bpf: Add tests for new BPF atomic operations

The prog_test that's added depends on Clang/LLVM features added by
Yonghong in commit 286daafd6512 (was https://reviews.llvm.org/D72184

).

Note the use of a define called ENABLE_ATOMICS_TESTS: this is used
to:

 - Avoid breaking the build for people on old versions of Clang
 - Avoid needing separate lists of test objects for no_alu32, where
   atomics are not supported even if Clang has the feature.

The atomics_test.o BPF object is built unconditionally both for
test_progs and test_progs-no_alu32. For test_progs, if Clang supports
atomics, ENABLE_ATOMICS_TESTS is defined, so it includes the proper
test code. Otherwise, progs and global vars are defined anyway, as
stubs; this means that the skeleton user code still builds.

The atomics_test.o userspace object is built once and used for both
test_progs and test_progs-no_alu32. A variable called skip_tests is
defined in the BPF object's data section, which tells the userspace
object whether to skip the atomics test.

Signed-off-by: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210114181751.768687-11-jackmanb@google.com

tools/testing/selftests/bpf/Makefile

@@ -414,10 +414,12 @@ TRUNNER_EXTRA_FILES := $(OUTPUT)/urandom_read $(OUTPUT)/bpf_testmod.ko	\
 		       $(wildcard progs/btf_dump_test_case_*.c)
 TRUNNER_BPF_BUILD_RULE := CLANG_BPF_BUILD_RULE
 TRUNNER_BPF_CFLAGS := $(BPF_CFLAGS) $(CLANG_CFLAGS)
+TRUNNER_BPF_CFLAGS += -DENABLE_ATOMICS_TESTS
 $(eval $(call DEFINE_TEST_RUNNER,test_progs))
 
 # Define test_progs-no_alu32 test runner.
 TRUNNER_BPF_BUILD_RULE := CLANG_NOALU32_BPF_BUILD_RULE
+TRUNNER_BPF_CFLAGS := $(BPF_CFLAGS) $(CLANG_CFLAGS)
 $(eval $(call DEFINE_TEST_RUNNER,test_progs,no_alu32))
 
