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| author | Daniel Borkmann <daniel@iogearbox.net> | 2026-03-28 01:06:29 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-03-29 19:57:39 +0300 |
| commit | 398ad123e83045cd187c74689cd46851b0a0459f (patch) | |
| tree | bf7174820391597f4307bd0f2fde4b62652ca4c7 /tools/testing | |
| parent | 101a9d9df8e794af8bf06e1e09c176e2dab2abf6 (diff) | |
| download | linux-398ad123e83045cd187c74689cd46851b0a0459f.tar.xz | |
selftests/bpf: Add few tests for alu32 shift value tracking and zext
Add few more alu32 shift tests using div-by-zero on provably dead paths
to check both verifier and JIT xlation resp. runtime correctness.
If the verifier mistracks the result, it rejects due to the div by 0;
if the JIT computes a wrong value, then runtime hits the dead path and
retval changes.
# LDLIBS=-static PKG_CONFIG='pkg-config --static' ./vmtest.sh -- ./test_progs -t verifier_subreg
[...]
#644/76 verifier_subreg/arsh32_imm1_value:OK
#644/77 verifier_subreg/lsh32_reg0_zero_extend_check:OK
#644/78 verifier_subreg/rsh32_reg0_zero_extend_check:OK
#644/79 verifier_subreg/arsh32_reg0_zero_extend_check:OK
#644/80 verifier_subreg/lsh32_imm31_value:OK
#644/81 verifier_subreg/rsh32_imm31_value:OK
#644/82 verifier_subreg/arsh32_imm31_value:OK
#644/83 verifier_subreg/lsh32_unknown_precise_bounds:OK
#644/84 verifier_subreg/rsh32_unknown_bounds:OK
#644 verifier_subreg:OK
Summary: 1/84 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20260327220629.343327-1-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/testing')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/verifier_subreg.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/verifier_subreg.c b/tools/testing/selftests/bpf/progs/verifier_subreg.c index be328100ba53..31832a306f91 100644 --- a/tools/testing/selftests/bpf/progs/verifier_subreg.c +++ b/tools/testing/selftests/bpf/progs/verifier_subreg.c @@ -823,4 +823,169 @@ __naked void arsh_63_or(void) : __clobber_all); } +SEC("socket") +__success __retval(42) +__naked void arsh32_imm1_value(void) +{ + asm volatile (" \ + r0 = 42; \ + r1 = -2147483648; \ + w1 s>>= 1; /* r1 = 0xC0000000 */ \ + r2 = 0xC0000000 ll; \ + if r1 == r2 goto l0_%=; \ + r0 /= 0; /* unreachable */ \ +l0_%=: exit; \ +" : + : + : __clobber_all); +} + +SEC("socket") +__success __retval(1) +__naked void lsh32_reg0_zero_extend_check(void) +{ + asm volatile (" \ + r6 = 1; \ + call %[bpf_get_prandom_u32]; \ + r1 = 0x1000000000 ll; \ + r0 |= r1; \ + w1 = 0; \ + w0 <<= w1; /* reg shift by 0 */ \ + r0 >>= 32; /* must be 0 */ \ + if r0 == 0 goto l0_%=; \ + r6 /= 0; /* unreachable */ \ +l0_%=: r0 = r6; \ + exit; \ +" : + : __imm(bpf_get_prandom_u32) + : __clobber_all); +} + +SEC("socket") +__success __retval(1) +__naked void rsh32_reg0_zero_extend_check(void) +{ + asm volatile (" \ + r6 = 1; \ + call %[bpf_get_prandom_u32]; \ + r1 = 0x1000000000 ll; \ + r0 |= r1; \ + w1 = 0; \ + w0 >>= w1; /* reg rsh by 0 */ \ + r0 >>= 32; /* must be 0 */ \ + if r0 == 0 goto l0_%=; \ + r6 /= 0; /* unreachable */ \ +l0_%=: r0 = r6; \ + exit; \ +" : + : __imm(bpf_get_prandom_u32) + : __clobber_all); +} + +SEC("socket") +__success __retval(1) +__naked void arsh32_reg0_zero_extend_check(void) +{ + asm volatile (" \ + r6 = 1; \ + call %[bpf_get_prandom_u32]; \ + r1 = 0x1000000000 ll; \ + r0 |= r1; \ + w1 = 0; \ + w0 s>>= w1; /* reg arsh by 0 */ \ + r0 >>= 32; /* must be 0 */ \ + if r0 == 0 goto l0_%=; \ + r6 /= 0; /* unreachable */ \ +l0_%=: r0 = r6; \ + exit; \ +" : + : __imm(bpf_get_prandom_u32) + : __clobber_all); +} + +SEC("socket") +__success __retval(42) +__naked void lsh32_imm31_value(void) +{ + asm volatile (" \ + r0 = 42; \ + r1 = 1; \ + w1 <<= 31; /* r1 = 0x80000000 */ \ + r2 = 0x80000000 ll; \ + if r1 == r2 goto l0_%=; \ + r0 /= 0; /* unreachable */ \ +l0_%=: exit; \ +" : + : + : __clobber_all); +} + +SEC("socket") +__success __retval(42) +__naked void rsh32_imm31_value(void) +{ + asm volatile (" \ + r0 = 42; \ + r1 = -2147483648; /* 0x80000000 */ \ + w1 >>= 31; /* r1 = 1 */ \ + if r1 == 1 goto l0_%=; \ + r0 /= 0; /* unreachable */ \ +l0_%=: exit; \ +" : + : + : __clobber_all); +} + +SEC("socket") +__success __retval(42) +__naked void arsh32_imm31_value(void) +{ + asm volatile (" \ + r0 = 42; \ + r1 = -2147483648; /* 0x80000000 */ \ + w1 s>>= 31; /* r1 = 0xFFFFFFFF */ \ + r2 = 0xFFFFFFFF ll; \ + if r1 == r2 goto l0_%=; \ + r0 /= 0; /* unreachable */ \ +l0_%=: exit; \ +" : + : + : __clobber_all); +} + +SEC("socket") +__success __retval(1) +__naked void lsh32_unknown_precise_bounds(void) +{ + asm volatile (" \ + r6 = 1; \ + call %[bpf_get_prandom_u32]; \ + w0 &= 3; /* u32: [0, 3] */ \ + w0 <<= 1; /* u32: [0, 6] */ \ + if w0 < 7 goto l0_%=; \ + r6 /= 0; /* unreachable */ \ +l0_%=: r0 = r6; \ + exit; \ +" : + : __imm(bpf_get_prandom_u32) + : __clobber_all); +} + +SEC("socket") +__success __retval(1) +__naked void rsh32_unknown_bounds(void) +{ + asm volatile (" \ + r6 = 1; \ + call %[bpf_get_prandom_u32]; \ + w0 >>= 28; /* u32: [0, 15] */ \ + if w0 < 16 goto l0_%=; \ + r6 /= 0; /* unreachable */ \ +l0_%=: r0 = r6; \ + exit; \ +" : + : __imm(bpf_get_prandom_u32) + : __clobber_all); +} + char _license[] SEC("license") = "GPL"; |