From 68813605dea69ca0af26af7dd00384c78c1df05d Mon Sep 17 00:00:00 2001 From: Johan Almbladh Date: Fri, 1 Oct 2021 15:03:47 +0200 Subject: bpf/tests: Add test of ALU shifts with operand register aliasing This patch adds a tests of ALU32 and ALU64 LSH/RSH/ARSH operations for the case when the two operands are the same register. Mainly intended to test JITs that implement ALU64 shifts with 32-bit CPU instructions. Also renamed related helper functions for consistency with the new tests. Signed-off-by: Johan Almbladh Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20211001130348.3670534-10-johan.almbladh@anyfinetworks.com --- lib/test_bpf.c | 162 ++++++++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 149 insertions(+), 13 deletions(-) (limited to 'lib/test_bpf.c') diff --git a/lib/test_bpf.c b/lib/test_bpf.c index 40db4cee4f51..dfcbdff714b6 100644 --- a/lib/test_bpf.c +++ b/lib/test_bpf.c @@ -660,37 +660,37 @@ static int __bpf_fill_alu_shift(struct bpf_test *self, u8 op, self->u.ptr.insns = insn; self->u.ptr.len = len; - BUG_ON(i > len); + BUG_ON(i != len); return 0; } -static int bpf_fill_alu_lsh_imm(struct bpf_test *self) +static int bpf_fill_alu64_lsh_imm(struct bpf_test *self) { return __bpf_fill_alu_shift(self, BPF_LSH, BPF_K, false); } -static int bpf_fill_alu_rsh_imm(struct bpf_test *self) +static int bpf_fill_alu64_rsh_imm(struct bpf_test *self) { return __bpf_fill_alu_shift(self, BPF_RSH, BPF_K, false); } -static int bpf_fill_alu_arsh_imm(struct bpf_test *self) +static int bpf_fill_alu64_arsh_imm(struct bpf_test *self) { return __bpf_fill_alu_shift(self, BPF_ARSH, BPF_K, false); } -static int bpf_fill_alu_lsh_reg(struct bpf_test *self) +static int bpf_fill_alu64_lsh_reg(struct bpf_test *self) { return __bpf_fill_alu_shift(self, BPF_LSH, BPF_X, false); } -static int bpf_fill_alu_rsh_reg(struct bpf_test *self) +static int bpf_fill_alu64_rsh_reg(struct bpf_test *self) { return __bpf_fill_alu_shift(self, BPF_RSH, BPF_X, false); } -static int bpf_fill_alu_arsh_reg(struct bpf_test *self) +static int bpf_fill_alu64_arsh_reg(struct bpf_test *self) { return __bpf_fill_alu_shift(self, BPF_ARSH, BPF_X, false); } @@ -725,6 +725,86 @@ static int bpf_fill_alu32_arsh_reg(struct bpf_test *self) return __bpf_fill_alu_shift(self, BPF_ARSH, BPF_X, true); } +/* + * Test an ALU register shift operation for all valid shift values + * for the case when the source and destination are the same. + */ +static int __bpf_fill_alu_shift_same_reg(struct bpf_test *self, u8 op, + bool alu32) +{ + int bits = alu32 ? 32 : 64; + int len = 3 + 6 * bits; + struct bpf_insn *insn; + int i = 0; + u64 val; + + insn = kmalloc_array(len, sizeof(*insn), GFP_KERNEL); + if (!insn) + return -ENOMEM; + + insn[i++] = BPF_ALU64_IMM(BPF_MOV, R0, 0); + + for (val = 0; val < bits; val++) { + u64 res; + + /* Perform operation */ + insn[i++] = BPF_ALU64_IMM(BPF_MOV, R1, val); + if (alu32) + insn[i++] = BPF_ALU32_REG(op, R1, R1); + else + insn[i++] = BPF_ALU64_REG(op, R1, R1); + + /* Compute the reference result */ + __bpf_alu_result(&res, val, val, op); + if (alu32) + res = (u32)res; + i += __bpf_ld_imm64(&insn[i], R2, res); + + /* Check the actual 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; +} + +static int bpf_fill_alu64_lsh_same_reg(struct bpf_test *self) +{ + return __bpf_fill_alu_shift_same_reg(self, BPF_LSH, false); +} + +static int bpf_fill_alu64_rsh_same_reg(struct bpf_test *self) +{ + return __bpf_fill_alu_shift_same_reg(self, BPF_RSH, false); +} + +static