 # Define test_progs BPF-GCC-flavored test runner.

tools/testing/selftests/bpf/prog_tests/atomics.c

+// SPDX-License-Identifier: GPL-2.0
+
+#include <test_progs.h>
+
+#include "atomics.skel.h"
+
+static void test_add(struct atomics *skel)
+{
+	int err, prog_fd;
+	__u32 duration = 0, retval;
+	struct bpf_link *link;
+
+	link = bpf_program__attach(skel->progs.add);
+	if (CHECK(IS_ERR(link), "attach(add)", "err: %ld\n", PTR_ERR(link)))
+		return;
+
+	prog_fd = bpf_program__fd(skel->progs.add);
+	err = bpf_prog_test_run(prog_fd, 1, NULL, 0,
+				NULL, NULL, &retval, &duration);
+	if (CHECK(err || retval, "test_run add",
+		  "err %d errno %d retval %d duration %d\n", err, errno, retval, duration))
+		goto cleanup;
+
+	ASSERT_EQ(skel->data->add64_value, 3, "add64_value");
+	ASSERT_EQ(skel->bss->add64_result, 1, "add64_result");
+
+	ASSERT_EQ(skel->data->add32_value, 3, "add32_value");
+	ASSERT_EQ(skel->bss->add32_result, 1, "add32_result");
+
+	ASSERT_EQ(skel->bss->add_stack_value_copy, 3, "add_stack_value");
+	ASSERT_EQ(skel->bss->add_stack_result, 1, "add_stack_result");
+
+	ASSERT_EQ(skel->data->add_noreturn_value, 3, "add_noreturn_value");
+
+cleanup:
+	bpf_link__destroy(link);
+}
+
+static void test_sub(struct atomics *skel)
+{
+	int err, prog_fd;
+	__u32 duration = 0, retval;
+	struct bpf_link *link;
+
+	link = bpf_program__attach(skel->progs.sub);
+	if (CHECK(IS_ERR(link), "attach(sub)", "err: %ld\n", PTR_ERR(link)))
+		return;
+
+	prog_fd = bpf_program__fd(skel->progs.sub);
+	err = bpf_prog_test_run(prog_fd, 1, NULL, 0,
+				NULL, NULL, &retval, &duration);
+	if (CHECK(err || retval, "test_run sub",
+		  "err %d errno %d retval %d duration %d\n",
+		  err, errno, retval, duration))
+		goto cleanup;
+
+	ASSERT_EQ(skel->data->sub64_value, -1, "sub64_value");
+	ASSERT_EQ(skel->bss->sub64_result, 1, "sub64_result");
+
+	ASSERT_EQ(skel->data->sub32_value, -1, "sub32_value");
+	ASSERT_EQ(skel->bss->sub32_result, 1, "sub32_result");
+
+	ASSERT_EQ(skel->bss->sub_stack_value_copy, -1, "sub_stack_value");
+	ASSERT_EQ(skel->bss->sub_stack_result, 1, "sub_stack_result");
+
+	ASSERT_EQ(skel->data->sub_noreturn_value, -1, "sub_noreturn_value");
+
+cleanup:
+	bpf_link__destroy(link);
+}
+
+static void test_and(struct atomics *skel)
+{
+	int err, prog_fd;
+	__u32 duration = 0, retval;
+	struct bpf_link *link;
+
+	link = bpf_program__attach(skel->progs.and);
+	if (CHECK(IS_ERR(link), "attach(and)", "err: %ld\n", PTR_ERR(link)))
+		return;
+
+	prog_fd = bpf_program__fd(skel->progs.and);
+	err = bpf_prog_test_run(prog_fd, 1, NULL, 0,
+				NULL, NULL, &retval, &duration);
+	if (CHECK(err || retval, "test_run and",
+		  "err %d errno %d retval %d duration %d\n", err, errno, retval, duration))
+		goto cleanup;
+
+	ASSERT_EQ(skel->data->and64_value, 0x010ull << 32, "and64_value");
+	ASSERT_EQ(skel->bss->and64_result, 0x110ull << 32, "and64_result");
+
+	ASSERT_EQ(skel->data->and32_value, 0x010, "and32_value");
+	ASSERT_EQ(skel->bss->and32_result, 0x110, "and32_result");
+
+	ASSERT_EQ(skel->data->and_noreturn_value, 0x010ull << 32, "and_noreturn_value");
+cleanup:
+	bpf_link__destroy(link);
+}
+
+static void test_or(struct atomics *skel)
+{
+	int err, prog_fd;
+	__u32 duration = 0, retval;
+	struct bpf_link *link;
+
+	link = bpf_program__attach(skel->progs.or);
+	if (CHECK(IS_ERR(link), "attach(or)", "err: %ld\n", PTR_ERR(link)))
+		return;
+
+	prog_fd = bpf_program__fd(skel->progs.or);
+	err = bpf_prog_test_run(prog_fd, 1, NULL, 0,
+				NULL, NULL, &retval, &duration);
+	if (CHECK(err || retval, "test_run or",
+		  "err %d errno %d retval %d duration %d\n",
+		  err, errno, retval, duration))
+		goto cleanup;
+
+	ASSERT_EQ(skel->data->or64_value, 0x111ull << 32, "or64_value");
+	ASSERT_EQ(skel->bss->or64_result, 0x110ull << 32, "or64_result");
