516422d9382313144aa58f9e46ee7a2c0a28 (patch)
tree84cb8aa63f068bd4609723b43cdfd41ec74c9665
parent16e48e7e7929d841273d87027079660bca5e37bd (diff)
downloadblackbird-op-linux-cadd516422d9382313144aa58f9e46ee7a2c0a28.tar.gz
blackbird-op-linux-cadd516422d9382313144aa58f9e46ee7a2c0a28.zip
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>
-rw-r--r--arch/x86/vdso/vdso32/int80.S2
-rw-r--r--arch/x86/vdso/vdso32/syscall.S2
-rw-r--r--arch/x86/vdso/vdso32/sysenter.S18
3 files changed, 8 insertions, 14 deletions
diff --git a/arch/x86/vdso/vdso32/int80.S b/arch/x86/vdso/vdso32/int80.S
index be4b7a9a7cdd..b15b7c01aedb 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 fe88d34f822f..5415b5613d55 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 902d5fc11f1b..e2800affa754 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
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