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-rw-r--r--tools/lib/bpf/Build2
-rw-r--r--tools/lib/bpf/bpf.c37
-rw-r--r--tools/lib/bpf/bpf.h35
-rw-r--r--tools/lib/bpf/bpf_core_read.h32
-rw-r--r--tools/lib/bpf/btf.c7
-rw-r--r--tools/lib/bpf/elf.c2
-rw-r--r--tools/lib/bpf/features.c478
-rw-r--r--tools/lib/bpf/libbpf.c584
-rw-r--r--tools/lib/bpf/libbpf.h37
-rw-r--r--tools/lib/bpf/libbpf.map1
-rw-r--r--tools/lib/bpf/libbpf_internal.h36
-rw-r--r--tools/lib/bpf/libbpf_probes.c8
-rw-r--r--tools/lib/bpf/linker.c24
-rw-r--r--tools/lib/bpf/str_error.h3
14 files changed, 804 insertions, 482 deletions
diff --git a/tools/lib/bpf/Build b/tools/lib/bpf/Build
index 2d0c282c8588..b6619199a706 100644
--- a/tools/lib/bpf/Build
+++ b/tools/lib/bpf/Build
@@ -1,4 +1,4 @@
libbpf-y := libbpf.o bpf.o nlattr.o btf.o libbpf_errno.o str_error.o \
netlink.o bpf_prog_linfo.o libbpf_probes.o hashmap.o \
btf_dump.o ringbuf.o strset.o linker.o gen_loader.o relo_core.o \
- usdt.o zip.o elf.o
+ usdt.o zip.o elf.o features.o
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 9dc9625651dc..0ad8e532b3cf 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -103,7 +103,7 @@ int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size, int attempts)
* [0] https://lore.kernel.org/bpf/20201201215900.3569844-1-guro@fb.com/
* [1] d05512618056 ("bpf: Add bpf_ktime_get_coarse_ns helper")
*/
-int probe_memcg_account(void)
+int probe_memcg_account(int token_fd)
{
const size_t attr_sz = offsetofend(union bpf_attr, attach_btf_obj_fd);
struct bpf_insn insns[] = {
@@ -120,6 +120,7 @@ int probe_memcg_account(void)
attr.insns = ptr_to_u64(insns);
attr.insn_cnt = insn_cnt;
attr.license = ptr_to_u64("GPL");
+ attr.prog_token_fd = token_fd;
prog_fd = sys_bpf_fd(BPF_PROG_LOAD, &attr, attr_sz);
if (prog_fd >= 0) {
@@ -146,7 +147,7 @@ int bump_rlimit_memlock(void)
struct rlimit rlim;
/* if kernel supports memcg-based accounting, skip bumping RLIMIT_MEMLOCK */
- if (memlock_bumped || kernel_supports(NULL, FEAT_MEMCG_ACCOUNT))
+ if (memlock_bumped || feat_supported(NULL, FEAT_MEMCG_ACCOUNT))
return 0;
memlock_bumped = true;
@@ -169,7 +170,7 @@ int bpf_map_create(enum bpf_map_type map_type,
__u32 max_entries,
const struct bpf_map_create_opts *opts)
{
- const size_t attr_sz = offsetofend(union bpf_attr, map_extra);
+ const size_t attr_sz = offsetofend(union bpf_attr, map_token_fd);
union bpf_attr attr;
int fd;
@@ -181,7 +182,7 @@ int bpf_map_create(enum bpf_map_type map_type,
return libbpf_err(-EINVAL);
attr.map_type = map_type;
- if (map_name && kernel_supports(NULL, FEAT_PROG_NAME))
+ if (map_name && feat_supported(NULL, FEAT_PROG_NAME))
libbpf_strlcpy(attr.map_name, map_name, sizeof(attr.map_name));
attr.key_size = key_size;
attr.value_size = value_size;
@@ -198,6 +199,8 @@ int bpf_map_create(enum bpf_map_type map_type,
attr.numa_node = OPTS_GET(opts, numa_node, 0);
attr.map_ifindex = OPTS_GET(opts, map_ifindex, 0);
+ attr.map_token_fd = OPTS_GET(opts, token_fd, 0);
+
fd = sys_bpf_fd(BPF_MAP_CREATE, &attr, attr_sz);
return libbpf_err_errno(fd);
}
@@ -232,7 +235,7 @@ int bpf_prog_load(enum bpf_prog_type prog_type,
const struct bpf_insn *insns, size_t insn_cnt,
struct bpf_prog_load_opts *opts)
{
- const size_t attr_sz = offsetofend(union bpf_attr, log_true_size);
+ const size_t attr_sz = offsetofend(union bpf_attr, prog_token_fd);
void *finfo = NULL, *linfo = NULL;
const char *func_info, *line_info;
__u32 log_size, log_level, attach_prog_fd, attach_btf_obj_fd;
@@ -261,8 +264,9 @@ int bpf_prog_load(enum bpf_prog_type prog_type,
attr.prog_flags = OPTS_GET(opts, prog_flags, 0);
attr.prog_ifindex = OPTS_GET(opts, prog_ifindex, 0);
attr.kern_version = OPTS_GET(opts, kern_version, 0);
+ attr.prog_token_fd = OPTS_GET(opts, token_fd, 0);
- if (prog_name && kernel_supports(NULL, FEAT_PROG_NAME))
+ if (prog_name && feat_supported(NULL, FEAT_PROG_NAME))
libbpf_strlcpy(attr.prog_name, prog_name, sizeof(attr.prog_name));
attr.license = ptr_to_u64(license);