+
+	ASSERT_EQ(skel->data->or32_value, 0x111, "or32_value");
+	ASSERT_EQ(skel->bss->or32_result, 0x110, "or32_result");
+
+	ASSERT_EQ(skel->data->or_noreturn_value, 0x111ull << 32, "or_noreturn_value");
+cleanup:
+	bpf_link__destroy(link);
+}
+
+static void test_xor(struct atomics *skel)
+{
+	int err, prog_fd;
+	__u32 duration = 0, retval;
+	struct bpf_link *link;
+
+	link = bpf_program__attach(skel->progs.xor);
+	if (CHECK(IS_ERR(link), "attach(xor)", "err: %ld\n", PTR_ERR(link)))
+		return;
+
+	prog_fd = bpf_program__fd(skel->progs.xor);
+	err = bpf_prog_test_run(prog_fd, 1, NULL, 0,
+				NULL, NULL, &retval, &duration);
+	if (CHECK(err || retval, "test_run xor",
+		  "err %d errno %d retval %d duration %d\n", err, errno, retval, duration))
+		goto cleanup;
+
+	ASSERT_EQ(skel->data->xor64_value, 0x101ull << 32, "xor64_value");
+	ASSERT_EQ(skel->bss->xor64_result, 0x110ull << 32, "xor64_result");
+
+	ASSERT_EQ(skel->data->xor32_value, 0x101, "xor32_value");
+	ASSERT_EQ(skel->bss->xor32_result, 0x110, "xor32_result");
+
+	ASSERT_EQ(skel->data->xor_noreturn_value, 0x101ull << 32, "xor_nxoreturn_value");
+cleanup:
+	bpf_link__destroy(link);
+}
+
+static void test_cmpxchg(struct atomics *skel)
+{
+	int err, prog_fd;
+	__u32 duration = 0, retval;
+	struct bpf_link *link;
+
+	link = bpf_program__attach(skel->progs.cmpxchg);
+	if (CHECK(IS_ERR(link), "attach(cmpxchg)", "err: %ld\n", PTR_ERR(link)))
+		return;
+
+	prog_fd = bpf_program__fd(skel->progs.cmpxchg);
+	err = bpf_prog_test_run(prog_fd, 1, NULL, 0,
+				NULL, NULL, &retval, &duration);
+	if (CHECK(err || retval, "test_run add",
+		  "err %d errno %d retval %d duration %d\n", err, errno, retval, duration))
+		goto cleanup;
+
+	ASSERT_EQ(skel->data->cmpxchg64_value, 2, "cmpxchg64_value");
+	ASSERT_EQ(skel->bss->cmpxchg64_result_fail, 1, "cmpxchg_result_fail");
+	ASSERT_EQ(skel->bss->cmpxchg64_result_succeed, 1, "cmpxchg_result_succeed");
+
+	ASSERT_EQ(skel->data->cmpxchg32_value, 2, "lcmpxchg32_value");
+	ASSERT_EQ(skel->bss->cmpxchg32_result_fail, 1, "cmpxchg_result_fail");
+	ASSERT_EQ(skel->bss->cmpxchg32_result_succeed, 1, "cmpxchg_result_succeed");
+
+cleanup:
+	bpf_link__destroy(link);
+}
+
+static void test_xchg(struct atomics *skel)
+{
+	int err, prog_fd;
+	__u32 duration = 0, retval;
+	struct bpf_link *link;
+
+	link = bpf_program__attach(skel->progs.xchg);
+	if (CHECK(IS_ERR(link), "attach(xchg)", "err: %ld\n", PTR_ERR(link)))
+		return;
+
+	prog_fd = bpf_program__fd(skel->progs.xchg);
+	err = bpf_prog_test_run(prog_fd, 1, NULL, 0,
+				NULL, NULL, &retval, &duration);
+	if (CHECK(err || retval, "test_run add",
+		  "err %d errno %d retval %d duration %d\n", err, errno, retval, duration))
+		goto cleanup;
+
+	ASSERT_EQ(skel->data->xchg64_value, 2, "xchg64_value");
+	ASSERT_EQ(skel->bss->xchg64_result, 1, "xchg64_result");
+
+	ASSERT_EQ(skel->data->xchg32_value, 2, "xchg32_value");
+	ASSERT_EQ(skel->bss->xchg32_result, 1, "xchg32_result");
+
+cleanup:
+	bpf_link__destroy(link);
+}
+
+void test_atomics(void)
+{
+	struct atomics *skel;
+	__u32 duration = 0;
+
+	skel = atomics__open_and_load();
+	if (CHECK(!skel, "skel_load", "atomics skeleton failed\n"))
+		return;
+
+	if (skel->data->skip_tests) {
+		printf("%s:SKIP:no ENABLE_ATOMICS_TESTS (missing Clang BPF atomics support)",
+		       __func__);
+		test__skip();
+		goto cleanup;
+	}
+
+	if (test__start_subtest("add"))
+		test_add(skel);
+	if (test__start_subtest("sub"))
+		test_sub(skel);
+	if (test__start_subtest("and"))
+		test_and(skel);
+	if (test__start_subtest("or"))
+		test_or(skel);
+	if (test__start_subtest("xor"))
+		test_xor(skel);
+	if (test__start_subtest("cmpxchg"))
+		test_cmpxchg(skel);
+	if (test__start_subtest("xchg"))
+		test_xchg(skel);
+
+cleanup:
+	atomics__destroy(skel);
+}

