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-rw-r--r--tools/lib/bpf/btf.c7
-rw-r--r--tools/lib/bpf/btf.h1
-rw-r--r--tools/lib/bpf/libbpf.c150
-rw-r--r--tools/lib/bpf/libbpf.map1
-rw-r--r--tools/testing/selftests/bpf/prog_tests/core_retro.c33
-rw-r--r--tools/testing/selftests/bpf/prog_tests/perf_buffer.c42
-rw-r--r--tools/testing/selftests/bpf/progs/test_core_retro.c30
-rw-r--r--tools/testing/selftests/bpf/progs/test_perf_buffer.c4
8 files changed, 167 insertions, 101 deletions
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index bfef3d606b54..c8861c9e3635 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -389,7 +389,7 @@ void btf__free(struct btf *btf)
if (!btf)
return;
- if (btf->fd != -1)
+ if (btf->fd >= 0)
close(btf->fd);
free(btf->data);
@@ -700,6 +700,11 @@ int btf__fd(const struct btf *btf)
return btf->fd;
}
+void btf__set_fd(struct btf *btf, int fd)
+{
+ btf->fd = fd;
+}
+
const void *btf__get_raw_data(const struct btf *btf, __u32 *size)
{
*size = btf->data_size;
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index 06cd1731c154..173eff23c472 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -79,6 +79,7 @@ LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id);
LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id);
LIBBPF_API int btf__align_of(const struct btf *btf, __u32 id);
LIBBPF_API int btf__fd(const struct btf *btf);
+LIBBPF_API void btf__set_fd(struct btf *btf, int fd);
LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size);
LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset);
LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf);
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 88a483627a2b..6602eb479596 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -2338,18 +2338,23 @@ static bool section_have_execinstr(struct bpf_object *obj, int idx)
return false;
}
-static void bpf_object__sanitize_btf(struct bpf_object *obj)
+static bool btf_needs_sanitization(struct bpf_object *obj)
+{
+ bool has_func_global = obj->caps.btf_func_global;
+ bool has_datasec = obj->caps.btf_datasec;
+ bool has_func = obj->caps.btf_func;
+
+ return !has_func || !has_datasec || !has_func_global;
+}
+
+static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
{
bool has_func_global = obj->caps.btf_func_global;
bool has_datasec = obj->caps.btf_datasec;
bool has_func = obj->caps.btf_func;
- struct btf *btf = obj->btf;
struct btf_type *t;
int i, j, vlen;
- if (!obj->btf || (has_func && has_datasec && has_func_global))
- return;
-
for (i = 1; i <= btf__get_nr_types(btf); i++) {
t = (struct btf_type *)btf__type_by_id(btf, i);
@@ -2402,17 +2407,6 @@ static void bpf_object__sanitize_btf(struct bpf_object *obj)
}
}
-static void bpf_object__sanitize_btf_ext(struct bpf_object *obj)
-{
- if (!obj->btf_ext)
- return;
-
- if (!obj->caps.btf_func) {
- btf_ext__free(obj->btf_ext);
- obj->btf_ext = NULL;
- }
-}
-
static bool libbpf_needs_btf(const struct bpf_object *obj)
{
return obj->efile.btf_maps_shndx >= 0 ||
@@ -2473,19 +2467,11 @@ static int bpf_object__finalize_btf(struct bpf_object *obj)
return 0;
err = btf__finalize_data(obj, obj->btf);
- if (!err)
- return 0;
-
- pr_warn("Error finalizing %s: %d.\n", BTF_ELF_SEC, err);
- btf__free(obj->btf);
- obj->btf = NULL;
- btf_ext__free(obj->btf_ext);
- obj->btf_ext = NULL;
-
- if (libbpf_needs_btf(obj)) {
- pr_warn("BTF is required, but is missing or corrupted.\n");
- return -ENOENT;
+ if (err) {
+ pr_warn("Error finalizing %s: %d.\n", BTF_ELF_SEC, err);
+ return err;
}
+
return 0;
}
@@ -2538,30 +2524,50 @@ static int bpf_object__load_vmlinux_btf(struct bpf_object *obj)
