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| author | Andrii Nakryiko <andriin@fb.com> | 2020-05-13 01:59:25 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-05-14 21:40:04 +0200 |
| commit | 333291ce5055f2039afc907badaf5b66bc1adfdc (patch) | |
| tree | 27c603d11355ab26e741a267cf52b112b70a91b5 /tools | |
| parent | samples: bpf: Fix build error (diff) | |
| download | linux-333291ce5055f2039afc907badaf5b66bc1adfdc.tar.xz linux-333291ce5055f2039afc907badaf5b66bc1adfdc.zip | |
bpf: Fix bug in mmap() implementation for BPF array map
mmap() subsystem allows user-space application to memory-map region with
initial page offset. This wasn't taken into account in initial implementation
of BPF array memory-mapping. This would result in wrong pages, not taking into
account requested page shift, being memory-mmaped into user-space. This patch
fixes this gap and adds a test for such scenario.
Fixes: fc9702273e2e ("bpf: Add mmap() support for BPF_MAP_TYPE_ARRAY")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200512235925.3817805-1-andriin@fb.com
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/mmap.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/mmap.c b/tools/testing/selftests/bpf/prog_tests/mmap.c index 56d80adcf4bd..6b9dce431d41 100644 --- a/tools/testing/selftests/bpf/prog_tests/mmap.c +++ b/tools/testing/selftests/bpf/prog_tests/mmap.c @@ -217,6 +217,14 @@ void test_mmap(void) munmap(tmp2, 4 * page_size); + /* map all 4 pages, but with pg_off=1 page, should fail */ + tmp1 = mmap(NULL, 4 * page_size, PROT_READ, MAP_SHARED | MAP_FIXED, + data_map_fd, page_size /* initial page shift */); + if (CHECK(tmp1 != MAP_FAILED, "adv_mmap7", "unexpected success")) { + munmap(tmp1, 4 * page_size); + goto cleanup; + } + tmp1 = mmap(NULL, map_sz, PROT_READ, MAP_SHARED, data_map_fd, 0); if (CHECK(tmp1 == MAP_FAILED, "last_mmap", "failed %d\n", errno)) goto cleanup; |