bpf/tests: Add exhaustive tests of BPF_ATOMIC register combinations
authorJohan Almbladh <johan.almbladh@anyfinetworks.com>
Fri, 1 Oct 2021 13:03:46 +0000 (15:03 +0200)
committerDaniel Borkmann <daniel@iogearbox.net>
Fri, 1 Oct 2021 15:04:26 +0000 (17:04 +0200)
This patch adds tests of all register combinations for BPF_ATOMIC
operations on both BPF_W and BPF_DW sizes.

Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211001130348.3670534-9-johan.almbladh@anyfinetworks.com
lib/test_bpf.c

index 924bf4c..40db4ce 100644 (file)
@@ -1806,6 +1806,246 @@ static int bpf_fill_cmpxchg32(struct bpf_test *self)
 }
 
 /*
+ * Test JITs that implement ATOMIC operations as function calls or
+ * other primitives, and must re-arrange operands for argument passing.
+ */
+static int __bpf_fill_atomic_reg_pairs(struct bpf_test *self, u8 width, u8 op)
+{
+       struct bpf_insn *insn;
+       int len = 2 + 34 * 10 * 10;
+       u64 mem, upd, res;
+       int rd, rs, i = 0;
+
+       insn = kmalloc_array(len, sizeof(*insn), GFP_KERNEL);
+       if (!insn)
+               return -ENOMEM;
+
+       /* Operand and memory values */
+       if (width == BPF_DW) {
+               mem = 0x0123456789abcdefULL;
+               upd = 0xfedcba9876543210ULL;
+       } else { /* BPF_W */
+               mem = 0x01234567U;
+               upd = 0x76543210U;
+       }
+
+       /* Memory updated according to operation */
+       switch (op) {
+       case BPF_XCHG:
+               res = upd;
+               break;
+       case BPF_CMPXCHG:
+               res = mem;
+               break;
+       default:
+               __bpf_alu_result(&res, mem, upd, BPF_OP(op));
+       }
+
+       /* Test all operand registers */
+       for (rd = R0; rd <= R9; rd++) {
+               for (rs = R0; rs <= R9; rs++) {
+                       u64 cmp, src;
+
+                       /* Initialize value in memory */
+                       i += __bpf_ld_imm64(&insn[i], R0, mem);
+                       insn[i++] = BPF_STX_MEM(width, R10, R0, -8);
+
+                       /* Initialize registers in order */
+                       i += __bpf_ld_imm64(&insn[i], R0, ~mem);
+                       i += __bpf_ld_imm64(&insn[i], rs, upd);
+                       insn[i++] = BPF_MOV64_REG(rd, R10);
+
+                       /* Perform atomic operation */
+                       insn[i++] = BPF_ATOMIC_OP(width, op, rd, rs, -8);
+                       if (op == BPF_CMPXCHG && width == BPF_W)
+                               insn[i++] = BPF_ZEXT_REG(R0);
+
+                       /* Check R0 register value */
+                       if (op == BPF_CMPXCHG)
+                               cmp = mem;  /* Expect value from memory */
+                       else if (R0 == rd || R0 == rs)
+                               cmp = 0;    /* Aliased, checked below */
+                       else
+                               cmp = ~mem; /* Expect value to be preserved */
+                       if (cmp) {
+                               insn[i++] = BPF_JMP32_IMM(BPF_JEQ, R0,
+                                                          (u32)cmp, 2);
+                               insn[i++] = BPF_MOV32_IMM(R0, __LINE__);
+                               insn[i++] = BPF_EXIT_INSN();
+                               insn[i++] = BPF_ALU64_IMM(BPF_RSH, R0, 32);
+                               insn[i++] = BPF_JMP32_IMM(BPF_JEQ, R0,
+                                                          cmp >> 32, 2);
+                               insn[i++] = BPF_MOV32_IMM(R0, __LINE__);
+                               insn[i++] = BPF_EXIT_INSN();
+                       }
+
+                       /* Check source register value */
+                       if (rs == R0 && op == BPF_CMPXCHG)
+                               src = 0;   /* Aliased with R0, checked above */
+                       else if (rs == rd && (op == BPF_CMPXCHG ||
+                                             !(op & BPF_FETCH)))
