使用gcore生成当前崩溃进程生成dump文件并定位错误
1. 源代码 main.cpp
#include <stdio.h>
#include <signal.h>
#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>
static void signal_handler(int);
static void dumpstack(void);
static void cleanup(void);
void init_signals(void);
void panic(const char *, ...);
struct sigaction sigact;
char *progname;
int main(int argc, char **argv) {
char *s;
progname = *(argv);
system("ulimit -c");
atexit(cleanup);
init_signals();
printf("About to seg fault by assigning zero to *s\n");
*s = 0;
sigemptyset(&sigact.sa_mask);
return 0;
}
void init_signals(void) {
sigact.sa_handler = signal_handler;
sigemptyset(&sigact.sa_mask);
sigact.sa_flags = 0;
sigaction(SIGINT, &sigact, (struct sigaction *)NULL);
sigaddset(&sigact.sa_mask, SIGSEGV);
sigaction(SIGSEGV, &sigact, (struct sigaction *)NULL);
sigaddset(&sigact.sa_mask, SIGBUS);
sigaction(SIGBUS, &sigact, (struct sigaction *)NULL);
sigaddset(&sigact.sa_mask, SIGQUIT);
sigaction(SIGQUIT, &sigact, (struct sigaction *)NULL);
sigaddset(&sigact.sa_mask, SIGHUP);
sigaction(SIGHUP, &sigact, (struct sigaction *)NULL);
sigaddset(&sigact.sa_mask, SIGKILL);
sigaction(SIGKILL, &sigact, (struct sigaction *)NULL);
}
static void signal_handler(int sig) {
if (sig == SIGHUP) panic("FATAL: Program hanged up\n");
if (sig == SIGSEGV || sig == SIGBUS){
dumpstack();
panic("FATAL: %s Fault. Logged StackTrace\n", (sig == SIGSEGV) ? "Segmentation" : ((sig == SIGBUS) ? "Bus" : "Unknown"));
}
if (sig == SIGQUIT) panic("QUIT signal ended program\n");
if (sig == SIGKILL) panic("KILL signal ended program\n");
if (sig == SIGINT) ;
}
void panic(const char *fmt, ...) {
char buf[50];
va_list argptr;
va_start(argptr, fmt);
vsprintf(buf, fmt, argptr);
va_end(argptr);
fprintf(stderr, buf);
exit(-1);
}
static void dumpstack(void) {
char dbx[160];
printf("pid=%d\n", getpid());
//sprintf(dbx, "sudo gdb -p %d ", getpid());
sprintf(dbx, "sudo gcore %d ", getpid());
system(dbx);
return;
}
void cleanup(void) {
sigemptyset(&sigact.sa_mask);
}2.编译生成文件
g++ -g main.cpp -o a.out
3.运行程序
程序异常，自动打开gdb调试当前进程，在gdb输入指令: generate-core-file
将在程序目录下生成一个dump文件。
4. 定位错误
在终端运行: gdb a.out core.9762
其中core.9762是步骤3中生成的转储文件，在gdb中执行 r 指令，将自动定位到出错点。
