From: Hou Tao <houtao1@huawei.com> mainline inclusion from mainline-v6.12-rc6 commit ebafc1e535db19505aec3b94a4a641fe735a2eac category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IDC9YK Reference: https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commi... -------------------------------- Add more test cases for bits iterator: (1) huge word test Verify the multiplication overflow of nr_bits in bits_iter. Without the overflow check, when nr_words is 67108865, nr_bits becomes 64, causing bpf_probe_read_kernel_common() to corrupt the stack. (2) max word test Verify correct handling of maximum nr_words value (511). (3) bad word test Verify early termination of bits iteration when bits iterator initialization fails. Also rename bits_nomem to bits_too_big to better reflect its purpose. Signed-off-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20241030100516.3633640-6-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Zicheng Qu <quzicheng@huawei.com> --- .../selftests/bpf/progs/verifier_bits_iter.c | 61 ++++++++++++++++++- 1 file changed, 58 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/bpf/progs/verifier_bits_iter.c b/tools/testing/selftests/bpf/progs/verifier_bits_iter.c index 716113c2bce2..e1421d846ac8 100644 --- a/tools/testing/selftests/bpf/progs/verifier_bits_iter.c +++ b/tools/testing/selftests/bpf/progs/verifier_bits_iter.c @@ -15,6 +15,8 @@ int bpf_iter_bits_new(struct bpf_iter_bits *it, const u64 *unsafe_ptr__ign, int *bpf_iter_bits_next(struct bpf_iter_bits *it) __ksym __weak; void bpf_iter_bits_destroy(struct bpf_iter_bits *it) __ksym __weak; +u64 bits_array[511] = {}; + SEC("iter.s/cgroup") __description("bits iter without destroy") __failure __msg("Unreleased reference") @@ -110,16 +112,16 @@ int bit_index(void) } SEC("syscall") -__description("bits nomem") +__description("bits too big") __success __retval(0) -int bits_nomem(void) +int bits_too_big(void) { u64 data[4]; int nr = 0; int *bit; __builtin_memset(&data, 0xff, sizeof(data)); - bpf_for_each(bits, bit, &data[0], 513) /* Be greater than 512 */ + bpf_for_each(bits, bit, &data[0], 512) /* Be greater than 511 */ nr++; return nr; } @@ -151,3 +153,56 @@ int zero_words(void) nr++; return nr; } + +SEC("syscall") +__description("huge words") +__success __retval(0) +int huge_words(void) +{ + u64 data[8] = {0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1}; + int nr = 0; + int *bit; + + bpf_for_each(bits, bit, &data[0], 67108865) + nr++; + return nr; +} + +SEC("syscall") +__description("max words") +__success __retval(4) +int max_words(void) +{ + volatile int nr = 0; + int *bit; + + bits_array[0] = (1ULL << 63) | 1U; + bits_array[510] = (1ULL << 33) | (1ULL << 32); + + bpf_for_each(bits, bit, bits_array, 511) { + if (nr == 0 && *bit != 0) + break; + if (nr == 2 && *bit != 32672) + break; + nr++; + } + return nr; +} + +SEC("syscall") +__description("bad words") +__success __retval(0) +int bad_words(void) +{ + void *bad_addr = (void *)(3UL << 30); + int nr = 0; + int *bit; + + bpf_for_each(bits, bit, bad_addr, 1) + nr++; + + bpf_for_each(bits, bit, bad_addr, 4) + nr++; + + return nr; +} -- 2.34.1