https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=f4abb28ea81bd5d7f651ec8f3ac944c3c82493ac
commit f4abb28ea81bd5d7f651ec8f3ac944c3c82493ac Author: Corinna Vinschen <[email protected]> Date: Mon Jun 22 13:09:55 2015 +0200 Don't push on original stack during alternate signal stack setup * exceptions.cc (_cygtls::call_signal_handler): Drop pushing a register on the original stack, it confuses GCC. Rearrange the assembler code so that $rax/$eax is not used by GCC to prepare an argument value. Use $rax/$eax without saving. Drop clearing $rbp/$epb. Signed-off-by: Corinna Vinschen <[email protected]> Diff: --- winsup/cygwin/ChangeLog | 7 +++ winsup/cygwin/exceptions.cc | 105 +++++++++++++++++++++----------------------- 2 files changed, 56 insertions(+), 56 deletions(-) diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog index 6b01539..9f99268 100644 --- a/winsup/cygwin/ChangeLog +++ b/winsup/cygwin/ChangeLog @@ -1,3 +1,10 @@ +2015-06-22 Corinna Vinschen <[email protected]> + + * exceptions.cc (_cygtls::call_signal_handler): Drop pushing a register + on the original stack, it confuses GCC. Rearrange the assembler code + so that $rax/$eax is not used by GCC to prepare an argument value. + Use $rax/$eax without saving. Drop clearing $rbp/$epb. + 2015-06-21 Corinna Vinschen <[email protected]> * exceptions.cc (_cygtls::call_signal_handler): Drop subtracting 16 diff --git a/winsup/cygwin/exceptions.cc b/winsup/cygwin/exceptions.cc index 8d34179..d493abb 100644 --- a/winsup/cygwin/exceptions.cc +++ b/winsup/cygwin/exceptions.cc @@ -1604,76 +1604,69 @@ _cygtls::call_signal_handler () /* In assembler: Save regs on new stack, move to alternate stack, call thisfunc, revert stack regs. */ #ifdef __x86_64__ - /* Clobbered regs: rax, rcx, rdx, r8, r9, r10, r11, rbp, rsp */ + /* Clobbered regs: rcx, rdx, r8, r9, r10, r11, rbp, rsp */ __asm__ ("\n\ - pushq %%r9 # Push r9 on orig stack \n\ - movq %[NEW_SP], %%r9 # Load alt stack into r9 \n\ - subq $0x40, %%r9 # Make room on alt stack to \n\ - # save clobbered regs \n\ - movq %%rax, (%%r9) # Save other clobbered regs \n\ - movq %%rcx, 0x8(%%r9) \n\ - movq %%rdx, 0x10(%%r9) \n\ - movq %%r8, 0x18(%%r9) \n\ - movq %%r10, 0x20(%%r9) \n\ - movq %%r11, 0x28(%%r9) \n\ - movq %%rbp, 0x30(%%r9) \n\ - movq %%rsp, 0x38(%%r9) \n\ + movq %[NEW_SP], %%rax # Load alt stack into rax \n\ + subq $0x60, %%rax # Make room on alt stack \n\ + # for clobbered regs and \n\ + # required shadow space \n\ + movq %%rcx, 0x20(%%rax)# Save clobbered regs \n\ + movq %%rdx, 0x28(%%rax) \n\ + movq %%r8, 0x30(%%rax) \n\ + movq %%r9, 0x38(%%rax) \n\ + movq %%r10, 0x40(%%rax) \n\ + movq %%r11, 0x48(%%rax) \n\ + movq %%rbp, 0x50(%%rax) \n\ + movq %%rsp, 0x58(%%rax) \n\ movl %[SIG], %%ecx # thissig to 1st arg reg \n\ - movq %[SI], %%rdx # &thissi to 2nd arg reg \n\ + leaq %[SI], %%rdx # &thissi to 2nd arg reg \n\ movq %[CTX], %%r8 # thiscontext to 3rd arg reg \n\ - movq %[FUNC], %%rax # thisfunc to rax \n\ - movq %%r9, %%rsp # Move