diff mbox series

rcu: Annotate struct kvfree_rcu_bulk_data with __counted_by()

Message ID 20240807095459.1400-2-thorsten.blum@toblux.com (mailing list archive)
State Mainlined
Commit fb579e6656a8d5e042e65062f68ca41321817237
Headers show
Series rcu: Annotate struct kvfree_rcu_bulk_data with __counted_by() | expand

Commit Message

Thorsten Blum Aug. 7, 2024, 9:55 a.m. UTC
Add the __counted_by compiler attribute to the flexible array member
records to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
CONFIG_FORTIFY_SOURCE.

Increment nr_records before adding a new pointer to the records array.

Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
---
 kernel/rcu/tree.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Comments

Gustavo A. R. Silva Aug. 7, 2024, 3:29 p.m. UTC | #1
On 07/08/24 03:55, Thorsten Blum wrote:
> Add the __counted_by compiler attribute to the flexible array member
> records to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
> CONFIG_FORTIFY_SOURCE.
> 
> Increment nr_records before adding a new pointer to the records array.
> 

Looks good.

> Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>

Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Thanks
--
Gustavo

> ---
>   kernel/rcu/tree.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
> index e641cc681901..76d8d75dd8b3 100644
> --- a/kernel/rcu/tree.c
> +++ b/kernel/rcu/tree.c
> @@ -3227,7 +3227,7 @@ struct kvfree_rcu_bulk_data {
>   	struct list_head list;
>   	struct rcu_gp_oldstate gp_snap;
>   	unsigned long nr_records;
> -	void *records[];
> +	void *records[] __counted_by(nr_records);
>   };
>   
>   /*
> @@ -3767,7 +3767,8 @@ add_ptr_to_bulk_krc_lock(struct kfree_rcu_cpu **krcp,
>   	}
>   
>   	// Finally insert and update the GP for this page.
> -	bnode->records[bnode->nr_records++] = ptr;
> +	bnode->nr_records++;
> +	bnode->records[bnode->nr_records - 1] = ptr;
>   	get_state_synchronize_rcu_full(&bnode->gp_snap);
>   	atomic_inc(&(*krcp)->bulk_count[idx]);
>
Uladzislau Rezki (Sony) Aug. 7, 2024, 3:35 p.m. UTC | #2
On Wed, Aug 07, 2024 at 11:55:00AM +0200, Thorsten Blum wrote:
> Add the __counted_by compiler attribute to the flexible array member
> records to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
> CONFIG_FORTIFY_SOURCE.
> 
> Increment nr_records before adding a new pointer to the records array.
> 
> Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
> ---
>  kernel/rcu/tree.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
> index e641cc681901..76d8d75dd8b3 100644
> --- a/kernel/rcu/tree.c
> +++ b/kernel/rcu/tree.c
> @@ -3227,7 +3227,7 @@ struct kvfree_rcu_bulk_data {
>  	struct list_head list;
>  	struct rcu_gp_oldstate gp_snap;
>  	unsigned long nr_records;
> -	void *records[];
> +	void *records[] __counted_by(nr_records);
>  };
>  
>  /*
> @@ -3767,7 +3767,8 @@ add_ptr_to_bulk_krc_lock(struct kfree_rcu_cpu **krcp,
>  	}
>  
>  	// Finally insert and update the GP for this page.
> -	bnode->records[bnode->nr_records++] = ptr;
> +	bnode->nr_records++;
> +	bnode->records[bnode->nr_records - 1] = ptr;
>  	get_state_synchronize_rcu_full(&bnode->gp_snap);
>  	atomic_inc(&(*krcp)->bulk_count[idx]);
>  
> -- 
> 2.45.2
> 
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>

--
Uladzislau Rezki
Paul E. McKenney Aug. 8, 2024, 6:02 p.m. UTC | #3
On Wed, Aug 07, 2024 at 11:55:00AM +0200, Thorsten Blum wrote:
> Add the __counted_by compiler attribute to the flexible array member
> records to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
> CONFIG_FORTIFY_SOURCE.
> 
> Increment nr_records before adding a new pointer to the records array.
> 
> Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>

Reviewed-by: Paul E. McKenney <paulmck@kernel.org>

> ---
>  kernel/rcu/tree.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
> index e641cc681901..76d8d75dd8b3 100644
> --- a/kernel/rcu/tree.c
> +++ b/kernel/rcu/tree.c
> @@ -3227,7 +3227,7 @@ struct kvfree_rcu_bulk_data {
>  	struct list_head list;
>  	struct rcu_gp_oldstate gp_snap;
>  	unsigned long nr_records;
> -	void *records[];
> +	void *records[] __counted_by(nr_records);
>  };
>  
>  /*
> @@ -3767,7 +3767,8 @@ add_ptr_to_bulk_krc_lock(struct kfree_rcu_cpu **krcp,
>  	}
>  
>  	// Finally insert and update the GP for this page.
> -	bnode->records[bnode->nr_records++] = ptr;
> +	bnode->nr_records++;
> +	bnode->records[bnode->nr_records - 1] = ptr;
>  	get_state_synchronize_rcu_full(&bnode->gp_snap);
>  	atomic_inc(&(*krcp)->bulk_count[idx]);
>  
> -- 
> 2.45.2
>
diff mbox series

Patch

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index e641cc681901..76d8d75dd8b3 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3227,7 +3227,7 @@  struct kvfree_rcu_bulk_data {
 	struct list_head list;
 	struct rcu_gp_oldstate gp_snap;
 	unsigned long nr_records;
-	void *records[];
+	void *records[] __counted_by(nr_records);
 };
 
 /*
@@ -3767,7 +3767,8 @@  add_ptr_to_bulk_krc_lock(struct kfree_rcu_cpu **krcp,
 	}
 
 	// Finally insert and update the GP for this page.
-	bnode->records[bnode->nr_records++] = ptr;
+	bnode->nr_records++;
+	bnode->records[bnode->nr_records - 1] = ptr;
 	get_state_synchronize_rcu_full(&bnode->gp_snap);
 	atomic_inc(&(*krcp)->bulk_count[idx]);