From: Andrii Nakryiko andrii@kernel.org
mainline inclusion from mainline-5.11-rc1 commit 6bcd39d366b64318562785d5b47c2837e3a53ae5 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
-------------------------------------------------
Add a self-tests validating libbpf is able to perform CO-RE relocations against the type defined in kernel module BTF. if bpf_testmod.o is not supported by the kernel (e.g., due to version mismatch), skip tests, instead of failing.
Signed-off-by: Andrii Nakryiko andrii@kernel.org Signed-off-by: Alexei Starovoitov ast@kernel.org Link: https://lore.kernel.org/bpf/20201203204634.1325171-9-andrii@kernel.org (cherry picked from commit 6bcd39d366b64318562785d5b47c2837e3a53ae5) Signed-off-by: Wang Yufen wangyufen@huawei.com --- .../selftests/bpf/prog_tests/core_reloc.c | 79 ++++++++++++++++--- .../selftests/bpf/progs/core_reloc_types.h | 17 ++++ .../bpf/progs/test_core_reloc_module.c | 66 ++++++++++++++++ 3 files changed, 151 insertions(+), 11 deletions(-) create mode 100644 tools/testing/selftests/bpf/progs/test_core_reloc_module.c
diff --git a/tools/testing/selftests/bpf/prog_tests/core_reloc.c b/tools/testing/selftests/bpf/prog_tests/core_reloc.c index 5b52985cb60e..e2cfbb4b4113 100644 --- a/tools/testing/selftests/bpf/prog_tests/core_reloc.c +++ b/tools/testing/selftests/bpf/prog_tests/core_reloc.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 #include <test_progs.h> #include "progs/core_reloc_types.h" +#include "bpf_testmod/bpf_testmod.h" #include <sys/mman.h> #include <sys/syscall.h> #include <bpf/btf.h> @@ -9,6 +10,30 @@ static int duration = 0;
#define STRUCT_TO_CHAR_PTR(struct_name) (const char *)&(struct struct_name)
+#define MODULES_CASE(name, sec_name, tp_name) { \ + .case_name = name, \ + .bpf_obj_file = "test_core_reloc_module.o", \ + .btf_src_file = NULL, /* find in kernel module BTFs */ \ + .input = "", \ + .input_len = 0, \ + .output = STRUCT_TO_CHAR_PTR(core_reloc_module_output) { \ + .read_ctx_sz = sizeof(struct bpf_testmod_test_read_ctx),\ + .read_ctx_exists = true, \ + .buf_exists = true, \ + .len_exists = true, \ + .off_exists = true, \ + .len = 123, \ + .off = 0, \ + .comm = "test_progs", \ + .comm_len = sizeof("test_progs"), \ + }, \ + .output_len = sizeof(struct core_reloc_module_output), \ + .prog_sec_name = sec_name, \ + .raw_tp_name = tp_name, \ + .trigger = trigger_module_test_read, \ + .needs_testmod = true, \ +} + #define FLAVORS_DATA(struct_name) STRUCT_TO_CHAR_PTR(struct_name) { \ .a = 42, \ .b = 0xc001, \ @@ -206,7 +231,7 @@ static int duration = 0; .output = STRUCT_TO_CHAR_PTR(core_reloc_bitfields_output) \ __VA_ARGS__, \ .output_len = sizeof(struct core_reloc_bitfields_output), \ - .direct_raw_tp = true, \ + .prog_sec_name = "tp_btf/sys_enter", \ }
@@ -217,7 +242,7 @@ static int duration = 0; }, { \ BITFIELDS_CASE_COMMON("test_core_reloc_bitfields_direct.o", \ "direct:", name), \ - .direct_raw_tp = true, \ + .prog_sec_name = "tp_btf/sys_enter", \ .fails = true, \ }
@@ -304,6 +329,7 @@ static int duration = 0; struct core_reloc_test_case;
typedef int (*setup_test_fn)(struct core_reloc_test_case *test); +typedef int (*trigger_test_fn)(const struct core_reloc_test_case *test);
struct core_reloc_test_case { const char *case_name; @@ -314,9 +340,12 @@ struct core_reloc_test_case { const char *output; int output_len; bool fails; + bool needs_testmod; bool relaxed_core_relocs; - bool direct_raw_tp; + const char *prog_sec_name; + const char *raw_tp_name; setup_test_fn setup; + trigger_test_fn trigger; };
static int find_btf_type(const struct btf *btf, const char *name, __u32 kind) @@ -446,6 +475,23 @@ static int setup_type_id_case_failure(struct core_reloc_test_case *test) return 0; }
+static int trigger_module_test_read(const struct core_reloc_test_case *test) +{ + struct core_reloc_module_output *exp = (void *)test->output; + int fd, err; + + fd = open("/sys/kernel/bpf_testmod", O_RDONLY); + err = -errno; + if (CHECK(fd < 0, "testmod_file_open", "failed: %d\n", err)) + return err; + + read(fd, NULL, exp->len); /* request expected number of bytes */ + close(fd); + + return 0; +} + + static struct core_reloc_test_case test_cases[] = { /* validate we can find kernel image and use its BTF for relocs */ { @@ -462,6 +508,9 @@ static struct core_reloc_test_case test_cases[] = { .output_len = sizeof(struct core_reloc_kernel_output), },
