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Diffstat (limited to '')
| -rw-r--r-- | src/ps/stacktrace.c | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/src/ps/stacktrace.c b/src/ps/stacktrace.c new file mode 100644 index 0000000..fdd2aa9 --- /dev/null +++ b/src/ps/stacktrace.c @@ -0,0 +1,191 @@ +/* + * stacktrace.c - ps debugging additions + * + * Gnu debugger stack trace code provided by Peter Mattis + * <petm@CSUA.Berkeley.EDU> on Thu, 2 Nov 1995 + * Modified for easy use by Albert Cahalan. + * + * Copyright © 2004-2023 Craig Small <csmall@dropbear.xyz> + * Copyright © 2011-2016 Jim Warner <james.warner@comcast.net + * Copyright © 1998-2004 Albert Cahalan + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <errno.h> +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> + +#include <sys/time.h> +#include <sys/types.h> +#include <sys/wait.h> + +#include "common.h" + +#define INTERACTIVE 0 +#define STACK_TRACE 1 + +char *stored_prog_name = "you forgot to set \"program\""; +static int stack_trace_done; + +/***********/ +static void debug_stop(char **args){ + execvp (args[0], args); + perror ("exec failed"); + _exit (0); +} + +/***********/ +static void stack_trace_sigchld(int signum){ + (void)signum; + stack_trace_done = 1; +} + +/************/ +static void stack_trace(char **args){ + pid_t pid; + int in_fd[2]; + int out_fd[2]; + fd_set fdset; + fd_set readset; + struct timeval tv; + int sel, index, state; + char buffer[256]; + char c; + + stack_trace_done = 0; + signal(SIGCHLD, stack_trace_sigchld); + + if((pipe (in_fd) == -1) || (pipe (out_fd) == -1)){ + perror ("could open pipe"); + _exit (0); + } + + pid = fork (); + if (pid == 0){ + close (0); dup (in_fd[0]); /* set the stdin to the in pipe */ + close (1); dup (out_fd[1]); /* set the stdout to the out pipe */ + close (2); dup (out_fd[1]); /* set the stderr to the out pipe */ + execvp (args[0], args); /* exec gdb */ + perror ("exec failed"); + _exit (0); + } else { + if(pid == (pid_t) -1){ + perror ("could not fork"); + _exit (0); + } + } + + FD_ZERO (&fdset); + FD_SET (out_fd[0], &fdset); + + write (in_fd[1], "backtrace\n", 10); + write (in_fd[1], "p x = 0\n", 8); + write (in_fd[1], "quit\n", 5); + + index = 0; + state = 0; + + for(;;){ + readset = fdset; + tv.tv_sec = 1; + tv.tv_usec = 0; + + sel = select (FD_SETSIZE, &readset, NULL, NULL, &tv); + if (sel == -1) break; + + if((sel > 0) && (FD_ISSET (out_fd[0], &readset))){ + if(read (out_fd[0], &c, 1)){ + switch(state){ + case 0: + if(c == '#'){ + state = 1; + index = 0; + buffer[index++] = c; + } + break; + case 1: + buffer[index++] = c; + if((c == '\n') || (c == '\r')){ + buffer[index] = 0; + fprintf (stderr, "%s", buffer); + state = 0; + index = 0; + } + break; + default: + break; + } + } + } + else if(stack_trace_done) break; + } + + close (in_fd[0]); + close (in_fd[1]); + close (out_fd[0]); + close (out_fd[1]); + _exit (0); +} + +/************/ +void debug(int method, char *prog_name){ + pid_t pid; + char buf[16]; + char *args[4] = { "gdb", NULL, NULL, NULL }; + int x; + + snprintf (buf, sizeof(buf), "%d", getpid ()); + + args[1] = prog_name; + args[2] = buf; + + pid = fork (); + if(pid == 0){ + switch (method){ + case INTERACTIVE: + fprintf (stderr, "debug_stop\n"); + debug_stop(args); + break; + case STACK_TRACE: + fprintf (stderr, "stack_trace\n"); + stack_trace(args); + break; + } + _exit(0); + } else if(pid == (pid_t) -1){ + perror ("could not fork"); + return; + } + + x = 1; + while(x); /* wait for debugger? */ +} + +#ifdef DEBUG +/************/ +static void stack_trace_sigsegv(int signum){ + (void)signum; + debug(STACK_TRACE, stored_prog_name); +} + +/************/ +void init_stack_trace(char *prog_name){ + stored_prog_name = prog_name; + signal(SIGSEGV, stack_trace_sigsegv); +} +#endif |