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From: Michel Lespinasse <walken@google.com>
To: Andrew Morton <akpm@linux-foundation.org>,
	Rik van Riel <riel@redhat.com>, Hugh Dickins <hughd@google.com>,
	linux-kernel@vger.kernel.org,
	Russell King <linux@arm.linux.org.uk>,
	Ralf Baechle <ralf@linux-mips.org>,
	Paul Mundt <lethal@linux-sh.org>,
	"David S. Miller" <davem@davemloft.net>,
	Chris Metcalf <cmetcalf@tilera.com>,
	x86@kernel.org, William Irwin <wli@holomorphy.com>
Cc: linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org,
	linux-mips@linux-mips.org, linux-sh@vger.kernel.org,
	sparclinux@vger.kernel.org
Subject: [PATCH 03/16] mm: check rb_subtree_gap correctness
Date: Mon,  5 Nov 2012 14:47:00 -0800	[thread overview]
Message-ID: <1352155633-8648-4-git-send-email-walken@google.com> (raw)
In-Reply-To: <1352155633-8648-1-git-send-email-walken@google.com>

When CONFIG_DEBUG_VM_RB is enabled, check that rb_subtree_gap is
correctly set for every vma and that mm->highest_vm_end is also correct.

Also add an explicit 'bug' variable to track if browse_rb() detected any
invalid condition.

Signed-off-by: Michel Lespinasse <walken@google.com>
Reviewed-by: Rik van Riel <riel@redhat.com>

---
 mm/mmap.c |   24 ++++++++++++++++--------
 1 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index 2de8bcfe859d..769a09cc71af 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -365,7 +365,7 @@ static void vma_rb_erase(struct vm_area_struct *vma, struct rb_root *root)
 #ifdef CONFIG_DEBUG_VM_RB
 static int browse_rb(struct rb_root *root)
 {
-	int i = 0, j;
+	int i = 0, j, bug = 0;
 	struct rb_node *nd, *pn = NULL;
 	unsigned long prev = 0, pend = 0;
 
@@ -373,29 +373,33 @@ static int browse_rb(struct rb_root *root)
 		struct vm_area_struct *vma;
 		vma = rb_entry(nd, struct vm_area_struct, vm_rb);
 		if (vma->vm_start < prev)
-			printk("vm_start %lx prev %lx\n", vma->vm_start, prev), i = -1;
+			printk("vm_start %lx prev %lx\n", vma->vm_start, prev), bug = 1;
 		if (vma->vm_start < pend)
-			printk("vm_start %lx pend %lx\n", vma->vm_start, pend);
+			printk("vm_start %lx pend %lx\n", vma->vm_start, pend), bug = 1;
 		if (vma->vm_start > vma->vm_end)
-			printk("vm_end %lx < vm_start %lx\n", vma->vm_end, vma->vm_start);
+			printk("vm_end %lx < vm_start %lx\n", vma->vm_end, vma->vm_start), bug = 1;
+		if (vma->rb_subtree_gap != vma_compute_subtree_gap(vma))
+			printk("free gap %lx, correct %lx\n",
+			       vma->rb_subtree_gap,
+			       vma_compute_subtree_gap(vma)), bug = 1;
 		i++;
 		pn = nd;
 		prev = vma->vm_start;
 		pend = vma->vm_end;
 	}
 	j = 0;
-	for (nd = pn; nd; nd = rb_prev(nd)) {
+	for (nd = pn; nd; nd = rb_prev(nd))
 		j++;
-	}
 	if (i != j)
-		printk("backwards %d, forwards %d\n", j, i), i = 0;
-	return i;
+		printk("backwards %d, forwards %d\n", j, i), bug = 1;
+	return bug ? -1 : i;
 }
 
 void validate_mm(struct mm_struct *mm)
 {
 	int bug = 0;
 	int i = 0;
+	unsigned long highest_address = 0;
 	struct vm_area_struct *vma = mm->mmap;
 	while (vma) {
 		struct anon_vma_chain *avc;
@@ -403,11 +407,15 @@ void validate_mm(struct mm_struct *mm)
 		list_for_each_entry(avc, &vma->anon_vma_chain, same_vma)
 			anon_vma_interval_tree_verify(avc);
 		anon_vma_unlock(vma->anon_vma);
+		highest_address = vma->vm_end;
 		vma = vma->vm_next;
 		i++;
 	}
 	if (i != mm->map_count)
 		printk("map_count %d vm_next %d\n", mm->map_count, i), bug = 1;
+	if (highest_address != mm->highest_vm_end)
+		printk("mm->highest_vm_end %lx, found %lx\n",
+		       mm->highest_vm_end, highest_address), bug = 1;
 	i = browse_rb(&mm->mm_rb);
 	if (i != mm->map_count)
 		printk("map_count %d rb %d\n", mm->map_count, i), bug = 1;
-- 
1.7.7.3

