ash: do not leave SIGQUIT ignored on "exec CMD"

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

3 files changed, 20 insertions, 1 deletions

diff --git a/shell/ash.c b/shell/ash.c
index faa45a8dc..4f6376f78 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -323,7 +323,7 @@ struct globals_misc {
 #define S_DFL      1            /* default signal handling (SIG_DFL) */
 #define S_CATCH    2            /* signal is caught */
 #define S_IGN      3            /* signal is ignored (SIG_IGN) */
-#define S_HARD_IGN 4            /* signal is ignored permenantly */
+#define S_HARD_IGN 4            /* signal is ignored permanently */
 
         /* indicates specified signal received */
         uint8_t gotsig[NSIG - 1]; /* offset by 1: "signal" 0 is meaningless */
@@ -9024,7 +9024,20 @@ execcmd(int argc UNUSED_PARAM, char **argv)
                 iflag = 0;              /* exit on error */
                 mflag = 0;
                 optschanged();
+                /* We should set up signals for "exec CMD"
+                 * the same way as for "CMD" without "exec".
+                 * But optschanged->setinteractive->setsignal
+                 * still thought we are a root shell. Therefore, for example,
+                 * SIGQUIT is still set to IGN. Fix it:
+                 */
+                shlvl++;
+                setsignal(SIGQUIT);
+                /*setsignal(SIGTERM); - unnecessary because of iflag=0 */
+                /*setsignal(SIGTSTP); - unnecessary because of mflag=0 */
+                /*setsignal(SIGTTOU); - unnecessary because of mflag=0 */
+
                 shellexec(argv + 1, pathval(), 0);
+                /* NOTREACHED */
         }
         return 0;
 }
diff --git a/shell/ash_test/ash-signals/sigquit_exec.right b/shell/ash_test/ash-signals/sigquit_exec.right
new file mode 100644
index 000000000..a8041929a
--- /dev/null
+++ b/shell/ash_test/ash-signals/sigquit_exec.right
@@ -0,0 +1,2 @@
+SigIgn: 0000000000000000
+SigIgn: 0000000000000000
diff --git a/shell/ash_test/ash-signals/sigquit_exec.tests b/shell/ash_test/ash-signals/sigquit_exec.tests
new file mode 100755
index 000000000..24bda6921
--- /dev/null
+++ b/shell/ash_test/ash-signals/sigquit_exec.tests
@@ -0,0 +1,4 @@
+# Should show no masked signals in both cases.
+# We had a bug where SIGQUIT was masked on exec.
+grep SigIgn: /proc/self/status
+exec grep SigIgn: /proc/self/status