tools/testing/selftests/bpf/progs/atomics.c

+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <stdbool.h>
+
+#ifdef ENABLE_ATOMICS_TESTS
+bool skip_tests __attribute((__section__(".data"))) = false;
+#else
+bool skip_tests = true;
+#endif
+
+__u64 add64_value = 1;
+__u64 add64_result = 0;
+__u32 add32_value = 1;
+__u32 add32_result = 0;
+__u64 add_stack_value_copy = 0;
+__u64 add_stack_result = 0;
+__u64 add_noreturn_value = 1;
+
+SEC("fentry/bpf_fentry_test1")
+int BPF_PROG(add, int a)
+{
+#ifdef ENABLE_ATOMICS_TESTS
+	__u64 add_stack_value = 1;
+
+	add64_result = __sync_fetch_and_add(&add64_value, 2);
+	add32_result = __sync_fetch_and_add(&add32_value, 2);
+	add_stack_result = __sync_fetch_and_add(&add_stack_value, 2);
+	add_stack_value_copy = add_stack_value;
+	__sync_fetch_and_add(&add_noreturn_value, 2);
+#endif
+
+	return 0;
+}
+
+__s64 sub64_value = 1;
+__s64 sub64_result = 0;
+__s32 sub32_value = 1;
+__s32 sub32_result = 0;
+__s64 sub_stack_value_copy = 0;
+__s64 sub_stack_result = 0;
+__s64 sub_noreturn_value = 1;
+
+SEC("fentry/bpf_fentry_test1")
+int BPF_PROG(sub, int a)
+{
+#ifdef ENABLE_ATOMICS_TESTS
+	__u64 sub_stack_value = 1;
+
+	sub64_result = __sync_fetch_and_sub(&sub64_value, 2);
+	sub32_result = __sync_fetch_and_sub(&sub32_value, 2);
+	sub_stack_result = __sync_fetch_and_sub(&sub_stack_value, 2);
+	sub_stack_value_copy = sub_stack_value;
+	__sync_fetch_and_sub(&sub_noreturn_value, 2);
+#endif
+
+	return 0;
+}
+
+__u64 and64_value = (0x110ull << 32);
+__u64 and64_result = 0;
+__u32 and32_value = 0x110;
+__u32 and32_result = 0;
+__u64 and_noreturn_value = (0x110ull << 32);
+
+SEC("fentry/bpf_fentry_test1")
+int BPF_PROG(and, int a)
+{
+#ifdef ENABLE_ATOMICS_TESTS
+
+	and64_result = __sync_fetch_and_and(&and64_value, 0x011ull << 32);
+	and32_result = __sync_fetch_and_and(&and32_value, 0x011);
+	__sync_fetch_and_and(&and_noreturn_value, 0x011ull << 32);
+#endif
+
+	return 0;
+}
+
+__u64 or64_value = (0x110ull << 32);
+__u64 or64_result = 0;
+__u32 or32_value = 0x110;
+__u32 or32_result = 0;
+__u64 or_noreturn_value = (0x110ull << 32);
+
+SEC("fentry/bpf_fentry_test1")
+int BPF_PROG(or, int a)
+{
+#ifdef ENABLE_ATOMICS_TESTS
+	or64_result = __sync_fetch_and_or(&or64_value, 0x011ull << 32);
+	or32_result = __sync_fetch_and_or(&or32_value, 0x011);
+	__sync_fetch_and_or(&or_noreturn_value, 0x011ull << 32);
+#endif
+
+	return 0;
+}
+
+__u64 xor64_value = (0x110ull << 32);
+__u64 xor64_result = 0;
+__u32 xor32_value = 0x110;
+__u32 xor32_result = 0;
+__u64 xor_noreturn_value = (0x110ull << 32);
+
+SEC("fentry/bpf_fentry_test1")
+int BPF_PROG(xor, int a)
+{
+#ifdef ENABLE_ATOMICS_TESTS
+	xor64_result = __sync_fetch_and_xor(&xor64_value, 0x011ull << 32);
+	xor32_result = __sync_fetch_and_xor(&xor32_value, 0x011);
+	__sync_fetch_and_xor(&xor_noreturn_value, 0x011ull << 32);
+#endif
+
+	return 0;
+}
+
+__u64 cmpxchg64_value = 1;
+__u64 cmpxchg64_result_fail = 0;
+__u64 cmpxchg64_result_succeed = 0;
+__u32 cmpxchg32_value = 1;
+__u32 cmpxchg32_result_fail = 0;
+__u32 cmpxchg32_result_succeed = 0;
+
+SEC("fentry/bpf_fentry_test1")
+int BPF_PROG(cmpxchg, int a)
+{
+#ifdef ENABLE_ATOMICS_TESTS
+	cmpxchg64_result_fail = __sync_val_compare_and_swap(&cmpxchg64_value, 0, 3);
+	cmpxchg64_result_succeed = __sync_val_compare_and_swap(&cmpxchg64_value, 1, 2);
+
+	cmpxchg32_result_fail = __sync_val_compare_and_swap(&cmpxchg32_value, 0, 3);
+	cmpxchg32_result_succeed = __sync_val_compare_and_swap(&cmpxchg32_value, 1, 2);
+#endif
+
+	return 0;
+}
+
+__u64 xchg64_value = 1;
+__u64 xchg64_result = 0;
+__u32 xchg32_value = 1;
+__u32 xchg32_result = 0;
+
+SEC("fentry/bpf_fentry_test1")
+int BPF_PROG(xchg, int a)
+{
+#ifdef ENABLE_ATOMICS_TESTS
+	__u64 val64 = 2;
+	__u32 val32 = 2;
+
+	xchg64_result = __sync_lock_test_and_set(&xchg64_value, val64);
+	xchg32_result = __sync_lock_test_and_set(&xchg32_value, val32);
+#endif
+
+	return 0;
+}

