dash.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Denys Vlasenko <vda.linux@googlemail.com>
To: Martijn Dekker <martijn@inlv.org>,
	Herbert Xu <herbert@gondor.apana.org.au>
Cc: dash@vger.kernel.org, busybox <busybox@busybox.net>
Subject: Re: [BUG] Interactive (d)ash exits on assigning to readonly from 'command eval'
Date: Fri, 28 Oct 2016 15:55:59 +0200	[thread overview]
Message-ID: <CAK1hOcO25fYP71DRxk=Dga5UZ6=FfmdDHTj6AWNNGSu_J0B+Dw@mail.gmail.com> (raw)
In-Reply-To: <177dba07-fb53-4958-3455-e047c7f32ee6@inlv.org>

This will probably be mangled by gmail, but here is the proposed fix:

Date: Fri, 28 Oct 2016 15:43:50 +0200
Subject: [PATCH] ash: fix interactive "command eval STRING" exiting on errors.

This bug is also present in current dash

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
---
 shell/ash.c                             | 25 ++++++++++++++++++++++++-
 shell/ash_test/ash-vars/readonly1.right |  2 ++
 shell/ash_test/ash-vars/readonly1.tests |  7 +++++++
 3 files changed, 33 insertions(+), 1 deletion(-)
 create mode 100644 shell/ash_test/ash-vars/readonly1.right
 create mode 100755 shell/ash_test/ash-vars/readonly1.tests

diff --git a/shell/ash.c b/shell/ash.c
index 1ef02b8..fe11245 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -2180,6 +2180,7 @@ setvareq(char *s, int flags)
             if (flags & VNOSAVE)
                 free(s);
             n = vp->var_text;
+            exitstatus = 1;
             ash_msg_and_raise_error("%.*s: is read only",
strchrnul(n, '=') - n, n);
         }

@@ -9599,7 +9600,7 @@ evalcommand(union node *cmd, int flags)
         if (evalbltin(cmdentry.u.cmd, argc, argv, flags)) {
             if (exception_type == EXERROR && spclbltin <= 0) {
                 FORCE_INT_ON;
-                break;
+                goto readstatus;
             }
  raise:
             longjmp(exception_handler->loc, 1);
@@ -12280,6 +12281,10 @@ expandstr(const char *ps)
 static int
 evalstring(char *s, int flags)
 {
+    struct jmploc *volatile savehandler = exception_handler;
+    struct jmploc jmploc;
+    int ex;
+
     union node *n;
     struct stackmark smark;
     int status;
@@ -12289,6 +12294,19 @@ evalstring(char *s, int flags)
     setstackmark(&smark);

     status = 0;
+    /* On exception inside execution loop, we must popfile().
+     * Try interactively:
+     *    readonly a=a
+     *    command eval "a=b"  # throws "is read only" error
+     * "command BLTIN" is not supposed to abort (even in non-interactive use).
+     * But if we skip popfile(), we hit EOF in eval's string, and exit.
+     */
+    savehandler = exception_handler;
+    exception_handler = &jmploc;
+    ex = setjmp(jmploc.loc);
+    if (ex)
+        goto out;
+
     while ((n = parsecmd(0)) != NODE_EOF) {
         int i;

@@ -12299,10 +12317,15 @@ evalstring(char *s, int flags)
         if (evalskip)
             break;
     }
+ out:
     popstackmark(&smark);
     popfile();
     stunalloc(s);

+    exception_handler = savehandler;
+    if (ex)
+                longjmp(exception_handler->loc, ex);
+
     return status;
 }

diff --git a/shell/ash_test/ash-vars/readonly1.right
b/shell/ash_test/ash-vars/readonly1.right
new file mode 100644
index 0000000..2b363e3
--- /dev/null
+++ b/shell/ash_test/ash-vars/readonly1.right
@@ -0,0 +1,2 @@
+One:1
+One:1
diff --git a/shell/ash_test/ash-vars/readonly1.tests
b/shell/ash_test/ash-vars/readonly1.tests
new file mode 100755
index 0000000..81b461f
--- /dev/null
+++ b/shell/ash_test/ash-vars/readonly1.tests
@@ -0,0 +1,7 @@
+readonly bla=123
+# Bare "eval bla=123" should abort ("eval" is a special builtin):
+(eval bla=123 2>/dev/null; echo BUG)
+echo One:$?
+# "command BLTIN" disables "special-ness", should not abort:
+command eval bla=123 2>/dev/null
+echo One:$?
-- 
2.9.2

  reply	other threads:[~2016-10-28 13:56 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-10-27 21:40 Martijn Dekker
2016-10-28 13:55 ` Denys Vlasenko [this message]
2016-10-29 18:22   ` Harald van Dijk
2016-10-30 17:32     ` Denys Vlasenko

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAK1hOcO25fYP71DRxk=Dga5UZ6=FfmdDHTj6AWNNGSu_J0B+Dw@mail.gmail.com' \
    --to=vda.linux@googlemail.com \
    --cc=busybox@busybox.net \
    --cc=dash@vger.kernel.org \
    --cc=herbert@gondor.apana.org.au \
    --cc=martijn@inlv.org \
    --subject='Re: [BUG] Interactive (d)ash exits on assigning to readonly from '\''command eval'\''' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).