* Re: [PATCH v4] mm/vmalloc: replace BUG_ON to a simple if statement
2023-02-01 11:51 [PATCH v4] mm/vmalloc: replace BUG_ON to a simple if statement Hyunmin Lee
@ 2023-02-01 11:59 ` Christophe Leroy
2023-02-01 12:13 ` Hyeonggon Yoo
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Christophe Leroy @ 2023-02-01 11:59 UTC (permalink / raw)
To: Hyunmin Lee, Andrew Morton, Uladzislau Rezki, Christoph Hellwig
Cc: linux-mm, linux-kernel, Gwan-gyeong Mun, Jeungwoo Yoo,
Sangyun Kim, Mike Rapoport
Le 01/02/2023 à 12:51, Hyunmin Lee a écrit :
> As per the coding standards, in the event of an abnormal condition that
> should not occur under normal circumstances, the kernel should attempt
> recovery and proceed with execution, rather than halting the machine.
>
> Specifically, in the alloc_vmap_area() function, use a simple if()
> instead of using BUG_ON() halting the machine.
>
> Co-Developed-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
> Co-Developed-by: Jeungwoo Yoo <casionwoo@gmail.com>
> Co-Developed-by: Sangyun Kim <sangyun.kim@snu.ac.kr>
> Signed-off-by: Hyunmin Lee <hn.min.lee@gmail.com>
> Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
> Signed-off-by: Jeungwoo Yoo <casionwoo@gmail.com>
> Signed-off-by: Sangyun Kim <sangyun.kim@snu.ac.kr>
> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
> v1->v2 : Add commit description
> v2->v3 : Change WARN_ON() to if()
> v3->v4 : Use only one if() for three conditions
> ---
> mm/vmalloc.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index 74afa2208558..3b7e8856be35 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -1587,9 +1587,8 @@ static struct vmap_area *alloc_vmap_area(unsigned long size,
> int purged = 0;
> int ret;
>
> - BUG_ON(!size);
> - BUG_ON(offset_in_page(size));
> - BUG_ON(!is_power_of_2(align));
> + if (unlikely(!size || offset_in_page(size) || !is_power_of_2(align)))
> + return ERR_PTR(-EINVAL);
>
> if (unlikely(!vmap_initialized))
> return ERR_PTR(-EBUSY);
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH v4] mm/vmalloc: replace BUG_ON to a simple if statement
2023-02-01 11:51 [PATCH v4] mm/vmalloc: replace BUG_ON to a simple if statement Hyunmin Lee
2023-02-01 11:59 ` Christophe Leroy
@ 2023-02-01 12:13 ` Hyeonggon Yoo
2023-02-01 12:19 ` Mike Rapoport
2023-02-01 14:22 ` Uladzislau Rezki
3 siblings, 0 replies; 5+ messages in thread
From: Hyeonggon Yoo @ 2023-02-01 12:13 UTC (permalink / raw)
To: Hyunmin Lee
Cc: Andrew Morton, Uladzislau Rezki, Christoph Hellwig, linux-mm,
linux-kernel, Gwan-gyeong Mun, Jeungwoo Yoo, Sangyun Kim,
Mike Rapoport, Christophe Leroy
On Wed, Feb 01, 2023 at 08:51:42PM +0900, Hyunmin Lee wrote:
> As per the coding standards, in the event of an abnormal condition that
> should not occur under normal circumstances, the kernel should attempt
> recovery and proceed with execution, rather than halting the machine.
>
> Specifically, in the alloc_vmap_area() function, use a simple if()
> instead of using BUG_ON() halting the machine.
>
> Co-Developed-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
> Co-Developed-by: Jeungwoo Yoo <casionwoo@gmail.com>
> Co-Developed-by: Sangyun Kim <sangyun.kim@snu.ac.kr>
> Signed-off-by: Hyunmin Lee <hn.min.lee@gmail.com>
> Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
> Signed-off-by: Jeungwoo Yoo <casionwoo@gmail.com>
> Signed-off-by: Sangyun Kim <sangyun.kim@snu.ac.kr>
> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
> ---
> v1->v2 : Add commit description
> v2->v3 : Change WARN_ON() to if()
> v3->v4 : Use only one if() for three conditions
> ---
> mm/vmalloc.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index 74afa2208558..3b7e8856be35 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -1587,9 +1587,8 @@ static struct vmap_area *alloc_vmap_area(unsigned long size,
> int purged = 0;
> int ret;
>
> - BUG_ON(!size);
> - BUG_ON(offset_in_page(size));
> - BUG_ON(!is_power_of_2(align));
> + if (unlikely(!size || offset_in_page(size) || !is_power_of_2(align)))
> + return ERR_PTR(-EINVAL);
>
> if (unlikely(!vmap_initialized))
> return ERR_PTR(-EBUSY);
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Thanks!