tools/testing/selftests/bpf/verifier/atomic_and.c

+{
+	"BPF_ATOMIC_AND without fetch",
+	.insns = {
+		/* val = 0x110; */
+		BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0x110),
+		/* atomic_and(&val, 0x011); */
+		BPF_MOV64_IMM(BPF_REG_1, 0x011),
+		BPF_ATOMIC_OP(BPF_DW, BPF_AND, BPF_REG_10, BPF_REG_1, -8),
+		/* if (val != 0x010) exit(2); */
+		BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_10, -8),
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0x010, 2),
+		BPF_MOV64_IMM(BPF_REG_0, 2),
+		BPF_EXIT_INSN(),
+		/* r1 should not be clobbered, no BPF_FETCH flag */
+		BPF_MOV64_IMM(BPF_REG_0, 0),
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0x011, 1),
+		BPF_MOV64_IMM(BPF_REG_0, 1),
+		BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+},
+{
+	"BPF_ATOMIC_AND with fetch",
+	.insns = {
+		BPF_MOV64_IMM(BPF_REG_0, 123),
+		/* val = 0x110; */
+		BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0x110),
+		/* old = atomic_fetch_and(&val, 0x011); */
+		BPF_MOV64_IMM(BPF_REG_1, 0x011),
+		BPF_ATOMIC_OP(BPF_DW, BPF_AND | BPF_FETCH, BPF_REG_10, BPF_REG_1, -8),
+		/* if (old != 0x110) exit(3); */
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0x110, 2),
+		BPF_MOV64_IMM(BPF_REG_0, 3),
+		BPF_EXIT_INSN(),
+		/* if (val != 0x010) exit(2); */
+		BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_10, -8),
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0x010, 2),
+		BPF_MOV64_IMM(BPF_REG_1, 2),
+		BPF_EXIT_INSN(),
+		/* Check R0 wasn't clobbered (for fear of x86 JIT bug) */
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 123, 2),
+		BPF_MOV64_IMM(BPF_REG_0, 1),
+		BPF_EXIT_INSN(),
+		/* exit(0); */
+		BPF_MOV64_IMM(BPF_REG_0, 0),
+		BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+},
+{
+	"BPF_ATOMIC_AND with fetch 32bit",
+	.insns = {
+		/* r0 = (s64) -1 */
+		BPF_MOV64_IMM(BPF_REG_0, 0),
+		BPF_ALU64_IMM(BPF_SUB, BPF_REG_0, 1),
+		/* val = 0x110; */
+		BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 0x110),
+		/* old = atomic_fetch_and(&val, 0x011); */
+		BPF_MOV32_IMM(BPF_REG_1, 0x011),
+		BPF_ATOMIC_OP(BPF_W, BPF_AND | BPF_FETCH, BPF_REG_10, BPF_REG_1, -4),
+		/* if (old != 0x110) exit(3); */
+		BPF_JMP32_IMM(BPF_JEQ, BPF_REG_1, 0x110, 2),
+		BPF_MOV32_IMM(BPF_REG_0, 3),
+		BPF_EXIT_INSN(),
+		/* if (val != 0x010) exit(2); */
+		BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_10, -4),
+		BPF_JMP32_IMM(BPF_JEQ, BPF_REG_1, 0x010, 2),
+		BPF_MOV32_IMM(BPF_REG_1, 2),
+		BPF_EXIT_INSN(),
+		/* Check R0 wasn't clobbered (for fear of x86 JIT bug)
+		 * It should be -1 so add 1 to get exit code.
+		 */
+		BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 1),
+		BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+},

tools/testing/selftests/bpf/verifier/atomic_cmpxchg.c

+{
+	"atomic compare-and-exchange smoketest - 64bit",
+	.insns = {
+		/* val = 3; */
+		BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 3),
+		/* old = atomic_cmpxchg(&val, 2, 4); */
+		BPF_MOV64_IMM(BPF_REG_1, 4),
+		BPF_MOV64_IMM(BPF_REG_0, 2),
+		BPF_ATOMIC_OP(BPF_DW, BPF_CMPXCHG, BPF_REG_10, BPF_REG_1, -8),
+		/* if (old != 3) exit(2); */
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 3, 2),
+		BPF_MOV64_IMM(BPF_REG_0, 2),
+		BPF_EXIT_INSN(),
+		/* if (val != 3) exit(3); */
+		BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 3, 2),
+		BPF_MOV64_IMM(BPF_REG_0, 3),
+		BPF_EXIT_INSN(),
+		/* old = atomic_cmpxchg(&val, 3, 4); */
+		BPF_MOV64_IMM(BPF_REG_1, 4),
+		BPF_MOV64_IMM(BPF_REG_0, 3),
+		BPF_ATOMIC_OP(BPF_DW, BPF_CMPXCHG, BPF_REG_10, BPF_REG_1, -8),
+		/* if (old != 3) exit(4); */
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 3, 2),
+		BPF_MOV64_IMM(BPF_REG_0, 4),
+		BPF_EXIT_INSN(),
+		/* if (val != 4) exit(5); */
+		BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 4, 2),
+		BPF_MOV64_IMM(BPF_REG_0, 5),
+		BPF_EXIT_INSN(),
+		/* exit(0); */
+		BPF_MOV64_IMM(BPF_REG_0, 0),
+		BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+},
+{
+	"atomic compare-and-exchange smoketest - 32bit",
+	.insns = {
+		/* val = 3; */
+		BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 3),
+		/* old = atomic_cmpxchg(&val, 2, 4); */
+		BPF_MOV32_IMM(BPF_REG_1, 4),
+		BPF_MOV32_IMM(BPF_REG_0, 2),
+		BPF_ATOMIC_OP(BPF_W, BPF_CMPXCHG, BPF_REG_10, BPF_REG_1, -4),
+		/* if (old != 3) exit(2); */
+		BPF_JMP32_IMM(BPF_JEQ, BPF_REG_0, 3, 2),
+		BPF_MOV32_IMM(BPF_REG_0, 2),
+		BPF_EXIT_INSN(),
+		/* if (val != 3) exit(3); */
+		BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_10, -4),
+		BPF_JMP32_IMM(BPF_JEQ, BPF_REG_0, 3, 2),
+		BPF_MOV32_IMM(BPF_REG_0, 3),
+		BPF_EXIT_INSN(),
+		/* old = atomic_cmpxchg(&val, 3, 4); */
+		BPF_MOV32_IMM(BPF_REG_1, 4),
+		BPF_MOV32_IMM(BPF_REG_0, 3),
+		BPF_ATOMIC_OP(BPF_W, BPF_CMPXCHG, BPF_REG_10, BPF_REG_1, -4),
+		/* if (old != 3) exit(4); */
+		BPF_JMP32_IMM(BPF_JEQ, BPF_REG_0, 3, 2),
+		BPF_MOV32_IMM(BPF_REG_0, 4),
+		BPF_EXIT_INSN(),
+		/* if (val != 4) exit(5); */
+		BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_10, -4),
+		BPF_JMP32_IMM(BPF_JEQ, BPF_REG_0, 4, 2),
+		BPF_MOV32_IMM(BPF_REG_0, 5),
+		BPF_EXIT_INSN(),
+		/* exit(0); */
+		BPF_MOV32_IMM(BPF_REG_0, 0),
+		BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+},
+{
+	"Can't use cmpxchg on uninit src reg",
+	.insns = {
+		BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 3),
+		BPF_MOV64_IMM(BPF_REG_0, 3),
+		BPF_ATOMIC_OP(BPF_DW, BPF_CMPXCHG, BPF_REG_10, BPF_REG_2, -8),
+		BPF_EXIT_INSN(),
+	},
+	.result = REJECT,
+	.errstr = "!read_ok",
+},
+{
+	"Can't use cmpxchg on uninit memory",
+	.insns = {
+		BPF_MOV64_IMM(BPF_REG_0, 3),
+		BPF_MOV64_IMM(BPF_REG_2, 4),
+		BPF_ATOMIC_OP(BPF_DW, BPF_CMPXCHG, BPF_REG_10, BPF_REG_2, -8),
+		BPF_EXIT_INSN(),
+	},
+	.result = REJECT,
+	.errstr = "invalid read from stack",
+},

