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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/i386/kernel/vsyscall-sysenter.S
downloadlinux-stericsson-2.6.12-rc2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/i386/kernel/vsyscall-sysenter.S')
-rw-r--r--arch/i386/kernel/vsyscall-sysenter.S104
1 files changed, 104 insertions, 0 deletions
diff --git a/arch/i386/kernel/vsyscall-sysenter.S b/arch/i386/kernel/vsyscall-sysenter.S
new file mode 100644
index 000000000000..4daefb2ec1b2
--- /dev/null
+++ b/arch/i386/kernel/vsyscall-sysenter.S
@@ -0,0 +1,104 @@
+/*
+ * Code for the vsyscall page. This version uses the sysenter instruction.
+ *
+ * NOTE:
+ * 1) __kernel_vsyscall _must_ be first in this page.
+ * 2) there are alignment constraints on this stub, see vsyscall-sigreturn.S
+ * for details.
+ */
+
+ .text
+ .globl __kernel_vsyscall
+ .type __kernel_vsyscall,@function
+__kernel_vsyscall:
+.LSTART_vsyscall:
+ push %ecx
+.Lpush_ecx:
+ push %edx
+.Lpush_edx:
+ push %ebp
+.Lenter_kernel:
+ movl %esp,%ebp
+ sysenter
+
+ /* 7: align return point with nop's to make disassembly easier */
+ .space 7,0x90
+
+ /* 14: System call restart point is here! (SYSENTER_RETURN - 2) */
+ jmp .Lenter_kernel
+ /* 16: System call normal return point is here! */
+ .globl SYSENTER_RETURN /* Symbol used by entry.S. */
+SYSENTER_RETURN:
+ pop %ebp
+.Lpop_ebp:
+ pop %edx
+.Lpop_edx:
+ pop %ecx
+.Lpop_ecx:
+ 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
+ /* 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 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 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 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 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 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 0x0e /* DW_CFA_def_cfa_offset */
+ .byte 0x04 /* RA at offset 4 now */
+ .align 4
+.LENDFDEDLSI:
+ .previous
+
+/*
+ * Get the common code for the sigreturn entry points.
+ */
+#include "vsyscall-sigreturn.S"