@@ -1182,7 +1186,7 @@ int bpf_raw_tracepoint_open(const char *name, int prog_fd)
int bpf_btf_load(const void *btf_data, size_t btf_size, struct bpf_btf_load_opts *opts)
{
- const size_t attr_sz = offsetofend(union bpf_attr, btf_log_true_size);
+ const size_t attr_sz = offsetofend(union bpf_attr, btf_token_fd);
union bpf_attr attr;
char *log_buf;
size_t log_size;
@@ -1207,6 +1211,8 @@ int bpf_btf_load(const void *btf_data, size_t btf_size, struct bpf_btf_load_opts
attr.btf = ptr_to_u64(btf_data);
attr.btf_size = btf_size;
+ attr.btf_token_fd = OPTS_GET(opts, token_fd, 0);
+
/* log_level == 0 and log_buf != NULL means "try loading without
* log_buf, but retry with log_buf and log_level=1 on error", which is
* consistent across low-level and high-level BTF and program loading
@@ -1287,3 +1293,20 @@ int bpf_prog_bind_map(int prog_fd, int map_fd,
ret = sys_bpf(BPF_PROG_BIND_MAP, &attr, attr_sz);
return libbpf_err_errno(ret);
}
+
+int bpf_token_create(int bpffs_fd, struct bpf_token_create_opts *opts)
+{
+ const size_t attr_sz = offsetofend(union bpf_attr, token_create);
+ union bpf_attr attr;
+ int fd;
+
+ if (!OPTS_VALID(opts, bpf_token_create_opts))
+ return libbpf_err(-EINVAL);
+
+ memset(&attr, 0, attr_sz);
+ attr.token_create.bpffs_fd = bpffs_fd;
+ attr.token_create.flags = OPTS_GET(opts, flags, 0);
+
+ fd = sys_bpf_fd(BPF_TOKEN_CREATE, &attr, attr_sz);
+ return libbpf_err_errno(fd);
+}
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index d0f53772bdc0..991b86bfe7e4 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -51,8 +51,11 @@ struct bpf_map_create_opts {
__u32 numa_node;
__u32 map_ifindex;
+
+ __u32 token_fd;
+ size_t :0;
};
-#define bpf_map_create_opts__last_field map_ifindex
+#define bpf_map_create_opts__last_field token_fd
LIBBPF_API int bpf_map_create(enum bpf_map_type map_type,
const char *map_name,
@@ -102,9 +105,10 @@ struct bpf_prog_load_opts {
* If kernel doesn't support this feature, log_size is left unchanged.
*/
__u32 log_true_size;
+ __u32 token_fd;
size_t :0;
};
-#define bpf_prog_load_opts__last_field log_true_size
+#define bpf_prog_load_opts__last_field token_fd
LIBBPF_API int bpf_prog_load(enum bpf_prog_type prog_type,
const char *prog_name, const char *license,
@@ -130,9 +134,10 @@ struct bpf_btf_load_opts {
* If kernel doesn't support this feature, log_size is left unchanged.
*/
__u32 log_true_size;
+ __u32 token_fd;
size_t :0;
};
-#define bpf_btf_load_opts__last_field log_true_size
+#define bpf_btf_load_opts__last_field token_fd
LIBBPF_API int bpf_btf_load(const void *btf_data, size_t btf_size,
struct bpf_btf_load_opts *opts);
@@ -640,6 +645,30 @@ struct bpf_test_run_opts {
LIBBPF_API int bpf_prog_test_run_opts(int prog_fd,
struct bpf_test_run_opts *opts);
+struct bpf_token_create_opts {
+ size_t sz; /* size of this struct for forward/backward compatibility */
+ __u32 flags;
+ size_t :0;
+};
+#define bpf_token_create_opts__last_field flags
+
+/**
+ * @brief **bpf_token_create()** creates a new instance of BPF token derived
+ * from specified BPF FS mount point.
+ *
+ * BPF token created with this API can be passed to bpf() syscall for
+ * commands like BPF_PROG_LOAD, BPF_MAP_CREATE, etc.
+ *
+ * @param bpffs_fd FD for BPF FS instance from which to derive a BPF token
+ * instance.
+ * @param opts optional BPF token creation options, can be NULL
+ *
+ * @return BPF token FD > 0, on success; negative error code, otherwise (errno
+ * is also set to the error code)
+ */
+LIBBPF_API int bpf_token_create(int bpffs_fd,
+ struct bpf_token_create_opts *opts);
+
#ifdef __cplusplus
} /* extern "C" */
#endif
diff --git a/tools/lib/bpf/bpf_core_read.h b/tools/lib/bpf/bpf_core_read.h
index 1ac57bb7ac55..7325a12692a3 100644
--- a/tools/lib/bpf/bpf_core_read.h
+++ b/tools/lib/bpf/bpf_core_read.h
@@ -111,6 +111,38 @@ enum bpf_enum_value_kind {
val; \
})
+/*
+ * Write to a bitfield, identified by s->field.
+ * This is the inverse of BPF_CORE_WRITE_BITFIELD().
