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// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
#include "runtime.h"
#include "defs.h"
#include "signals.h"
#include "os.h"
void
dumpregs(Sigcontext *r)
{
printf("rax %X\n", r->rax);
printf("rbx %X\n", r->rbx);
printf("rcx %X\n", r->rcx);
printf("rdx %X\n", r->rdx);
printf("rdi %X\n", r->rdi);
printf("rsi %X\n", r->rsi);
printf("rbp %X\n", r->rbp);
printf("rsp %X\n", r->rsp);
printf("r8 %X\n", r->r8 );
printf("r9 %X\n", r->r9 );
printf("r10 %X\n", r->r10);
printf("r11 %X\n", r->r11);
printf("r12 %X\n", r->r12);
printf("r13 %X\n", r->r13);
printf("r14 %X\n", r->r14);
printf("r15 %X\n", r->r15);
printf("rip %X\n", r->rip);
printf("rflags %X\n", r->eflags);
printf("cs %X\n", (uint64)r->cs);
printf("fs %X\n", (uint64)r->fs);
printf("gs %X\n", (uint64)r->gs);
}
/*
* This assembler routine takes the args from registers, puts them on the stack,
* and calls sighandler().
*/
extern void sigtramp(void);
extern void sigignore(void); // just returns
extern void sigreturn(void); // calls sigreturn
String
signame(int32 sig)
{
if(sig < 0 || sig >= NSIG)
return emptystring;
return gostringnocopy((byte*)sigtab[sig].name);
}
void
sighandler(int32 sig, Siginfo* info, void* context)
{
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 && (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
// the unwinding code.
gp->sig = sig;
gp->sigcode0 = info->si_code;
gp->sigcode1 = ((uintptr*)info)[2];
// Only push sigpanic if r->rip != 0.
// If r->rip == 0, probably panicked because of a
// call to a nil func. Not pushing that onto sp will
// make the trace look like a call to sigpanic instead.
// (Otherwise the trace will end at sigpanic and we
// won't get to see who faulted.)
if(r->rip != 0) {
sp = (uintptr*)r->rsp;
*--sp = r->rip;
r->rsp = (uintptr)sp;
}
r->rip = (uintptr)sigpanic;
return;
}
if(sigtab[sig].flags & SigQueue) {
if(sigsend(sig) || (sigtab[sig].flags & SigIgnore))
return;
exit(2); // SIGINT, SIGTERM, etc
}
if(panicking) // traceback already printed
exit(2);
panicking = 1;
if(sig < 0 || sig >= NSIG)
printf("Signal %d\n", sig);
else
printf("%s\n", sigtab[sig].name);
printf("PC=%X\n", r->rip);
printf("\n");
if(gotraceback()){
traceback((void*)r->rip, (void*)r->rsp, 0, (void*)r->r15);
tracebackothers((void*)r->r15);
dumpregs(r);
}
breakpoint();
exit(2);
}
void
signalstack(byte *p, int32 n)
{
Sigaltstack st;
st.ss_sp = p;
st.ss_size = n;
st.ss_flags = 0;
sigaltstack(&st, nil);
}
void
initsig(void)
{
static Sigaction sa;
siginit();
int32 i;
sa.sa_flags = SA_ONSTACK | SA_SIGINFO | SA_RESTORER;
sa.sa_mask = 0xFFFFFFFFFFFFFFFFULL;
sa.sa_restorer = (void*)sigreturn;
for(i = 0; i<NSIG; i++) {
if(sigtab[i].flags) {
if(sigtab[i].flags & (SigCatch | SigQueue))
sa.sa_handler = (void*)sigtramp;
else
sa.sa_handler = (void*)sigignore;
if(sigtab[i].flags & SigRestart)
sa.sa_flags |= SA_RESTART;
else
sa.sa_flags &= ~SA_RESTART;
rt_sigaction(i, &sa, nil, 8);
}
}
}
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