From 690291a2c008ec4adf754a394437f1e9f6d46aba Mon Sep 17 00:00:00 2001 From: Russ Cox Date: Wed, 23 Feb 2011 14:47:42 -0500 Subject: [PATCH] runtime: pass to signal handler value of g at time of signal The existing code assumed that signals only arrived while executing on the goroutine stack (g == m->curg), not while executing on the scheduler stack (g == m->g0). Most of the signal handling trampolines correctly saved and restored g already, but the sighandler C code did not have access to it. Some rewriting of assembly to make the various implementations as similar as possible. Will need to change Windows too but I don't understand how sigtramp gets called there. R=r CC=golang-dev https://golang.org/cl/4203042 --- src/pkg/runtime/darwin/386/signal.c | 9 +++--- src/pkg/runtime/darwin/386/sys.s | 29 +++++++++--------- src/pkg/runtime/darwin/amd64/signal.c | 9 +++--- src/pkg/runtime/darwin/amd64/sys.s | 19 +++++++----- src/pkg/runtime/freebsd/386/signal.c | 9 +++--- src/pkg/runtime/freebsd/386/sys.s | 42 +++++++++++++++----------- src/pkg/runtime/freebsd/amd64/signal.c | 9 +++--- src/pkg/runtime/freebsd/amd64/sys.s | 24 ++++++++++++--- src/pkg/runtime/linux/386/signal.c | 9 +++--- src/pkg/runtime/linux/386/sys.s | 7 +++-- src/pkg/runtime/linux/amd64/signal.c | 9 +++--- src/pkg/runtime/linux/amd64/sys.s | 10 +++--- src/pkg/runtime/linux/arm/signal.c | 9 +++--- src/pkg/runtime/linux/arm/sys.s | 13 ++++++++ 14 files changed, 120 insertions(+), 87 deletions(-) diff --git a/src/pkg/runtime/darwin/386/signal.c b/src/pkg/runtime/darwin/386/signal.c index 33f47d44f9..dd3050f033 100644 --- a/src/pkg/runtime/darwin/386/signal.c +++ b/src/pkg/runtime/darwin/386/signal.c @@ -34,20 +34,19 @@ runtime·signame(int32 sig) } void -runtime·sighandler(int32 sig, Siginfo *info, void *context) +runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp) { Ucontext *uc; Mcontext *mc; Regs *r; uintptr *sp; - G *gp; byte *pc; uc = context; mc = uc->uc_mcontext; r = &mc->ss; - if((gp = m->curg) != nil && (runtime·sigtab[sig].flags & SigPanic)) { + if(gp != nil && (runtime·sigtab[sig].flags & SigPanic)) { // Work around Leopard bug that doesn't set FPE_INTDIV. // Look at instruction to see if it is a divide. // Not necessary in Snow Leopard (si_code will be != 0). @@ -103,8 +102,8 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context) runtime·printf("\n"); if(runtime·gotraceback()){ - runtime·traceback((void*)r->eip, (void*)r->esp, 0, m->curg); - runtime·tracebackothers(m->curg); + runtime·traceback((void*)r->eip, (void*)r->esp, 0, gp); + runtime·tracebackothers(gp); runtime·dumpregs(r); } diff --git a/src/pkg/runtime/darwin/386/sys.s b/src/pkg/runtime/darwin/386/sys.s index 7961e369c3..9d2caca0a1 100644 --- a/src/pkg/runtime/darwin/386/sys.s +++ b/src/pkg/runtime/darwin/386/sys.s @@ -80,33 +80,34 @@ TEXT runtime·sigtramp(SB),7,$40 get_tls(CX) // save g - MOVL g(CX), BP - MOVL BP, 20(SP) + MOVL g(CX), DI + MOVL DI, 20(SP) // g = m->gsignal MOVL m(CX), BP MOVL m_gsignal(BP), BP MOVL