Clean up the x86-64 and x86 setjmp families.
Bug: 16918359
Change-Id: Ic8ca0af9ea99636bc71f19d46071f1cea6eef982
diff --git a/libc/arch-x86_64/bionic/setjmp.S b/libc/arch-x86_64/bionic/setjmp.S
index f356877..a8f614f 100644
--- a/libc/arch-x86_64/bionic/setjmp.S
+++ b/libc/arch-x86_64/bionic/setjmp.S
@@ -1,6 +1,3 @@
-/* $OpenBSD: setjmp.S,v 1.3 2012/08/22 17:19:34 pascal Exp $ */
-/* $NetBSD: __setjmp14.S,v 1.1 2001/06/19 00:25:02 fvdl Exp $ */
-
/*
* Copyright (c) 2001 Wasabi Systems, Inc.
* All rights reserved.
@@ -37,60 +34,98 @@
*/
#include <private/bionic_asm.h>
-#include <machine/setjmp.h>
-/*
- * C library -- _setjmp, _longjmp
- *
- * longjmp(a,v)
- * will generate a "return(v)" from the last call to
- * setjmp(a)
- * by restoring registers from the stack.
- * The previous signal state is restored.
- */
+// These are only the callee-saved registers. Code calling setjmp
+// will expect the rest to be clobbered anyway.
+
+#define _JB_RBX 0
+#define _JB_RBP 1
+#define _JB_R12 2
+#define _JB_R13 3
+#define _JB_R14 4
+#define _JB_R15 5
+#define _JB_RSP 6
+#define _JB_PC 7
+#define _JB_SIGFLAG 8
+#define _JB_SIGMASK 9
ENTRY(setjmp)
- pushq %rdi
- xorq %rdi,%rdi
- call PIC_PLT(sigblock)
- popq %rdi
- movq %rax,(_JB_SIGMASK * 8)(%rdi)
-
- movq (%rsp),%r11
- movq %rbx,(_JB_RBX * 8)(%rdi)
- movq %rbp,(_JB_RBP * 8)(%rdi)
- movq %r12,(_JB_R12 * 8)(%rdi)
- movq %r13,(_JB_R13 * 8)(%rdi)
- movq %r14,(_JB_R14 * 8)(%rdi)
- movq %r15,(_JB_R15 * 8)(%rdi)
- movq %rsp,(_JB_RSP * 8)(%rdi)
- movq %r11,(_JB_PC * 8)(%rdi)
-
-2: xorl %eax,%eax
- ret
+ movl $1,%esi
+ jmp PIC_PLT(sigsetjmp)
END(setjmp)
-ENTRY(longjmp)
- movq %rdi,%r12
- movl %esi,%r8d
+ENTRY(_setjmp)
+ movl $0,%esi
+ jmp PIC_PLT(sigsetjmp)
+END(_setjmp)
- movq (_JB_SIGMASK * 8)(%rdi),%rdi
- pushq %r8
- call PIC_PLT(sigsetmask)
- popq %r8
- movq (_JB_RBX * 8)(%r12),%rbx
- movq (_JB_RBP * 8)(%r12),%rbp
- movq (_JB_R13 * 8)(%r12),%r13
- movq (_JB_R14 * 8)(%r12),%r14
- movq (_JB_R15 * 8)(%r12),%r15
- movq (_JB_RSP * 8)(%r12),%rsp
- movq (_JB_PC * 8)(%r12),%r11
- movq (_JB_R12 * 8)(%r12),%r12
+// int sigsetjmp(sigjmp_buf env, int save_signal_mask);
+ENTRY(sigsetjmp)
+ // Record whether or not we're saving the signal mask.
+ movl %esi,(_JB_SIGFLAG * 8)(%rdi)
- movl %r8d,%eax
- testl %eax,%eax
- jnz 1f
- incl %eax
-1: movq %r11,0(%rsp)
- ret
-END(longjmp)
+ // Do we need to save the signal mask?
+ testl %esi,%esi
+ jz 2f
+
+ // Save the signal mask.
+ pushq %rdi
+ xorq %rdi,%rdi
+ call PIC_PLT(sigblock)
+ popq %rdi
+ movq %rax,(_JB_SIGMASK * 8)(%rdi)
+
+2:
+ // Save the callee-save registers.
+ movq (%rsp),%r11
+ movq %rbx,(_JB_RBX * 8)(%rdi)
+ movq %rbp,(_JB_RBP * 8)(%rdi)
+ movq %r12,(_JB_R12 * 8)(%rdi)
+ movq %r13,(_JB_R13 * 8)(%rdi)
+ movq %r14,(_JB_R14 * 8)(%rdi)
+ movq %r15,(_JB_R15 * 8)(%rdi)
+ movq %rsp,(_JB_RSP * 8)(%rdi)
+ movq %r11,(_JB_PC * 8)(%rdi)
+
+ xorl %eax,%eax
+ ret
+END(sigsetjmp)
+
+// void siglongjmp(sigjmp_buf env, int value);
+ENTRY(siglongjmp)
+ movq %rdi,%r12
+ pushq %rsi // Push 'value'.
+
+ // Do we need to restore the signal mask?
+ cmpl $0, (_JB_SIGFLAG * 8)(%rdi)
+ jz 2f
+
+ // Restore the signal mask.
+ movq (_JB_SIGMASK * 8)(%rdi),%rdi
+ call PIC_PLT(sigsetmask)
+
+2:
+ popq %rax // Pop 'value'.
+
+ // Restore the callee-save registers.
+ movq (_JB_RBX * 8)(%r12),%rbx
+ movq (_JB_RBP * 8)(%r12),%rbp
+ movq (_JB_R13 * 8)(%r12),%r13
+ movq (_JB_R14 * 8)(%r12),%r14
+ movq (_JB_R15 * 8)(%r12),%r15
+ movq (_JB_RSP * 8)(%r12),%rsp
+ movq (_JB_PC * 8)(%r12),%r11
+ movq (_JB_R12 * 8)(%r12),%r12
+
+ testl %eax,%eax
+ jnz 1f
+ incl %eax
+1:
+ movq %r11,0(%rsp)
+ ret
+END(siglongjmp)
+
+ .globl longjmp
+ .equ longjmp, siglongjmp
+ .globl _longjmp
+ .equ _longjmp, siglongjmp