+                               src = 0;   /* Aliased with rd, checked below */
+                       else if (op == BPF_CMPXCHG)
+                               src = upd; /* Expect value to be preserved */
+                       else if (op & BPF_FETCH)
+                               src = mem; /* Expect fetched value from mem */
+                       else /* no fetch */
+                               src = upd; /* Expect value to be preserved */
+                       if (src) {
+                               insn[i++] = BPF_JMP32_IMM(BPF_JEQ, rs,
+                                                          (u32)src, 2);
+                               insn[i++] = BPF_MOV32_IMM(R0, __LINE__);
+                               insn[i++] = BPF_EXIT_INSN();
+                               insn[i++] = BPF_ALU64_IMM(BPF_RSH, rs, 32);
+                               insn[i++] = BPF_JMP32_IMM(BPF_JEQ, rs,
+                                                          src >> 32, 2);
+                               insn[i++] = BPF_MOV32_IMM(R0, __LINE__);
+                               insn[i++] = BPF_EXIT_INSN();
+                       }
+
+                       /* Check destination register value */
+                       if (!(rd == R0 && op == BPF_CMPXCHG) &&
+                           !(rd == rs && (op & BPF_FETCH))) {
+                               insn[i++] = BPF_JMP_REG(BPF_JEQ, rd, R10, 2);
+                               insn[i++] = BPF_MOV32_IMM(R0, __LINE__);
+                               insn[i++] = BPF_EXIT_INSN();
+                       }
+
+                       /* Check value in memory */
+                       if (rs != rd) {                  /* No aliasing */
+                               i += __bpf_ld_imm64(&insn[i], R1, res);
+                       } else if (op == BPF_XCHG) {     /* Aliased, XCHG */
+                               insn[i++] = BPF_MOV64_REG(R1, R10);
+                       } else if (op == BPF_CMPXCHG) {  /* Aliased, CMPXCHG */
+                               i += __bpf_ld_imm64(&insn[i], R1, mem);
+                       } else {                        /* Aliased, ALU oper */
+                               i += __bpf_ld_imm64(&insn[i], R1, mem);
+                               insn[i++] = BPF_ALU64_REG(BPF_OP(op), R1, R10);
+                       }
+
+                       insn[i++] = BPF_LDX_MEM(width, R0, R10, -8);
+                       if (width == BPF_DW)
+                               insn[i++] = BPF_JMP_REG(BPF_JEQ, R0, R1, 2);
+                       else /* width == BPF_W */
+                               insn[i++] = BPF_JMP32_REG(BPF_JEQ, R0, R1, 2);
+                       insn[i++] = BPF_MOV32_IMM(R0, __LINE__);
+                       insn[i++] = BPF_EXIT_INSN();
+               }
+       }
+
+       insn[i++] = BPF_MOV64_IMM(R0, 1);
+       insn[i++] = BPF_EXIT_INSN();
+
+       self->u.ptr.insns = insn;
+       self->u.ptr.len = i;
+       BUG_ON(i > len);
+
+       return 0;
+}
+
+/* 64-bit atomic register tests */
+static int bpf_fill_atomic64_add_reg_pairs(struct bpf_test *self)
+{
+       return __bpf_fill_atomic_reg_pairs(self, BPF_DW, BPF_ADD);
+}
+
+static int bpf_fill_atomic64_and_reg_pairs(struct bpf_test *self)
+{
+       return __bpf_fill_atomic_reg_pairs(self, BPF_DW, BPF_AND);
+}
+
+static int bpf_fill_atomic64_or_reg_pairs(struct bpf_test *self)
+{
+       return __bpf_fill_atomic_reg_pairs(self, BPF_DW, BPF_OR);
+}
+
+static int bpf_fill_atomic64_xor_reg_pairs(struct bpf_test *self)
+{
+       return __bpf_fill_atomic_reg_pairs(self, BPF_DW, BPF_XOR);
+}
+
+static int bpf_fill_atomic64_add_fetch_reg_pairs(struct bpf_test *self)
+{
+       return __bpf_fill_atomic_reg_pairs(self, BPF_DW, BPF_ADD | BPF_FETCH);
+}
+
+static int bpf_fill_atomic64_and_fetch_reg_pairs(struct bpf_test *self)
+{
+       return __bpf_fill_atomic_reg_pairs(self, BPF_DW, BPF_AND | BPF_FETCH);
+}
+
+static int bpf_fill_atomic64_or_fetch_reg_pairs(struct bpf_test *self)
+{