BP, g(CX) - MOVL handler+0(FP), DI - // 4(FP) is sigstyle - MOVL signo+8(FP), AX - MOVL siginfo+12(FP), BX - MOVL context+16(FP), CX - - MOVL AX, 0(SP) + // copy arguments to sighandler + MOVL sig+8(FP), BX + MOVL BX, 0(SP) + MOVL info+12(FP), BX MOVL BX, 4(SP) - MOVL CX, 8(SP) - CALL DI + MOVL context+16(FP), BX + MOVL BX, 8(SP) + MOVL DI, 12(SP) + + MOVL handler+0(FP), BX + CALL BX // restore g get_tls(CX) - MOVL 20(SP), BP - MOVL BP, g(CX) + MOVL 20(SP), DI + MOVL DI, g(CX) + // call sigreturn MOVL context+16(FP), CX MOVL style+4(FP), BX - MOVL $0, 0(SP) // "caller PC" - ignored MOVL CX, 4(SP) MOVL BX, 8(SP) diff --git a/src/pkg/runtime/darwin/amd64/signal.c b/src/pkg/runtime/darwin/amd64/signal.c index 948b6c9c20..d12b12f3e6 100644 --- a/src/pkg/runtime/darwin/amd64/signal.c +++ b/src/pkg/runtime/darwin/amd64/signal.c @@ -42,12 +42,11 @@ runtime·signame(int32 sig) } void -runtime·sighandler(int32 sig, Siginfo *info, void *context) +runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp) { Ucontext *uc; Mcontext *mc; Regs *r; - G *gp; uintptr *sp; byte *pc; @@ -55,7 +54,7 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context) mc = uc->uc_mcontext; r = &mc->ss; - if((gp = m->curg) != nil && (runtime·sigtab[sig].flags & SigPanic)) { + if(gp != nil && (runtime·sigtab[sig].flags & SigPanic)) { // Work around Leopard bug that doesn't set FPE_INTDIV. // Look at instruction to see if it is a divide. // Not necessary in Snow Leopard (si_code will be != 0). @@ -113,8 +112,8 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context) runtime·printf("\n"); if(runtime·gotraceback()){ - runtime·traceback((void*)r->rip, (void*)r->rsp, 0, g); - runtime·tracebackothers(g); + runtime·traceback((void*)r->rip, (void*)r->rsp, 0, gp); + runtime·tracebackothers(gp); runtime·dumpregs(r); } diff --git a/src/pkg/runtime/darwin/amd64/sys.s b/src/pkg/runtime/darwin/amd64/sys.s index bc970156a3..4f9e0d77a5 100644 --- a/src/pkg/runtime/darwin/amd64/sys.s +++ b/src/pkg/runtime/darwin/amd64/sys.s @@ -66,8 +66,8 @@ TEXT runtime·sigtramp(SB),7,$64 get_tls(BX) // save g - MOVQ g(BX), BP - MOVQ BP, 40(SP) + MOVQ g(BX), R10 + MOVQ R10, 48(SP) // g = m->gsignal MOVQ m(BX), BP @@ -77,18 +77,21 @@ TEXT runtime·sigtramp(SB),7,$64 MOVL DX, 0(SP) MOVQ CX, 8(SP) MOVQ R8, 16(SP) - MOVQ R8, 24(SP) // save ucontext - MOVQ SI, 32(SP) // save infostyle + MOVQ R10, 24(SP) + + MOVQ R8, 32(SP) // save ucontext + MOVQ SI, 40(SP) // save infostyle CALL DI // restore g get_tls(BX) - MOVQ 40(SP), BP - MOVQ BP, g(BX) + MOVQ 48(SP), R10 + MOVQ R10, g(BX) + // call sigreturn MOVL $(0x2000000+184), AX // sigreturn(ucontext, infostyle) - MOVQ 24(SP), DI // saved ucontext - MOVQ 32(SP), SI // saved infostyle + MOVQ 32(SP), DI // saved ucontext + MOVQ 40(SP), SI // saved infostyle SYSCALL INT $3 // not reached diff --git a/src/pkg/runtime/freebsd/386/signal.c b/src/pkg/runtime/freebsd/386/signal.c index ddb11fc3ba..bf40c8bd02 100644 --- a/src/pkg/runtime/freebsd/386/signal.c +++ b/src/pkg/runtime/freebsd/386/signal.c @@ -45,17 +45,16 @@ runtime·signame(int32 sig) } void -runtime·sighandler(int32 sig, Siginfo* info, void* context) +runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp) { Ucontext *uc; Mcontext *r; - G *gp; uintptr *sp; uc = context; r = &uc->uc_mcontext; - if((gp = m->curg) != nil && (runtime·sigtab[sig].flags & SigPanic)) { + if(gp != nil && (runtime·sigtab[sig].flags & SigPanic)) { // Make it look like a call to the signal func. // Have to pass arguments out of band since // augmenting the stack frame would break @@ -99,8 +98,8 @@ runtime·sighandler(int32 sig, Siginfo* info, void* context) runtime·printf("\n"); if(runtime·gotraceback()){ - runtime·traceback((void*)r->mc_eip, (void*)r->mc_esp, 0, m->curg); - runtime·tracebackothers(m->curg); + runtime·traceback((void*)r->mc_eip, (void*)r->mc_esp, 0, gp); + runtime·tracebackothers(gp); runtime·dumpregs(r); } diff --git a/src/pkg/runtime/freebsd/386/sys.s b/src/pkg/runtime/freebsd/386/sys.s index 7110e6924e..60c189bf83 100644 --- a/src/pkg/runtime/freebsd/386/sys.s +++ b/src/pkg/runtime/freebsd/386/sys.s @@ -111,30 +111,36 @@ TEXT runtime·sigaction(SB),7,$-4 CALL runtime·notok(SB) RET -TEXT runtime·sigtramp(SB),7,$40 +TEXT runtime·sigtramp(SB),7,$44 + get_tls(CX) + + // save g + MOVL g(CX), DI + MOVL DI, 20(SP) + // g = m->gsignal - get_tls(DX) - MOVL m(DX), BP - MOVL m_gsignal(BP), BP - MOVL BP, g(DX) + MOVL m(CX), BX + MOVL m_gsignal(BX), BX + MOVL BX, g(CX) - MOVL signo+0(FP), AX - MOVL siginfo+4(FP), BX - MOVL context+8(FP), CX - - MOVL AX, 0(SP) + // copy arguments for call to sighandler + MOVL signo+0(FP), BX + MOVL BX, 0(SP) + MOVL info+4(FP), BX MOVL BX, 4(SP) - MOVL CX, 8(SP) + MOVL context+8(FP), BX + MOVL BX, 8(SP) + MOVL DI, 12(SP) + CALL runtime·sighandler(SB) - // g = m->curg - get_tls(DX) - MOVL m(DX), BP - MOVL m_curg(BP), BP - MOVL BP, g(DX) - + // restore g + get_tls(CX) + MOVL 20(SP), BX + MOVL BX, g(CX) + + // call sigreturn MOVL context+8(FP), AX - MOVL $0, 0(SP) // syscall gap MOVL AX, 4(SP) MOVL $417, AX // sigreturn(ucontext) diff --git a/src/pkg/runtime/freebsd/amd64/signal.c b/src/pkg/runtime/freebsd/amd64/signal.c index 9f873d276b..b2313fad32 100644 --- a/src/pkg/runtime/freebsd/amd64/signal.c +++ b/src/pkg/runtime/freebsd/amd64/signal.c @@ -53,17 +53,16 @@ runtime·signame(int32 sig) } void -runtime·sighandler(int32 sig, Siginfo* info, void* context) +runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp) { Ucontext *uc; Mcontext *r; - G *gp; uintptr *sp; uc = context; r = &uc->uc_mcontext; - if((gp = m->curg) != nil && (runtime·sigtab[sig].flags & SigPanic)) { + if(gp != nil && (runtime·sigtab[sig].flags & SigPanic)) { // Make it look like a call to the signal func. // Have to pass arguments out of band since // augmenting the stack frame would break @@ -107,8 +106,8 @@ runtime·sighandler(int32 sig, Siginfo* info, void* context) runtime·printf("\n"); if(runtime·gotraceback()){ - runtime·traceback((void*)r->mc_rip, (void*)r->mc_rsp, 0, g); - runtime·tracebackothers(g); + runtime·traceback((void*)r->mc_rip, (void*)r->mc_rsp, 