diff options
| author | Alexei Starovoitov <ast@kernel.org> | 2026-01-12 12:13:58 -0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-01-13 09:33:38 -0800 |
| commit | 9160335317cb404f54ad2f509546c666ddd4d0eb (patch) | |
| tree | 6357e2f47ee6e2cea79d41f8ed0bbc100f248427 | |
| parent | bffacdb80b93b7b5e96b26fad64cc490a6c7d6c7 (diff) | |
selftests/bpf: Add tests for s>>=31 and s>>=63
Add tests for special arithmetic shift right.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Co-developed-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Link: https://lore.kernel.org/r/20260112201424.816836-3-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | tools/testing/selftests/bpf/progs/verifier_subreg.c | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/verifier_subreg.c b/tools/testing/selftests/bpf/progs/verifier_subreg.c index b3e1c3eef9ae..be328100ba53 100644 --- a/tools/testing/selftests/bpf/progs/verifier_subreg.c +++ b/tools/testing/selftests/bpf/progs/verifier_subreg.c @@ -738,4 +738,89 @@ __naked void ldx_w_zero_extend_check(void) : __clobber_all); } +SEC("socket") +__success __success_unpriv __retval(0) +__naked void arsh_31_and(void) +{ + /* Below is what LLVM generates in cilium's bpf_wiregard.o */ + asm volatile (" \ + call %[bpf_get_prandom_u32]; \ + w2 = w0; \ + w2 s>>= 31; \ + w2 &= -134; /* w2 becomes 0 or -134 */ \ + if w2 s> -1 goto +2; \ + /* Branch always taken because w2 = -134 */ \ + if w2 != -136 goto +1; \ + w0 /= 0; \ + w0 = 0; \ + exit; \ +" : + : __imm(bpf_get_prandom_u32) + : __clobber_all); +} + +SEC("socket") +__success __success_unpriv __retval(0) +__naked void arsh_63_and(void) +{ + /* Copy of arsh_31 with s/w/r/ */ + asm volatile (" \ + call %[bpf_get_prandom_u32]; \ + r2 = r0; \ + r2 <<= 32; \ + r2 s>>= 63; \ + r2 &= -134; \ + if r2 s> -1 goto +2; \ + /* Branch always taken because w2 = -134 */ \ + if r2 != -136 goto +1; \ + r0 /= 0; \ + r0 = 0; \ + exit; \ +" : + : __imm(bpf_get_prandom_u32) + : __clobber_all); +} + +SEC("socket") +__success __success_unpriv __retval(0) +__naked void arsh_31_or(void) +{ + asm volatile (" \ + call %[bpf_get_prandom_u32]; \ + w2 = w0; \ + w2 s>>= 31; \ + w2 |= 134; /* w2 becomes -1 or 134 */ \ + if w2 s> -1 goto +2; \ + /* Branch always taken because w2 = -1 */ \ + if w2 == -1 goto +1; \ + w0 /= 0; \ + w0 = 0; \ + exit; \ +" : + : __imm(bpf_get_prandom_u32) + : __clobber_all); +} + +SEC("socket") +__success __success_unpriv __retval(0) +__naked void arsh_63_or(void) +{ + /* Copy of arsh_31 with s/w/r/ */ + asm volatile (" \ + call %[bpf_get_prandom_u32]; \ + r2 = r0; \ + r2 <<= 32; \ + r2 s>>= 63; \ + r2 |= 134; /* r2 becomes -1 or 134 */ \ + if r2 s> -1 goto +2; \ + /* Branch always taken because w2 = -1 */ \ + if r2 == -1 goto +1; \ + r0 /= 0; \ + r0 = 0; \ + exit; \ +" : + : __imm(bpf_get_prandom_u32) + : __clobber_all); +} + char _license[] SEC("license") = "GPL"; |