+ */
+#define BPF_CORE_WRITE_BITFIELD(s, field, new_val) ({ \
+ void *p = (void *)s + __CORE_RELO(s, field, BYTE_OFFSET); \
+ unsigned int byte_size = __CORE_RELO(s, field, BYTE_SIZE); \
+ unsigned int lshift = __CORE_RELO(s, field, LSHIFT_U64); \
+ unsigned int rshift = __CORE_RELO(s, field, RSHIFT_U64); \
+ unsigned long long mask, val, nval = new_val; \
+ unsigned int rpad = rshift - lshift; \
+ \
+ asm volatile("" : "+r"(p)); \
+ \
+ switch (byte_size) { \
+ case 1: val = *(unsigned char *)p; break; \
+ case 2: val = *(unsigned short *)p; break; \
+ case 4: val = *(unsigned int *)p; break; \
+ case 8: val = *(unsigned long long *)p; break; \
+ } \
+ \
+ mask = (~0ULL << rshift) >> lshift; \
+ val = (val & ~mask) | ((nval << rpad) & mask); \
+ \
+ switch (byte_size) { \
+ case 1: *(unsigned char *)p = val; break; \
+ case 2: *(unsigned short *)p = val; break; \
+ case 4: *(unsigned int *)p = val; break; \
+ case 8: *(unsigned long long *)p = val; break; \
+ } \
+})
+
#define ___bpf_field_ref1(field) (field)
#define ___bpf_field_ref2(type, field) (((typeof(type) *)0)->field)
#define ___bpf_field_ref(args...) \
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index ee95fd379d4d..63033c334320 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -1317,7 +1317,9 @@ struct btf *btf__parse_split(const char *path, struct btf *base_btf)
static void *btf_get_raw_data(const struct btf *btf, __u32 *size, bool swap_endian);
-int btf_load_into_kernel(struct btf *btf, char *log_buf, size_t log_sz, __u32 log_level)
+int btf_load_into_kernel(struct btf *btf,
+ char *log_buf, size_t log_sz, __u32 log_level,
+ int token_fd)
{
LIBBPF_OPTS(bpf_btf_load_opts, opts);
__u32 buf_sz = 0, raw_size;
@@ -1367,6 +1369,7 @@ retry_load:
opts.log_level = log_level;
}
+ opts.token_fd = token_fd;
btf->fd = bpf_btf_load(raw_data, raw_size, &opts);
if (btf->fd < 0) {
/* time to turn on verbose mode and try again */
@@ -1394,7 +1397,7 @@ done:
int btf__load_into_kernel(struct btf *btf)
{
- return btf_load_into_kernel(btf, NULL, 0, 0);
+ return btf_load_into_kernel(btf, NULL, 0, 0, 0);
}
int btf__fd(const struct btf *btf)
diff --git a/tools/lib/bpf/elf.c b/tools/lib/bpf/elf.c
index b02faec748a5..c92e02394159 100644
--- a/tools/lib/bpf/elf.c
+++ b/tools/lib/bpf/elf.c
@@ -11,8 +11,6 @@
#include "libbpf_internal.h"
#include "str_error.h"
-#define STRERR_BUFSIZE 128
-
/* A SHT_GNU_versym section holds 16-bit words. This bit is set if
* the symbol is hidden and can only be seen when referenced using an
* explicit version number. This is a GNU extension.
diff --git a/tools/lib/bpf/features.c b/tools/lib/bpf/features.c
new file mode 100644
index 000000000000..ce98a334be21
--- /dev/null
+++ b/tools/lib/bpf/features.c
@@ -0,0 +1,478 @@
+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
+#include <linux/kernel.h>
+#include <linux/filter.h>
+#include "bpf.h"
+#include "libbpf.h"
+#include "libbpf_common.h"
+#include "libbpf_internal.h"
+#include "str_error.h"
+
+static inline __u64 ptr_to_u64(const void *ptr)
+{
+ return (__u64)(unsigned long)ptr;
+}
+
+static int probe_fd(int fd)
+{
+ if (fd >= 0)
+ close(fd);
+ return fd >= 0;
+}
+
+static int probe_kern_prog_name(int token_fd)
+{
+ const size_t attr_sz = offsetofend(union bpf_attr, prog_name);
+ struct bpf_insn insns[] = {
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ };
+ union bpf_attr attr;
+ int ret;
+
+ memset(&attr, 0, attr_sz);
+ attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
+ attr.license = ptr_to_u64("GPL");
+ attr.insns = ptr_to_u64(insns);
+ attr.insn_cnt = (__u32)ARRAY_SIZE(insns);
+ attr.prog_token_fd = token_fd;
+ libbpf_strlcpy(attr.prog_name, "libbpf_nametest", sizeof(attr.prog_name));
+
+ /* make sure loading with name works */
+ ret = sys_bpf_prog_load(&attr, attr_sz, PROG_LOAD_ATTEMPTS);
+ return probe_fd(ret);
+}
+
+static int probe_kern_global_data(int token_fd)
+{
+ char *cp, errmsg[STRERR_BUFSIZE];
+ struct bpf_insn insns[] = {
