void print_ucontext(ucontext_t *a_uc, int fd)
{
unw_cursor_t cursor;
unw_context_t *uc=(unw_context_t *)(a_uc);
unw_word_t ip, sp;
static char symname[10000];
static char cxx_name[102400];
static char outbuf[102400];
#define uc_out(x, ...) \
do {\
int len = snprintf(outbuf, sizeof(outbuf)-1, x "\n", ##__VA_ARGS__);\
if (len > (int) sizeof(outbuf)) len = sizeof(outbuf); \
write(fd, outbuf, len);\
} while(0) \
for(int i = 0; i < (int) NGREG; ++i) {
uc_out("reg[%02d:%s]=\t0x" REGFORMAT, i, g_regs_name[i], uc->uc_mcontext.gregs[i]);
}
uc_out("Stack trace:");
int ret = unw_init_local(&cursor, uc);
do {
if (ret) break;
ret = unw_get_reg(&cursor, UNW_REG_IP, &ip);
ret = unw_get_reg(&cursor, UNW_REG_SP, &sp);
ret = unw_get_proc_name(&cursor, symname, sizeof(symname), NULL);
size_t name_len = sizeof(cxx_name);
int status = 0;
__cxa_demangle(symname, cxx_name, &name_len, &status);
char *pname = symname;
if (status == 0)
pname = cxx_name;
uc_out("%s: ip: %lx, sp: %lx", pname, (long) ip, (long) sp);
} while (unw_step(&cursor) > 0);
uc_out("End of stack trace.");
}
static void signal_segv(int signum, siginfo_t* info, void*ptr) {
//if(info->si_signo == SIGSEGV)
// _exit (-1);
static const char *si_codes[3] = {"", "SEGV_MAPERR", "SEGV_ACCERR"};
int i, f = 0;
ucontext_t *ucontext = (ucontext_t*)ptr;
Dl_info dlinfo;
void **bp = 0;
void *ip = 0;
/*
sigsegv_outp("Segmentation Fault!");
sigsegv_outp("info.si_signo = %d", signum);
sigsegv_outp("info.si_errno = %d", info->si_errno);
sigsegv_outp("info.si_code = %d (%s)", info->si_code, si_codes[info->si_code]);
sigsegv_outp("info.si_addr = %p", info->si_addr);
for(i = 0; i < NGREG; i++)
sigsegv_outp("reg[%02d] = 0x" REGFORMAT, i, ucontext->uc_mcontext.gregs[i]);
*/
#ifndef SIGSEGV_NOSTACK
ip = (void*)ucontext->uc_mcontext.gregs[REG_EIP];
bp = (void**)ucontext->uc_mcontext.gregs[REG_EBP];
sigsegv_outp("Stack trace:");
i = 10;
while(bp && ip && i) {
i--;
if(!dladdr(ip, &dlinfo))
break;
const char *symname = dlinfo.dli_sname;
#ifndef NO_CPP_DEMANGLE
int status;
char * tmp = __cxa_demangle(symname, NULL, 0, &status);
if (status == 0 && tmp)
symname = tmp;
#endif
sigsegv_outp("% 2d: %p <%s+%lu> (%s)",
++f,
ip,
symname,
(unsigned long)ip - (unsigned long)dlinfo.dli_saddr,
dlinfo.dli_fname);
#ifndef NO_CPP_DEMANGLE
if (tmp)
free(tmp);
#endif
if(dlinfo.dli_sname && !strcmp(dlinfo.dli_sname, "main"))
break;
ip = bp[1];
bp = (void**)bp[0];
}
sigsegv_outp("End of stack trace.");
#else
sigsegv_outp("Not printing stack strace.");
#endif
if(info->si_signo == SIGSEGV)
_exit (-1);
}
