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Diffstat (limited to 'shell/hush.c')
-rw-r--r--shell/hush.c62
1 files changed, 30 insertions, 32 deletions
diff --git a/shell/hush.c b/shell/hush.c
index b08fe10b6..9dc85d0ba 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -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;
}