+ BPF_LD_MAP_VALUE(BPF_REG_1, 0, 16),
+ BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 42),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ };
+ LIBBPF_OPTS(bpf_map_create_opts, map_opts, .token_fd = token_fd);
+ LIBBPF_OPTS(bpf_prog_load_opts, prog_opts, .token_fd = token_fd);
+ int ret, map, insn_cnt = ARRAY_SIZE(insns);
+
+ map = bpf_map_create(BPF_MAP_TYPE_ARRAY, "libbpf_global", sizeof(int), 32, 1, &map_opts);
+ if (map < 0) {
+ ret = -errno;
+ cp = libbpf_strerror_r(ret, errmsg, sizeof(errmsg));
+ pr_warn("Error in %s():%s(%d). Couldn't create simple array map.\n",
+ __func__, cp, -ret);
+ return ret;
+ }
+
+ insns[0].imm = map;
+
+ ret = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, NULL, "GPL", insns, insn_cnt, &prog_opts);
+ close(map);
+ return probe_fd(ret);
+}
+
+static int probe_kern_btf(int token_fd)
+{
+ static const char strs[] = "\0int";
+ __u32 types[] = {
+ /* int */
+ BTF_TYPE_INT_ENC(1, BTF_INT_SIGNED, 0, 32, 4),
+ };
+
+ return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
+ strs, sizeof(strs), token_fd));
+}
+
+static int probe_kern_btf_func(int token_fd)
+{
+ static const char strs[] = "\0int\0x\0a";
+ /* void x(int a) {} */
+ __u32 types[] = {
+ /* int */
+ BTF_TYPE_INT_ENC(1, BTF_INT_SIGNED, 0, 32, 4), /* [1] */
+ /* FUNC_PROTO */ /* [2] */
+ BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_FUNC_PROTO, 0, 1), 0),
+ BTF_PARAM_ENC(7, 1),
+ /* FUNC x */ /* [3] */
+ BTF_TYPE_ENC(5, BTF_INFO_ENC(BTF_KIND_FUNC, 0, 0), 2),
+ };
+
+ return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
+ strs, sizeof(strs), token_fd));
+}
+
+static int probe_kern_btf_func_global(int token_fd)
+{
+ static const char strs[] = "\0int\0x\0a";
+ /* static void x(int a) {} */
+ __u32 types[] = {
+ /* int */
+ BTF_TYPE_INT_ENC(1, BTF_INT_SIGNED, 0, 32, 4), /* [1] */
+ /* FUNC_PROTO */ /* [2] */
+ BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_FUNC_PROTO, 0, 1), 0),
+ BTF_PARAM_ENC(7, 1),
+ /* FUNC x BTF_FUNC_GLOBAL */ /* [3] */
+ BTF_TYPE_ENC(5, BTF_INFO_ENC(BTF_KIND_FUNC, 0, BTF_FUNC_GLOBAL), 2),
+ };
+
+ return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
+ strs, sizeof(strs), token_fd));
+}
+
+static int probe_kern_btf_datasec(int token_fd)
+{
+ static const char strs[] = "\0x\0.data";
+ /* static int a; */
+ __u32 types[] = {
+ /* int */
+ BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */
+ /* VAR x */ /* [2] */
+ BTF_TYPE_ENC(1, BTF_INFO_ENC(BTF_KIND_VAR, 0, 0), 1),
+ BTF_VAR_STATIC,
+ /* DATASEC val */ /* [3] */
+ BTF_TYPE_ENC(3, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 4),
+ BTF_VAR_SECINFO_ENC(2, 0, 4),
+ };
+
+ return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
+ strs, sizeof(strs), token_fd));
+}
+
+static int probe_kern_btf_float(int token_fd)
+{
+ static const char strs[] = "\0float";
+ __u32 types[] = {
+ /* float */
+ BTF_TYPE_FLOAT_ENC(1, 4),
+ };
+
+ return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
+ strs, sizeof(strs), token_fd));
+}
+
+static int probe_kern_btf_decl_tag(int token_fd)
+{
+ static const char strs[] = "\0tag";
+ __u32 types[] = {
+ /* int */
+ BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */
+ /* VAR x */ /* [2] */
+ BTF_TYPE_ENC(1, BTF_INFO_ENC(BTF_KIND_VAR, 0, 0), 1),
+ BTF_VAR_STATIC,
+ /* attr */
+ BTF_TYPE_DECL_TAG_ENC(1, 2, -1),
+ };
+
+ return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
+ strs, sizeof(strs), token_fd));
+}
+
+static int probe_kern_btf_type_tag(int token_fd)
+{
+ static const char strs[] = "\0tag";
+ __u32 types[] = {
+ /* int */
+ BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */
+ /* attr */
+ BTF_TYPE_TYPE_TAG_ENC(1, 1), /* [2] */
+ /* ptr */
+ BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_PTR, 0, 0), 2), /* [3] */
+ };
+
+ return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
+ strs, sizeof(strs), token_fd));
+}
+
+static int probe_kern_array_mmap(int token_fd)
+{
+ LIBBPF_OPTS(bpf_map_create_opts, opts,
