From: Alexander Nyberg <alexn@telia.com>
This patch stores the 3 last function addresses of the call chain
allocating the object (it won't work on certain large caches though, that
fall backs to the now existing way).
Signed-off-by: Alexander Nyberg <alexn@telia.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
mm/slab.c | 99 ++++++++++++++++++++++++++++++++++++++++++++++----------------
1 files changed, 74 insertions(+), 25 deletions(-)
diff -puN mm/slab.c~slab-leak-detector-give-longer-traces mm/slab.c
--- devel/mm/slab.c~slab-leak-detector-give-longer-traces 2005-08-06 15:35:04.000000000 -0700
+++ devel-akpm/mm/slab.c 2005-08-06 15:35:04.000000000 -0700
@@ -521,16 +521,28 @@ static unsigned long *dbg_redzone2(kmem_
{
BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
if (cachep->flags & SLAB_STORE_USER)
- return (unsigned long*) (objp+cachep->objsize-2*BYTES_PER_WORD);
+ return (unsigned long*) (objp+cachep->objsize-4*BYTES_PER_WORD);
return (unsigned long*) (objp+cachep->objsize-BYTES_PER_WORD);
}
-static void **dbg_userword(kmem_cache_t *cachep, void *objp)
+static void **dbg_userword3(kmem_cache_t *cachep, void *objp)
{
BUG_ON(!(cachep->flags & SLAB_STORE_USER));
return (void**)(objp+cachep->objsize-BYTES_PER_WORD);
}
+static void **dbg_userword2(kmem_cache_t *cachep, void *objp)
+{
+ BUG_ON(!(cachep->flags & SLAB_STORE_USER));
+ return (void**)(objp+cachep->objsize-2*BYTES_PER_WORD);
+}
+
+static void **dbg_userword1(kmem_cache_t *cachep, void *objp)
+{
+ BUG_ON(!(cachep->flags & SLAB_STORE_USER));
+ return (void**)(objp+cachep->objsize-3*BYTES_PER_WORD);
+}
+
#else
#define obj_dbghead(x) 0
@@ -1312,12 +1324,16 @@ static void print_objinfo(kmem_cache_t *
}
if (cachep->flags & SLAB_STORE_USER) {
- printk(KERN_ERR "Last user: [<%p>]",
- *dbg_userword(cachep, objp));
- print_symbol("(%s)",
- (unsigned long)*dbg_userword(cachep, objp));
+ printk(KERN_ERR "Last user:\n");
+ printk(KERN_ERR "[<%p>]", *dbg_userword1(cachep, objp));
+ print_symbol("(%s)", (unsigned long) *dbg_userword1(cachep, objp));
+ printk(KERN_ERR "[<%p>]", *dbg_userword2(cachep, objp));
+ print_symbol("(%s)", (unsigned long) *dbg_userword2(cachep, objp));
+ printk(KERN_ERR "[<%p>]", *dbg_userword2(cachep, objp));
+ print_symbol("(%s)", (unsigned long) *dbg_userword2(cachep, objp));
printk("\n");
}
+
realobj = (char*)objp+obj_dbghead(cachep);
size = obj_reallen(cachep);
for (i=0; i<size && lines;i+=16, lines--) {
@@ -1532,7 +1548,7 @@ kmem_cache_create (const char *name, siz
* above the next power of two: caches with object sizes just above a
* power of two have a significant amount of internal fragmentation.
*/
- if ((size < 4096 || fls(size-1) == fls(size-1+3*BYTES_PER_WORD)))
+ if ((size < 4096 || fls(size-1) == fls(size-1+5*BYTES_PER_WORD)))
flags |= SLAB_RED_ZONE|SLAB_STORE_USER;
if (!(flags & SLAB_DESTROY_BY_RCU))
flags |= SLAB_POISON;
@@ -1612,7 +1628,7 @@ kmem_cache_create (const char *name, siz
* object.
