diff options
Diffstat (limited to 'libc/arch-x86_64/bionic/setjmp.S')
| -rw-r--r-- | libc/arch-x86_64/bionic/setjmp.S | 147 |
1 files changed, 92 insertions, 55 deletions
diff --git a/libc/arch-x86_64/bionic/setjmp.S b/libc/arch-x86_64/bionic/setjmp.S index f356877..5559f54 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 +34,100 @@ */ #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 +#define _JB_SIGMASK_RT 10 // sigprocmask will write here too. 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 - - 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 - - movl %r8d,%eax - testl %eax,%eax - jnz 1f - incl %eax -1: movq %r11,0(%rsp) - ret -END(longjmp) +ENTRY(_setjmp) + movl $0,%esi + jmp PIC_PLT(sigsetjmp) +END(_setjmp) + +// 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) + + // Do we need to save the signal mask? + testl %esi,%esi + jz 2f + + // Save current signal mask. + pushq %rdi // Push 'env'. + // The 'how' argument is ignored if new_mask is NULL. + xorq %rsi,%rsi // NULL. + leaq (_JB_SIGMASK * 8)(%rdi),%rdx // old_mask. + call PIC_PLT(sigprocmask) + popq %rdi // Pop 'env'. + +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 $2,%rdi // SIG_SETMASK. + leaq (_JB_SIGMASK * 8)(%r12),%rsi // new_mask. + xorq %rdx,%rdx // NULL. + call PIC_PLT(sigprocmask) + +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) + +ALIAS_SYMBOL(longjmp, siglongjmp) +ALIAS_SYMBOL(_longjmp, siglongjmp) |