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-rw-r--r--include/linux/mm.h3
-rw-r--r--include/linux/rmap.h3
-rw-r--r--lib/Kconfig.debug9
-rw-r--r--mm/interval_tree.c41
-rw-r--r--mm/mmap.c19
5 files changed, 64 insertions, 11 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 0cdab4e0f814..0e6f9c9f2123 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1386,6 +1386,9 @@ struct anon_vma_chain *anon_vma_interval_tree_iter_first(
struct rb_root *root, unsigned long start, unsigned long last);
struct anon_vma_chain *anon_vma_interval_tree_iter_next(
struct anon_vma_chain *node, unsigned long start, unsigned long last);
+#ifdef CONFIG_DEBUG_VM_RB
+void anon_vma_interval_tree_verify(struct anon_vma_chain *node);
+#endif
#define anon_vma_interval_tree_foreach(avc, root, start, last) \
for (avc = anon_vma_interval_tree_iter_first(root, start, last); \
diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index dce44f7d3ed8..b2cce644ffc7 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -66,6 +66,9 @@ struct anon_vma_chain {
struct list_head same_vma; /* locked by mmap_sem & page_table_lock */
struct rb_node rb; /* locked by anon_vma->mutex */
unsigned long rb_subtree_last;
+#ifdef CONFIG_DEBUG_VM_RB
+ unsigned long cached_vma_start, cached_vma_last;
+#endif
};
#ifdef CONFIG_MMU
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index a6e7e7741523..28e9d6c98941 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -798,6 +798,15 @@ config DEBUG_VM
If unsure, say N.
+config DEBUG_VM_RB
+ bool "Debug VM red-black trees"
+ depends on DEBUG_VM
+ help
+ Enable this to turn on more extended checks in the virtual-memory
+ system that may impact performance.
+
+ If unsure, say N.
+
config DEBUG_VIRTUAL
bool "Debug VM translations"
depends on DEBUG_KERNEL && X86
diff --git a/mm/interval_tree.c b/mm/interval_tree.c
index f7c72cd35e1d..4a5822a586e6 100644
--- a/mm/interval_tree.c
+++ b/mm/interval_tree.c
@@ -70,4 +70,43 @@ static inline unsigned long avc_last_pgoff(struct anon_vma_chain *avc)
}
INTERVAL_TREE_DEFINE(struct anon_vma_chain, rb, unsigned long, rb_subtree_last,
- avc_start_pgoff, avc_last_pgoff,, anon_vma_interval_tree)
+ avc_start_pgoff, avc_last_pgoff,
+ static inline, __anon_vma_interval_tree)
+
+void anon_vma_interval_tree_insert(struct anon_vma_chain *node,
+ struct rb_root *root)
+{
+#ifdef CONFIG_DEBUG_VM_RB
+ node->cached_vma_start = avc_start_pgoff(node);
+ node->cached_vma_last = avc_last_pgoff(node);
+#endif
+ __anon_vma_interval_tree_insert(node, root);
+}
+
+void anon_vma_interval_tree_remove(struct anon_vma_chain *node,
+ struct rb_root *root)
+{
+ __anon_vma_interval_tree_remove(node, root);
+}
+
+struct anon_vma_chain *
+anon_vma_interval_tree_iter_first(struct rb_root *root,
+ unsigned long first, unsigned long last)
+{
+ return __anon_vma_interval_tree_iter_first(root, first, last);
+}
+
+struct anon_vma_chain *
+anon_vma_interval_tree_iter_next(struct anon_vma_chain *node,
+ unsigned long first, unsigned long last)
+{
+ return __anon_vma_interval_tree_iter_next(node, first, last);
+}
+
+#ifdef CONFIG_DEBUG_VM_RB
+void anon_vma_interval_tree_verify(struct anon_vma_chain *node)
+{
+ WARN_ON_ONCE(node->cached_vma_start != avc_start_pgoff(node));
+ WARN_ON_ONCE(node->cached_vma_last != avc_last_pgoff(node));
+}
+#endif
diff --git a/mm/mmap.c b/mm/mmap.c
index 2e580ed79211..deb422c39e21 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -51,12 +51,6 @@ static void unmap_region(struct mm_struct *mm,
struct vm_area_struct *vma, struct vm_area_struct *prev,
unsigned long start, unsigned long end);
-/*
- * WARNING: the debugging will use recursive algorithms so never enable this
- * unless you know what you are doing.
- */
-#undef DEBUG_MM_RB
-
/* description of effects of mapping type and prot in current implementation.
* this is due to the limited x86 page protection hardware. The expected
* behavior is in parens:
@@ -303,7 +297,7 @@ out:
return retval;
}
-#ifdef DEBUG_MM_RB
+#ifdef CONFIG_DEBUG_VM_RB
static int browse_rb(struct rb_root *root)
{
int i = 0, j;
@@ -337,9 +331,12 @@ void validate_mm(struct mm_struct *mm)
{
int bug = 0;
int i = 0;
- struct vm_area_struct *tmp = mm->mmap;
- while (tmp) {
- tmp = tmp->vm_next;
+ struct vm_area_struct *vma = mm->mmap;
+ while (vma) {
+ struct anon_vma_chain *avc;
+ list_for_each_entry(avc, &vma->anon_vma_chain, same_vma)
+ anon_vma_interval_tree_verify(avc);
+ vma = vma->vm_next;
i++;
}
if (i != mm->map_count)
@@ -1790,6 +1787,7 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
}
vma_unlock_anon_vma(vma);
khugepaged_enter_vma_merge(vma);
+ validate_mm(vma->vm_mm);
return error;
}
#endif /* CONFIG_STACK_GROWSUP || CONFIG_IA64 */
@@ -1843,6 +1841,7 @@ int expand_downwards(struct vm_area_struct *vma,
}
vma_unlock_anon_vma(vma);
khugepaged_enter_vma_merge(vma);
+ validate_mm(vma->vm_mm);
return error;
}