tools/testing/selftests/bpf/verifier/atomic_fetch_add.c

+{
+	"BPF_ATOMIC_FETCH_ADD smoketest - 64bit",
+	.insns = {
+		BPF_MOV64_IMM(BPF_REG_0, 0),
+		/* Write 3 to stack */
+		BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 3),
+		/* Put a 1 in R1, add it to the 3 on the stack, and load the value back into R1 */
+		BPF_MOV64_IMM(BPF_REG_1, 1),
+		BPF_ATOMIC_OP(BPF_DW, BPF_ADD | BPF_FETCH, BPF_REG_10, BPF_REG_1, -8),
+		/* Check the value we loaded back was 3 */
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 3, 2),
+		BPF_MOV64_IMM(BPF_REG_0, 1),
+		BPF_EXIT_INSN(),
+		/* Load value from stack */
+		BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_10, -8),
+		/* Check value loaded from stack was 4 */
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 4, 1),
+		BPF_MOV64_IMM(BPF_REG_0, 2),
+		BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+},
+{
+	"BPF_ATOMIC_FETCH_ADD smoketest - 32bit",
+	.insns = {
+		BPF_MOV64_IMM(BPF_REG_0, 0),
+		/* Write 3 to stack */
+		BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 3),
+		/* Put a 1 in R1, add it to the 3 on the stack, and load the value back into R1 */
+		BPF_MOV32_IMM(BPF_REG_1, 1),
+		BPF_ATOMIC_OP(BPF_W, BPF_ADD | BPF_FETCH, BPF_REG_10, BPF_REG_1, -4),
+		/* Check the value we loaded back was 3 */
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 3, 2),
+		BPF_MOV64_IMM(BPF_REG_0, 1),
+		BPF_EXIT_INSN(),
+		/* Load value from stack */
+		BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_10, -4),
+		/* Check value loaded from stack was 4 */
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 4, 1),
+		BPF_MOV64_IMM(BPF_REG_0, 2),
+		BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+},
+{
+	"Can't use ATM_FETCH_ADD on frame pointer",
+	.insns = {
+		BPF_MOV64_IMM(BPF_REG_0, 0),
+		BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 3),
+		BPF_ATOMIC_OP(BPF_DW, BPF_ADD | BPF_FETCH, BPF_REG_10, BPF_REG_10, -8),
+		BPF_EXIT_INSN(),
+	},
+	.result = REJECT,
+	.errstr_unpriv = "R10 leaks addr into mem",
+	.errstr = "frame pointer is read only",
+},
+{
+	"Can't use ATM_FETCH_ADD on uninit src reg",
+	.insns = {
+		BPF_MOV64_IMM(BPF_REG_0, 0),
+		BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 3),
+		BPF_ATOMIC_OP(BPF_DW, BPF_ADD | BPF_FETCH, BPF_REG_10, BPF_REG_2, -8),
+		BPF_EXIT_INSN(),
+	},
+	.result = REJECT,
+	/* It happens that the address leak check is first, but it would also be
+	 * complain about the fact that we're trying to modify R10.
+	 */
+	.errstr = "!read_ok",
+},
+{
+	"Can't use ATM_FETCH_ADD on uninit dst reg",
+	.insns = {
+		BPF_MOV64_IMM(BPF_REG_0, 0),
+		BPF_ATOMIC_OP(BPF_DW, BPF_ADD | BPF_FETCH, BPF_REG_2, BPF_REG_0, -8),
+		BPF_EXIT_INSN(),
+	},
+	.result = REJECT,
+	/* It happens that the address leak check is first, but it would also be
+	 * complain about the fact that we're trying to modify R10.
+	 */
+	.errstr = "!read_ok",
+},
+{
+	"Can't use ATM_FETCH_ADD on kernel memory",
+	.insns = {
+		/* This is an fentry prog, context is array of the args of the
+		 * kernel function being called. Load first arg into R2.
+		 */
+		BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_1, 0),
+		/* First arg of bpf_fentry_test7 is a pointer to a struct.
+		 * Attempt to modify that struct. Verifier shouldn't let us
+		 * because it's kernel memory.
+		 */
+		BPF_MOV64_IMM(BPF_REG_3, 1),
+		BPF_ATOMIC_OP(BPF_DW, BPF_ADD | BPF_FETCH, BPF_REG_2, BPF_REG_3, 0),
+		/* Done */
+		BPF_MOV64_IMM(BPF_REG_0, 0),
+		BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_TRACING,
+	.expected_attach_type = BPF_TRACE_FENTRY,
+	.kfunc = "bpf_fentry_test7",
+	.result = REJECT,
+	.errstr = "only read is supported",
+},

