The big_alloc1 test in verifier_arena_large assumes that the arena base and the first page allocated by bpf_arena_alloc_pages are identical. This is not the case, because the first page in the arena is populated by global arena data. The test still passes because the code makes the tacit assumption that the first page is on offset PAGE_SIZE instead of 0. Make this distinction explicit in the code, and adjust the page offsets requested during the test to count from the beginning of the arena instead of using the address of the first allocated page. Signed-off-by: Emil Tsalapatis --- .../selftests/bpf/progs/verifier_arena_large.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/bpf/progs/verifier_arena_large.c b/tools/testing/selftests/bpf/progs/verifier_arena_large.c index f19e15400b3e..bd430a34c3ab 100644 --- a/tools/testing/selftests/bpf/progs/verifier_arena_large.c +++ b/tools/testing/selftests/bpf/progs/verifier_arena_large.c @@ -23,18 +23,25 @@ int big_alloc1(void *ctx) { #if defined(__BPF_FEATURE_ADDR_SPACE_CAST) volatile char __arena *page1, *page2, *no_page, *page3; - void __arena *base; + u64 base; - page1 = base = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0); + base = (u64)arena_base(&arena); + + page1 = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0); if (!page1) return 1; + + /* Account for global arena data. */ + if ((u64)page1 != base + PAGE_SIZE) + return 15; + *page1 = 1; - page2 = bpf_arena_alloc_pages(&arena, base + ARENA_SIZE - PAGE_SIZE * 2, + page2 = bpf_arena_alloc_pages(&arena, (void __arena *)(ARENA_SIZE - PAGE_SIZE), 1, NUMA_NO_NODE, 0); if (!page2) return 2; *page2 = 2; - no_page = bpf_arena_alloc_pages(&arena, base + ARENA_SIZE - PAGE_SIZE, + no_page = bpf_arena_alloc_pages(&arena, (void __arena *)ARENA_SIZE, 1, NUMA_NO_NODE, 0); if (no_page) return 3; -- 2.49.0