0, gp); + runtime·tracebackothers(gp); runtime·dumpregs(r); } diff --git a/src/pkg/runtime/freebsd/amd64/sys.s b/src/pkg/runtime/freebsd/amd64/sys.s index b9cf3832dd..d986e9ac07 100644 --- a/src/pkg/runtime/freebsd/amd64/sys.s +++ b/src/pkg/runtime/freebsd/amd64/sys.s @@ -90,15 +90,29 @@ TEXT runtime·sigaction(SB),7,$-8 CALL runtime·notok(SB) RET -TEXT runtime·sigtramp(SB),7,$24-16 - get_tls(CX) - MOVQ m(CX), AX - MOVQ m_gsignal(AX), AX - MOVQ AX, g(CX) +TEXT runtime·sigtramp(SB),7,$64 + get_tls(BX) + + // save g + MOVQ g(BX), R10 + MOVQ R10, 40(SP) + + // g = m->signal + MOVQ m(BX), BP + MOVQ m_gsignal(BP), BP + MOVQ BP, g(BX) + MOVQ DI, 0(SP) MOVQ SI, 8(SP) MOVQ DX, 16(SP) + MOVQ R10, 24(SP) + CALL runtime·sighandler(SB) + + // restore g + get_tls(BX) + MOVQ 40(SP), R10 + MOVQ R10, g(BX) RET TEXT runtime·mmap(SB),7,$0 diff --git a/src/pkg/runtime/linux/386/signal.c b/src/pkg/runtime/linux/386/signal.c index 9651a6f280..7f20d058b8 100644 --- a/src/pkg/runtime/linux/386/signal.c +++ b/src/pkg/runtime/linux/386/signal.c @@ -42,17 +42,16 @@ runtime·signame(int32 sig) } void -runtime·sighandler(int32 sig, Siginfo* info, void* context) +runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp) { Ucontext *uc; Sigcontext *r; uintptr *sp; - G *gp; uc = context; r = &uc->uc_mcontext; - if((gp = m->curg) != nil && (runtime·sigtab[sig].flags & SigPanic)) { + if(gp != nil && (runtime·sigtab[sig].flags & SigPanic)) { // Make it look like a call to the signal func. // Have to pass arguments out of band since // augmenting the stack frame would break @@ -96,8 +95,8 @@ runtime·sighandler(int32 sig, Siginfo* info, void* context) runtime·printf("\n"); if(runtime·gotraceback()){ - runtime·traceback((void*)r->eip, (void*)r->esp, 0, m->curg); - runtime·tracebackothers(m->curg); + runtime·traceback((void*)r->eip, (void*)r->esp, 0, gp); + runtime·tracebackothers(gp); runtime·dumpregs(r); } diff --git a/src/pkg/runtime/linux/386/sys.s b/src/pkg/runtime/linux/386/sys.s index a1505b0b06..a684371bea 100644 --- a/src/pkg/runtime/linux/386/sys.s +++ b/src/pkg/runtime/linux/386/sys.s @@ -56,12 +56,12 @@ TEXT runtime·rt_sigaction(SB),7,$0 INT $0x80 RET -TEXT runtime·sigtramp(SB),7,$40 +TEXT runtime·sigtramp(SB),7,$44 get_tls(CX) // save g - MOVL g(CX), BX - MOVL BX, 20(SP) + MOVL g(CX), DI + MOVL DI, 20(SP) // g = m->gsignal MOVL m(CX), BX @@ -75,6 +75,7 @@ TEXT runtime·sigtramp(SB),7,$40 MOVL BX, 4(SP) MOVL context+8(FP), BX MOVL BX, 8(SP) + MOVL DI, 12(SP) CALL runtime·sighandler(SB) diff --git a/src/pkg/runtime/linux/amd64/signal.c b/src/pkg/runtime/linux/amd64/signal.c index 9e501c96d8..462f9a74d7 100644 --- a/src/pkg/runtime/linux/amd64/signal.c +++ b/src/pkg/runtime/linux/amd64/signal.c @@ -50,19 +50,18 @@ runtime·signame(int32 sig) } void -runtime·sighandler(int32 sig, Siginfo* info, void* context) +runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp) { Ucontext *uc; Mcontext *mc; Sigcontext *r; uintptr *sp; - G *gp; uc = context; mc = &uc->uc_mcontext; r = (Sigcontext*)mc; // same layout, more conveient names - if((gp = m->curg) != nil && (runtime·sigtab[sig].flags & SigPanic)) { + if(gp != nil && (runtime·sigtab[sig].flags & SigPanic)) { // Make it look like a call to the signal func. // Have to pass arguments out of band since // augmenting the stack frame would break @@ -106,8 +105,8 @@ runtime·sighandler(int32 sig, Siginfo* info, void* context) runtime·printf("\n"); if(runtime·gotraceback()){ - runtime·traceback((void*)r->rip, (void*)r->rsp, 0, g); - runtime·tracebackothers(g); + runtime·traceback((void*)r->rip, (void*)r->rsp, 0, gp); + runtime·tracebackothers(gp); runtime·dumpregs(r); } diff --git a/src/pkg/runtime/linux/amd64/sys.s b/src/pkg/runtime/linux/amd64/sys.s index 170b659fc8..1bf734dc06 100644 --- a/src/pkg/runtime/linux/amd64/sys.s +++ b/src/pkg/runtime/linux/amd64/sys.s @@ -64,8 +64,8 @@ TEXT runtime·sigtramp(SB),7,$64 get_tls(BX) // save g - MOVQ g(BX), BP - MOVQ BP, 40(SP) + MOVQ g(BX), R10 + MOVQ R10, 40(SP) // g = m->gsignal MOVQ m(BX), BP @@ -75,12 +75,14 @@ TEXT runtime·sigtramp(SB),7,$64 MOVQ DI, 0(SP) MOVQ SI, 8(SP) MOVQ DX, 16(SP) + MOVQ R10, 24(SP) + CALL runtime·sighandler(SB) // restore g get_tls(BX) - MOVQ 40(SP), BP - MOVQ BP, g(BX) + MOVQ 40(SP), R10 + MOVQ R10, g(BX) RET TEXT runtime·sigignore(SB),7,$0 diff --git a/src/pkg/runtime/linux/arm/signal.c b/src/pkg/runtime/linux/arm/signal.c index 481bd13c62..843c40b683 100644 --- a/src/pkg/runtime/linux/arm/signal.c +++ b/src/pkg/runtime/linux/arm/signal.c @@ -50,16 +50,15 @@ runtime·signame(int32 sig) } void -runtime·sighandler(int32 sig, Siginfo *info, void *context) +runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp) { Ucontext *uc; Sigcontext *r; - G *gp; uc = context; r = &uc->uc_mcontext; - if((gp = m->curg) != nil && (runtime·sigtab[sig].flags & SigPanic)) { + if(gp != nil && (runtime·sigtab[sig].flags & SigPanic)) { // Make it look like a call to the signal func. // Have to pass arguments out of band since // augmenting the stack frame would break @@ -99,8 +98,8 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context) runtime·printf("\n"); if(runtime·gotraceback()){ - runtime·traceback((void*)r->arm_pc, (void*)r->arm_sp, (void*)r->arm_lr, m->curg); - runtime·tracebackothers(m->curg); + runtime·traceback((void*)r->arm_pc, (void*)r->arm_sp, (void*)r->arm_lr, gp); + runtime·tracebackothers(gp); runtime·printf("\n"); runtime·dumpregs(r); } diff --git a/src/pkg/runtime/linux/arm/sys.s b/src/pkg/runtime/linux/arm/sys.s index b25cf81aaa..6c222fc8aa 100644 --- a/src/pkg/runtime/linux/arm/sys.s +++ b/src/pkg/runtime/linux/arm/sys.s @@ -197,11 +197,24 @@ TEXT runtime·sigignore(SB),7,$0 RET TEXT runtime·sigtramp(SB),7,$24 + // save g + MOVW g, R3 + MOVW g, 20(R13) + + // g = m->gsignal MOVW m_gsignal(m), g + + // copy arguments for call to sighandler MOVW R0, 4(R13) MOVW R1, 8(R13) MOVW R2, 12(R13) + MOVW R3, 16(R13) + BL runtime·sighandler(SB) + + // restore g + MOVW 20(R13), g + RET TEXT runtime·rt_sigaction(SB),7,$0