This relies on the work done by Yonghong Song in https://reviews.llvm.org/D72184 Signed-off-by: Brendan Jackman <jackmanb@xxxxxxxxxx> --- tools/testing/selftests/bpf/Makefile | 2 +- .../selftests/bpf/prog_tests/atomics_test.c | 145 ++++++++++++++++++ .../selftests/bpf/progs/atomics_test.c | 61 ++++++++ .../selftests/bpf/verifier/atomic_cmpxchg.c | 96 ++++++++++++ .../selftests/bpf/verifier/atomic_fetch_add.c | 106 +++++++++++++ .../selftests/bpf/verifier/atomic_xchg.c | 113 ++++++++++++++ 6 files changed, 522 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/atomics_test.c create mode 100644 tools/testing/selftests/bpf/progs/atomics_test.c create mode 100644 tools/testing/selftests/bpf/verifier/atomic_cmpxchg.c create mode 100644 tools/testing/selftests/bpf/verifier/atomic_fetch_add.c create mode 100644 tools/testing/selftests/bpf/verifier/atomic_xchg.c diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 3d5940cd110d..4e28640ca2d8 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -250,7 +250,7 @@ define CLANG_BPF_BUILD_RULE $(call msg,CLNG-LLC,$(TRUNNER_BINARY),$2) $(Q)($(CLANG) $3 -O2 -target bpf -emit-llvm \ -c $1 -o - || echo "BPF obj compilation failed") | \ - $(LLC) -mattr=dwarfris -march=bpf -mcpu=v3 $4 -filetype=obj -o $2 + $(LLC) -mattr=dwarfris -march=bpf -mcpu=v4 $4 -filetype=obj -o $2 endef # Similar to CLANG_BPF_BUILD_RULE, but with disabled alu32 define CLANG_NOALU32_BPF_BUILD_RULE diff --git a/tools/testing/selftests/bpf/prog_tests/atomics_test.c b/tools/testing/selftests/bpf/prog_tests/atomics_test.c new file mode 100644 index 000000000000..a4859d88fc11 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/atomics_test.c @@ -0,0 +1,145 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <test_progs.h> + +#include "atomics_test.skel.h" + +static void test_add(void) +{ + struct atomics_test *atomics_skel = NULL; + int err, prog_fd; + __u32 duration = 0, retval; + + atomics_skel = atomics_test__open_and_load(); + if (CHECK(!atomics_skel, "atomics_skel_load", "atomics skeleton failed\n")) + goto cleanup; + + err = atomics_test__attach(atomics_skel); + if (CHECK(err, "atomics_attach", "atomics attach failed: %d\n", err)) + goto cleanup; + + prog_fd = bpf_program__fd(atomics_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; + + CHECK(atomics_skel->data->add64_value != 3, "add64_value", + "64bit atomic add value was not incremented (got %lld want 2)\n", + atomics_skel->data->add64_value); + CHECK(atomics_skel->bss->add64_result != 1, "add64_result", + "64bit atomic add bad return value (got %lld want 1)\n", + atomics_skel->bss->add64_result); + + CHECK(atomics_skel->data->add32_value != 3, "add32_value", + "32bit atomic add value was not incremented (got %d want 2)\n", + atomics_skel->data->add32_value); + CHECK(atomics_skel->bss->add32_result != 1, "add32_result", + "32bit atomic add bad return value (got %d want 1)\n", + atomics_skel->bss->add32_result); + + CHECK(atomics_skel->bss->add_stack_value_copy != 3, "add_stack_value", + "_stackbit atomic add value was not incremented (got %lld want 2)\n", + atomics_skel->bss->add_stack_value_copy); + CHECK(atomics_skel->bss->add_stack_result != 1, "add_stack_result", + "_stackbit atomic add bad return value (got %lld want 1)\n", + atomics_skel->bss->add_stack_result); + +cleanup: + atomics_test__destroy(atomics_skel); +} + +static void test_cmpxchg(void) +{ + struct atomics_test *atomics_skel = NULL; + int err, prog_fd; + __u32 duration = 0, retval; + + atomics_skel = atomics_test__open_and_load(); + if (CHECK(!atomics_skel, "atomics_skel_load", "atomics skeleton failed\n")) + goto cleanup; + + err = atomics_test__attach(atomics_skel); + if (CHECK(err, "atomics_attach", "atomics attach failed: %d\n", err)) + goto cleanup; + + prog_fd = bpf_program__fd(atomics_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; + + CHECK(atomics_skel->data->cmpxchg64_value != 2, "cmpxchg64_value", + "64bit cmpxchg left unexpected value (got %lld want 2)\n", + atomics_skel->data->cmpxchg64_value); + CHECK(atomics_skel->bss->cmpxchg64_result_fail != 1, "cmpxchg_result_fail", + "64bit cmpxchg returned bad result (got %lld want 1)\n", + atomics_skel->bss->cmpxchg64_result_fail); + CHECK(atomics_skel->bss->cmpxchg64_result_succeed != 1, "cmpxchg_result_succeed", + "64bit cmpxchg returned bad result (got %lld want 1)\n", + atomics_skel->bss->cmpxchg64_result_succeed); + + CHECK(atomics_skel->data->cmpxchg32_value != 2, "cmpxchg32_value", + "32bit cmpxchg left unexpected value (got %d want 2)\n", + atomics_skel->data->cmpxchg32_value); + CHECK(atomics_skel->bss->cmpxchg32_result_fail != 1, "cmpxchg_result_fail", + "32bit cmpxchg returned bad result (got %d want 1)\n", + atomics_skel->bss->cmpxchg32_result_fail); + CHECK(atomics_skel->bss->cmpxchg32_result_succeed != 1, "cmpxchg_result_succeed", + "32bit cmpxchg returned bad result (got %d want 1)\n", + atomics_skel->bss->cmpxchg32_result_succeed); + +cleanup: + atomics_test__destroy(atomics_skel); +} + +static void test_xchg(void) +{ + struct atomics_test *atomics_skel = NULL; + int err, prog_fd; + __u32 duration = 0, retval; + + atomics_skel = atomics_test__open_and_load(); + if (CHECK(!atomics_skel, "atomics_skel_load", "atomics skeleton failed\n")) + goto cleanup; + + err = atomics_test__attach(atomics_skel); + if (CHECK(err, "atomics_attach", "atomics attach failed: %d\n", err)) + goto cleanup; + + prog_fd = bpf_program__fd(atomics_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; + + CHECK(atomics_skel->data->xchg64_value != 2, "xchg64_value", + "64bit xchg left unexpected value (got %lld want 2)\n", + atomics_skel->data->xchg64_value); + CHECK(atomics_skel->bss->xchg64_result != 1, "xchg_result", + "64bit xchg returned bad result (got %lld want 1)\n", + atomics_skel->bss->xchg64_result); + + CHECK(atomics_skel->data->xchg32_value != 2, "xchg32_value", + "32bit xchg left unexpected value (got %d want 2)\n", + atomics_skel->data->xchg32_value); + CHECK(atomics_skel->bss->xchg32_result != 1, "xchg_result", + "32bit xchg returned bad result (got %d want 1)\n", + atomics_skel->bss->xchg32_result); + +cleanup: + atomics_test__destroy(atomics_skel); +} + +void test_atomics_test(void) +{ + test_add(); + test_cmpxchg(); + test_xchg(); +} diff --git a/tools/testing/selftests/bpf/progs/atomics_test.c b/tools/testing/selftests/bpf/progs/atomics_test.c new file mode 100644 index 000000000000..d81f45eb6c45 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/atomics_test.c @@ -0,0 +1,61 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/bpf.