+ .map_flags = BPF_F_MMAPABLE,
+ .token_fd = token_fd,
+ );
+ int fd;
+
+ fd = bpf_map_create(BPF_MAP_TYPE_ARRAY, "libbpf_mmap", sizeof(int), sizeof(int), 1, &opts);
+ return probe_fd(fd);
+}
+
+static int probe_kern_exp_attach_type(int token_fd)
+{
+ LIBBPF_OPTS(bpf_prog_load_opts, opts,
+ .expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE,
+ .token_fd = token_fd,
+ );
+ struct bpf_insn insns[] = {
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ };
+ int fd, insn_cnt = ARRAY_SIZE(insns);
+
+ /* use any valid combination of program type and (optional)
+ * non-zero expected attach type (i.e., not a BPF_CGROUP_INET_INGRESS)
+ * to see if kernel supports expected_attach_type field for
+ * BPF_PROG_LOAD command
+ */
+ fd = bpf_prog_load(BPF_PROG_TYPE_CGROUP_SOCK, NULL, "GPL", insns, insn_cnt, &opts);
+ return probe_fd(fd);
+}
+
+static int probe_kern_probe_read_kernel(int token_fd)
+{
+ LIBBPF_OPTS(bpf_prog_load_opts, opts, .token_fd = token_fd);
+ struct bpf_insn insns[] = {
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), /* r1 = r10 (fp) */
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8), /* r1 += -8 */
+ BPF_MOV64_IMM(BPF_REG_2, 8), /* r2 = 8 */
+ BPF_MOV64_IMM(BPF_REG_3, 0), /* r3 = 0 */
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_probe_read_kernel),
+ BPF_EXIT_INSN(),
+ };
+ int fd, insn_cnt = ARRAY_SIZE(insns);
+
+ fd = bpf_prog_load(BPF_PROG_TYPE_TRACEPOINT, NULL, "GPL", insns, insn_cnt, &opts);
+ return probe_fd(fd);
+}
+
+static int probe_prog_bind_map(int token_fd)
+{
+ char *cp, errmsg[STRERR_BUFSIZE];
+ struct bpf_insn insns[] = {
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ };
+ LIBBPF_OPTS(bpf_map_create_opts, map_opts, .token_fd = token_fd);
+ LIBBPF_OPTS(bpf_prog_load_opts, prog_opts, .token_fd = token_fd);
+ int ret, map, prog, insn_cnt = ARRAY_SIZE(insns);
+
+ map = bpf_map_create(BPF_MAP_TYPE_ARRAY, "libbpf_det_bind", sizeof(int), 32, 1, &map_opts);
+ if (map < 0) {
+ ret = -errno;
+ cp = libbpf_strerror_r(ret, errmsg, sizeof(errmsg));
+ pr_warn("Error in %s():%s(%d). Couldn't create simple array map.\n",
+ __func__, cp, -ret);
+ return ret;
+ }
+
+ prog = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, NULL, "GPL", insns, insn_cnt, &prog_opts);
+ if (prog < 0) {
+ close(map);
+ return 0;
+ }
+
+ ret = bpf_prog_bind_map(prog, map, NULL);
+
+ close(map);
+ close(prog);
+
+ return ret >= 0;
+}
+
+static int probe_module_btf(int token_fd)
+{
+ static const char strs[] = "\0int";
+ __u32 types[] = {
+ /* int */
+ BTF_TYPE_INT_ENC(1, BTF_INT_SIGNED, 0, 32, 4),
+ };
+ struct bpf_btf_info info;
+ __u32 len = sizeof(info);
+ char name[16];
+ int fd, err;
+
+ fd = libbpf__load_raw_btf((char *)types, sizeof(types), strs, sizeof(strs), token_fd);
+ if (fd < 0)
+ return 0; /* BTF not supported at all */
+
+ memset(&info, 0, sizeof(info));
+ info.name = ptr_to_u64(name);
+ info.name_len = sizeof(name);
+
+ /* check that BPF_OBJ_GET_INFO_BY_FD supports specifying name pointer;
+ * kernel's module BTF support coincides with support for
+ * name/name_len fields in struct bpf_btf_info.
+ */
+ err = bpf_btf_get_info_by_fd(fd, &info, &len);
+ close(fd);
+ return !err;
+}
+
+static int probe_perf_link(int token_fd)
+{
+ struct bpf_insn insns[] = {
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ };
+ LIBBPF_OPTS(bpf_prog_load_opts, opts, .token_fd = token_fd);
+ int prog_fd, link_fd, err;
+
+ prog_fd = bpf_prog_load(BPF_PROG_TYPE_TRACEPOINT, NULL, "GPL",
+ insns, ARRAY_SIZE(insns), &opts);
+ if (prog_fd < 0)
+ return -errno;
+
+ /* use invalid perf_event FD to get EBADF, if link is supported;
+ * otherwise EINVAL should be returned
+ */
+ link_fd = bpf_link_create(prog_fd, -1, BPF_PERF_EVENT, NULL);
+ err = -errno; /* close() can clobber errno */
+
+ if (link_fd >= 0)
+ close(link_fd);
+ close(prog_fd);
+
+ return link_fd < 0 && err == -EBADF;
+}
+
+static int probe_uprobe_multi_link(int token_fd)
+{
