2023-07-11 04:35:11

by Peng Zhang

Subject: [PATCH v2 5/8] maple_tree: make mas_validate_limits() check root node and node limit

Update mas_validate_limits() to check root node, check node limit pivot
if there is enough room for it to exist and check data_end. Remove the
check for child existence as it is done in mas_validate_child_slot().

Signed-off-by: Peng Zhang <[email protected]>
---
lib/maple_tree.c | 30 ++++++++++++++----------------
1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index f750ebef595f..072532fa18ee 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -7146,7 +7146,9 @@ static void mas_validate_child_slot(struct ma_state *mas)
}

/*
- * Validate all pivots are within mas->min and mas->max.
+ * Validate all pivots are within mas->min and mas->max, check metadata ends
+ * where the maximum ends and ensure there is no slots or pivots set outside of
+ * the end of the data.
*/
static void mas_validate_limits(struct ma_state *mas)
{
@@ -7156,26 +7158,15 @@ static void mas_validate_limits(struct ma_state *mas)
void __rcu **slots = ma_slots(mte_to_node(mas->node), type);
unsigned long *pivots = ma_pivots(mas_mn(mas), type);

- /* all limits are fine here. */
- if (mte_is_root(mas->node))
- return;
-
for (i = 0; i < mt_slots[type]; i++) {
unsigned long piv;

piv = mas_safe_pivot(mas, pivots, i, type);

- if (!piv && (i != 0))
- break;
-
- if (!mte_is_leaf(mas->node)) {
- void *entry = mas_slot(mas, slots, i);
-
- if (!entry)
- pr_err("%p[%u] cannot be null\n",
- mas_mn(mas), i);
-
- MT_BUG_ON(mas->tree, !entry);
+ if (!piv && (i != 0)) {
+ pr_err("Missing node limit pivot at %p[%u]",
+ mas_mn(mas), i);
+ MAS_WARN_ON(mas, 1);
}

if (prev_piv > piv) {
@@ -7198,6 +7189,13 @@ static void mas_validate_limits(struct ma_state *mas)
if (piv == mas->max)
break;
}
+
+ if (mas_data_end(mas) != i) {
+ pr_err("node%p: data_end %u != the last slot offset %u\n",
+ mas_mn(mas), mas_data_end(mas), i);
+ MT_BUG_ON(mas->tree, 1);
+ }
+
for (i += 1; i < mt_slots[type]; i++) {
void *entry = mas_slot(mas, slots, i);

--
2.20.1

2023-07-12 02:21:30

by Liam R. Howlett

Subject: Re: [PATCH v2 5/8] maple_tree: make mas_validate_limits() check root node and node limit

* Peng Zhang <[email protected]> [230710 23:55]:
> Update mas_validate_limits() to check root node, check node limit pivot
> if there is enough room for it to exist and check data_end. Remove the
> check for child existence as it is done in mas_validate_child_slot().
>
> Signed-off-by: Peng Zhang <[email protected]>

Reviewed-by: Liam R. Howlett <[email protected]>

> ---
> lib/maple_tree.c | 30 ++++++++++++++----------------
> 1 file changed, 14 insertions(+), 16 deletions(-)
>
> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> index f750ebef595f..072532fa18ee 100644
> --- a/lib/maple_tree.c
> +++ b/lib/maple_tree.c
> @@ -7146,7 +7146,9 @@ static void mas_validate_child_slot(struct ma_state *mas)
> }
>
> /*
> - * Validate all pivots are within mas->min and mas->max.
> + * Validate all pivots are within mas->min and mas->max, check metadata ends
> + * where the maximum ends and ensure there is no slots or pivots set outside of
> + * the end of the data.
> */
> static void mas_validate_limits(struct ma_state *mas)
> {
> @@ -7156,26 +7158,15 @@ static void mas_validate_limits(struct ma_state *mas)
> void __rcu **slots = ma_slots(mte_to_node(mas->node), type);
> unsigned long *pivots = ma_pivots(mas_mn(mas), type);
>
> - /* all limits are fine here. */
> - if (mte_is_root(mas->node))
> - return;
> -
> for (i = 0; i < mt_slots[type]; i++) {
> unsigned long piv;
>
> piv = mas_safe_pivot(mas, pivots, i, type);
>
> - if (!piv && (i != 0))
> - break;
> -
> - if (!mte_is_leaf(mas->node)) {
> - void *entry = mas_slot(mas, slots, i);
> -
> - if (!entry)
> - pr_err("%p[%u] cannot be null\n",
> - mas_mn(mas), i);
> -
> - MT_BUG_ON(mas->tree, !entry);
> + if (!piv && (i != 0)) {
> + pr_err("Missing node limit pivot at %p[%u]",
> + mas_mn(mas), i);
> + MAS_WARN_ON(mas, 1);
> }
>
> if (prev_piv > piv) {
> @@ -7198,6 +7189,13 @@ static void mas_validate_limits(struct ma_state *mas)
> if (piv == mas->max)
> break;
> }
> +
> + if (mas_data_end(mas) != i) {
> + pr_err("node%p: data_end %u != the last slot offset %u\n",
> + mas_mn(mas), mas_data_end(mas), i);
> + MT_BUG_ON(mas->tree, 1);
> + }
> +
> for (i += 1; i < mt_slots[type]; i++) {
> void *entry = mas_slot(mas, slots, i);
>
> --
> 2.20.1
>
>