Re: [PATCH] drivers: gpu: Fix warning using plain integer as NULL

From: Abhinav Singh
Date: Mon Nov 06 2023 - 10:21:20 EST


On 11/6/23 16:53, Jani Nikula wrote:
On Fri, 03 Nov 2023, Abhinav Singh <singhabhinav9051571833@xxxxxxxxx> wrote:
sparse static analysis tools generate a warning with this message
"Using plain integer as NULL pointer". In this case this warning is
being shown because we are trying to intialize a pointer to NULL using
integer value 0.

Signed-off-by: Abhinav Singh <singhabhinav9051571833@xxxxxxxxx>
---
drivers/gpu/drm/radeon/clearstate_evergreen.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/radeon/clearstate_evergreen.h b/drivers/gpu/drm/radeon/clearstate_evergreen.h
index 63a1ffbb3ced..3b645558f133 100644
--- a/drivers/gpu/drm/radeon/clearstate_evergreen.h
+++ b/drivers/gpu/drm/radeon/clearstate_evergreen.h
@@ -1049,7 +1049,7 @@ static const struct cs_extent_def SECT_CONTEXT_defs[] =
{SECT_CONTEXT_def_5, 0x0000a29e, 5 },
{SECT_CONTEXT_def_6, 0x0000a2a5, 56 },
{SECT_CONTEXT_def_7, 0x0000a2de, 290 },
- { 0, 0, 0 }
+ { NULL, 0, 0 }

Random drive-by comment:

I'd just use {} as the sentinel.

BR,
Jani.

};
static const u32 SECT_CLEAR_def_1[] =
{
@@ -1060,7 +1060,7 @@ static const u32 SECT_CLEAR_def_1[] =
static const struct cs_extent_def SECT_CLEAR_defs[] =
{
{SECT_CLEAR_def_1, 0x0000ffc0, 3 },
- { 0, 0, 0 }
+ { NULL, 0, 0 }
};
static const u32 SECT_CTRLCONST_def_1[] =
{
@@ -1070,11 +1070,11 @@ static const u32 SECT_CTRLCONST_def_1[] =
static const struct cs_extent_def SECT_CTRLCONST_defs[] =
{
{SECT_CTRLCONST_def_1, 0x0000f3fc, 2 },
- { 0, 0, 0 }
+ { NULL, 0, 0 }
};
static const struct cs_section_def evergreen_cs_data[] = {
{ SECT_CONTEXT_defs, SECT_CONTEXT },
{ SECT_CLEAR_defs, SECT_CLEAR },
{ SECT_CTRLCONST_defs, SECT_CTRLCONST },
- { 0, SECT_NONE }
+ { NULL, SECT_NONE }
};
--
2.39.2


Hi, Thanks for dropping by and the suggestion. I thought of using NULL instead of {} is because, first the warning itself says that 0 is used to intialize pointers with NULL, and second due this link https://www.spinics.net/lists/linux-sparse/msg10066.html where linus is talking about not using 0 NULL intialization of pointer variable and he thinks this is a legitimate issue and not some false positive