tools/testing/selftests/bpf/verifier/atomic_or.c

+{
+	"BPF_ATOMIC OR without fetch",
+	.insns = {
+		/* val = 0x110; */
+		BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0x110),
+		/* atomic_or(&val, 0x011); */
+		BPF_MOV64_IMM(BPF_REG_1, 0x011),
+		BPF_ATOMIC_OP(BPF_DW, BPF_OR, BPF_REG_10, BPF_REG_1, -8),
+		/* if (val != 0x111) exit(2); */
+		BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_10, -8),
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0x111, 2),
+		BPF_MOV64_IMM(BPF_REG_0, 2),
+		BPF_EXIT_INSN(),
+		/* r1 should not be clobbered, no BPF_FETCH flag */
+		BPF_MOV64_IMM(BPF_REG_0, 0),
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0x011, 1),
+		BPF_MOV64_IMM(BPF_REG_0, 1),
+		BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+},
+{
+	"BPF_ATOMIC OR with fetch",
+	.insns = {
+		BPF_MOV64_IMM(BPF_REG_0, 123),
+		/* val = 0x110; */
+		BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0x110),
+		/* old = atomic_fetch_or(&val, 0x011); */
+		BPF_MOV64_IMM(BPF_REG_1, 0x011),
+		BPF_ATOMIC_OP(BPF_DW, BPF_OR | BPF_FETCH, BPF_REG_10, BPF_REG_1, -8),
+		/* if (old != 0x110) exit(3); */
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0x110, 2),
+		BPF_MOV64_IMM(BPF_REG_0, 3),
+		BPF_EXIT_INSN(),
+		/* if (val != 0x111) exit(2); */
+		BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_10, -8),
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0x111, 2),
+		BPF_MOV64_IMM(BPF_REG_1, 2),
+		BPF_EXIT_INSN(),
+		/* Check R0 wasn't clobbered (for fear of x86 JIT bug) */
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 123, 2),
+		BPF_MOV64_IMM(BPF_REG_0, 1),
+		BPF_EXIT_INSN(),
+		/* exit(0); */
+		BPF_MOV64_IMM(BPF_REG_0, 0),
+		BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+},
+{
+	"BPF_ATOMIC OR with fetch 32bit",
+	.insns = {
+		/* r0 = (s64) -1 */
+		BPF_MOV64_IMM(BPF_REG_0, 0),
+		BPF_ALU64_IMM(BPF_SUB, BPF_REG_0, 1),
+		/* val = 0x110; */
+		BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 0x110),
+		/* old = atomic_fetch_or(&val, 0x011); */
+		BPF_MOV32_IMM(BPF_REG_1, 0x011),
+		BPF_ATOMIC_OP(BPF_W, BPF_OR | BPF_FETCH, BPF_REG_10, BPF_REG_1, -4),
+		/* if (old != 0x110) exit(3); */
+		BPF_JMP32_IMM(BPF_JEQ, BPF_REG_1, 0x110, 2),
+		BPF_MOV32_IMM(BPF_REG_0, 3),
+		BPF_EXIT_INSN(),
+		/* if (val != 0x111) exit(2); */
+		BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_10, -4),
+		BPF_JMP32_IMM(BPF_JEQ, BPF_REG_1, 0x111, 2),
+		BPF_MOV32_IMM(BPF_REG_1, 2),
+		BPF_EXIT_INSN(),
+		/* Check R0 wasn't clobbered (for fear of x86 JIT bug)
+		 * It should be -1 so add 1 to get exit code.
+		 */
+		BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 1),
+		BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+},