static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj)
{
+ struct btf *kern_btf = obj->btf;
+ bool btf_mandatory, sanitize;
int err = 0;
if (!obj->btf)
return 0;
- bpf_object__sanitize_btf(obj);
- bpf_object__sanitize_btf_ext(obj);
+ sanitize = btf_needs_sanitization(obj);
+ if (sanitize) {
+ const void *orig_data;
+ void *san_data;
+ __u32 sz;
- err = btf__load(obj->btf);
- if (err) {
- pr_warn("Error loading %s into kernel: %d.\n",
- BTF_ELF_SEC, err);
- btf__free(obj->btf);
- obj->btf = NULL;
- /* btf_ext can't exist without btf, so free it as well */
- if (obj->btf_ext) {
- btf_ext__free(obj->btf_ext);
- obj->btf_ext = NULL;
- }
+ /* clone BTF to sanitize a copy and leave the original intact */
+ orig_data = btf__get_raw_data(obj->btf, &sz);
+ san_data = malloc(sz);
+ if (!san_data)
+ return -ENOMEM;
+ memcpy(san_data, orig_data, sz);
+ kern_btf = btf__new(san_data, sz);
+ if (IS_ERR(kern_btf))
+ return PTR_ERR(kern_btf);
- if (kernel_needs_btf(obj))
- return err;
+ bpf_object__sanitize_btf(obj, kern_btf);
}
- return 0;
+
+ err = btf__load(kern_btf);
+ if (sanitize) {
+ if (!err) {
+ /* move fd to libbpf's BTF */
+ btf__set_fd(obj->btf, btf__fd(kern_btf));
+ btf__set_fd(kern_btf, -1);
+ }
+ btf__free(kern_btf);
+ }
+ if (err) {
+ btf_mandatory = kernel_needs_btf(obj);
+ pr_warn("Error loading .BTF into kernel: %d. %s\n", err,
+ btf_mandatory ? "BTF is mandatory, can't proceed."
+ : "BTF is optional, ignoring.");
+ if (!btf_mandatory)
+ err = 0;
+ }
+ return err;
}
static int bpf_object__elf_collect(struct bpf_object *obj)
@@ -3785,7 +3791,7 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map)
create_attr.btf_fd = 0;
create_attr.btf_key_type_id = 0;
create_attr.btf_value_type_id = 0;
- if (obj->btf && !bpf_map_find_btf_info(obj, map)) {
+ if (obj->btf && btf__fd(obj->btf) >= 0 && !bpf_map_find_btf_info(obj, map)) {
create_attr.btf_fd = btf__fd(obj->btf);
create_attr.btf_key_type_id = map->btf_key_type_id;
create_attr.btf_value_type_id = map->btf_value_type_id;
@@ -5369,18 +5375,17 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
load_attr.kern_version = kern_version;
load_attr.prog_ifindex = prog->prog_ifindex;
}
- /* if .BTF.ext was loaded, kernel supports associated BTF for prog */
- if (prog->obj->btf_ext)
- btf_fd = bpf_object__btf_fd(prog->obj);
- else
- btf_fd = -1;
- load_attr.prog_btf_fd = btf_fd >= 0 ? btf_fd : 0;
- load_attr.func_info = prog->func_info;
- load_attr.func_info_rec_size = prog->func_info_rec_size;
- load_attr.func_info_cnt = prog->func_info_cnt;
- load_attr.line_info = prog->line_info;
- load_attr.line_info_rec_size = prog->line_info_rec_size;
- load_attr.line_info_cnt = prog->line_info_cnt;
+ /* specify func_info/line_info only if kernel supports them */
+ btf_fd = bpf_object__btf_fd(prog->obj);
+ if (btf_fd >= 0 && prog->obj->caps.btf_func) {
+ load_attr.prog_btf_fd = btf_fd;
+ load_attr.func_info = prog->func_info;
+ load_attr.func_info_rec_size = prog->func_info_rec_size;
+ load_attr.func_info_cnt = prog->func_info_cnt;
+ load_attr.line_info = prog->line_info;
+ load_attr.line_info_rec_size = prog->line_info_rec_size;
+ load_attr.line_info_cnt = prog->line_info_cnt;
+ }
load_attr.log_level = prog->log_level;
load_attr.prog_flags = prog->prog_flags;
@@ -8586,7 +8591,7 @@ static struct perf_buffer *__perf_buffer__new(int map_fd, size_t page_cnt,
struct perf_buffer_params *p)
{
const char *online_cpus_file = "/sys/devices/system/cpu/online";
- struct bpf_map_info map = {};
+ struct bpf_map_info map;
char msg[STRERR_BUFSIZE];
struct perf_buffer *pb;
