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hush: report [v]fork failures

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hush: more correct handling of piping
config: add CONFIG_NOMMU
This commit is contained in:
Denis Vlasenko
2008-01-08 20:32:12 +00:00
parent 474d1c57c8
commit d2c450ce81
4 changed files with 53 additions and 37 deletions
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62
shell/hush.c
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@ -1777,8 +1777,8 @@ static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
static int run_pipe_real(struct pipe *pi)
{
int i;
int nextin, nextout;
int pipefds[2]; /* pipefds[0] is for reading */
int nextin;
int pipefds[2]; /* pipefds[0] is for reading */
struct child_prog *child;
const struct built_in_command *x;
char *p;
@ -1789,7 +1789,6 @@ static int run_pipe_real(struct pipe *pi)
debug_printf_exec("run_pipe_real start: single_fg=%d\n", single_fg);
nextin = 0;
#if ENABLE_HUSH_JOB
pi->pgrp = -1;
#endif
@ -1874,13 +1873,14 @@ static int run_pipe_real(struct pipe *pi)
#endif
}
/* Going to fork a child per each pipe member */
pi->running_progs = 0;
/* Disable job control signals for shell (parent) and
* for initial child code after fork */
set_jobctrl_sighandler(SIG_IGN);
/* Going to fork a child per each pipe member */
pi->running_progs = 0;
nextin = 0;
for (i = 0; i < pi->num_progs; i++) {
child = &(pi->progs[i]);
if (child->argv)
@ -1889,24 +1889,20 @@ static int run_pipe_real(struct pipe *pi)
debug_printf_exec(": pipe member with no argv\n");
/* pipes are inserted between pairs of commands */
if ((i + 1) < pi->num_progs) {
pipe(pipefds);
nextout = pipefds[1];
} else {
nextout = 1;
pipefds[0] = -1;
}
pipefds[0] = 0;
pipefds[1] = 1;
if ((i + 1) < pi->num_progs)
xpipe(pipefds);
/* XXX test for failed fork()? */
#if BB_MMU
child->pid = fork();
#else
child->pid = vfork();
#endif
if (!child->pid) { /* child */
#if ENABLE_HUSH_JOB
/* Every child adds itself to new process group
* with pgid == pid of first child in pipe */
#if ENABLE_HUSH_JOB
if (run_list_level == 1 && interactive_fd) {
/* Don't do pgrp restore anymore on fatal signals */
set_fatal_sighandler(SIG_DFL);
@ -1919,12 +1915,10 @@ static int run_pipe_real(struct pipe *pi)
}
}
#endif
/* in non-interactive case fatal sigs are already SIG_DFL */
xmove_fd(nextin, 0);
xmove_fd(nextout, 1);
if (pipefds[0] != -1) {
close(pipefds[0]); /* opposite end of our output pipe */
}
xmove_fd(pipefds[1], 1); /* write end */
if (pipefds[0] > 1)
close(pipefds[0]); /* read end */
/* Like bash, explicit redirects override pipes,
* and the pipe fd is available for dup'ing. */
setup_redirects(child, NULL);
@ -1933,25 +1927,29 @@ static int run_pipe_real(struct pipe *pi)
set_jobctrl_sighandler(SIG_DFL);
set_misc_sighandler(SIG_DFL);
signal(SIGCHLD, SIG_DFL);
pseudo_exec(child);
pseudo_exec(child); /* does not return */
}
pi->running_progs++;
if (child->pid < 0) { /* [v]fork failed */
/* Clearly indicate, was it fork or vfork */
bb_perror_msg(BB_MMU ? "cannot fork" : "cannot vfork");
} else {
pi->running_progs++;
#if ENABLE_HUSH_JOB
/* Second and next children need to know pid of first one */
if (pi->pgrp < 0)
pi->pgrp = child->pid;
/* Second and next children need to know pid of first one */
if (pi->pgrp < 0)
pi->pgrp = child->pid;
#endif
if (nextin != 0)
close(nextin);
if (nextout != 1)
close(nextout);
}
/* If there isn't another process, nextin is garbage
but it doesn't matter */
if (i)
close(nextin);
if ((i + 1) < pi->num_progs)
close(pipefds[1]); /* write end */
/* Pass read (output) pipe end to next iteration */
nextin = pipefds[0];
}
debug_printf_exec("run_pipe_real return -1\n");
return -1;
}