summaryrefslogtreecommitdiff
path: root/arch/x86/entry/vdso/vdso32/system_call.S
diff options
context:
space:
mode:
authorAndy Lutomirski <luto@kernel.org>2015-10-06 03:47:56 +0300
committerIngo Molnar <mingo@kernel.org>2015-10-07 12:34:08 +0300
commit0a6d1fa0d2b48fbae444e46e7f37a4832b2f8bdf (patch)
tree56ab2ecf8d7a61c3cfbf96534cdef688c6f84a57 /arch/x86/entry/vdso/vdso32/system_call.S
parentb611acf4736b5b00c89dcc238f640337832abcb4 (diff)
downloadlinux-0a6d1fa0d2b48fbae444e46e7f37a4832b2f8bdf.tar.xz
x86/vdso: Remove runtime 32-bit vDSO selection
32-bit userspace will now always see the same vDSO, which is exactly what used to be the int80 vDSO. Subsequent patches will clean it up and make it support SYSENTER and SYSCALL using alternatives. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/e7e6b3526fa442502e6125fe69486aab50813c32.1444091584.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/entry/vdso/vdso32/system_call.S')
-rw-r--r--arch/x86/entry/vdso/vdso32/system_call.S56
1 files changed, 56 insertions, 0 deletions
diff --git a/arch/x86/entry/vdso/vdso32/system_call.S b/arch/x86/entry/vdso/vdso32/system_call.S
new file mode 100644
index 000000000000..b15b7c01aedb
--- /dev/null
+++ b/arch/x86/entry/vdso/vdso32/system_call.S
@@ -0,0 +1,56 @@
+/*
+ * Code for the vDSO. This version uses the old int $0x80 method.
+ *
+ * First get the common code for the sigreturn entry points.
+ * This must come first.
+ */
+#include "sigreturn.S"
+
+ .text
+ .globl __kernel_vsyscall
+ .type __kernel_vsyscall,@function
+ ALIGN
+__kernel_vsyscall:
+.LSTART_vsyscall:
+ int $0x80
+ 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
+ .align 4
+.LENDFDEDLSI:
+ .previous
+
+ /*
+ * Pad out the segment to match the size of the sysenter.S version.
+ */
+VDSO32_vsyscall_eh_frame_size = 0x40
+ .section .data,"aw",@progbits
+ .space VDSO32_vsyscall_eh_frame_size-(.LENDFDEDLSI-.LSTARTFRAMEDLSI), 0
+ .previous