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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
This commit is contained in:
Russ Cox 2011-02-23 14:47:42 -05:00
parent 4b376ef328
commit 690291a2c0
14 changed files with 120 additions and 87 deletions

View File

@ -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);
}

View File

@ -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)

View File

@ -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);
}

View File

@ -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

View File

@ -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);
}

View File

@ -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)

View File

@ -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);
}

View File

@ -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

View File

@ -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);
}

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@ -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)

View File

@ -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);
}

View File

@ -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

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@ -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);
}

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@ -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