diff options
Diffstat (limited to 'lib/test_bpf.c')
| -rw-r--r-- | lib/test_bpf.c | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/lib/test_bpf.c b/lib/test_bpf.c index 7b3d801275e8..8aef42cfb5fe 100644 --- a/lib/test_bpf.c +++ b/lib/test_bpf.c @@ -1104,6 +1104,60 @@ static int bpf_fill_alu32_mod_reg(struct bpf_test *self) return __bpf_fill_alu32_reg(self, BPF_MOD); } +/* + * Test the two-instruction 64-bit immediate load operation for all + * power-of-two magnitudes of the immediate operand. For each MSB, a block + * of immediate values centered around the power-of-two MSB are tested, + * both for positive and negative values. The test is designed to verify + * the operation for JITs that emit different code depending on the magnitude + * of the immediate value. This is often the case if the native instruction + * immediate field width is narrower than 32 bits. + */ +static int bpf_fill_ld_imm64(struct bpf_test *self) +{ + int block = 64; /* Increase for more tests per MSB position */ + int len = 3 + 8 * 63 * block * 2; + struct bpf_insn *insn; + int bit, adj, sign; + int i = 0; + + insn = kmalloc_array(len, sizeof(*insn), GFP_KERNEL); + if (!insn) + return -ENOMEM; + + insn[i++] = BPF_ALU64_IMM(BPF_MOV, R0, 0); + + for (bit = 0; bit <= 62; bit++) { + for (adj = -block / 2; adj < block / 2; adj++) { + for (sign = -1; sign <= 1; sign += 2) { + s64 imm = sign * ((1LL << bit) + adj); + + /* Perform operation */ + i += __bpf_ld_imm64(&insn[i], R1, imm); + + /* Load reference */ + insn[i++] = BPF_ALU32_IMM(BPF_MOV, R2, imm); + insn[i++] = BPF_ALU32_IMM(BPF_MOV, R3, + (u32)(imm >> 32)); + insn[i++] = BPF_ALU64_IMM(BPF_LSH, R3, 32); + insn[i++] = BPF_ALU64_REG(BPF_OR, R2, R3); + + /* Check result */ + insn[i++] = BPF_JMP_REG(BPF_JEQ, R1, R2, 1); + insn[i++] = BPF_EXIT_INSN(); + } + } + } + + insn[i++] = BPF_ALU64_IMM(BPF_MOV, R0, 1); + insn[i++] = BPF_EXIT_INSN(); + + self->u.ptr.insns = insn; + self->u.ptr.len = len; + BUG_ON(i != len); + + return 0; +} /* * Exhaustive tests of JMP operations for all combinations of power-of-two @@ -10245,6 +10299,15 @@ static struct bpf_test tests[] = { .fill_helper = bpf_fill_alu32_mod_reg, .nr_testruns = NR_PATTERN_RUNS, }, + /* LD_IMM64 immediate magnitudes */ + { + "LD_IMM64: all immediate value magnitudes", + { }, + INTERNAL | FLAG_NO_DATA, + { }, + { { 0, 1 } }, + .fill_helper = bpf_fill_ld_imm64, + }, /* JMP immediate magnitudes */ { "JMP_JSET_K: all immediate value magnitudes", |