+ /* validate we can find kernel module BTF types for relocs/attach */ + MODULES_CASE("module", "raw_tp/bpf_testmod_test_read", "bpf_testmod_test_read"), + /* validate BPF program can use multiple flavors to match against * single target BTF type */ @@ -785,6 +834,11 @@ void test_core_reloc(void) if (!test__start_subtest(test_case->case_name)) continue;
+ if (test_case->needs_testmod && !env.has_testmod) { + test__skip(); + continue; + } + if (test_case->setup) { err = test_case->setup(test_case); if (CHECK(err, "test_setup", "test #%d setup failed: %d\n", i, err)) @@ -796,13 +850,11 @@ void test_core_reloc(void) test_case->bpf_obj_file, PTR_ERR(obj))) continue;
- /* for typed raw tracepoints, NULL should be specified */ - if (test_case->direct_raw_tp) { - probe_name = "tp_btf/sys_enter"; - tp_name = NULL; - } else { - probe_name = "raw_tracepoint/sys_enter"; - tp_name = "sys_enter"; + probe_name = "raw_tracepoint/sys_enter"; + tp_name = "sys_enter"; + if (test_case->prog_sec_name) { + probe_name = test_case->prog_sec_name; + tp_name = test_case->raw_tp_name; /* NULL for tp_btf */ }
prog = bpf_object__find_program_by_title(obj, probe_name); @@ -850,7 +902,12 @@ void test_core_reloc(void) goto cleanup;
/* trigger test run */ - usleep(1); + if (test_case->trigger) { + if (!ASSERT_OK(test_case->trigger(test_case), "test_trigger")) + goto cleanup; + } else { + usleep(1); + }
if (data->skip) { test__skip(); diff --git a/tools/testing/selftests/bpf/progs/core_reloc_types.h b/tools/testing/selftests/bpf/progs/core_reloc_types.h index af58ef9a28ca..664eea1013aa 100644 --- a/tools/testing/selftests/bpf/progs/core_reloc_types.h +++ b/tools/testing/selftests/bpf/progs/core_reloc_types.h @@ -15,6 +15,23 @@ struct core_reloc_kernel_output { int comm_len; };
+/* + * MODULE + */ + +struct core_reloc_module_output { + long long len; + long long off; + int read_ctx_sz; + bool read_ctx_exists; + bool buf_exists; + bool len_exists; + bool off_exists; + /* we have test_progs[-flavor], so cut flavor part */ + char comm[sizeof("test_progs")]; + int comm_len; +}; + /* * FLAVORS */ diff --git a/tools/testing/selftests/bpf/progs/test_core_reloc_module.c b/tools/testing/selftests/bpf/progs/test_core_reloc_module.c new file mode 100644 index 000000000000..d1840c1a9d36 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_core_reloc_module.c @@ -0,0 +1,66 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Facebook */ + +#include "vmlinux.h" +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_core_read.h> +#include <bpf/bpf_tracing.h> + +char _license[] SEC("license") = "GPL"; + +struct bpf_testmod_test_read_ctx { + /* field order is mixed up */ + size_t len; + char *buf; + loff_t off; +} __attribute__((preserve_access_index)); + +struct { + char in[256]; + char out[256]; + bool skip; + uint64_t my_pid_tgid; +} data = {}; + +struct core_reloc_module_output { + long long len; + long long off; + int read_ctx_sz; + bool read_ctx_exists; + bool buf_exists; + bool len_exists; + bool off_exists; + /* we have test_progs[-flavor], so cut flavor part */ + char comm[sizeof("test_progs")]; + int comm_len; +}; + +SEC("raw_tp/bpf_testmod_test_read") +int BPF_PROG(test_core_module, + struct task_struct *task, + struct bpf_testmod_test_read_ctx *read_ctx) +{ + struct core_reloc_module_output *out = (void *)&data.out; + __u64 pid_tgid = bpf_get_current_pid_tgid(); + __u32 real_tgid = (__u32)(pid_tgid >> 32); + __u32 real_pid = (__u32)pid_tgid; + + if (data.my_pid_tgid != pid_tgid) + return 0; + + if (BPF_CORE_READ(task, pid) != real_pid || BPF_CORE_READ(task, tgid) != real_tgid) + return 0; + + out->len = BPF_CORE_READ(read_ctx, len); + out->off = BPF_CORE_READ(read_ctx, off); + + out->read_ctx_sz = bpf_core_type_size(struct bpf_testmod_test_read_ctx); + out->read_ctx_exists = bpf_core_type_exists(struct bpf_testmod_test_read_ctx); + out->buf_exists = bpf_core_field_exists(read_ctx->buf); + out->off_exists = bpf_core_field_exists(read_ctx->off); + out->len_exists = bpf_core_field_exists(read_ctx->len); + + out->comm_len = BPF_CORE_READ_STR_INTO(&out->comm, task, comm); + + return 0; +}