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  parent reply	other threads:[~2012-11-05 22:47 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-11-05 22:46 [PATCH 00/16] mm: use augmented rbtrees for finding unmapped areas Michel Lespinasse
2012-11-05 22:46 ` [PATCH 01/16] mm: add anon_vma_lock to validate_mm() Michel Lespinasse
2012-11-05 23:06   ` Rik van Riel
2012-11-06  8:00     ` Michel Lespinasse
2012-11-05 22:46 ` [PATCH 02/16] mm: augment vma rbtree with rb_subtree_gap Michel Lespinasse
2012-11-05 22:47 ` Michel Lespinasse [this message]
2012-11-06 22:38   ` [PATCH 03/16] mm: check rb_subtree_gap correctness Andrew Morton
2012-11-09 14:13   ` Sasha Levin
2012-11-09 20:06     ` Hugh Dickins
2012-11-12 11:55     ` Michel Lespinasse
2012-11-05 22:47 ` [PATCH 04/16] mm: rearrange vm_area_struct for fewer cache misses Michel Lespinasse
2012-11-05 22:47 ` [PATCH 05/16] mm: vm_unmapped_area() lookup function Michel Lespinasse
2012-11-05 22:47 ` [PATCH 06/16] mm: use vm_unmapped_area() on x86_64 architecture Michel Lespinasse
2012-11-05 22:47 ` [PATCH 07/16] mm: fix cache coloring " Michel Lespinasse
2012-11-06 22:38   ` Andrew Morton
2012-11-05 22:47 ` [PATCH 08/16] mm: use vm_unmapped_area() in hugetlbfs Michel Lespinasse
2012-11-05 23:33   ` Rik van Riel
2012-11-05 22:47 ` [PATCH 09/16] mm: use vm_unmapped_area() in hugetlbfs on i386 architecture Michel Lespinasse
2012-11-05 23:07   ` Rik van Riel
2012-11-06 22:38   ` Andrew Morton
2012-11-06 22:48     ` Rik van Riel
2012-11-05 22:47 ` [PATCH 10/16] mm: use vm_unmapped_area() on mips architecture Michel Lespinasse
2012-11-05 23:34   ` Rik van Riel
2012-11-06 22:38   ` Andrew Morton
2012-11-05 22:47 ` [PATCH 11/16] mm: use vm_unmapped_area() on arm architecture Michel Lespinasse
2012-11-05 23:35   ` Rik van Riel
2012-11-06 22:38   ` Andrew Morton
2012-11-05 22:47 ` [PATCH 12/16] mm: use vm_unmapped_area() on sh architecture Michel Lespinasse
2012-11-05 23:35   ` Rik van Riel
2012-11-05 22:47 ` [PATCH 13/16] mm: use vm_unmapped_area() on sparc64 architecture Michel Lespinasse
2012-11-05 23:36   ` Rik van Riel
2012-11-05 22:47 ` [PATCH 14/16] mm: use vm_unmapped_area() in hugetlbfs " Michel Lespinasse
2012-11-05 23:36   ` Rik van Riel
2012-11-05 22:47 ` [PATCH 15/16] mm: use vm_unmapped_area() on sparc32 architecture Michel Lespinasse
2012-11-05 23:37   ` Rik van Riel
2012-11-06  1:25   ` David Miller
2012-11-06  3:13     ` Michel Lespinasse
2012-11-06  7:30     ` Rik van Riel
2012-11-06 17:41       ` David Miller
2012-11-05 22:47 ` [PATCH 16/16] mm: use vm_unmapped_area() in hugetlbfs on tile architecture Michel Lespinasse
2012-11-05 23:37   ` Rik van Riel
2012-11-06 22:11 ` [PATCH 00/16] mm: use augmented rbtrees for finding unmapped areas Andrew Morton

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