Applied. Thanks!

On Wed, May 29, 2024 at 5:54 PM Nathan Chancellor nathan@kernel.org wrote:

From: Bill Wendling morbo@google.com

Work for __counted_by on generic pointers in structures (not just flexible array members) has started landing in Clang 19 (current tip of tree). During the development of this feature, a restriction was added to __counted_by to prevent the flexible array member's element type from including a flexible array member itself such as:

struct foo { int count; char buf[]; };

struct bar { int count; struct foo data[] __counted_by(count); };

because the size of data cannot be calculated with the standard array size formula:

sizeof(struct foo) * count

This restriction was downgraded to a warning but due to CONFIG_WERROR, it can still break the build. The application of __counted_by on the states member of 'struct _StateArray' triggers this restriction, resulting in:

drivers/gpu/drm/radeon/pptable.h:442:5: error: 'counted_by' should not be applied to an array with element of unknown size because 'ATOM_PPLIB_STATE_V2' (aka 'struct _ATOM_PPLIB_STATE_V2') is a struct type with a flexible array member. This will be an error in a future compiler version [-Werror,-Wbounds-safety-counted-by-elt-type-unknown-size] 442 | ATOM_PPLIB_STATE_V2 states[] __counted_by(ucNumEntries); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1 error generated.

Remove this use of __counted_by to fix the warning/error. However, rather than remove it altogether, leave it commented, as it may be possible to support this in future compiler releases.

Cc: stable@vger.kernel.org Closes: https://github.com/ClangBuiltLinux/linux/issues/2028 Fixes: efade6fe50e7 ("drm/radeon: silence UBSAN warning (v3)") Signed-off-by: Bill Wendling morbo@google.com Co-developed-by: Nathan Chancellor nathan@kernel.org Signed-off-by: Nathan Chancellor nathan@kernel.org

---

drivers/gpu/drm/radeon/pptable.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/radeon/pptable.h b/drivers/gpu/drm/radeon/pptable.h index b7f22597ee95..969a8fb0ee9e 100644 --- a/drivers/gpu/drm/radeon/pptable.h +++ b/drivers/gpu/drm/radeon/pptable.h @@ -439,7 +439,7 @@ typedef struct _StateArray{ //how many states we have UCHAR ucNumEntries;

• ATOM_PPLIB_STATE_V2 states[] __counted_by(ucNumEntries);

• ATOM_PPLIB_STATE_V2 states[] /* __counted_by(ucNumEntries) */;

}StateArray;

---

base-commit: e64e8f7c178e5228e0b2dbb504b9dc75953a319f change-id: 20240529-drop-counted-by-radeon-states-state-array-01936ded4c18

Best regards,

Nathan Chancellor nathan@kernel.org