[git commit] ash,hush: fix SIGCHLD interrupting read builtin
Denys Vlasenko
vda.linux at googlemail.com
Mon May 22 17:34:45 UTC 2017
commit: https://git.busybox.net/busybox/commit/?id=f5470419404d643070db99d058405b714695b817
branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master
function old new delta
readcmd 169 217 +48
shell_builtin_read 1087 1097 +10
localcmd 366 364 -2
builtin_read 197 193 -4
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/2 up/down: 58/-6) Total: 52 bytes
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
shell/ash.c | 7 +++++++
shell/ash_test/ash-read/read_SIGCHLD.right | 2 ++
shell/ash_test/ash-read/read_SIGCHLD.tests | 4 ++++
shell/hush.c | 5 ++++-
shell/hush_test/hush-read/read_SIGCHLD.right | 2 ++
shell/hush_test/hush-read/read_SIGCHLD.tests | 4 ++++
shell/shell_common.c | 20 +++++++++++---------
7 files changed, 34 insertions(+), 10 deletions(-)
diff --git a/shell/ash.c b/shell/ash.c
index 70ee15e..60c8ffe 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -13268,6 +13268,7 @@ readcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
/* "read -s" needs to save/restore termios, can't allow ^C
* to jump out of it.
*/
+ again:
INT_OFF;
r = shell_builtin_read(setvar0,
argptr,
@@ -13280,6 +13281,12 @@ readcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
);
INT_ON;
+ if ((uintptr_t)r == 1 && errno == EINTR) {
+ /* to get SIGCHLD: sleep 1 & read x; echo $x */
+ if (pending_sig == 0)
+ goto again;
+ }
+
if ((uintptr_t)r > 1)
ash_msg_and_raise_error(r);
diff --git a/shell/ash_test/ash-read/read_SIGCHLD.right b/shell/ash_test/ash-read/read_SIGCHLD.right
new file mode 100644
index 0000000..b3dc7ab
--- /dev/null
+++ b/shell/ash_test/ash-read/read_SIGCHLD.right
@@ -0,0 +1,2 @@
+x='Ok'
+exitcode:0
diff --git a/shell/ash_test/ash-read/read_SIGCHLD.tests b/shell/ash_test/ash-read/read_SIGCHLD.tests
new file mode 100755
index 0000000..c5f673a
--- /dev/null
+++ b/shell/ash_test/ash-read/read_SIGCHLD.tests
@@ -0,0 +1,4 @@
+x=BAD
+{ sleep 0.4; echo Ok; } | { sleep 0.2 & read x; echo "x='$x'"; }
+echo "exitcode:$?"
+
diff --git a/shell/hush.c b/shell/hush.c
index e18920f..125463a 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -9038,6 +9038,9 @@ static int FAST_FUNC builtin_type(char **argv)
* - terminates shell (regardless of interactivity);
* if it has non-empty trap:
* - executes trap and returns to read;
+ * SIGCHLD from children:
+ * - does not interrupt read regardless of interactivity:
+ * try: sleep 1 & read x; echo $x
*/
static int FAST_FUNC builtin_read(char **argv)
{
@@ -9071,7 +9074,7 @@ static int FAST_FUNC builtin_read(char **argv)
if ((uintptr_t)r == 1 && errno == EINTR) {
unsigned sig = check_and_run_traps();
- if (sig && sig != SIGINT)
+ if (sig != SIGINT)
goto again;
}
diff --git a/shell/hush_test/hush-read/read_SIGCHLD.right b/shell/hush_test/hush-read/read_SIGCHLD.right
new file mode 100644
index 0000000..b3dc7ab
--- /dev/null
+++ b/shell/hush_test/hush-read/read_SIGCHLD.right
@@ -0,0 +1,2 @@
+x='Ok'
+exitcode:0
diff --git a/shell/hush_test/hush-read/read_SIGCHLD.tests b/shell/hush_test/hush-read/read_SIGCHLD.tests
new file mode 100755
index 0000000..c5f673a
--- /dev/null
+++ b/shell/hush_test/hush-read/read_SIGCHLD.tests
@@ -0,0 +1,4 @@
+x=BAD
+{ sleep 0.4; echo Ok; } | { sleep 0.2 & read x; echo "x='$x'"; }
+echo "exitcode:$?"
+
diff --git a/shell/shell_common.c b/shell/shell_common.c
index fb86e68..03b7d0b 100644
--- a/shell/shell_common.c
+++ b/shell/shell_common.c
@@ -204,15 +204,17 @@ shell_builtin_read(void FAST_FUNC (*setvar)(const char *name, const char *val),
c = buffer[bufpos];
if (c == '\0')
continue;
- if (backslash) {
- backslash = 0;
- if (c != '\n')
- goto put;
- continue;
- }
- if (!(read_flags & BUILTIN_READ_RAW) && c == '\\') {
- backslash = 1;
- continue;
+ if (!(read_flags & BUILTIN_READ_RAW)) {
+ if (backslash) {
+ backslash = 0;
+ if (c != '\n')
+ goto put;
+ continue;
+ }
+ if (c == '\\') {
+ backslash = 1;
+ continue;
+ }
}
if (c == '\n')
break;
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