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Tracking info wasn't always retrieved with the cache locked.

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Getting the object slab does a hash lookup which needs to be protected
by the cache lock. Otherwise the hash table may be resized or otherwise
modified while we do the lookup, leading to errors.
This commit is contained in:
Michael Lotz 2011-11-29 00:15:34 +01:00
parent d240743e9b
commit a139657921
2 changed files with 9 additions and 1 deletions
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3
src/system/kernel/slab/HashedObjectCache.cpp
View File

@ -157,11 +157,14 @@ HashedObjectCache::ReturnSlab(slab* _slab, uint32 flags)
slab*
HashedObjectCache::ObjectSlab(void* object) const
{
ASSERT_LOCKED_MUTEX(&lock);
HashedSlab* slab = hash_table.Lookup(::lower_boundary(object, slab_size));
if (slab == NULL) {
panic("hash object cache %p: unknown object %p", this, object);
return NULL;
}
return slab;
}

7
src/system/kernel/slab/Slab.cpp
View File

@ -823,6 +823,7 @@ add_alloc_tracing_entry(ObjectCache* cache, uint32 flags, void* object)
{
#if SLAB_OBJECT_CACHE_TRACING
#if SLAB_OBJECT_CACHE_ALLOCATION_TRACKING
MutexLocker _(cache->lock);
cache->TrackingInfoFor(object)->Init(T(Alloc(cache, flags, object)));
#else
T(Alloc(cache, flags, object));
@ -1220,7 +1221,7 @@ object_cache_alloc(object_cache* cache, uint32 flags)
}
}
MutexLocker _(cache->lock);
MutexLocker locker(cache->lock);
slab* source = NULL;
while (true) {
@ -1264,6 +1265,8 @@ object_cache_alloc(object_cache* cache, uint32 flags)
}
void* object = link_to_object(link, cache->object_size);
locker.Unlock();
add_alloc_tracing_entry(cache, flags, object);
return fill_allocated_block(object, cache->object_size);
}
@ -1295,7 +1298,9 @@ object_cache_free(object_cache* cache, void* object, uint32 flags)
#endif
#if SLAB_OBJECT_CACHE_ALLOCATION_TRACKING
mutex_lock(&cache->lock);
cache->TrackingInfoFor(object)->Clear();
mutex_unlock(&cache->lock);
#endif
if ((cache->flags & CACHE_NO_DEPOT) == 0) {