+       return __bpf_fill_atomic_reg_pairs(self, BPF_DW, BPF_OR | BPF_FETCH);
+}
+
+static int bpf_fill_atomic64_xor_fetch_reg_pairs(struct bpf_test *self)
+{
+       return __bpf_fill_atomic_reg_pairs(self, BPF_DW, BPF_XOR | BPF_FETCH);
+}
+
+static int bpf_fill_atomic64_xchg_reg_pairs(struct bpf_test *self)
+{
+       return __bpf_fill_atomic_reg_pairs(self, BPF_DW, BPF_XCHG);
+}
+
+static int bpf_fill_atomic64_cmpxchg_reg_pairs(struct bpf_test *self)
+{
+       return __bpf_fill_atomic_reg_pairs(self, BPF_DW, BPF_CMPXCHG);
+}
+
+/* 32-bit atomic register tests */
+static int bpf_fill_atomic32_add_reg_pairs(struct bpf_test *self)
+{
+       return __bpf_fill_atomic_reg_pairs(self, BPF_W, BPF_ADD);
+}
+
+static int bpf_fill_atomic32_and_reg_pairs(struct bpf_test *self)
+{
+       return __bpf_fill_atomic_reg_pairs(self, BPF_W, BPF_AND);
+}
+
+static int bpf_fill_atomic32_or_reg_pairs(struct bpf_test *self)
+{
+       return __bpf_fill_atomic_reg_pairs(self, BPF_W, BPF_OR);
+}
+
+static int bpf_fill_atomic32_xor_reg_pairs(struct bpf_test *self)
+{
+       return __bpf_fill_atomic_reg_pairs(self, BPF_W, BPF_XOR);
+}
+
+static int bpf_fill_atomic32_add_fetch_reg_pairs(struct bpf_test *self)
+{
+       return __bpf_fill_atomic_reg_pairs(self, BPF_W, BPF_ADD | BPF_FETCH);
+}
+
+static int bpf_fill_atomic32_and_fetch_reg_pairs(struct bpf_test *self)
+{
+       return __bpf_fill_atomic_reg_pairs(self, BPF_W, BPF_AND | BPF_FETCH);
+}
+
+static int bpf_fill_atomic32_or_fetch_reg_pairs(struct bpf_test *self)
+{
+       return __bpf_fill_atomic_reg_pairs(self, BPF_W, BPF_OR | BPF_FETCH);
+}
+
+static int bpf_fill_atomic32_xor_fetch_reg_pairs(struct bpf_test *self)
+{
+       return __bpf_fill_atomic_reg_pairs(self, BPF_W, BPF_XOR | BPF_FETCH);
+}
+
+static int bpf_fill_atomic32_xchg_reg_pairs(struct bpf_test *self)
+{
+       return __bpf_fill_atomic_reg_pairs(self, BPF_W, BPF_XCHG);
+}
+
+static int bpf_fill_atomic32_cmpxchg_reg_pairs(struct bpf_test *self)
+{
+       return __bpf_fill_atomic_reg_pairs(self, BPF_W, BPF_CMPXCHG);
+}
+
+/*
  * 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,
@@ -11976,6 +12216,188 @@ static struct bpf_test tests[] = {
                { { 0, 1 } },
                .fill_helper = bpf_fill_ld_imm64,
        },
+       /* 64-bit ATOMIC register combinations */
+       {
+               "ATOMIC_DW_ADD: register combinations",
+               { },
+               INTERNAL,
+               { },
+               { { 0, 1 } },
+               .fill_helper = bpf_fill_atomic64_add_reg_pairs,
+               .stack_depth = 8,
+       },
+       {
+               "ATOMIC_DW_AND: register combinations",
+               { },
+               INTERNAL,
+               { },
+               { { 0, 1 } },
+               .fill_helper = bpf_fill_atomic64_and_reg_pairs,
+               .stack_depth = 8,
+       },
+       {
+               "ATOMIC_DW_OR: register combinations",
+               { },
+               INTERNAL,
+               { },
+               { { 0, 1 } },
+               .fill_helper = bpf_fill_atomic64_or_reg_pairs,
+               .stack_depth = 8,
+       },
+       {
+               "ATOMIC_DW_XOR: register combinations",
+               { },
+               INTERNAL,
+               { },
+               { { 0, 1 } },
+               .fill_helper = bpf_fill_atomic64_xor_reg_pairs,
+               .stack_depth = 8,
+       },
+       {
+               "ATOMIC_DW_ADD_FETCH: register combinations",
+               { },
+               INTERNAL,
+               { },
+               { { 0, 1 } },
+               .fill_helper = bpf_fill_atomic64_add_fetch_reg_pairs,
+               .stack_depth = 8,
+       },
+       {
+               "ATOMIC_DW_AND_FETCH: register combinations",
+               { },
+               INTERNAL,
+               { },
+               { { 0, 1 } },
+               .fill_helper = bpf_fill_atomic64_and_fetch_reg_pairs,
+               .stack_depth = 8,
+       },
+       {
+               "ATOMIC_DW_OR_FETCH: register combinations",
