The patch titled
Subject: mm: check rb_subtree_gap correctness
has been added to the -mm tree. Its filename is
mm-check-rb_subtree_gap-correctness.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Michel Lespinasse <walken@xxxxxxxxxx>
Subject: mm: check rb_subtree_gap correctness
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@xxxxxxxxxx>
Reviewed-by: Rik van Riel <riel@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: Paul Mundt <lethal@xxxxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Chris Metcalf <cmetcalf@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mmap.c | 24 ++++++++++++++++--------
1 file changed, 16 insertions(+), 8 deletions(-)
diff -puN mm/mmap.c~mm-check-rb_subtree_gap-correctness mm/mmap.c
--- a/mm/mmap.c~mm-check-rb_subtree_gap-correctness
+++ a/mm/mmap.c
@@ -365,7 +365,7 @@ static void vma_rb_erase(struct vm_area_
#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 *roo
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);
vma_unlock_anon_vma(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;
_
Patches currently in -mm which might be from walken@xxxxxxxxxx are
linux-next.patch
mm-add-anon_vma_lock-to-validate_mm.patch
mm-augment-vma-rbtree-with-rb_subtree_gap.patch
mm-check-rb_subtree_gap-correctness.patch
mm-check-rb_subtree_gap-correctness-fix.patch
mm-rearrange-vm_area_struct-for-fewer-cache-misses.patch
mm-rearrange-vm_area_struct-for-fewer-cache-misses-checkpatch-fixes.patch
mm-vm_unmapped_area-lookup-function.patch
mm-vm_unmapped_area-lookup-function-checkpatch-fixes.patch
mm-use-vm_unmapped_area-on-x86_64-architecture.patch
mm-fix-cache-coloring-on-x86_64-architecture.patch
mm-use-vm_unmapped_area-in-hugetlbfs.patch
mm-use-vm_unmapped_area-in-hugetlbfs-on-i386-architecture.patch
mm-use-vm_unmapped_area-on-mips-architecture.patch
mm-use-vm_unmapped_area-on-mips-architecture-fix.patch
mm-use-vm_unmapped_area-on-arm-architecture.patch
mm-use-vm_unmapped_area-on-arm-architecture-fix.patch
mm-use-vm_unmapped_area-on-sh-architecture.patch
mm-use-vm_unmapped_area-on-sh-architecture-fix.patch
mm-use-vm_unmapped_area-on-sparc64-architecture.patch
mm-use-vm_unmapped_area-on-sparc64-architecture-fix.patch
mm-use-vm_unmapped_area-in-hugetlbfs-on-sparc64-architecture.patch
mm-use-vm_unmapped_area-on-sparc32-architecture.patch
mm-use-vm_unmapped_area-in-hugetlbfs-on-tile-architecture.patch
--
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