This puts the syscall version of the 32-bit vDSO in arch/x86/vdso/vdso32/
for 64-bit IA32 support. This is not used yet, but it paves the way for
consolidating the 32-bit vDSO source and build logic all in one place.
Signed-off-by: Roland McGrath <[email protected]>
---
arch/x86/vdso/Makefile | 1 +
arch/x86/vdso/vdso32/sigreturn.S | 9 +++--
arch/x86/vdso/vdso32/syscall.S | 69 ++++++++++++++++++++++++++++++++++++++
3 files changed, 76 insertions(+), 3 deletions(-)
create mode 100644 arch/x86/vdso/vdso32/syscall.S
diff --git a/arch/x86/vdso/Makefile b/arch/x86/vdso/Makefile
index 9ffd03f..64e4f47 100644
--- a/arch/x86/vdso/Makefile
+++ b/arch/x86/vdso/Makefile
@@ -71,6 +71,7 @@ $(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE
#
obj-$(VDSO32-y) += vdso32-syms.lds
vdso32.so-$(CONFIG_X86_32) += int80
+vdso32.so-$(CONFIG_COMPAT) += syscall
vdso32.so-$(VDSO32-y) += sysenter
CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
diff --git a/arch/x86/vdso/vdso32/sigreturn.S b/arch/x86/vdso/vdso32/sigreturn.S
index e939253..f222889 100644
--- a/arch/x86/vdso/vdso32/sigreturn.S
+++ b/arch/x86/vdso/vdso32/sigreturn.S
@@ -6,9 +6,12 @@
* routines are constant for all vsyscall implementations.
*/
-#include <asm/unistd.h>
+#include <asm/unistd_32.h>
#include <asm/asm-offsets.h>
+#ifndef SYSCALL_ENTER_KERNEL
+#define SYSCALL_ENTER_KERNEL int $0x80
+#endif
/* XXX
Should these be named "_sigtramp" or something?
@@ -22,7 +25,7 @@ __kernel_sigreturn:
.LSTART_sigreturn:
popl %eax /* XXX does this mean it needs unwind info? */
movl $__NR_sigreturn, %eax
- int $0x80
+ SYSCALL_ENTER_KERNEL
.LEND_sigreturn:
.size __kernel_sigreturn,.-.LSTART_sigreturn
@@ -32,7 +35,7 @@ __kernel_sigreturn:
__kernel_rt_sigreturn:
.LSTART_rt_sigreturn:
movl $__NR_rt_sigreturn, %eax
- int $0x80
+ SYSCALL_ENTER_KERNEL
.LEND_rt_sigreturn:
.size __kernel_rt_sigreturn,.-.LSTART_rt_sigreturn
.balign 32
diff --git a/arch/x86/vdso/vdso32/syscall.S b/arch/x86/vdso/vdso32/syscall.S
new file mode 100644
index 0000000..333bfb5
--- /dev/null
+++ b/arch/x86/vdso/vdso32/syscall.S
@@ -0,0 +1,69 @@
+/*
+ * Code for the vsyscall page. This version uses the syscall instruction.
+ */
+
+#include <asm/asm-offsets.h>
+#include <asm/segment.h>
+
+ .text
+ .globl __kernel_vsyscall
+ .type __kernel_vsyscall,@function
+__kernel_vsyscall:
+.LSTART_vsyscall:
+ push %ebp
+.Lpush_ebp:
+ movl %ecx, %ebp
+ syscall
+ movl $__USER32_DS, %ecx
+ movl %ecx, %ss
+ movl %ebp, %ecx
+ popl %ebp
+.Lpop_ebp:
+ ret
+.LEND_vsyscall:
+ .size __kernel_vsyscall,.-.LSTART_vsyscall
+
+ .section .eh_frame,"a",@progbits
+.LSTARTFRAME:
+ .long .LENDCIE-.LSTARTCIE
+.LSTARTCIE:
+ .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
+.LENDCIE:
+
+ .long .LENDFDE1-.LSTARTFDE1 /* Length FDE */
+.LSTARTFDE1:
+ .long .LSTARTFDE1-.LSTARTFRAME /* CIE pointer */
+ .long .LSTART_vsyscall-. /* PC-relative start address */
+ .long .LEND_vsyscall-.LSTART_vsyscall
+ .uleb128 0 /* Augmentation length */
+ /* What follows are the instructions for the table generation.
+ We have to record all changes of the stack pointer. */
+ .byte 0x40 + .Lpush_ebp-.LSTART_vsyscall /* DW_CFA_advance_loc */
+ .byte 0x0e /* DW_CFA_def_cfa_offset */
+ .uleb128 8
+ .byte 0x85, 0x02 /* DW_CFA_offset %ebp -8 */
+ .byte 0x40 + .Lpop_ebp-.Lpush_ebp /* DW_CFA_advance_loc */
+ .byte 0xc5 /* DW_CFA_restore %ebp */
+ .byte 0x0e /* DW_CFA_def_cfa_offset */
+ .uleb128 4
+ .align 4
+.LENDFDE1:
+
+/*
+ * Get the common code for the sigreturn entry points.
+ */
+#define SYSCALL_ENTER_KERNEL syscall
+#include "sigreturn.S"
-
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