From: Alexei Starovoitov ast@kernel.org

Add a test that verifies specific behavior of arena range tree algorithm and adjust existing big_alloc1 test due to use of global data in arena.

Signed-off-by: Alexei Starovoitov ast@kernel.org Signed-off-by: Andrii Nakryiko andrii@kernel.org Acked-by: Kumar Kartikeya Dwivedi memxor@gmail.com Link: https://lore.kernel.org/bpf/20241108025616.17625-3-alexei.starovoitov@gmail.... (cherry picked from commit e58358afa84e8e271a296459d35d1715c7572013)

[Yifei: This commit fixes the failure of verifier_arena_large test over 64k page size kernels. This commit also introduce some new tests targeting the new feature, arena range tree algorithm, which is not in linux-6.12.y, I just comment out the test headers so that it would not be run here. If this feature is introduced later, we can just uncomment those two lines.]

Signed-off-by: Yifei Liu yifei.l.liu@oracle.com --- .../bpf/progs/verifier_arena_large.c | 110 +++++++++++++++++- 1 file changed, 108 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/verifier_arena_large.c b/tools/testing/selftests/bpf/progs/verifier_arena_large.c index 6065f862d964..f318675814c6 100644 --- a/tools/testing/selftests/bpf/progs/verifier_arena_large.c +++ b/tools/testing/selftests/bpf/progs/verifier_arena_large.c @@ -29,12 +29,12 @@ int big_alloc1(void *ctx) if (!page1) return 1; *page1 = 1; - page2 = bpf_arena_alloc_pages(&arena, base + ARENA_SIZE - PAGE_SIZE, + page2 = bpf_arena_alloc_pages(&arena, base + ARENA_SIZE - PAGE_SIZE * 2, 1, NUMA_NO_NODE, 0); if (!page2) return 2; *page2 = 2; - no_page = bpf_arena_alloc_pages(&arena, base + ARENA_SIZE, + no_page = bpf_arena_alloc_pages(&arena, base + ARENA_SIZE - PAGE_SIZE, 1, NUMA_NO_NODE, 0); if (no_page) return 3; @@ -66,4 +66,110 @@ int big_alloc1(void *ctx) #endif return 0; } + +#if defined(__BPF_FEATURE_ADDR_SPACE_CAST) +#define PAGE_CNT 100 +__u8 __arena * __arena page[PAGE_CNT]; /* occupies the first page */ +__u8 __arena *base; + +/* + * Check that arena's range_tree algorithm allocates pages sequentially + * on the first pass and then fills in all gaps on the second pass. + */ +__noinline int alloc_pages(int page_cnt, int pages_atonce, bool first_pass, + int max_idx, int step) +{ + __u8 __arena *pg; + int i, pg_idx; + + for (i = 0; i < page_cnt; i++) { + pg = bpf_arena_alloc_pages(&arena, NULL, pages_atonce, + NUMA_NO_NODE, 0); + if (!pg) + return step; + pg_idx = (pg - base) / PAGE_SIZE; + if (first_pass) { + /* Pages must be allocated sequentially */ + if (pg_idx != i) + return step + 100; + } else { + /* Allocator must fill into gaps */ + if (pg_idx >= max_idx || (pg_idx & 1)) + return step + 200; + } + *pg = pg_idx; + page[pg_idx] = pg; + cond_break; + } + return 0; +} + +//SEC("syscall") +//__success __retval(0) +int big_alloc2(void *ctx) +{ + __u8 __arena *pg; + int i, err; + + base = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0); + if (!base) + return 1; + bpf_arena_free_pages(&arena, (void __arena *)base, 1); + + err = alloc_pages(PAGE_CNT, 1, true, PAGE_CNT, 2); + if (err) + return err; + + /* Clear all even pages */ + for (i = 0; i < PAGE_CNT; i += 2) { + pg = page[i]; + if (*pg != i) + return 3; + bpf_arena_free_pages(&arena, (void __arena *)pg, 1); + page[i] = NULL; + cond_break; + } + + /* Allocate into freed gaps */ + err = alloc_pages(PAGE_CNT / 2, 1, false, PAGE_CNT, 4); + if (err) + return err; + + /* Free pairs of pages */ + for (i = 0; i < PAGE_CNT; i += 4) { + pg = page[i]; + if (*pg != i) + return 5; + bpf_arena_free_pages(&arena, (void __arena *)pg, 2); + page[i] = NULL; + page[i + 1] = NULL; + cond_break; + } + + /* Allocate 2 pages at a time into freed gaps */ + err = alloc_pages(PAGE_CNT / 4, 2, false, PAGE_CNT, 6); + if (err) + return err; + + /* Check pages without freeing */ + for (i = 0; i < PAGE_CNT; i += 2) { + pg = page[i]; + if (*pg != i) + return 7; + cond_break; + } + + pg = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0); + + if (!pg) + return 8; + /* + * The first PAGE_CNT pages are occupied. The new page + * must be above. + */ + if ((pg - base) / PAGE_SIZE < PAGE_CNT) + return 9; + return 0; +} +#endif char _license[] SEC("license") = "GPL";