+ LIBBPF_OPTS(bpf_prog_load_opts, load_opts,
+ .expected_attach_type = BPF_TRACE_UPROBE_MULTI,
+ .token_fd = token_fd,
+ );
+ LIBBPF_OPTS(bpf_link_create_opts, link_opts);
+ struct bpf_insn insns[] = {
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ };
+ int prog_fd, link_fd, err;
+ unsigned long offset = 0;
+
+ prog_fd = bpf_prog_load(BPF_PROG_TYPE_KPROBE, NULL, "GPL",
+ insns, ARRAY_SIZE(insns), &load_opts);
+ if (prog_fd < 0)
+ return -errno;
+
+ /* Creating uprobe in '/' binary should fail with -EBADF. */
+ link_opts.uprobe_multi.path = "/";
+ link_opts.uprobe_multi.offsets = &offset;
+ link_opts.uprobe_multi.cnt = 1;
+
+ link_fd = bpf_link_create(prog_fd, -1, BPF_TRACE_UPROBE_MULTI, &link_opts);
+ err = -errno; /* close() can clobber errno */
+
+ if (link_fd >= 0)
+ close(link_fd);
+ close(prog_fd);
+
+ return link_fd < 0 && err == -EBADF;
+}
+
+static int probe_kern_bpf_cookie(int token_fd)
+{
+ struct bpf_insn insns[] = {
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_get_attach_cookie),
+ BPF_EXIT_INSN(),
+ };
+ LIBBPF_OPTS(bpf_prog_load_opts, opts, .token_fd = token_fd);
+ int ret, insn_cnt = ARRAY_SIZE(insns);
+
+ ret = bpf_prog_load(BPF_PROG_TYPE_TRACEPOINT, NULL, "GPL", insns, insn_cnt, &opts);
+ return probe_fd(ret);
+}
+
+static int probe_kern_btf_enum64(int token_fd)
+{
+ static const char strs[] = "\0enum64";
+ __u32 types[] = {
+ BTF_TYPE_ENC(1, BTF_INFO_ENC(BTF_KIND_ENUM64, 0, 0), 8),
+ };
+
+ return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
+ strs, sizeof(strs), token_fd));
+}
+
+typedef int (*feature_probe_fn)(int /* token_fd */);
+
+static struct kern_feature_cache feature_cache;
+
+static struct kern_feature_desc {
+ const char *desc;
+ feature_probe_fn probe;
+} feature_probes[__FEAT_CNT] = {
+ [FEAT_PROG_NAME] = {
+ "BPF program name", probe_kern_prog_name,
+ },
+ [FEAT_GLOBAL_DATA] = {
+ "global variables", probe_kern_global_data,
+ },
+ [FEAT_BTF] = {
+ "minimal BTF", probe_kern_btf,
+ },
+ [FEAT_BTF_FUNC] = {
+ "BTF functions", probe_kern_btf_func,
+ },
+ [FEAT_BTF_GLOBAL_FUNC] = {
+ "BTF global function", probe_kern_btf_func_global,
+ },
+ [FEAT_BTF_DATASEC] = {
+ "BTF data section and variable", probe_kern_btf_datasec,
+ },
+ [FEAT_ARRAY_MMAP] = {
+ "ARRAY map mmap()", probe_kern_array_mmap,
+ },
+ [FEAT_EXP_ATTACH_TYPE] = {
+ "BPF_PROG_LOAD expected_attach_type attribute",
+ probe_kern_exp_attach_type,
+ },
+ [FEAT_PROBE_READ_KERN] = {
+ "bpf_probe_read_kernel() helper", probe_kern_probe_read_kernel,
+ },
+ [FEAT_PROG_BIND_MAP] = {
+ "BPF_PROG_BIND_MAP support", probe_prog_bind_map,
+ },
+ [FEAT_MODULE_BTF] = {
+ "module BTF support", probe_module_btf,
+ },
+ [FEAT_BTF_FLOAT] = {
+ "BTF_KIND_FLOAT support", probe_kern_btf_float,
+ },
+ [FEAT_PERF_LINK] = {
+ "BPF perf link support", probe_perf_link,
+ },
+ [FEAT_BTF_DECL_TAG] = {
+ "BTF_KIND_DECL_TAG support", probe_kern_btf_decl_tag,
+ },
+ [FEAT_BTF_TYPE_TAG] = {
+ "BTF_KIND_TYPE_TAG support", probe_kern_btf_type_tag,
+ },
+ [FEAT_MEMCG_ACCOUNT] = {
+ "memcg-based memory accounting", probe_memcg_account,
+ },
+ [FEAT_BPF_COOKIE] = {
+ "BPF cookie support", probe_kern_bpf_cookie,
+ },
+ [FEAT_BTF_ENUM64] = {
+ "BTF_KIND_ENUM64 support", probe_kern_btf_enum64,
+ },
+ [FEAT_SYSCALL_WRAPPER] = {
+ "Kernel using syscall wrapper", probe_kern_syscall_wrapper,
+ },
+ [FEAT_UPROBE_MULTI_LINK] = {
+ "BPF multi-uprobe link support", probe_uprobe_multi_link,
+ },
+};
+
+bool feat_supported(struct kern_feature_cache *cache, enum kern_feature_id feat_id)
+{
+ struct kern_feature_desc *feat = &feature_probes[feat_id];
+ int ret;
+
+ /* assume global feature cache, unless custom one is provided */
+ if (!cache)
+ cache = &feature_cache;
+
+ if (READ_ONCE(cache->res[feat_id]) == FEAT_UNKNOWN) {
+ ret = feat->probe(cache->token_fd);
+ if (ret > 0) {
+ WRITE_ONCE(cache->res[feat_id], FEAT_SUPPORTED);
+ } else if (ret == 0) {
+ WRITE_ONCE(cache->res[feat_id], FEAT_MISSING);
+ } else {