tools/testing/selftests/bpf/verifier/atomic_xchg.c

+{
+	"atomic exchange smoketest - 64bit",
+	.insns = {
+		/* val = 3; */
+		BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 3),
+		/* old = atomic_xchg(&val, 4); */
+		BPF_MOV64_IMM(BPF_REG_1, 4),
+		BPF_ATOMIC_OP(BPF_DW, BPF_XCHG, BPF_REG_10, BPF_REG_1, -8),
+		/* if (old != 3) exit(1); */
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 3, 2),
+		BPF_MOV64_IMM(BPF_REG_0, 1),
+		BPF_EXIT_INSN(),
+		/* if (val != 4) exit(2); */
+		BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 4, 2),
+		BPF_MOV64_IMM(BPF_REG_0, 2),
+		BPF_EXIT_INSN(),
+		/* exit(0); */
+		BPF_MOV64_IMM(BPF_REG_0, 0),
+		BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+},
+{
+	"atomic exchange smoketest - 32bit",
+	.insns = {
+		/* val = 3; */
+		BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 3),
+		/* old = atomic_xchg(&val, 4); */
+		BPF_MOV32_IMM(BPF_REG_1, 4),
+		BPF_ATOMIC_OP(BPF_W, BPF_XCHG, BPF_REG_10, BPF_REG_1, -4),
+		/* if (old != 3) exit(1); */
+		BPF_JMP32_IMM(BPF_JEQ, BPF_REG_1, 3, 2),
+		BPF_MOV32_IMM(BPF_REG_0, 1),
+		BPF_EXIT_INSN(),
+		/* if (val != 4) exit(2); */
+		BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_10, -4),
+		BPF_JMP32_IMM(BPF_JEQ, BPF_REG_0, 4, 2),
+		BPF_MOV32_IMM(BPF_REG_0, 2),
+		BPF_EXIT_INSN(),
+		/* exit(0); */
+		BPF_MOV32_IMM(BPF_REG_0, 0),
+		BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+},

tools/testing/selftests/bpf/verifier/atomic_xor.c

+{
+	"BPF_ATOMIC XOR without fetch",
+	.insns = {
+		/* val = 0x110; */
+		BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0x110),
+		/* atomic_xor(&val, 0x011); */
+		BPF_MOV64_IMM(BPF_REG_1, 0x011),
+		BPF_ATOMIC_OP(BPF_DW, BPF_XOR, BPF_REG_10, BPF_REG_1, -8),
+		/* if (val != 0x101) exit(2); */
+		BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_10, -8),
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0x101, 2),
+		BPF_MOV64_IMM(BPF_REG_0, 2),
+		BPF_EXIT_INSN(),
+		/* r1 should not be clobbered, no BPF_FETCH flag */
+		BPF_MOV64_IMM(BPF_REG_0, 0),
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0x011, 1),
+		BPF_MOV64_IMM(BPF_REG_0, 1),
+		BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+},
+{
+	"BPF_ATOMIC XOR with fetch",
+	.insns = {
+		BPF_MOV64_IMM(BPF_REG_0, 123),
+		/* val = 0x110; */
+		BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0x110),
+		/* old = atomic_fetch_xor(&val, 0x011); */
+		BPF_MOV64_IMM(BPF_REG_1, 0x011),
+		BPF_ATOMIC_OP(BPF_DW, BPF_XOR | BPF_FETCH, BPF_REG_10, BPF_REG_1, -8),
+		/* if (old != 0x110) exit(3); */
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0x110, 2),
+		BPF_MOV64_IMM(BPF_REG_0, 3),
+		BPF_EXIT_INSN(),
+		/* if (val != 0x101) exit(2); */
+		BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_10, -8),
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0x101, 2),
+		BPF_MOV64_IMM(BPF_REG_1, 2),
+		BPF_EXIT_INSN(),
+		/* Check R0 wasn't clobbered (fxor fear of x86 JIT bug) */
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 123, 2),
+		BPF_MOV64_IMM(BPF_REG_0, 1),
+		BPF_EXIT_INSN(),
+		/* exit(0); */
+		BPF_MOV64_IMM(BPF_REG_0, 0),
+		BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+},
+{
+	"BPF_ATOMIC XOR with fetch 32bit",
+	.insns = {
+		/* r0 = (s64) -1 */
+		BPF_MOV64_IMM(BPF_REG_0, 0),
+		BPF_ALU64_IMM(BPF_SUB, BPF_REG_0, 1),
+		/* val = 0x110; */
+		BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 0x110),
+		/* old = atomic_fetch_xor(&val, 0x011); */
+		BPF_MOV32_IMM(BPF_REG_1, 0x011),
+		BPF_ATOMIC_OP(BPF_W, BPF_XOR | BPF_FETCH, BPF_REG_10, BPF_REG_1, -4),
+		/* if (old != 0x110) exit(3); */
+		BPF_JMP32_IMM(BPF_JEQ, BPF_REG_1, 0x110, 2),
+		BPF_MOV32_IMM(BPF_REG_0, 3),
+		BPF_EXIT_INSN(),
+		/* if (val != 0x101) exit(2); */
+		BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_10, -4),
+		BPF_JMP32_IMM(BPF_JEQ, BPF_REG_1, 0x101, 2),
+		BPF_MOV32_IMM(BPF_REG_1, 2),
+		BPF_EXIT_INSN(),
+		/* Check R0 wasn't clobbered (fxor fear of x86 JIT bug)
+		 * It should be -1 so add 1 to get exit code.
+		 */
+		BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 1),
+		BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+},