lockdep: in_range() fix
Torsten Kaiser wrote: | static inline int in_range(const void *start, const void *addr, const void *end) | { | return addr >= start && addr <= end; | } | This will return true, if addr is in the range of start (including) | to end (including). | | But debug_check_no_locks_freed() seems does: | const void *mem_to = mem_from + mem_len | -> mem_to is the last byte of the freed range, that fits in_range | lock_from = (void *)hlock->instance; | -> first byte of the lock | lock_to = (void *)(hlock->instance + 1); | -> first byte of the next lock, not last byte of the lock that is being checked! | | The test is: | if (!in_range(mem_from, lock_from, mem_to) && | !in_range(mem_from, lock_to, mem_to)) | continue; | So it tests, if the first byte of the lock is in the range that is freed ->OK | And if the first byte of the *next* lock is in the range that is freed | -> Not OK. We can also simplify in_range checks, we need only 2 comparisons, not 4. If the lock is not in memory range, it should be either at the left of range or at the right. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
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@ -3054,11 +3054,6 @@ void __init lockdep_info(void)
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#endif
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#endif
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}
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}
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static inline int in_range(const void *start, const void *addr, const void *end)
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{
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return addr >= start && addr <= end;
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}
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static void
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static void
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print_freed_lock_bug(struct task_struct *curr, const void *mem_from,
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print_freed_lock_bug(struct task_struct *curr, const void *mem_from,
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const void *mem_to, struct held_lock *hlock)
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const void *mem_to, struct held_lock *hlock)
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@ -3080,6 +3075,13 @@ print_freed_lock_bug(struct task_struct *curr, const void *mem_from,
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dump_stack();
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dump_stack();
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}
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}
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static inline int not_in_range(const void* mem_from, unsigned long mem_len,
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const void* lock_from, unsigned long lock_len)
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{
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return lock_from + lock_len <= mem_from ||
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mem_from + mem_len <= lock_from;
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}
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/*
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/*
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* Called when kernel memory is freed (or unmapped), or if a lock
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* Called when kernel memory is freed (or unmapped), or if a lock
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* is destroyed or reinitialized - this code checks whether there is
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* is destroyed or reinitialized - this code checks whether there is
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@ -3087,7 +3089,6 @@ print_freed_lock_bug(struct task_struct *curr, const void *mem_from,
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*/
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*/
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void debug_check_no_locks_freed(const void *mem_from, unsigned long mem_len)
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void debug_check_no_locks_freed(const void *mem_from, unsigned long mem_len)
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{
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{
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const void *mem_to = mem_from + mem_len, *lock_from, *lock_to;
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struct task_struct *curr = current;
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struct task_struct *curr = current;
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struct held_lock *hlock;
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struct held_lock *hlock;
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unsigned long flags;
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unsigned long flags;
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@ -3100,14 +3101,11 @@ void debug_check_no_locks_freed(const void *mem_from, unsigned long mem_len)
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for (i = 0; i < curr->lockdep_depth; i++) {
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for (i = 0; i < curr->lockdep_depth; i++) {
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hlock = curr->held_locks + i;
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hlock = curr->held_locks + i;
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lock_from = (void *)hlock->instance;
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if (not_in_range(mem_from, mem_len, hlock->instance,
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lock_to = (void *)(hlock->instance + 1);
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sizeof(*hlock->instance)))
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if (!in_range(mem_from, lock_from, mem_to) &&
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!in_range(mem_from, lock_to, mem_to))
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continue;
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continue;
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print_freed_lock_bug(curr, mem_from, mem_to, hlock);
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print_freed_lock_bug(curr, mem_from, mem_from + mem_len, hlock);
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break;
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break;
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}
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}
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local_irq_restore(flags);
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local_irq_restore(flags);
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