From: Justin Cinkelj <justin.cink...@xlab.si>
Committer: Nadav Har'El <n...@scylladb.com>
Branch: master
busybox ash: do not exit if command doesn't exist
0004 patch prevents poping up spurious error message 'command not found'
when running in ash say 'ls /'. It requires patch to osv_execve to be
applied - osv_execve should clear errno on success, and set errno on
failure.
0005 patch prevent ash exit when non-existent command is tried.
As @nyh suggested, symlink /usr/bin -> /usr/lib is added, so that
ash works without adding /usr/lib to PATH environ.
Signed-off-by: Justin Cinkelj <justin.cink...@xlab.si>
Message-Id: <20170818120212.5470-1-justin.cink...@xlab.si>
---
diff --git a/busybox/GET b/busybox/GET
--- a/busybox/GET
+++ b/busybox/GET
@@ -34,7 +34,10 @@ cat <<EOF > usr.manifest
/usr/lib/echo: ->/usr/lib/busybox
/usr/lib/ping: ->/usr/lib/busybox
#
+# Link /usr/bin (in ash's default PATH) to /usr/lib where we put the
executables
+/usr/bin: ->/usr/lib
+#
# test scripts
## /**: \${MODULE_DIR}/test-script/**
-EOF
\ No newline at end of file
+EOF
diff --git
a/busybox/patches/0004-OSv-ash-fix-command-not-found-error-message-when-com.patch
b/busybox/patches/0004-OSv-ash-fix-command-not-found-error-message-when-com.patch
---
a/busybox/patches/0004-OSv-ash-fix-command-not-found-error-message-when-com.patch
+++
b/busybox/patches/0004-OSv-ash-fix-command-not-found-error-message-when-com.patch
@@ -0,0 +1,39 @@
+From 1512e2b29f3d5c19d0735470d74c546bd15ed15a Mon Sep 17 00:00:00 2001
+From: Justin Cinkelj <justin.cink...@xlab.si>
+Date: Fri, 18 Aug 2017 07:01:58 +0200
+Subject: [PATCH 4/5] OSv ash: fix command not found error message when
command
+ was found
+
+Running simple 'ls' in ash showed directory content. But at the end,
+spurious error message 'command not found' was shown. This was due to
+errno not being cleared by osv_execve. This was fixed in osv_execve, now
+it clears errno on success, or sets it to meanigful value (currently
+always ENOENT).
+
+Signed-off-by: Justin Cinkelj <justin.cink...@xlab.si>
+---
+ shell/ash.c | 8 ++++----
+ 1 file changed, 4 insertions(+), 4 deletions(-)
+
+diff --git a/shell/ash.c b/shell/ash.c
+index bc16394..dc88bd8 100644
+--- a/shell/ash.c
++++ b/shell/ash.c
+@@ -7731,10 +7731,10 @@ tryexec(IF_FEATURE_SH_STANDALONE(int applet_no,)
char *cmd, char **argv, char **
+ int ret = 0;
+ pid_t ch_pid = -1;
+ ret = osv_execve(cmd, argv, envp, (long*)&ch_pid, -1);
+- //errno = 0; // osv_execve should clear errno on success
+- if(ret)
+- errno = ENOSYS;
+- osv_waittid(ch_pid, NULL, 0);
++ // osv_execve now clears errno on success, as expected by
caller.
++ if(ret == 0) {
++ osv_waittid(ch_pid, NULL, 0);
++ }
+ return;
+ }
+ #endif
+--
+2.9.4
+
diff --git
a/busybox/patches/0005-OSv-ash-do-not-exit-if-program-to-be-run-fails-to-st.patch
b/busybox/patches/0005-OSv-ash-do-not-exit-if-program-to-be-run-fails-to-st.patch
---
a/busybox/patches/0005-OSv-ash-do-not-exit-if-program-to-be-run-fails-to-st.patch
+++
b/busybox/patches/0005-OSv-ash-do-not-exit-if-program-to-be-run-fails-to-st.patch
@@ -0,0 +1,140 @@
+From 1009e202f7c1214e7ab6185782f1033506a634a8 Mon Sep 17 00:00:00 2001
+From: Justin Cinkelj <justin.cink...@xlab.si>
+Date: Fri, 18 Aug 2017 07:26:12 +0200
+Subject: [PATCH 5/5] OSv ash: do not exit if program to be run fails to
start
+
+If program to be started fails to start (executable file not found), ash
+should not return from its main loop, as this terminates shell.
+
+ash_main interceps exception from raise_exception, and exits because
+exception_type == EXEXIT. The exit is avoided if instead of returning from
+ash_main, code just continues with cmdloop(). Important detail - we have
+to first call popstackmark, and there re-execute setjmp, so that longjmp
+will work.
+
+As EXEXIT is used for both abnormal exit (exception handling, like
+file not found) and normal exit (entering 'exit' cmd into ash), this
+breaks 'exit' cmd. Thus we have to separete the two cases.
+This is done by replacing EXEXIT with:
+ - EXEXIT_CMD, when 'exit' was passed to ash interpreter.
+ - EXEXIT_VAR, for all other reasons.
