On 2023/8/21 15:04, Christophe JAILLET wrote:
Le 21/08/2023 à 08:22, Su Hui a écrit :
smatch error:
drivers/gpu/drm/ast/ast_dp501.c:227 ast_launch_m68k() error:
we previously assumed 'ast->dp501_fw' could be null (see line 223)
when "!ast->dp501_fw" and "ast_load_dp501_microcode(dev) >= 0" is true,
there will be a NULL dereference of 'ast->dp501_fw'.
Fixes: 12f8030e05c6 ("drm/ast: Actually load DP501 firmware when
required")
Signed-off-by: Su Hui <suhui@xxxxxxxxxxxx>
---
drivers/gpu/drm/ast/ast_dp501.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/ast/ast_dp501.c
b/drivers/gpu/drm/ast/ast_dp501.c
index 1bc35a992369..d9f3a0786a6f 100644
--- a/drivers/gpu/drm/ast/ast_dp501.c
+++ b/drivers/gpu/drm/ast/ast_dp501.c
@@ -224,8 +224,10 @@ static bool ast_launch_m68k(struct drm_device *dev)
ast_load_dp501_microcode(dev) < 0)
return false;
- fw_addr = (u8 *)ast->dp501_fw->data;
- len = ast->dp501_fw->size;
+ if (ast->dp501_fw) {
+ fw_addr = (u8 *)ast->dp501_fw->data;
+ len = ast->dp501_fw->size;
+ }
}
/* Get BootAddress */
ast_moutdwm(ast, 0x1e6e2000, 0x1688a8a8);
Hi,
this looks like a false positive.
If "!ast->dp501_fw", and ast_load_dp501_microcode()>=0, then
ast_load_dp501_microcode() will set a valid value in ast->dp501_fw.
Hi,
Sorry for the noise, you are right, this is a false positive.
I will take more careful next time.
Su Hui
CJ