int bpf_fill_alu64_arsh_same_reg(struct bpf_test *self) +{ + return __bpf_fill_alu_shift_same_reg(self, BPF_ARSH, false); +} + +static int bpf_fill_alu32_lsh_same_reg(struct bpf_test *self) +{ + return __bpf_fill_alu_shift_same_reg(self, BPF_LSH, true); +} + +static int bpf_fill_alu32_rsh_same_reg(struct bpf_test *self) +{ + return __bpf_fill_alu_shift_same_reg(self, BPF_RSH, true); +} + +static int bpf_fill_alu32_arsh_same_reg(struct bpf_test *self) +{ + return __bpf_fill_alu_shift_same_reg(self, BPF_ARSH, true); +} + /* * Common operand pattern generator for exhaustive power-of-two magnitudes * tests. The block size parameters can be adjusted to increase/reduce the @@ -11788,7 +11868,7 @@ static struct bpf_test tests[] = { INTERNAL | FLAG_NO_DATA, { }, { { 0, 1 } }, - .fill_helper = bpf_fill_alu_lsh_imm, + .fill_helper = bpf_fill_alu64_lsh_imm, }, { "ALU64_RSH_K: all shift values", @@ -11796,7 +11876,7 @@ static struct bpf_test tests[] = { INTERNAL | FLAG_NO_DATA, { }, { { 0, 1 } }, - .fill_helper = bpf_fill_alu_rsh_imm, + .fill_helper = bpf_fill_alu64_rsh_imm, }, { "ALU64_ARSH_K: all shift values", @@ -11804,7 +11884,7 @@ static struct bpf_test tests[] = { INTERNAL | FLAG_NO_DATA, { }, { { 0, 1 } }, - .fill_helper = bpf_fill_alu_arsh_imm, + .fill_helper = bpf_fill_alu64_arsh_imm, }, { "ALU64_LSH_X: all shift values", @@ -11812,7 +11892,7 @@ static struct bpf_test tests[] = { INTERNAL | FLAG_NO_DATA, { }, { { 0, 1 } }, - .fill_helper = bpf_fill_alu_lsh_reg, + .fill_helper = bpf_fill_alu64_lsh_reg, }, { "ALU64_RSH_X: all shift values", @@ -11820,7 +11900,7 @@ static struct bpf_test tests[] = { INTERNAL | FLAG_NO_DATA, { }, { { 0, 1 } }, - .fill_helper = bpf_fill_alu_rsh_reg, + .fill_helper = bpf_fill_alu64_rsh_reg, }, { "ALU64_ARSH_X: all shift values", @@ -11828,7 +11908,7 @@ static struct bpf_test tests[] = { INTERNAL | FLAG_NO_DATA, { }, { { 0, 1 } }, - .fill_helper = bpf_fill_alu_arsh_reg, + .fill_helper = bpf_fill_alu64_arsh_reg, }, /* Exhaustive test of ALU32 shift operations */ { @@ -11879,6 +11959,62 @@ static struct bpf_test tests[] = { { { 0, 1 } }, .fill_helper = bpf_fill_alu32_arsh_reg, }, + /* + * Exhaustive test of ALU64 shift operations when + * source and destination register are the same. + */ + { + "ALU64_LSH_X: all shift values with the same register", + { }, + INTERNAL | FLAG_NO_DATA, + { }, + { { 0, 1 } }, + .fill_helper = bpf_fill_alu64_lsh_same_reg, + }, + { + "ALU64_RSH_X: all shift values with the same register", + { }, + INTERNAL | FLAG_NO_DATA, + { }, + { { 0, 1 } }, + .fill_helper = bpf_fill_alu64_rsh_same_reg, + }, + { + "ALU64_ARSH_X: all shift values with the same register", + { }, + INTERNAL | FLAG_NO_DATA, + { }, + { { 0, 1 } }, + .fill_helper = bpf_fill_alu64_arsh_same_reg, + }, + /* + * Exhaustive test of ALU32 shift operations when + * source and destination register are the same. + */ + { + "ALU32_LSH_X: all shift values with the same register", + { }, + INTERNAL | FLAG_NO_DATA, + { }, + { { 0, 1 } }, + .fill_helper = bpf_fill_alu32_lsh_same_reg, + }, + { + "ALU32_RSH_X: all shift values with the same register", + { }, + INTERNAL | FLAG_NO_DATA, + { }, + { { 0, 1 } }, + .fill_helper = bpf_fill_alu32_rsh_same_reg, + }, + { + "ALU32_ARSH_X: all shift values with the same register", + { }, + INTERNAL | FLAG_NO_DATA, + { }, + { { 0, 1 } }, + .fill_helper = bpf_fill_alu32_arsh_same_reg, + }, /* ALU64 immediate magnitudes */ { "ALU64_MOV_K: all immediate value magnitudes", -- cgit v1.2.3-59-g8ed1b