bool *online = NULL;
@@ -8599,19 +8604,28 @@ static struct perf_buffer *__perf_buffer__new(int map_fd, size_t page_cnt,
return ERR_PTR(-EINVAL);
}
+ /* best-effort sanity checks */
+ memset(&map, 0, sizeof(map));
map_info_len = sizeof(map);
err = bpf_obj_get_info_by_fd(map_fd, &map, &map_info_len);
if (err) {
err = -errno;
- pr_warn("failed to get map info for map FD %d: %s\n",
- map_fd, libbpf_strerror_r(err, msg, sizeof(msg)));
- return ERR_PTR(err);
- }
-
- if (map.type != BPF_MAP_TYPE_PERF_EVENT_ARRAY) {
- pr_warn("map '%s' should be BPF_MAP_TYPE_PERF_EVENT_ARRAY\n",
- map.name);
- return ERR_PTR(-EINVAL);
+ /* if BPF_OBJ_GET_INFO_BY_FD is supported, will return
+ * -EBADFD, -EFAULT, or -E2BIG on real error
+ */
+ if (err != -EINVAL) {
+ pr_warn("failed to get map info for map FD %d: %s\n",
+ map_fd, libbpf_strerror_r(err, msg, sizeof(msg)));
+ return ERR_PTR(err);
+ }
+ pr_debug("failed to get map info for FD %d; API not supported? Ignoring...\n",
+ map_fd);
+ } else {
+ if (map.type != BPF_MAP_TYPE_PERF_EVENT_ARRAY) {
+ pr_warn("map '%s' should be BPF_MAP_TYPE_PERF_EVENT_ARRAY\n",
+ map.name);
+ return ERR_PTR(-EINVAL);
+ }
}
pb = calloc(1, sizeof(*pb));
@@ -8643,7 +8657,7 @@ static struct perf_buffer *__perf_buffer__new(int map_fd, size_t page_cnt,
err = pb->cpu_cnt;
goto error;
}
- if (map.max_entries < pb->cpu_cnt)
+ if (map.max_entries && map.max_entries < pb->cpu_cnt)
pb->cpu_cnt = map.max_entries;
}
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 6544d2cd1ed6..c5d5c7664c3b 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -288,4 +288,5 @@ LIBBPF_0.1.0 {
bpf_map__value_size;
bpf_program__autoload;
bpf_program__set_autoload;
+ btf__set_fd;
} LIBBPF_0.0.9;
diff --git a/tools/testing/selftests/bpf/prog_tests/core_retro.c b/tools/testing/selftests/bpf/prog_tests/core_retro.c
new file mode 100644
index 000000000000..78e30d3a23d5
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/core_retro.c
@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2020 Facebook
+#define _GNU_SOURCE
+#include <test_progs.h>
+#include "test_core_retro.skel.h"
+
+void test_core_retro(void)
+{
+ int err, zero = 0, res, duration = 0;
+ struct test_core_retro *skel;
+
+ /* load program */
+ skel = test_core_retro__open_and_load();
+ if (CHECK(!skel, "skel_load", "skeleton open/load failed\n"))
+ goto out_close;
+
+ /* attach probe */
+ err = test_core_retro__attach(skel);
+ if (CHECK(err, "attach_kprobe", "err %d\n", err))
+ goto out_close;
+
+ /* trigger */
+ usleep(1);
+
+ err = bpf_map_lookup_elem(bpf_map__fd(skel->maps.results), &zero, &res);
+ if (CHECK(err, "map_lookup", "failed to lookup result: %d\n", errno))
+ goto out_close;
+
+ CHECK(res != getpid(), "pid_check", "got %d != exp %d\n", res, getpid());
+
+out_close:
+ test_core_retro__destroy(skel);
+}
diff --git a/tools/testing/selftests/bpf/prog_tests/perf_buffer.c b/tools/testing/selftests/bpf/prog_tests/perf_buffer.c
index a122ce3b360e..c33ec180b3f2 100644
--- a/tools/testing/selftests/bpf/prog_tests/perf_buffer.c
+++ b/tools/testing/selftests/bpf/prog_tests/perf_buffer.c
@@ -4,6 +4,7 @@
#include <sched.h>
#include <sys/socket.h>
#include <test_progs.h>
+#include "test_perf_buffer.skel.h"
#include "bpf/libbpf_internal.h"
/* AddressSanitizer sometimes crashes due to data dereference below, due to
@@ -25,16 +26,11 @@ static void on_sample(void *ctx, int cpu, void *data, __u32 size)
void test_perf_buffer(void)
{
- int err, prog_fd, on_len, nr_on_cpus = 0, nr_cpus, i, duration = 0;
- const char *prog_name = "kprobe/sys_nanosleep";
- const char *file = "./test_perf_buffer.o";
