1 files changed, 122 insertions, 0 deletions
diff --git a/arch/x86/kernel/vsyscall-sysenter_32.S b/arch/x86/kernel/vsyscall-sysenter_32.S
new file mode 100644
index 000000000000..ed879bf42995
--- /dev/null
+++ b/arch/x86/kernel/vsyscall-sysenter_32.S
@@ -0,0 +1,122 @@
+/*
+ * 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.
+ */
+/*
+ * The caller puts arg2 in %ecx, which gets pushed. The kernel will use
+ * %ecx itself for arg2. The pushing is because the sysexit instruction
+ * (found in entry.S) requires that we clobber %ecx with the desired %esp.
+ * User code might expect that %ecx is unclobbered though, as it would be
+ * for returning via the iret instruction, so we must push and pop.
+ *
+ * The caller puts arg3 in %edx, which the sysexit instruction requires
+ * for %eip. Thus, exactly as for arg2, we must push and pop.
+ *
+ * Arg6 is different. The caller puts arg6 in %ebp. Since the sysenter
+ * instruction clobbers %esp, the user's %esp won't even survive entry
+ * into the kernel. We store %esp in %ebp. Code in entry.S must fetch
+ * arg6 from the stack.
+ *
+ * You can not use this vsyscall for the clone() syscall because the
+ * three dwords on the parent stack do not get copied to the child.
+ */
+        .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 sysenter.c  */
+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_32.S"

diff --git a/arch/x86/kernel/vsyscall-sysenter_32.S b/arch/x86/kernel/vsyscall-sysenter_32.S new file mode 100644 index 000000000000..ed879bf42995 --- /dev/null +++ b/arch/x86/kernel/vsyscall-sysenter_32.S
@@ -0,0 +1,122 @@
	1	/*
	2	* Code for the vsyscall page. This version uses the sysenter instruction.
	3	*
	4	* NOTE:
	5	* 1) __kernel_vsyscall _must_ be first in this page.
	6	* 2) there are alignment constraints on this stub, see vsyscall-sigreturn.S
	7	* for details.
	8	*/
	9
	10	/*
	11	* The caller puts arg2 in %ecx, which gets pushed. The kernel will use
	12	* %ecx itself for arg2. The pushing is because the sysexit instruction
	13	* (found in entry.S) requires that we clobber %ecx with the desired %esp.
	14	* User code might expect that %ecx is unclobbered though, as it would be
	15	* for returning via the iret instruction, so we must push and pop.
	16	*
	17	* The caller puts arg3 in %edx, which the sysexit instruction requires
	18	* for %eip. Thus, exactly as for arg2, we must push and pop.
	19	*
	20	* Arg6 is different. The caller puts arg6 in %ebp. Since the sysenter
	21	* instruction clobbers %esp, the user's %esp won't even survive entry
	22	* into the kernel. We store %esp in %ebp. Code in entry.S must fetch
	23	* arg6 from the stack.
	24	*
	25	* You can not use this vsyscall for the clone() syscall because the
	26	* three dwords on the parent stack do not get copied to the child.