+ pr_warn("Detection of kernel %s support failed: %d\n", feat->desc, ret);
+ WRITE_ONCE(cache->res[feat_id], FEAT_MISSING);
+ }
+ }
+
+ return READ_ONCE(cache->res[feat_id]) == FEAT_SUPPORTED;
+}
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index ea9b8158c20d..4b5ff9508e18 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -59,6 +59,8 @@
#define BPF_FS_MAGIC 0xcafe4a11
#endif
+#define BPF_FS_DEFAULT_PATH "/sys/fs/bpf"
+
#define BPF_INSN_SZ (sizeof(struct bpf_insn))
/* vsprintf() in __base_pr() uses nonliteral format string. It may break
@@ -693,6 +695,10 @@ struct bpf_object {
struct usdt_manager *usdt_man;
+ struct kern_feature_cache *feat_cache;
+ char *token_path;
+ int token_fd;
+
char path[];
};
@@ -2192,7 +2198,7 @@ static int build_map_pin_path(struct bpf_map *map, const char *path)
int err;
if (!path)
- path = "/sys/fs/bpf";
+ path = BPF_FS_DEFAULT_PATH;
err = pathname_concat(buf, sizeof(buf), path, bpf_map__name(map));
if (err)
@@ -3054,9 +3060,15 @@ static bool prog_needs_vmlinux_btf(struct bpf_program *prog)
return false;
}
+static bool map_needs_vmlinux_btf(struct bpf_map *map)
+{
+ return bpf_map__is_struct_ops(map);
+}
+
static bool obj_needs_vmlinux_btf(const struct bpf_object *obj)
{
struct bpf_program *prog;
+ struct bpf_map *map;
int i;
/* CO-RE relocations need kernel BTF, only when btf_custom_path
@@ -3081,6 +3093,11 @@ static bool obj_needs_vmlinux_btf(const struct bpf_object *obj)
return true;
}
+ bpf_object__for_each_map(map, obj) {
+ if (map_needs_vmlinux_btf(map))
+ return true;
+ }
+
return false;
}
@@ -3268,7 +3285,7 @@ skip_exception_cb:
} else {
/* currently BPF_BTF_LOAD only supports log_level 1 */
err = btf_load_into_kernel(kern_btf, obj->log_buf, obj->log_size,
- obj->log_level ? 1 : 0);
+ obj->log_level ? 1 : 0, obj->token_fd);
}
if (sanitize) {
if (!err) {
@@ -4591,6 +4608,63 @@ int bpf_map__set_max_entries(struct bpf_map *map, __u32 max_entries)
return 0;
}
+static int bpf_object_prepare_token(struct bpf_object *obj)
+{
+ const char *bpffs_path;
+ int bpffs_fd = -1, token_fd, err;
+ bool mandatory;
+ enum libbpf_print_level level;
+
+ /* token is already set up */
+ if (obj->token_fd > 0)
+ return 0;
+ /* token is explicitly prevented */
+ if (obj->token_fd < 0) {
+ pr_debug("object '%s': token is prevented, skipping...\n", obj->name);
+ /* reset to zero to avoid extra checks during map_create and prog_load steps */
+ obj->token_fd = 0;
+ return 0;
+ }
+
+ mandatory = obj->token_path != NULL;
+ level = mandatory ? LIBBPF_WARN : LIBBPF_DEBUG;
+
+ bpffs_path = obj->token_path ?: BPF_FS_DEFAULT_PATH;
+ bpffs_fd = open(bpffs_path, O_DIRECTORY, O_RDWR);
+ if (bpffs_fd < 0) {
+ err = -errno;
+ __pr(level, "object '%s': failed (%d) to open BPF FS mount at '%s'%s\n",
+ obj->name, err, bpffs_path,
+ mandatory ? "" : ", skipping optional step...");
+ return mandatory ? err : 0;
+ }
+
+ token_fd = bpf_token_create(bpffs_fd, 0);
+ close(bpffs_fd);
+ if (token_fd < 0) {
+ if (!mandatory && token_fd == -ENOENT) {
+ pr_debug("object '%s': BPF FS at '%s' doesn't have BPF token delegation set up, skipping...\n",
+ obj->name, bpffs_path);
+ return 0;
+ }
+ __pr(level, "object '%s': failed (%d) to create BPF token from '%s'%s\n",
+ obj->name, token_fd, bpffs_path,
+ mandatory ? "" : ", skipping optional step...");
+ return mandatory ? token_fd : 0;
+ }
+
+ obj->feat_cache = calloc(1, sizeof(*obj->feat_cache));
+ if (!obj->feat_cache) {
+ close(token_fd);
+ return -ENOMEM;
+ }
+
+ obj->token_fd = token_fd;
+ obj->feat_cache->token_fd = token_fd;
+
+ return 0;
+}
+
static int
bpf_object__probe_loading(struct bpf_object *obj)
{
@@ -4600,6 +4674,7 @@ bpf_object__probe_loading(struct bpf_object *obj)
BPF_EXIT_INSN(),
};
int ret, insn_cnt = ARRAY_SIZE(insns);
+ LIBBPF_OPTS(bpf_prog_load_opts, opts, .token_fd = obj->token_fd);
if (obj->gen_loader)
return 0;
@@ -4609,9 +4684,9 @@ bpf_object__probe_loading(struct bpf_object *obj)
pr_warn("Failed to bump RLIMIT_MEMLOCK (err = %d), you might need to do it explicitly!\n", ret);
