busybox: ash/hush fix for read-builtin command
this is a cherrypick from busybox-git HEAD: f5470419404d643070db99d058405b714695b817 and can be removed when upgrading to next busybox release. discussion here: http://lists.busybox.net/pipermail/busybox/2017-May/085439.html Signed-off-by: Bastian Bittorf <bb@npl.de>
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			| @@ -0,0 +1,147 @@ | ||||
| From f5470419404d643070db99d058405b714695b817 Mon Sep 17 00:00:00 2001 | ||||
| From: Denys Vlasenko <vda.linux@googlemail.com> | ||||
| Date: Mon, 22 May 2017 19:34:45 +0200 | ||||
| Subject: [PATCH] ash,hush: fix SIGCHLD interrupting read builtin | ||||
|  | ||||
| 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@googlemail.com> | ||||
| Signed-off-by: Bastian Bittorf <bb@npl.de> | ||||
| --- | ||||
|  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(-) | ||||
|  create mode 100644 shell/ash_test/ash-read/read_SIGCHLD.right | ||||
|  create mode 100755 shell/ash_test/ash-read/read_SIGCHLD.tests | ||||
|  create mode 100644 shell/hush_test/hush-read/read_SIGCHLD.right | ||||
|  create mode 100755 shell/hush_test/hush-read/read_SIGCHLD.tests | ||||
|  | ||||
| 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; | ||||
| --  | ||||
| 1.9.1 | ||||
|  | ||||
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