diff options
Diffstat (limited to 'shell/hush.c')
| -rw-r--r-- | shell/hush.c | 62 |
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; } |