6.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Nathan Chancellor nathan@kernel.org
commit 440e2051c577896275c0e0513ec26964e04c7810 upstream.
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 fod member of 'struct nvmet_fc_tgt_queue' triggers this restriction, resulting in:
drivers/nvme/target/fc.c:151:2: error: 'counted_by' should not be applied to an array with element of unknown size because 'struct nvmet_fc_fcp_iod' 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] 151 | struct nvmet_fc_fcp_iod fod[] __counted_by(sqsize); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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/2027 Fixes: ccd3129aca28 ("nvmet-fc: Annotate struct nvmet_fc_tgt_queue with __counted_by") Signed-off-by: Nathan Chancellor nathan@kernel.org Signed-off-by: Keith Busch kbusch@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/nvme/target/fc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/nvme/target/fc.c +++ b/drivers/nvme/target/fc.c @@ -148,7 +148,7 @@ struct nvmet_fc_tgt_queue { struct workqueue_struct *work_q; struct kref ref; /* array of fcp_iods */ - struct nvmet_fc_fcp_iod fod[] __counted_by(sqsize); + struct nvmet_fc_fcp_iod fod[] /* __counted_by(sqsize) */; } __aligned(sizeof(unsigned long long));
struct nvmet_fc_hostport {