+
+Signed-off-by: Justin Cinkelj <justin.cink...@xlab.si>
+---
+ shell/ash.c | 44 +++++++++++++++++++++++++++++++++++++-------
+ 1 file changed, 37 insertions(+), 7 deletions(-)
+
+diff --git a/shell/ash.c b/shell/ash.c
+index dc88bd8..d8111c0 100644
+--- a/shell/ash.c
++++ b/shell/ash.c
+@@ -324,7 +324,9 @@ struct globals_misc {
+ /* exceptions */
+ #define EXINT 0 /* SIGINT received */
+ #define EXERROR 1 /* a generic error */
+-#define EXEXIT 4 /* exit the shell */
++//#define EXEXIT 4 /* exit the shell */
++#define EXEXIT_CMD 4 /* exit the shell, due to exit command */
++#define EXEXIT_VAR 5 /* exit the shell, due to other reasons */
+
+ smallint isloginsh;
+ char nullstr[1]; /* zero length string */
+@@ -7831,7 +7833,7 @@ static void shellexec(char *prog, char **argv, const
char *path, int idx)
+ exitstatus = exerrno;
+ TRACE(("shellexec failed for %s, errno %d, suppress_int %d\n",
+ prog, e, suppress_int));
+- ash_msg_and_raise(EXEXIT, "%s: %s", prog, errmsg(e, "not found"));
++ ash_msg_and_raise(EXEXIT_VAR, "%s: %s", prog, errmsg(e, "not found"));
+ /* NOTREACHED */
+ }
+
+@@ -8850,9 +8852,9 @@ evaltree(union node *n, int flags)
+ dotrap();
+
+ if (checkexit & status)
+- raise_exception(EXEXIT);
++ raise_exception(EXEXIT_VAR);
+ if (flags & EV_EXIT)
+- raise_exception(EXEXIT);
++ raise_exception(EXEXIT_VAR);
+
+ TRACE(("leaving evaltree (no interrupts)\n"));
+ return exitstatus;
+@@ -12756,7 +12758,7 @@ exitcmd(int argc UNUSED_PARAM, char **argv)
+ return 0;
+ if (argv[1])
+ exitstatus = number(argv[1]);
+- raise_exception(EXEXIT);
++ raise_exception(EXEXIT_CMD);
+ /* NOTREACHED */
+ }
+
+@@ -13404,7 +13406,7 @@ exitshell(void)
+ status = exitstatus;
+ TRACE(("pid %d, exitshell(%d)\n", getpid(), status));
+ if (setjmp(loc.loc)) {
+- if (exception_type == EXEXIT)
++ if (exception_type == EXEXIT_CMD || exception_type ==
EXEXIT_VAR)
+ status = exitstatus;
+ goto out;
+ }
+@@ -13624,6 +13626,8 @@ int ash_main(int argc UNUSED_PARAM, char **argv)
+ line_input_state = new_line_input_t(FOR_SHELL | WITH_PATH_LOOKUP);
+ #endif
+ state = 0;
++do_setjmp:
++ // fprintf(stderr, "DBG BEFORE setjmp state=%d...\n", state);
fflush(stderr);
+ if (setjmp(jmploc.loc)) {
+ smallint e;
+ smallint s;
+@@ -13632,10 +13636,30 @@ int ash_main(int argc UNUSED_PARAM, char **argv)
+
+ e = exception_type;
+ s = state;
+- if (e == EXEXIT || s == 0 || iflag == 0 || shlvl) {
++ // fprintf(stderr, "DBG AFTER setjmp, ret=true e=%d state=%d iflag=%d
shlvl=%d\n", e,s,iflag,shlvl); fflush(stderr);
++ if (e == EXEXIT_CMD) {
++ // exit was explicitly requested, so do it.
++ // TODO - whas it requested in top level shell, or in
subshell/interpreted script?
++ // exit in called script should not terminate parent
shell.
+ exitshell();
+ return 0; // for OSv only
+ }
++ if (e == EXEXIT_VAR || s == 0 || iflag == 0 || shlvl) {
++ exitshell();
++ /*
++ After exception, we went out of cmdloop via longjmp.
++ In OSv, return would terminate the only thread we have
(while
++ in linux, it would terminate a subprocess).
++ Do not return, just let current thread continue, and
++ it will go back into cmdloop.
++
++ "let current thread continue" - this requires to
re-execute setjmp.
++ Then, we have to go into state4 (as s == 4) - we have to skip states
1,2,3.
++ */
++ popstackmark(&smark);
++ goto do_setjmp;
++
++ }
+ if (e == EXINT) {
+ newline_and_flush(stderr);
+ }
+@@ -13650,9 +13674,15 @@ int ash_main(int argc UNUSED_PARAM, char **argv)
+ goto state3;
+ goto state4;
+ }
++ // fprintf(stderr, "DBG AFTER setjmp, ret=false iflag=%d...\n", iflag);
fflush(stderr);
++
+ exception_handler = &jmploc;
+ rootpid = getpid();
+
++ if (state == 4)
++ goto state4; // OSv special case
++ assert(state == 0); // normal, initial execution path
++
+ init();
+ setstackmark(&smark);
+ procargs(argv);
+--
+2.9.4
+
diff --git a/busybox/test-script/cmd0.sh b/busybox/test-script/cmd0.sh
--- a/busybox/test-script/cmd0.sh
+++ b/busybox/test-script/cmd0.sh
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