Clang warns (or errors with CONFIG_WERROR):
drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c:509:29: error: variable 'dst_pitch' is uninitialized when used here [-Werror,-Wuninitialized]
src_offset = ddirty->top * dst_pitch + ddirty->left * stdu->cpp;
^~~~~~~~~
drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c:492:26: note: initialize the variable 'dst_pitch' to silence this warning
s32 src_pitch, dst_pitch;
^
= 0
1 error generated.
The assignments were switched around in such a way that dst_pitch was
used before it was assigned. Swap the pitch assignments to fix the issue
and make it clear which section they are used in.
Fixes: 39985eea5a6d ("drm/vmwgfx: Abstract placement selection")
Link: https://github.com/ClangBuiltLinux/linux/issues/1811
Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
---
I am not sure if this is the right fix, as it was not entirely clear to
me that src_pitch and dst_pitch were being used in the right assignments
but this is the obvious fix otherwise. Consider this a bug report if
not :)
---
drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c b/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c
index d79a6eccfaa4..030e977c68e2 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c
@@ -504,11 +504,11 @@ static void vmw_stdu_bo_cpu_commit(struct vmw_kms_dirty *dirty)
return;
/* Assume we are blitting from Guest (bo) to Host (display_srf) */
- src_pitch = stdu->display_srf->metadata.base_size.width * stdu->cpp;
+ dst_pitch = ddirty->pitch;
src_bo = &stdu->display_srf->res.guest_memory_bo->tbo;
src_offset = ddirty->top * dst_pitch + ddirty->left * stdu->cpp;
- dst_pitch = ddirty->pitch;
+ src_pitch = stdu->display_srf->metadata.base_size.width * stdu->cpp;
dst_bo = &ddirty->buf->tbo;
dst_offset = ddirty->fb_top * src_pitch + ddirty->fb_left * stdu->cpp;
---
base-commit: c87e859cdeb5d106cb861326e3135c606d61f88d
change-id: 20230314-vmware-wuninitialized-28666fb5a62b
Best regards,
--
Nathan Chancellor <nathan@xxxxxxxxxx>
