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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>
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@ -50,7 +50,7 @@ __kernel_vsyscall:
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/*
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* Pad out the segment to match the size of the sysenter.S version.
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*/
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VDSO32_vsyscall_eh_frame_size = 0x44
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VDSO32_vsyscall_eh_frame_size = 0x40
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.section .data,"aw",@progbits
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.space VDSO32_vsyscall_eh_frame_size-(.LENDFDEDLSI-.LSTARTFRAMEDLSI), 0
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.previous
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@ -71,7 +71,7 @@ __kernel_vsyscall:
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/*
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* Pad out the segment to match the size of the sysenter.S version.
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*/
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VDSO32_vsyscall_eh_frame_size = 0x44
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VDSO32_vsyscall_eh_frame_size = 0x40
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.section .data,"aw",@progbits
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.space VDSO32_vsyscall_eh_frame_size-(.LENDFDE1-.LSTARTFRAME), 0
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.previous
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@ -84,31 +84,25 @@ VDSO32_SYSENTER_RETURN: /* Symbol used by sysenter.c via vdso32-syms.h */
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.uleb128 0
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/* What follows are the instructions for the table generation.
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We have to record all changes of the stack pointer. */
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.byte 0x04 /* DW_CFA_advance_loc4 */
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.long .Lpush_ecx-.LSTART_vsyscall
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.byte 0x40 + (.Lpush_ecx-.LSTART_vsyscall) /* DW_CFA_advance_loc */
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.byte 0x0e /* DW_CFA_def_cfa_offset */
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.byte 0x08 /* RA at offset 8 now */
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.byte 0x04 /* DW_CFA_advance_loc4 */
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.long .Lpush_edx-.Lpush_ecx
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.byte 0x40 + (.Lpush_edx-.Lpush_ecx) /* DW_CFA_advance_loc */
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.byte 0x0e /* DW_CFA_def_cfa_offset */
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.byte 0x0c /* RA at offset 12 now */
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.byte 0x04 /* DW_CFA_advance_loc4 */
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.long .Lenter_kernel-.Lpush_edx
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.byte 0x40 + (.Lenter_kernel-.Lpush_edx) /* DW_CFA_advance_loc */
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.byte 0x0e /* DW_CFA_def_cfa_offset */
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.byte 0x10 /* RA at offset 16 now */
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.byte 0x85, 0x04 /* DW_CFA_offset %ebp -16 */
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/* Finally the epilogue. */
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.byte 0x04 /* DW_CFA_advance_loc4 */
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.long .Lpop_ebp-.Lenter_kernel
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.byte 0x40 + (.Lpop_ebp-.Lenter_kernel) /* DW_CFA_advance_loc */
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.byte 0x0e /* DW_CFA_def_cfa_offset */
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.byte 0x0c /* RA at offset 12 now */
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.byte 0xc5 /* DW_CFA_restore %ebp */
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.byte 0x04 /* DW_CFA_advance_loc4 */
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.long .Lpop_edx-.Lpop_ebp
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.byte 0x40 + (.Lpop_edx-.Lpop_ebp) /* DW_CFA_advance_loc */
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.byte 0x0e /* DW_CFA_def_cfa_offset */
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.byte 0x08 /* RA at offset 8 now */
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.byte 0x04 /* DW_CFA_advance_loc4 */
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.long .Lpop_ecx-.Lpop_edx
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.byte 0x40 + (.Lpop_ecx-.Lpop_edx) /* DW_CFA_advance_loc */
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.byte 0x0e /* DW_CFA_def_cfa_offset */
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.byte 0x04 /* RA at offset 4 now */
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.align 4
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