From 0937502af7c9b648ed4e884ccb7f504b01a005a1 Mon Sep 17 00:00:00 2001
From: Christoph Lameter <clameter@sgi.com>
Date: Wed, 28 May 2008 10:32:22 -0700
Subject: slub: Add check for kfree() of non slab objects.

We can detect kfree()s on non slab objects by checking for PageCompound().
Works in the same way as for ksize. This helped me catch an invalid
kfree().

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>

diff --git a/mm/slub.c b/mm/slub.c
index 5f6e2c4..b3f2e71 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2766,6 +2766,7 @@ void kfree(const void *x)
 
 	page = virt_to_head_page(x);
 	if (unlikely(!PageSlab(page))) {
+		BUG_ON(!PageCompound(page));
 		put_page(page);
 		return;
 	}
-- 
cgit v0.10.2


From 88e4ccf294ca62c2da998012a83533ce150c8dce Mon Sep 17 00:00:00 2001
From: Alexey Dobriyan <adobriyan@gmail.com>
Date: Mon, 23 Jun 2008 02:58:37 +0400
Subject: slub: current is always valid

Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>

diff --git a/mm/slub.c b/mm/slub.c
index b3f2e71..488400d 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -411,7 +411,7 @@ static void set_track(struct kmem_cache *s, void *object,
 	if (addr) {
 		p->addr = addr;
 		p->cpu = smp_processor_id();
-		p->pid = current ? current->pid : -1;
+		p->pid = current->pid;
 		p->when = jiffies;
 	} else
 		memset(p, 0, sizeof(struct track));
-- 
cgit v0.10.2


From e79aec291da55aa322ddb5d8f3bb04cdf69470d5 Mon Sep 17 00:00:00 2001
From: Rabin Vincent <rabin@rab.in>
Date: Fri, 4 Jul 2008 00:40:32 +0530
Subject: slab: rename slab_destroy_objs

With the removal of destructors, slab_destroy_objs no longer actually
destroys any objects, making the kernel doc incorrect and the function
name misleading.

In keeping with the other debug functions, rename it to
slab_destroy_debugcheck and drop the kernel doc.

Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>

diff --git a/mm/slab.c b/mm/slab.c
index 046607f..b4aa4c8 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1901,15 +1901,7 @@ static void check_poison_obj(struct kmem_cache *cachep, void *objp)
 #endif
 
 #if DEBUG
-/**
- * slab_destroy_objs - destroy a slab and its objects
- * @cachep: cache pointer being destroyed
- * @slabp: slab pointer being destroyed
- *
- * Call the registered destructor for each object in a slab that is being
- * destroyed.
- */
-static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
+static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slabp)
 {
 	int i;
 	for (i = 0; i < cachep->num; i++) {
@@ -1938,7 +1930,7 @@ static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
 	}
 }
 #else
-static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
+static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slabp)
 {
 }
 #endif
@@ -1956,7 +1948,7 @@ static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
 {
 	void *addr = slabp->s_mem - slabp->colouroff;
 
-	slab_destroy_objs(cachep, slabp);
+	slab_destroy_debugcheck(cachep, slabp);
 	if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) {
 		struct slab_rcu *slab_rcu;
 
-- 
cgit v0.10.2