]>
git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - mm/kmemcheck.c
2 #include <linux/mm_types.h>
4 #include <linux/slab.h>
6 #include <linux/kmemcheck.h>
8 void kmemcheck_alloc_shadow(struct page
*page
, int order
, gfp_t flags
, int node
)
17 * With kmemcheck enabled, we need to allocate a memory area for the
18 * shadow bits as well.
20 shadow
= alloc_pages_node(node
, flags
| __GFP_NOTRACK
, order
);
22 if (printk_ratelimit())
23 pr_err("kmemcheck: failed to allocate shadow bitmap\n");
27 for(i
= 0; i
< pages
; ++i
)
28 page
[i
].shadow
= page_address(&shadow
[i
]);
31 * Mark it as non-present for the MMU so that our accesses to
32 * this memory will trigger a page fault and let us analyze
33 * the memory accesses.
35 kmemcheck_hide_pages(page
, pages
);
38 void kmemcheck_free_shadow(struct page
*page
, int order
)
44 if (!kmemcheck_page_is_tracked(page
))
49 kmemcheck_show_pages(page
, pages
);
51 shadow
= virt_to_page(page
[0].shadow
);
53 for(i
= 0; i
< pages
; ++i
)
54 page
[i
].shadow
= NULL
;
56 __free_pages(shadow
, order
);
59 void kmemcheck_slab_alloc(struct kmem_cache
*s
, gfp_t gfpflags
, void *object
,
62 if (unlikely(!object
)) /* Skip object if allocation failed */
66 * Has already been memset(), which initializes the shadow for us
69 if (gfpflags
& __GFP_ZERO
)
72 /* No need to initialize the shadow of a non-tracked slab. */
73 if (s
->flags
& SLAB_NOTRACK
)
76 if (!kmemcheck_enabled
|| gfpflags
& __GFP_NOTRACK
) {
78 * Allow notracked objects to be allocated from
79 * tracked caches. Note however that these objects
80 * will still get page faults on access, they just
81 * won't ever be flagged as uninitialized. If page
82 * faults are not acceptable, the slab cache itself
83 * should be marked NOTRACK.
85 kmemcheck_mark_initialized(object
, size
);
86 } else if (!s
->ctor
) {
88 * New objects should be marked uninitialized before
89 * they're returned to the called.
91 kmemcheck_mark_uninitialized(object
, size
);
95 void kmemcheck_slab_free(struct kmem_cache
*s
, void *object
, size_t size
)
97 /* TODO: RCU freeing is unsupported for now; hide false positives. */
98 if (!s
->ctor
&& !(s
->flags
& SLAB_TYPESAFE_BY_RCU
))
99 kmemcheck_mark_freed(object
, size
);
102 void kmemcheck_pagealloc_alloc(struct page
*page
, unsigned int order
,
107 if (gfpflags
& (__GFP_HIGHMEM
| __GFP_NOTRACK
))
113 * NOTE: We choose to track GFP_ZERO pages too; in fact, they
114 * can become uninitialized by copying uninitialized memory
118 /* XXX: Can use zone->node for node? */
119 kmemcheck_alloc_shadow(page
, order
, gfpflags
, -1);
121 if (gfpflags
& __GFP_ZERO
)
122 kmemcheck_mark_initialized_pages(page
, pages
);
124 kmemcheck_mark_uninitialized_pages(page
, pages
);