hush: report [v]fork failures

hush: more correct handling of piping
config: add CONFIG_NOMMU

4 files changed, 53 insertions, 37 deletions

diff --git a/Config.in b/Config.in
index fa48ddd63..d2bb63200 100644
--- a/Config.in
+++ b/Config.in
@@ -280,6 +280,17 @@ config STATIC
 
           Most people will leave this set to 'N'.
 
+config NOMMU
+        bool "Force NOMMU build"
+        default n
+        help
+          Busybox tries to detect whether architecture it is being
+          built against supports MMU or not. If this detection fails,
+          or if you want to build NOMMU version of busybox for testing,
+          you may force NOMMU build here.
+
+          Most people will leave this set to 'N'.
+
 config BUILD_LIBBUSYBOX
         bool "Build shared libbusybox"
         default n
diff --git a/TODO_config_nommu b/TODO_config_nommu
index a4cc344ab..81db6db2f 100644
--- a/TODO_config_nommu
+++ b/TODO_config_nommu
@@ -1,7 +1,7 @@
 #
 # Automatically generated make config: don't edit
-# Busybox version: 1.9.0.svn
-# Mon Dec 24 14:21:28 2007
+# Busybox version: 1.10.0.svn
+# Tue Jan  8 20:29:22 2008
 #
 CONFIG_HAVE_DOT_CONFIG=y
 
@@ -39,6 +39,7 @@ CONFIG_FEATURE_HAVE_RPC=y
 # Build Options
 #
 # CONFIG_STATIC is not set
+CONFIG_NOMMU=y
 # CONFIG_BUILD_LIBBUSYBOX is not set
 # CONFIG_FEATURE_INDIVIDUAL is not set
 # CONFIG_FEATURE_SHARED_BUSYBOX is not set
@@ -222,6 +223,7 @@ CONFIG_FEATURE_STAT_FORMAT=y
 CONFIG_STTY=y
 CONFIG_SUM=y
 CONFIG_SYNC=y
+CONFIG_TAC=y
 CONFIG_TAIL=y
 CONFIG_FEATURE_FANCY_TAIL=y
 CONFIG_TEE=y
@@ -368,6 +370,8 @@ CONFIG_FEATURE_XARGS_SUPPORT_ZERO_TERM=y
 # CONFIG_INIT is not set
 # CONFIG_DEBUG_INIT is not set
 # CONFIG_FEATURE_USE_INITTAB is not set
+# CONFIG_FEATURE_KILL_REMOVED is not set
+CONFIG_FEATURE_KILL_DELAY=0
 # CONFIG_FEATURE_INIT_SCTTY is not set
 # CONFIG_FEATURE_INIT_SYSLOG is not set
 # CONFIG_FEATURE_EXTRA_QUIET is not set
@@ -679,6 +683,8 @@ CONFIG_FEATURE_PIDOF_OMIT=y
 CONFIG_PKILL=y
 CONFIG_PS=y
 CONFIG_FEATURE_PS_WIDE=y
+CONFIG_FEATURE_PS_TIME=y
+# CONFIG_FEATURE_PS_UNUSUAL_SYSTEMS is not set
 CONFIG_RENICE=y
 CONFIG_BB_SYSCTL=y
 CONFIG_TOP=y
@@ -713,7 +719,7 @@ CONFIG_FEATURE_SH_IS_NONE=y
 # CONFIG_ASH_EXPAND_PRMT is not set
 CONFIG_HUSH=y
 CONFIG_HUSH_HELP=y
-# CONFIG_HUSH_INTERACTIVE is not set
+CONFIG_HUSH_INTERACTIVE=y
 # CONFIG_HUSH_JOB is not set
 CONFIG_HUSH_TICK=y
 CONFIG_HUSH_IF=y
diff --git a/include/platform.h b/include/platform.h
index edb0f8ab0..4c38c6ae4 100644
--- a/include/platform.h
+++ b/include/platform.h
@@ -231,8 +231,9 @@ typedef unsigned smalluint;
  * for a mmu-less system; the user should pass EXTRA_CFLAGS="-DBB_NOMMU"
  * on his own.
  */
-#if defined __UCLIBC__ && __UCLIBC_MAJOR__ >= 0 && __UCLIBC_MINOR__ >= 9 && \
-    __UCLIBC_SUBLEVEL__ > 28 && !defined __ARCH_USE_MMU__
+#if ENABLE_NOMMU || \
+    (defined __UCLIBC__ && __UCLIBC_MAJOR__ >= 0 && __UCLIBC_MINOR__ >= 9 && \
+    __UCLIBC_SUBLEVEL__ > 28 && !defined __ARCH_USE_MMU__)
 #define BB_MMU 0
 #define BB_NOMMU 1
 #define USE_FOR_NOMMU(...) __VA_ARGS__
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;
 }