LinuxLists.cc - DRM/ttm: Unreachable code in ttm_bo_add

2009-12-07 20:42:20

Subject: DRM/ttm: Unreachable code in ttm_bo_add_ttm

2009-12-07 23:28:39

by Dave Airlie

[permalink] [raw]

Subject: Re: DRM/ttm: Unreachable code in ttm_bo_add_ttm

On Mon, 7 Dec 2009, Jiri Slaby wrote:

> Hi,
>
> Stanse found unreachable code in ttm_bo_add_ttm:
> http://decibel.fi.muni.cz/~xslaby/stanse/error.cgi?db=32&id=714#l238
>
> Excerpt from there:
> 230| case ttm_bo_type_user:
> 231| bo->ttm = ttm_tt_create(bdev, bo->num_pages << 12,
> 232| page_flags | (1 << 1),
> 233| glob->dummy_read_page);
> 234| if (bo->ttm == ((void *)0))
> 235| ret = -12;
> 236| break;
> 237|
> 238| ret = ttm_tt_set_user(bo->ttm, get_current(),
> |This node is unreachable prev next
> 239| bo->buffer_start, bo->num_pages);
> 240| if (ret != 0)
> 241| ttm_tt_destroy(bo->ttm);
> 242| break;
>
>

Thanks,
I've pushed this patch.

>From 447aeb907e417e0e837b4a4026d5081c88b6e8ca Mon Sep 17 00:00:00 2001
From: Dave Airlie <[email protected]>
Date: Tue, 8 Dec 2009 09:25:45 +1000
Subject: [PATCH] drm/ttm: fix unreachable code.

None of the in-tree drivers use user objects yet so this wasn't hitting
us.

Stanse found unreachable code in ttm_bo_add_ttm:
http://decibel.fi.muni.cz/~xslaby/stanse/error.cgi?db=32&id=714#l238

Reported-by: Jiri Slaby <[email protected]>
Signed-off-by: Dave Airlie <[email protected]>
---
drivers/gpu/drm/ttm/ttm_bo.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 87c0625..e13fd23 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -275,9 +275,10 @@ static int ttm_bo_add_ttm(struct ttm_buffer_object *bo, bool zero_alloc)
bo->ttm = ttm_tt_create(bdev, bo->num_pages << PAGE_SHIFT,
page_flags | TTM_PAGE_FLAG_USER,
glob->dummy_read_page);
- if (unlikely(bo->ttm == NULL))
+ if (unlikely(bo->ttm == NULL)) {
ret = -ENOMEM;
- break;
+ break;
+ }

ret = ttm_tt_set_user(bo->ttm, current,
bo->buffer_start, bo->num_pages);
--
1.6.5.2

2009-12-08 10:34:53

by Jiri Slaby

[permalink] [raw]

Subject: Re: DRM/ttm: Unreachable code in ttm_bo_add_ttm

On 12/08/2009 12:28 AM, Dave Airlie wrote:
> From 447aeb907e417e0e837b4a4026d5081c88b6e8ca Mon Sep 17 00:00:00 2001
> From: Dave Airlie <[email protected]>
> Date: Tue, 8 Dec 2009 09:25:45 +1000
> Subject: [PATCH] drm/ttm: fix unreachable code.
>
> None of the in-tree drivers use user objects yet so this wasn't hitting
> us.
>
> Stanse found unreachable code in ttm_bo_add_ttm:
> http://decibel.fi.muni.cz/~xslaby/stanse/error.cgi?db=32&id=714#l238

Please don't use the link in changelog, it's only temporary. Well, it
will probably be there for months, but the changelog will be there forever.

Thanks.