diff options
| author | Yonghong Song <yhs@fb.com> | 2023-04-17 15:21:39 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2023-04-17 15:50:02 -0700 |
| commit | 49859de997c3115b85544bce6b6ceab60a7fabc4 (patch) | |
| tree | dea1dee4515026d2088b98f53144c0631c608e6a /tools | |
| parent | 3be49f79555ee975acb4ad8b5de06fa4351264aa (diff) | |
selftests/bpf: Add a selftest for checking subreg equality
Add a selftest to ensure subreg equality if source register
upper 32bit is 0. Without previous patch, the test will
fail verification.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20230417222139.360607-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/verifier.c | 2 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/progs/verifier_reg_equal.c | 58 |
2 files changed, 60 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/verifier.c b/tools/testing/selftests/bpf/prog_tests/verifier.c index 73dff693d411..25bc8958dbfe 100644 --- a/tools/testing/selftests/bpf/prog_tests/verifier.c +++ b/tools/testing/selftests/bpf/prog_tests/verifier.c @@ -31,6 +31,7 @@ #include "verifier_meta_access.skel.h" #include "verifier_raw_stack.skel.h" #include "verifier_raw_tp_writable.skel.h" +#include "verifier_reg_equal.skel.h" #include "verifier_ringbuf.skel.h" #include "verifier_spill_fill.skel.h" #include "verifier_stack_ptr.skel.h" @@ -95,6 +96,7 @@ void test_verifier_masking(void) { RUN(verifier_masking); } void test_verifier_meta_access(void) { RUN(verifier_meta_access); } void test_verifier_raw_stack(void) { RUN(verifier_raw_stack); } void test_verifier_raw_tp_writable(void) { RUN(verifier_raw_tp_writable); } +void test_verifier_reg_equal(void) { RUN(verifier_reg_equal); } void test_verifier_ringbuf(void) { RUN(verifier_ringbuf); } void test_verifier_spill_fill(void) { RUN(verifier_spill_fill); } void test_verifier_stack_ptr(void) { RUN(verifier_stack_ptr); } diff --git a/tools/testing/selftests/bpf/progs/verifier_reg_equal.c b/tools/testing/selftests/bpf/progs/verifier_reg_equal.c new file mode 100644 index 000000000000..dc1d8c30fb0e --- /dev/null +++ b/tools/testing/selftests/bpf/progs/verifier_reg_equal.c @@ -0,0 +1,58 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/bpf.h> +#include <bpf/bpf_helpers.h> +#include "bpf_misc.h" + +SEC("socket") +__description("check w reg equal if r reg upper32 bits 0") +__success +__naked void subreg_equality_1(void) +{ + asm volatile (" \ + call %[bpf_ktime_get_ns]; \ + *(u64 *)(r10 - 8) = r0; \ + r2 = *(u32 *)(r10 - 8); \ + /* At this point upper 4-bytes of r2 are 0, \ + * thus insn w3 = w2 should propagate reg id, \ + * and w2 < 9 comparison would also propagate \ + * the range for r3. \ + */ \ + w3 = w2; \ + if w2 < 9 goto l0_%=; \ + exit; \ +l0_%=: if r3 < 9 goto l1_%=; \ + /* r1 read is illegal at this point */ \ + r0 -= r1; \ +l1_%=: exit; \ +" : + : __imm(bpf_ktime_get_ns) + : __clobber_all); +} + +SEC("socket") +__description("check w reg not equal if r reg upper32 bits not 0") +__failure __msg("R1 !read_ok") +__naked void subreg_equality_2(void) +{ + asm volatile (" \ + call %[bpf_ktime_get_ns]; \ + r2 = r0; \ + /* Upper 4-bytes of r2 may not be 0, thus insn \ + * w3 = w2 should not propagate reg id, and \ + * w2 < 9 comparison should not propagate \ + * the range for r3 either. \ + */ \ + w3 = w2; \ + if w2 < 9 goto l0_%=; \ + exit; \ +l0_%=: if r3 < 9 goto l1_%=; \ + /* r1 read is illegal at this point */ \ + r0 -= r1; \ +l1_%=: exit; \ +" : + : __imm(bpf_ktime_get_ns) + : __clobber_all); +} + +char _license[] SEC("license") = "GPL"; |