Attachment #725644 for bug #801259

View | Details | Raw Unified | Return to bug 801259
Collapse All | Expand All




 * Licensed under the GPL-2
 */

/* We're only wrapping fork() as a poor man's pthread_atfork().  That would
 * require dedicated linkage against libpthread.  So here we force the locks
 * to a consistent state before forking. #263657
 */

#define WRAPPER_ARGS_PROTO
#define WRAPPER_ARGS
#define WRAPPER_SAFE() 0
#define WRAPPER_PRE_CHECKS() \
({ \
	/* pthread_atfork(sb_lock, sb_unlock, sb_unlock); */ \
	sb_lock(); \
	result = SB_HIDDEN_FUNC(WRAPPER_NAME)(WRAPPER_ARGS_FULL); \
	sb_unlock(); \
	false; \
})
#include "__wrapper_simple.c"




 * Licensed under the GPL-2
 */

/* We implement vfork() as fork() because sandbox does not meet vfork()
 * requirements between vfork()/exec("some-static-bianary") because we launch
 * to a consistent state before forking.
 *
 * We also implement vfork() as fork() because sandbox does not meet vfork()
 * requirements bet ween vfork()/exec("some-static-bianary") because we launch
 * ptrace in the middle.
 *
 * vfork() can also cause races in multithreaded apps in sandbox code.
 * fork() does not as it unstares address space.
 */

#define WRAPPER_ARGS_PROTO

#define WRAPPER_SAFE() 0
#define WRAPPER_PRE_CHECKS() \
({ \
	/* pthread_atfork(sb_lock, sb_unlock, sb_unlock); */ \
	sb_lock(); \
	result = sb_unwrapped_fork_DEFAULT(WRAPPER_ARGS_FULL); \
	sb_unlock(); \
	false; \
})
#include "__wrapper_simple.c"
- 

Return to bug 801259

Lines 5-24 Link Here

(-)a/libsandbox/wrapper-funcs/fork.c (-8 lines)
5	* Licensed under the GPL-2	5	* Licensed under the GPL-2
6	*/	6	*/
7		7
8	/* We're only wrapping fork() as a poor man's pthread_atfork(). That would
9	* require dedicated linkage against libpthread. So here we force the locks
10	* to a consistent state before forking. #263657
11	*/
12
13	#define WRAPPER_ARGS_PROTO	8	#define WRAPPER_ARGS_PROTO
14	#define WRAPPER_ARGS	9	#define WRAPPER_ARGS
15	#define WRAPPER_SAFE() 0	10	#define WRAPPER_SAFE() 0
16	#define WRAPPER_PRE_CHECKS() \	11	#define WRAPPER_PRE_CHECKS() \
17	({ \	12	({ \
18	/* pthread_atfork(sb_lock, sb_unlock, sb_unlock); */ \
19	sb_lock(); \
20	result = SB_HIDDEN_FUNC(WRAPPER_NAME)(WRAPPER_ARGS_FULL); \	13	result = SB_HIDDEN_FUNC(WRAPPER_NAME)(WRAPPER_ARGS_FULL); \
21	sb_unlock(); \
22	false; \	14	false; \
23	})	15	})
24	#include "__wrapper_simple.c"	16	#include "__wrapper_simple.c"

Lines 5-17 Link Here

(-)a/libsandbox/wrapper-funcs/vfork.c (-10 / +5 lines)
5	* Licensed under the GPL-2	5	* Licensed under the GPL-2
6	*/	6	*/
7		7
8	/* We're only wrapping vfork() as a poor man's pthread_atfork(). That would	8	/* We implement vfork() as fork() because sandbox does not meet vfork()
9	* require dedicated linkage against libpthread. So here we force the locks	9	* requirements between vfork()/exec("some-static-bianary") because we launch
10	* to a consistent state before forking.
11	*
12	* We also implement vfork() as fork() because sandbox does not meet vfork()
13	* requirements bet ween vfork()/exec("some-static-bianary") because we launch
14	* ptrace in the middle.	10	* ptrace in the middle.
		11	*
		12	* vfork() can also cause races in multithreaded apps in sandbox code.
		13	* fork() does not as it unstares address space.
15	*/	14	*/
16		15
17	#define WRAPPER_ARGS_PROTO	16	#define WRAPPER_ARGS_PROTO
Lines 19-28 Link Here
19	#define WRAPPER_SAFE() 0	18	#define WRAPPER_SAFE() 0
20	#define WRAPPER_PRE_CHECKS() \	19	#define WRAPPER_PRE_CHECKS() \
21	({ \	20	({ \
22	/* pthread_atfork(sb_lock, sb_unlock, sb_unlock); */ \
23	sb_lock(); \
24	result = sb_unwrapped_fork_DEFAULT(WRAPPER_ARGS_FULL); \	21	result = sb_unwrapped_fork_DEFAULT(WRAPPER_ARGS_FULL); \
25	sb_unlock(); \
26	false; \	22	false; \
27	})	23	})
28	#include "__wrapper_simple.c"	24	#include "__wrapper_simple.c"
29	-