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![]() After acquiring the semlock spinlock, operations must test that the array is still valid. - semctl() and exit_sem() would walk stale linked lists (ugly, but should be ok: all lists are empty) - semtimedop() would sleep forever - and if woken up due to a signal - access memory after free. The patch also: - standardizes the tests for .deleted, so that all tests in one function leave the function with the same approach. - unconditionally tests for .deleted immediately after every call to sem_lock - even it it means that for semctl(GETALL), .deleted will be tested twice. Both changes make the review simpler: After every sem_lock, there must be a test of .deleted, followed by a goto to the cleanup code (if the function uses "goto cleanup"). The only exception is semctl_down(): If sem_ids().rwsem is locked, then the presence in ids->ipcs_idr is equivalent to !.deleted, thus no additional test is required. Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Mike Galbraith <efault@gmx.de> Acked-by: Davidlohr Bueso <davidlohr@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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.. | ||
compat.c | ||
compat_mq.c | ||
ipc_sysctl.c | ||
ipcns_notifier.c | ||
Makefile | ||
mq_sysctl.c | ||
mqueue.c | ||
msg.c | ||
msgutil.c | ||
namespace.c | ||
sem.c | ||
shm.c | ||
syscall.c | ||
util.c | ||
util.h |