	27	*/
	28	.text
	29	.globl __kernel_vsyscall
	30	.type __kernel_vsyscall,@function
	31	__kernel_vsyscall:
	32	.LSTART_vsyscall:
	33	push %ecx
	34	.Lpush_ecx:
	35	push %edx
	36	.Lpush_edx:
	37	push %ebp
	38	.Lenter_kernel:
	39	movl %esp,%ebp
	40	sysenter
	41
	42	/* 7: align return point with nop's to make disassembly easier */
	43	.space 7,0x90
	44
	45	/* 14: System call restart point is here! (SYSENTER_RETURN-2) */
	46	jmp .Lenter_kernel
	47	/* 16: System call normal return point is here! */
	48	.globl SYSENTER_RETURN /* Symbol used by sysenter.c */
	49	SYSENTER_RETURN:
	50	pop %ebp
	51	.Lpop_ebp:
	52	pop %edx
	53	.Lpop_edx:
	54	pop %ecx
	55	.Lpop_ecx:
	56	ret
	57	.LEND_vsyscall:
	58	.size __kernel_vsyscall,.-.LSTART_vsyscall
	59	.previous
	60
	61	.section .eh_frame,"a",@progbits
	62	.LSTARTFRAMEDLSI:
	63	.long .LENDCIEDLSI-.LSTARTCIEDLSI
	64	.LSTARTCIEDLSI:
	65	.long 0 /* CIE ID */
	66	.byte 1 /* Version number */
	67	.string "zR" /* NUL-terminated augmentation string */
	68	.uleb128 1 /* Code alignment factor */
	69	.sleb128 -4 /* Data alignment factor */
	70	.byte 8 /* Return address register column */
	71	.uleb128 1 /* Augmentation value length */
	72	.byte 0x1b /* DW_EH_PE_pcrel\|DW_EH_PE_sdata4. */
	73	.byte 0x0c /* DW_CFA_def_cfa */
	74	.uleb128 4
	75	.uleb128 4
	76	.byte 0x88 /* DW_CFA_offset, column 0x8 */
	77	.uleb128 1
	78	.align 4
	79	.LENDCIEDLSI:
	80	.long .LENDFDEDLSI-.LSTARTFDEDLSI /* Length FDE */
	81	.LSTARTFDEDLSI:
	82	.long .LSTARTFDEDLSI-.LSTARTFRAMEDLSI /* CIE pointer */
	83	.long .LSTART_vsyscall-. /* PC-relative start address */
	84	.long .LEND_vsyscall-.LSTART_vsyscall
	85	.uleb128 0
	86	/* What follows are the instructions for the table generation.
	87	We have to record all changes of the stack pointer. */
	88	.byte 0x04 /* DW_CFA_advance_loc4 */
	89	.long .Lpush_ecx-.LSTART_vsyscall
	90	.byte 0x0e /* DW_CFA_def_cfa_offset */
	91	.byte 0x08 /* RA at offset 8 now */
	92	.byte 0x04 /* DW_CFA_advance_loc4 */
	93	.long .Lpush_edx-.Lpush_ecx
	94	.byte 0x0e /* DW_CFA_def_cfa_offset */
	95	.byte 0x0c /* RA at offset 12 now */
	96	.byte 0x04 /* DW_CFA_advance_loc4 */
	97	.long .Lenter_kernel-.Lpush_edx
	98	.byte 0x0e /* DW_CFA_def_cfa_offset */
	99	.byte 0x10 /* RA at offset 16 now */
	100	.byte 0x85, 0x04 /* DW_CFA_offset %ebp -16 */
	101	/* Finally the epilogue. */
	102	.byte 0x04 /* DW_CFA_advance_loc4 */
	103	.long .Lpop_ebp-.Lenter_kernel
	104	.byte 0x0e /* DW_CFA_def_cfa_offset */
	105	.byte 0x0c /* RA at offset 12 now */
	106	.byte 0xc5 /* DW_CFA_restore %ebp */
	107	.byte 0x04 /* DW_CFA_advance_loc4 */
	108	.long .Lpop_edx-.Lpop_ebp
	109	.byte 0x0e /* DW_CFA_def_cfa_offset */
	110	.byte 0x08 /* RA at offset 8 now */
	111	.byte 0x04 /* DW_CFA_advance_loc4 */
	112	.long .Lpop_ecx-.Lpop_edx
	113	.byte 0x0e /* DW_CFA_def_cfa_offset */
	114	.byte 0x04 /* RA at offset 4 now */
	115	.align 4
	116	.LENDFDEDLSI:
	117	.previous
	118
	119	/*
	120	* Get the common code for the sigreturn entry points.
	121	*/
	122	#include "vsyscall-sigreturn_32.S"