+ int err, on_len, nr_on_cpus = 0, nr_cpus, i, duration = 0;
struct perf_buffer_opts pb_opts = {};
- struct bpf_map *perf_buf_map;
+ struct test_perf_buffer *skel;
cpu_set_t cpu_set, cpu_seen;
- struct bpf_program *prog;
- struct bpf_object *obj;
struct perf_buffer *pb;
- struct bpf_link *link;
bool *online;
nr_cpus = libbpf_num_possible_cpus();
@@ -51,33 +47,21 @@ void test_perf_buffer(void)
nr_on_cpus++;
/* load program */
- err = bpf_prog_load(file, BPF_PROG_TYPE_KPROBE, &obj, &prog_fd);
- if (CHECK(err, "obj_load", "err %d errno %d\n", err, errno)) {
- obj = NULL;
- goto out_close;
- }
-
- prog = bpf_object__find_program_by_title(obj, prog_name);
- if (CHECK(!prog, "find_probe", "prog '%s' not found\n", prog_name))
+ skel = test_perf_buffer__open_and_load();
+ if (CHECK(!skel, "skel_load", "skeleton open/load failed\n"))
goto out_close;
- /* load map */
- perf_buf_map = bpf_object__find_map_by_name(obj, "perf_buf_map");
- if (CHECK(!perf_buf_map, "find_perf_buf_map", "not found\n"))
- goto out_close;
-
- /* attach kprobe */
- link = bpf_program__attach_kprobe(prog, false /* retprobe */,
- SYS_NANOSLEEP_KPROBE_NAME);
- if (CHECK(IS_ERR(link), "attach_kprobe", "err %ld\n", PTR_ERR(link)))
+ /* attach probe */
+ err = test_perf_buffer__attach(skel);
+ if (CHECK(err, "attach_kprobe", "err %d\n", err))
goto out_close;
/* set up perf buffer */
pb_opts.sample_cb = on_sample;
pb_opts.ctx = &cpu_seen;
- pb = perf_buffer__new(bpf_map__fd(perf_buf_map), 1, &pb_opts);
+ pb = perf_buffer__new(bpf_map__fd(skel->maps.perf_buf_map), 1, &pb_opts);
if (CHECK(IS_ERR(pb), "perf_buf__new", "err %ld\n", PTR_ERR(pb)))
- goto out_detach;
+ goto out_close;
/* trigger kprobe on every CPU */
CPU_ZERO(&cpu_seen);
@@ -94,7 +78,7 @@ void test_perf_buffer(void)
&cpu_set);
if (err && CHECK(err, "set_affinity", "cpu #%d, err %d\n",
i, err))
- goto out_detach;
+ goto out_close;
usleep(1);
}
@@ -110,9 +94,7 @@ void test_perf_buffer(void)
out_free_pb:
perf_buffer__free(pb);
-out_detach:
- bpf_link__destroy(link);
out_close:
- bpf_object__close(obj);
+ test_perf_buffer__destroy(skel);
free(online);
}
diff --git a/tools/testing/selftests/bpf/progs/test_core_retro.c b/tools/testing/selftests/bpf/progs/test_core_retro.c
new file mode 100644
index 000000000000..75c60c3c29cf
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_core_retro.c
@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2020 Facebook
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_core_read.h>
+
+struct task_struct {
+ int tgid;
+} __attribute__((preserve_access_index));
+
+struct {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __uint(max_entries, 1);
+ __type(key, int);
+ __type(value, int);
+} results SEC(".maps");
+
+SEC("tp/raw_syscalls/sys_enter")
+int handle_sys_enter(void *ctx)
+{
+ struct task_struct *task = (void *)bpf_get_current_task();
+ int tgid = BPF_CORE_READ(task, tgid);
+ int zero = 0;
+
+ bpf_map_update_elem(&results, &zero, &tgid, 0);
+
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/test_perf_buffer.c b/tools/testing/selftests/bpf/progs/test_perf_buffer.c
index ad59c4c9aba8..8207a2dc2f9d 100644
--- a/tools/testing/selftests/bpf/progs/test_perf_buffer.c
+++ b/tools/testing/selftests/bpf/progs/test_perf_buffer.c
@@ -12,8 +12,8 @@ struct {
__uint(value_size, sizeof(int));
} perf_buf_map SEC(".maps");
-SEC("kprobe/sys_nanosleep")
-int BPF_KPROBE(handle_sys_nanosleep_entry)
+SEC("tp/raw_syscalls/sys_enter")
+int handle_sys_enter(void *ctx)
{
int cpu = bpf_get_smp_processor_id();
generated by cgit v1.2.3 (git 2.46.0) at 2025-09-27 11:50:35 +0000