104 lines
2.5 KiB
C
104 lines
2.5 KiB
C
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#include <linux/mm_types.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/kmemcheck.h>
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void kmemcheck_alloc_shadow(struct kmem_cache *s, gfp_t flags, int node,
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struct page *page, int order)
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{
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struct page *shadow;
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int pages;
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int i;
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pages = 1 << order;
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/*
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* With kmemcheck enabled, we need to allocate a memory area for the
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* shadow bits as well.
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*/
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shadow = alloc_pages_node(node, flags, order);
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if (!shadow) {
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if (printk_ratelimit())
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printk(KERN_ERR "kmemcheck: failed to allocate "
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"shadow bitmap\n");
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return;
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}
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for(i = 0; i < pages; ++i)
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page[i].shadow = page_address(&shadow[i]);
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/*
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* Mark it as non-present for the MMU so that our accesses to
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* this memory will trigger a page fault and let us analyze
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* the memory accesses.
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*/
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kmemcheck_hide_pages(page, pages);
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/*
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* Objects from caches that have a constructor don't get
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* cleared when they're allocated, so we need to do it here.
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*/
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if (s->ctor)
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kmemcheck_mark_uninitialized_pages(page, pages);
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else
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kmemcheck_mark_unallocated_pages(page, pages);
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}
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void kmemcheck_free_shadow(struct kmem_cache *s, struct page *page, int order)
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{
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struct page *shadow;
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int pages;
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int i;
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pages = 1 << order;
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kmemcheck_show_pages(page, pages);
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shadow = virt_to_page(page[0].shadow);
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for(i = 0; i < pages; ++i)
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page[i].shadow = NULL;
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__free_pages(shadow, order);
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}
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void kmemcheck_slab_alloc(struct kmem_cache *s, gfp_t gfpflags, void *object,
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size_t size)
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{
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/*
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* Has already been memset(), which initializes the shadow for us
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* as well.
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*/
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if (gfpflags & __GFP_ZERO)
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return;
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/* No need to initialize the shadow of a non-tracked slab. */
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if (s->flags & SLAB_NOTRACK)
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return;
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if (!kmemcheck_enabled || gfpflags & __GFP_NOTRACK) {
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/*
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* Allow notracked objects to be allocated from
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* tracked caches. Note however that these objects
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* will still get page faults on access, they just
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* won't ever be flagged as uninitialized. If page
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* faults are not acceptable, the slab cache itself
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* should be marked NOTRACK.
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*/
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kmemcheck_mark_initialized(object, size);
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} else if (!s->ctor) {
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/*
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* New objects should be marked uninitialized before
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* they're returned to the called.
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*/
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kmemcheck_mark_uninitialized(object, size);
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}
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}
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void kmemcheck_slab_free(struct kmem_cache *s, void *object, size_t size)
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{
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/* TODO: RCU freeing is unsupported for now; hide false positives. */
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if (!s->ctor && !(s->flags & SLAB_DESTROY_BY_RCU))
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kmemcheck_mark_freed(object, size);
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}
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