> --
> 2.25.1
Regards,
Hyeonggon
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v4] mm/vmalloc: replace BUG_ON to a simple if statement
2023-02-01 11:51 [PATCH v4] mm/vmalloc: replace BUG_ON to a simple if statement Hyunmin Lee
2023-02-01 11:59 ` Christophe Leroy
2023-02-01 12:13 ` Hyeonggon Yoo
@ 2023-02-01 12:19 ` Mike Rapoport
2023-02-01 14:22 ` Uladzislau Rezki
3 siblings, 0 replies; 5+ messages in thread
From: Mike Rapoport @ 2023-02-01 12:19 UTC (permalink / raw)
To: Hyunmin Lee
Cc: Andrew Morton, Uladzislau Rezki, Christoph Hellwig, linux-mm,
linux-kernel, Gwan-gyeong Mun, Jeungwoo Yoo, Sangyun Kim,
Christophe Leroy
On Wed, Feb 01, 2023 at 08:51:42PM +0900, Hyunmin Lee wrote:
> As per the coding standards, in the event of an abnormal condition that
> should not occur under normal circumstances, the kernel should attempt
> recovery and proceed with execution, rather than halting the machine.
>
> Specifically, in the alloc_vmap_area() function, use a simple if()
> instead of using BUG_ON() halting the machine.
>
> Co-Developed-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
> Co-Developed-by: Jeungwoo Yoo <casionwoo@gmail.com>
> Co-Developed-by: Sangyun Kim <sangyun.kim@snu.ac.kr>
> Signed-off-by: Hyunmin Lee <hn.min.lee@gmail.com>
> Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
> Signed-off-by: Jeungwoo Yoo <casionwoo@gmail.com>
> Signed-off-by: Sangyun Kim <sangyun.kim@snu.ac.kr>
> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
> ---
> v1->v2 : Add commit description
> v2->v3 : Change WARN_ON() to if()
> v3->v4 : Use only one if() for three conditions
> ---
> mm/vmalloc.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index 74afa2208558..3b7e8856be35 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -1587,9 +1587,8 @@ static struct vmap_area *alloc_vmap_area(unsigned long size,
> int purged = 0;
> int ret;
>
> - BUG_ON(!size);
> - BUG_ON(offset_in_page(size));
> - BUG_ON(!is_power_of_2(align));
> + if (unlikely(!size || offset_in_page(size) || !is_power_of_2(align)))
> + return ERR_PTR(-EINVAL);
>
> if (unlikely(!vmap_initialized))
> return ERR_PTR(-EBUSY);
> --
> 2.25.1
>
--
Sincerely yours,
Mike.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v4] mm/vmalloc: replace BUG_ON to a simple if statement
2023-02-01 11:51 [PATCH v4] mm/vmalloc: replace BUG_ON to a simple if statement Hyunmin Lee
` (2 preceding siblings ...)
2023-02-01 12:19 ` Mike Rapoport
@ 2023-02-01 14:22 ` Uladzislau Rezki
3 siblings, 0 replies; 5+ messages in thread
From: Uladzislau Rezki @ 2023-02-01 14:22 UTC (permalink / raw)
To: Hyunmin Lee
Cc: Andrew Morton, Uladzislau Rezki, Christoph Hellwig, linux-mm,
linux-kernel, Gwan-gyeong Mun, Jeungwoo Yoo, Sangyun Kim,
Mike Rapoport, Christophe Leroy
On Wed, Feb 01, 2023 at 08:51:42PM +0900, Hyunmin Lee wrote:
> As per the coding standards, in the event of an abnormal condition that
> should not occur under normal circumstances, the kernel should attempt
> recovery and proceed with execution, rather than halting the machine.
>
> Specifically, in the alloc_vmap_area() function, use a simple if()
> instead of using BUG_ON() halting the machine.
>
> Co-Developed-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
> Co-Developed-by: Jeungwoo Yoo <casionwoo@gmail.com>
> Co-Developed-by: Sangyun Kim <sangyun.kim@snu.ac.kr>
> Signed-off-by: Hyunmin Lee <hn.min.lee@gmail.com>
> Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
> Signed-off-by: Jeungwoo Yoo <casionwoo@gmail.com>
> Signed-off-by: Sangyun Kim <sangyun.kim@snu.ac.kr>
> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
> ---
> v1->v2 : Add commit description
> v2->v3 : Change WARN_ON() to if()
> v3->v4 : Use only one if() for three conditions
> ---
> mm/vmalloc.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index 74afa2208558..3b7e8856be35 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -1587,9 +1587,8 @@ static struct vmap_area *alloc_vmap_area(unsigned long size,
> int purged = 0;
> int ret;
>
> - BUG_ON(!size);
> - BUG_ON(offset_in_page(size));
> - BUG_ON(!is_power_of_2(align));
> + if (unlikely(!size || offset_in_page(size) || !is_power_of_2(align)))
> + return ERR_PTR(-EINVAL);
>
> if (unlikely(!vmap_initialized))
> return ERR_PTR(-EBUSY);
> --
> 2.25.1
>
Makes sense to me.
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
--
Uladzislau Rezki
^ permalink raw reply [flat|nested] 5+ messages in thread