When building with LTO (Link Time Optimization), GCC performs aggressive cross-compilation-unit inlining. This causes the compiler to analyze all code paths in __rte_ring_do_dequeue_elems(), including the 16-byte element path (__rte_ring_dequeue_elems_128), even when the runtime element size is only 4 bytes.
The static analyzer sees that the 16-byte path would copy 32 elements * 16 bytes = 512 bytes into a 128-byte buffer (uint32_t[32]), triggering -Wstringop-overflow warnings. The existing #pragma GCC diagnostic suppression in rte_ring_elem_pvt.h doesn't help because with LTO the warning context shifts to the test file where the inlined code is instantiated. Fix by sizing all buffers passed to soring acquire/dequeue functions for the worst-case element size (16 bytes = 4 * sizeof(uint32_t)). This satisfies the static analyzer without changing runtime behavior. Bugzilla ID: 1458 Signed-off-by: Stephen Hemminger <[email protected]> --- app/test/test_soring.c | 29 ++++++++++++++++++++++------- 1 file changed, 22 insertions(+), 7 deletions(-) diff --git a/app/test/test_soring.c b/app/test/test_soring.c index 3c1944424e..96be3935d4 100644 --- a/app/test/test_soring.c +++ b/app/test/test_soring.c @@ -31,6 +31,19 @@ #define MAX_ACQUIRED 20 +/* + * Buffer scaling factor for static analyzer appeasement. + * + * With LTO, GCC analyzes all code paths in __rte_ring_do_dequeue_elems(), + * including the 16-byte element path, even when runtime esize is smaller. + * Buffers passed to soring acquire/dequeue must be sized for the worst-case + * element size (16 bytes) to avoid -Wstringop-overflow warnings. + * + * Scale factor of 4 converts uint32_t count to 16-byte element capacity: + * N elements * 4 * sizeof(uint32_t) = N * 16 bytes + */ +#define SORING_TEST_BUFSIZE(n) ((n) * 4) + #define SORING_TEST_ASSERT(val, expected) do { \ RTE_TEST_ASSERT(expected == val, \ "%s: expected %u got %u\n", #val, expected, val); \ @@ -58,7 +71,8 @@ move_forward_stage(struct rte_soring *sor, { uint32_t acquired; uint32_t ftoken; - uint32_t *acquired_objs[MAX_ACQUIRED]; + /* Sized for 16-byte elements to satisfy LTO static analysis */ + uint32_t *acquired_objs[SORING_TEST_BUFSIZE(MAX_ACQUIRED)]; acquired = rte_soring_acquire_bulk(sor, acquired_objs, stage, num_packets, &ftoken, NULL); @@ -149,12 +163,13 @@ test_soring_stages(void) { struct rte_soring *sor = NULL; struct rte_soring_param prm; - uint32_t objs[32]; - uint32_t rcs[32]; - uint32_t acquired_objs[32]; - uint32_t acquired_rcs[32]; - uint32_t dequeued_rcs[32]; - uint32_t dequeued_objs[32]; + /* Buffers sized for 16-byte elements to satisfy LTO static analysis */ + uint32_t objs[SORING_TEST_BUFSIZE(32)]; + uint32_t rcs[SORING_TEST_BUFSIZE(32)]; + uint32_t acquired_objs[SORING_TEST_BUFSIZE(32)]; + uint32_t acquired_rcs[SORING_TEST_BUFSIZE(32)]; + uint32_t dequeued_rcs[SORING_TEST_BUFSIZE(32)]; + uint32_t dequeued_objs[SORING_TEST_BUFSIZE(32)]; size_t ssz; uint32_t stage, enqueued, dequeued, acquired; uint32_t i, ftoken; -- 2.51.0