alt stack into rsp \n\ - xorq %%rbp, %%rbp # Set rbp to 0 \n\ - subq $0x20, %%rsp # Setup shadow space \n\ - call *%%rax # Call thisfunc \n\ - addq $0x20, %%rsp # Revert shadow space \n\ - movq %%rsp, %%r9 # Restore clobbered regs \n\ - movq 0x38(%%r9), %%rsp \n\ - movq 0x30(%%r9), %%rbp \n\ - movq 0x28(%%r9), %%r11 \n\ - movq 0x20(%%r9), %%r10 \n\ - movq 0x18(%%r9), %%r8 \n\ - movq 0x10(%%r9), %%rdx \n\ - movq 0x8(%%r9), %%rcx \n\ - movq (%%r9), %%rax \n\ - popq %%r9 \n" + movq %[FUNC], %%r9 # thisfunc to r9 \n\ + movq %%rax, %%rsp # Move alt stack into rsp \n\ + call *%%r9 # Call thisfunc \n\ + movq %%rsp, %%rax # Restore clobbered regs \n\ + movq 0x58(%%rax), %%rsp \n\ + movq 0x50(%%rax), %%rbp \n\ + movq 0x48(%%rax), %%r11 \n\ + movq 0x40(%%rax), %%r10 \n\ + movq 0x38(%%rax), %%r9 \n\ + movq 0x30(%%rax), %%r8 \n\ + movq 0x28(%%rax), %%rdx \n\ + movq 0x20(%%rax), %%rcx \n" : : [NEW_SP] "o" (new_sp), [SIG] "o" (thissig), - [SI] "p" (&thissi), + [SI] "o" (thissi), [CTX] "o" (thiscontext), [FUNC] "o" (thisfunc) : "memory"); #else - /* Clobbered regs: eax, ecx, edx, ebp, esp */ + /* Clobbered regs: ecx, edx, ebp, esp */ __asm__ ("\n\ - push %%ecx # Push ecx on orig stack \n\ - movl %[NEW_SP], %%ecx # Load alt stack into ecx \n\ - subl $28, %%ecx # Make room on alt stack for \n\ + movl %[NEW_SP], %%eax # Load alt stack into eax \n\ + subl $28, %%eax # Make room on alt stack for \n\ # clobbered regs and args to \n\ # signal handler \n\ - movl %%eax, 12(%%ecx) # Save other clobbered regs \n\ - movl %%edx, 16(%%ecx) \n\ - movl %%ebp, 20(%%ecx) \n\ - movl %%esp, 24(%%ecx) \n\ - movl %[SIG], %%edx # thissig to 1st arg slot \n\ - movl %%edx, (%%ecx) \n\ - movl %[SI], %%edx # &thissi to 2nd arg slot \n\ - movl %%edx, 4(%%ecx) \n\ - movl %[CTX], %%edx # thiscontext to 3rd arg slot\n\ - movl %%edx, 8(%%ecx) \n\ - movl %[FUNC], %%eax # thisfunc to eax \n\ - movl %%ecx, %%esp # Move alt stack into esp \n\ - xorl %%ebp, %%ebp # Set ebp to 0 \n\ - call *%%eax # Call thisfunc \n\ - movl %%esp, %%ecx # Restore clobbered regs \n\ - movl 24(%%ecx), %%esp \n\ - movl 20(%%ecx), %%ebp \n\ - movl 16(%%ecx), %%edx \n\ - movl 12(%%ecx), %%eax \n\ - popl %%ecx \n" + movl %%ecx, 12(%%eax) # Save other clobbered regs \n\ + movl %%edx, 16(%%eax) \n\ + movl %%ebp, 20(%%eax) \n\ + movl %%esp, 24(%%eax) \n\ + movl %[SIG], %%ecx # thissig to 1st arg slot \n\ + movl %%ecx, (%%eax) \n\ + leal %[SI], %%ecx # &thissi to 2nd arg slot \n\ + movl %%ecx, 4(%%eax) \n\ + movl %[CTX], %%ecx # thiscontext to 3rd arg slot\n\ + movl %%ecx, 8(%%eax) \n\ + movl %[FUNC], %%ecx # thisfunc to ecx \n\ + movl %%eax, %%esp # Move alt stack into esp \n\ + call *%%ecx # Call thisfunc \n\ + movl %%esp, %%eax # Restore clobbered regs \n\ + movl 24(%%eax), %%esp \n\ + movl 20(%%eax), %%ebp \n\ + movl 16(%%eax), %%edx \n\ + movl 12(%%eax), %%eax \n" : : [NEW_SP] "o" (new_sp), [SIG] "o" (thissig), - [SI] "p" (&thissi), + [SI] "o" (thissi), [CTX] "o" (thiscontext), [FUNC] "o" (thisfunc) : "memory");