+               { },
+               INTERNAL,
+               { },
+               { { 0, 1 } },
+               .fill_helper = bpf_fill_atomic64_or_fetch_reg_pairs,
+               .stack_depth = 8,
+       },
+       {
+               "ATOMIC_DW_XOR_FETCH: register combinations",
+               { },
+               INTERNAL,
+               { },
+               { { 0, 1 } },
+               .fill_helper = bpf_fill_atomic64_xor_fetch_reg_pairs,
+               .stack_depth = 8,
+       },
+       {
+               "ATOMIC_DW_XCHG: register combinations",
+               { },
+               INTERNAL,
+               { },
+               { { 0, 1 } },
+               .fill_helper = bpf_fill_atomic64_xchg_reg_pairs,
+               .stack_depth = 8,
+       },
+       {
+               "ATOMIC_DW_CMPXCHG: register combinations",
+               { },
+               INTERNAL,
+               { },
+               { { 0, 1 } },
+               .fill_helper = bpf_fill_atomic64_cmpxchg_reg_pairs,
+               .stack_depth = 8,
+       },
+       /* 32-bit ATOMIC register combinations */
+       {
+               "ATOMIC_W_ADD: register combinations",
+               { },
+               INTERNAL,
+               { },
+               { { 0, 1 } },
+               .fill_helper = bpf_fill_atomic32_add_reg_pairs,
+               .stack_depth = 8,
+       },
+       {
+               "ATOMIC_W_AND: register combinations",
+               { },
+               INTERNAL,
+               { },
+               { { 0, 1 } },
+               .fill_helper = bpf_fill_atomic32_and_reg_pairs,
+               .stack_depth = 8,
+       },
+       {
+               "ATOMIC_W_OR: register combinations",
+               { },
+               INTERNAL,
+               { },
+               { { 0, 1 } },
+               .fill_helper = bpf_fill_atomic32_or_reg_pairs,
+               .stack_depth = 8,
+       },
+       {
+               "ATOMIC_W_XOR: register combinations",
+               { },
+               INTERNAL,
+               { },
+               { { 0, 1 } },
+               .fill_helper = bpf_fill_atomic32_xor_reg_pairs,
+               .stack_depth = 8,
+       },
+       {
+               "ATOMIC_W_ADD_FETCH: register combinations",
+               { },
+               INTERNAL,
+               { },
+               { { 0, 1 } },
+               .fill_helper = bpf_fill_atomic32_add_fetch_reg_pairs,
+               .stack_depth = 8,
+       },
+       {
+               "ATOMIC_W_AND_FETCH: register combinations",
+               { },
+               INTERNAL,
+               { },
+               { { 0, 1 } },
+               .fill_helper = bpf_fill_atomic32_and_fetch_reg_pairs,
+               .stack_depth = 8,
+       },
+       {
+               "ATOMIC_W_OR_FETCH: register combinations",
+               { },
+               INTERNAL,
+               { },
+               { { 0, 1 } },
+               .fill_helper = bpf_fill_atomic32_or_fetch_reg_pairs,
+               .stack_depth = 8,
+       },
+       {
+               "ATOMIC_W_XOR_FETCH: register combinations",
+               { },
+               INTERNAL,
+               { },
+               { { 0, 1 } },
+               .fill_helper = bpf_fill_atomic32_xor_fetch_reg_pairs,
+               .stack_depth = 8,
+       },
+       {
+               "ATOMIC_W_XCHG: register combinations",
+               { },
+               INTERNAL,
+               { },
+               { { 0, 1 } },
+               .fill_helper = bpf_fill_atomic32_xchg_reg_pairs,
+               .stack_depth = 8,
+       },
+       {
+               "ATOMIC_W_CMPXCHG: register combinations",
+               { },
+               INTERNAL,
+               { },
+               { { 0, 1 } },
+               .fill_helper = bpf_fill_atomic32_cmpxchg_reg_pairs,
+               .stack_depth = 8,
+       },
        /* 64-bit ATOMIC magnitudes */
        {
                "ATOMIC_DW_ADD: all operand magnitudes",