*/
align = BYTES_PER_WORD;
- size += BYTES_PER_WORD;
+ size += 3 * BYTES_PER_WORD;
}
#if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC)
if (size >= malloc_sizes[INDEX_L3+1].cs_size && cachep->reallen > cache_line_size() && size < PAGE_SIZE) {
@@ -2081,8 +2097,11 @@ static void cache_init_objs(kmem_cache_t
/* need to poison the objs? */
if (cachep->flags & SLAB_POISON)
poison_obj(cachep, objp, POISON_FREE);
- if (cachep->flags & SLAB_STORE_USER)
- *dbg_userword(cachep, objp) = NULL;
+ if (cachep->flags & SLAB_STORE_USER) {
+ *dbg_userword1(cachep, objp) = NULL;
+ *dbg_userword2(cachep, objp) = NULL;
+ *dbg_userword3(cachep, objp) = NULL;
+ }
if (cachep->flags & SLAB_RED_ZONE) {
*dbg_redzone1(cachep, objp) = RED_INACTIVE;
@@ -2256,7 +2275,7 @@ static void kfree_debugcheck(const void
}
}
-static void *cache_free_debugcheck(kmem_cache_t *cachep, void *objp,
+static void inline *cache_free_debugcheck(kmem_cache_t *cachep, void *objp,
void *caller)
{
struct page *page;
@@ -2286,8 +2305,11 @@ static void *cache_free_debugcheck(kmem_
*dbg_redzone1(cachep, objp) = RED_INACTIVE;
*dbg_redzone2(cachep, objp) = RED_INACTIVE;
}
- if (cachep->flags & SLAB_STORE_USER)
- *dbg_userword(cachep, objp) = caller;
+ if (cachep->flags & SLAB_STORE_USER) {
+ *dbg_userword1(cachep, objp) = caller; /* address(0) */
+ *dbg_userword2(cachep, objp) = __builtin_return_address(1);
+ *dbg_userword3(cachep, objp) = __builtin_return_address(2);
+ }
objnr = (objp-slabp->s_mem)/cachep->objsize;
@@ -2462,7 +2484,7 @@ cache_alloc_debugcheck_before(kmem_cache
}
#if DEBUG
-static void *
+static void inline *
cache_alloc_debugcheck_after(kmem_cache_t *cachep,
unsigned int __nocast flags, void *objp, void *caller)
{
@@ -2479,8 +2501,11 @@ cache_alloc_debugcheck_after(kmem_cache_
#endif
poison_obj(cachep, objp, POISON_INUSE);
}
- if (cachep->flags & SLAB_STORE_USER)
- *dbg_userword(cachep, objp) = caller;
+ if (cachep->flags & SLAB_STORE_USER) {
+ *dbg_userword1(cachep, objp) = caller; /* address(0) */
+ *dbg_userword2(cachep, objp) = __builtin_return_address(1);
+ *dbg_userword3(cachep, objp) = __builtin_return_address(2);
+ }
if (cachep->flags & SLAB_RED_ZONE) {
if (*dbg_redzone1(cachep, objp) != RED_INACTIVE || *dbg_redzone2(cachep, objp) != RED_INACTIVE) {
@@ -3529,6 +3554,37 @@ struct seq_operations slabinfo_op = {
.show = s_show,
};
+#if DEBUG
+#include <linux/nmi.h>
+static inline void dump_slab(kmem_cache_t *cachep, struct slab *slabp)
+{
+ int i;
+ int slab_user = cachep->flags & SLAB_STORE_USER;
+
+ for (i = 0; i < cachep->num; i++) {
+ if (slab_user) {
+ void *objp = slabp->s_mem + cachep->objsize * i;
+
+ printk("obj:%p [%p] ", objp, *dbg_userword1(cachep, objp));
+ print_symbol("<%s>", (unsigned long) *dbg_userword1(cachep, objp));
+ printk("\n");
+ printk("obj:%p [%p] ", objp, *dbg_userword2(cachep, objp));
+ print_symbol("<%s>", (unsigned long) *dbg_userword2(cachep, objp));
+ printk("\n");
+ printk("obj:%p [%p] ", objp, *dbg_userword3(cachep, objp));
+ print_symbol("<%s>", (unsigned long) *dbg_userword3(cachep, objp));
+ printk("\n");
+ } else {
+ unsigned long sym = slab_bufctl(slabp)[i];
+
+ printk("obj %p/%d: %p", slabp, i, (void *)sym);
+ print_symbol(" <%s>", sym);
+ printk("\n");
+ }
+ }
+}
+#endif
+
static void do_dump_slabp(kmem_cache_t *cachep)
{
#if DEBUG
@@ -3542,16 +3598,9 @@ static void do_dump_slabp(kmem_cache_t *
spin_lock(&rl3->list_lock);
list_for_each(q, &rl3->slabs_full) {
- int i;
struct slab *slabp = list_entry(q, struct slab, list);
-
- for (i = 0; i < cachep->num; i++) {
- unsigned long sym = slab_bufctl(slabp)[i];
-
- printk("obj %p/%d: %p", slabp, i, (void *)sym);
- print_symbol(" <%s>", sym);
- printk("\n");
- }
+ dump_slab(cachep, slabp);
+ touch_nmi_watchdog();
}
spin_unlock(&rl3->list_lock);
}
_