diff options
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/reg_bounds.c | 30 |
1 files changed, 26 insertions, 4 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/reg_bounds.c b/tools/testing/selftests/bpf/prog_tests/reg_bounds.c index 7a524b381ed3..10f3b6898274 100644 --- a/tools/testing/selftests/bpf/prog_tests/reg_bounds.c +++ b/tools/testing/selftests/bpf/prog_tests/reg_bounds.c @@ -748,16 +748,38 @@ static int reg_state_branch_taken_op(enum num_t t, struct reg_state *x, struct r /* OP_EQ and OP_NE are sign-agnostic */ enum num_t tu = t_unsigned(t); enum num_t ts = t_signed(t); - int br_u, br_s; + int br_u, br_s, br; br_u = range_branch_taken_op(tu, x->r[tu], y->r[tu], op); br_s = range_branch_taken_op(ts, x->r[ts], y->r[ts], op); if (br_u >= 0 && br_s >= 0 && br_u != br_s) ASSERT_FALSE(true, "branch taken inconsistency!\n"); - if (br_u >= 0) - return br_u; - return br_s; + + /* if 64-bit ranges are indecisive, use 32-bit subranges to + * eliminate always/never taken branches, if possible + */ + if (br_u == -1 && (t == U64 || t == S64)) { + br = range_branch_taken_op(U32, x->r[U32], y->r[U32], op); + /* we can only reject for OP_EQ, never take branch + * based on lower 32 bits + */ + if (op == OP_EQ && br == 0) + return 0; + /* for OP_NEQ we can be conclusive only if lower 32 bits + * differ and thus inequality branch is always taken + */ + if (op == OP_NE && br == 1) + return 1; + + br = range_branch_taken_op(S32, x->r[S32], y->r[S32], op); + if (op == OP_EQ && br == 0) + return 0; + if (op == OP_NE && br == 1) + return 1; + } + + return br_u >= 0 ? br_u : br_s; } return range_branch_taken_op(t, x->r[t], y->r[t], op); } |