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> + +__u64 add64_value = 1; +__u64 add64_result; +__u32 add32_value = 1; +__u32 add32_result; +__u64 add_stack_value_copy; +__u64 add_stack_result; +SEC("fentry/bpf_fentry_test1") +int BPF_PROG(add, int a) +{ + __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; + + return 0; +} + +__u64 cmpxchg64_value = 1; +__u64 cmpxchg64_result_fail; +__u64 cmpxchg64_result_succeed; +__u32 cmpxchg32_value = 1; +__u32 cmpxchg32_result_fail; +__u32 cmpxchg32_result_succeed; +SEC("fentry/bpf_fentry_test1") +int BPF_PROG(cmpxchg, int a) +{ + 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); + + return 0; +} + +__u64 xchg64_value = 1; +__u64 xchg64_result; +__u32 xchg32_value = 1; +__u32 xchg32_result; +SEC("fentry/bpf_fentry_test1") +int BPF_PROG(xchg, int a) +{ + __u64 val64 = 2; + __u32 val32 = 2; + + __atomic_exchange(&xchg64_value, &val64, &xchg64_result, __ATOMIC_RELAXED); + __atomic_exchange(&xchg32_value, &val32, &xchg32_result, __ATOMIC_RELAXED); + + return 0; +} diff --git a/tools/testing/selftests/bpf/verifier/atomic_cmpxchg.c b/tools/testing/selftests/bpf/verifier/atomic_cmpxchg.c new file mode 100644 index 000000000000..eb43a06428fa --- /dev/null +++ b/tools/testing/selftests/bpf/verifier/atomic_cmpxchg.c @@ -0,0 +1,96 @@ +{ + "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_CMPXCHG(BPF_DW, 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_CMPXCHG(BPF_DW, 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_CMPXCHG(BPF_W, 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_CMPXCHG(BPF_W, 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_CMPXCHG(BPF_DW, 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_CMPXCHG(BPF_DW, BPF_REG_10, BPF_REG_2, -8), + BPF_EXIT_INSN(), + }, + .result = REJECT, + .errstr = "invalid read from stack", +}, diff --git a/tools/testing/selftests/bpf/verifier/atomic_fetch_add.c b/tools/testing/selftests/bpf/verifier/atomic_fetch_add.c new file mode 100644 index 000000000000..c3236510cb64 --- /dev/null +++ b/tools/testing/selftests/bpf/verifier/atomic_fetch_add.c @@ -0,0 +1,106 @@ +{ + "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_FETCH_ADD(BPF_DW, 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_FETCH_ADD(BPF_W, 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_FETCH_ADD(BPF_DW, 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_FETCH_ADD(BPF_DW, 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_FETCH_ADD(BPF_DW, 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_FETCH_ADD(BPF_DW, 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", +}, diff --git a/tools/testing/selftests/bpf/verifier/atomic_xchg.c b/tools/testing/selftests/bpf/verifier/atomic_xchg.c new file mode 100644 index 000000000000..b39d8c0dabf9 --- /dev/null +++ b/tools/testing/selftests/bpf/verifier/atomic_xchg.c @@ -0,0 +1,113 @@ +{ + "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_XCHG(BPF_DW, 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_XCHG(BPF_W, 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, +}, +{ + "atomic set smoketest - 64bit", + .insns = { + /* val = 3; */ + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 3), + /* atomic_xchg(&val, 4); */ + BPF_MOV64_IMM(BPF_REG_1, 4), + BPF_ATOMIC_SET(BPF_DW, BPF_REG_10, BPF_REG_1, -8), + /* r1 should not be clobbered, no BPF_FETCH flag */ + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 4, 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 set smoketest - 32bit", + .insns = { + /* val = 3; */ + BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 3), + /* atomic_xchg(&val, 4); */ + BPF_MOV32_IMM(BPF_REG_1, 4), + BPF_ATOMIC_SET(BPF_W, BPF_REG_10, BPF_REG_1, -4), + /* r1 should not be clobbered, no BPF_FETCH flag */ + BPF_JMP32_IMM(BPF_JEQ, BPF_REG_1, 4, 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, +}, +{ + "Can't use atomic set 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_SET(BPF_DW, BPF_REG_2, BPF_REG_3, 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", +}, -- 2.29.2.454.gaff20da3a2-goog