/* make sure basic loading works */
- ret = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, NULL, "GPL", insns, insn_cnt, NULL);
+ ret = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, NULL, "GPL", insns, insn_cnt, &opts);
if (ret < 0)
- ret = bpf_prog_load(BPF_PROG_TYPE_TRACEPOINT, NULL, "GPL", insns, insn_cnt, NULL);
+ ret = bpf_prog_load(BPF_PROG_TYPE_TRACEPOINT, NULL, "GPL", insns, insn_cnt, &opts);
if (ret < 0) {
ret = errno;
cp = libbpf_strerror_r(ret, errmsg, sizeof(errmsg));
@@ -4626,462 +4701,18 @@ bpf_object__probe_loading(struct bpf_object *obj)
return 0;
}
-static int probe_fd(int fd)
-{
- if (fd >= 0)
- close(fd);
- return fd >= 0;
-}
-
-static int probe_kern_prog_name(void)
-{
- const size_t attr_sz = offsetofend(union bpf_attr, prog_name);
- struct bpf_insn insns[] = {
- BPF_MOV64_IMM(BPF_REG_0, 0),
- BPF_EXIT_INSN(),
- };
- union bpf_attr attr;
- int ret;
-
- memset(&attr, 0, attr_sz);
- attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
- attr.license = ptr_to_u64("GPL");
- attr.insns = ptr_to_u64(insns);
- attr.insn_cnt = (__u32)ARRAY_SIZE(insns);
- libbpf_strlcpy(attr.prog_name, "libbpf_nametest", sizeof(attr.prog_name));
-
- /* make sure loading with name works */
- ret = sys_bpf_prog_load(&attr, attr_sz, PROG_LOAD_ATTEMPTS);
- return probe_fd(ret);
-}
-
-static int probe_kern_global_data(void)
-{
- char *cp, errmsg[STRERR_BUFSIZE];
- struct bpf_insn insns[] = {
- BPF_LD_MAP_VALUE(BPF_REG_1, 0, 16),
- BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 42),
- BPF_MOV64_IMM(BPF_REG_0, 0),
- BPF_EXIT_INSN(),
- };
- int ret, map, insn_cnt = ARRAY_SIZE(insns);
-
- map = bpf_map_create(BPF_MAP_TYPE_ARRAY, "libbpf_global", sizeof(int), 32, 1, NULL);
- if (map < 0) {
- ret = -errno;
- cp = libbpf_strerror_r(ret, errmsg, sizeof(errmsg));
- pr_warn("Error in %s():%s(%d). Couldn't create simple array map.\n",
- __func__, cp, -ret);
- return ret;
- }
-
- insns[0].imm = map;
-
- ret = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, NULL, "GPL", insns, insn_cnt, NULL);
- close(map);
- return probe_fd(ret);
-}
-
-static int probe_kern_btf(void)
-{
- static const char strs[] = "\0int";
- __u32 types[] = {
- /* int */
- BTF_TYPE_INT_ENC(1, BTF_INT_SIGNED, 0, 32, 4),
- };
-
- return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
- strs, sizeof(strs)));
-}
-
-static int probe_kern_btf_func(void)
-{
- static const char strs[] = "\0int\0x\0a";
- /* void x(int a) {} */
- __u32 types[] = {
- /* int */
- BTF_TYPE_INT_ENC(1, BTF_INT_SIGNED, 0, 32, 4), /* [1] */
- /* FUNC_PROTO */ /* [2] */
- BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_FUNC_PROTO, 0, 1), 0),
- BTF_PARAM_ENC(7, 1),
- /* FUNC x */ /* [3] */
- BTF_TYPE_ENC(5, BTF_INFO_ENC(BTF_KIND_FUNC, 0, 0), 2),
- };
-
- return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
- strs, sizeof(strs)));
-}
-
-static int probe_kern_btf_func_global(void)
-{
- static const char strs[] = "\0int\0x\0a";
- /* static void x(int a) {} */
- __u32 types[] = {
- /* int */
- BTF_TYPE_INT_ENC(1, BTF_INT_SIGNED, 0, 32, 4), /* [1] */
- /* FUNC_PROTO */ /* [2] */
- BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_FUNC_PROTO, 0, 1), 0),
- BTF_PARAM_ENC(7, 1),
- /* FUNC x BTF_FUNC_GLOBAL */ /* [3] */
- BTF_TYPE_ENC(5, BTF_INFO_ENC(BTF_KIND_FUNC, 0, BTF_FUNC_GLOBAL), 2),
- };
-
- return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
- strs, sizeof(strs)));
-}
-
-static int probe_kern_btf_datasec(void)
-{
- static const char strs[] = "\0x\0.data";
- /* static int a; */
- __u32 types[] = {
- /* int */
- BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */
- /* VAR x */ /* [2] */
- BTF_TYPE_ENC(1, BTF_INFO_ENC(BTF_KIND_VAR, 0, 0), 1),
- BTF_VAR_STATIC,
- /* DATASEC val */ /* [3] */
- BTF_TYPE_ENC(3, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 4),
- BTF_VAR_SECINFO_ENC(2, 0, 4),
- };
-
- return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
- strs, sizeof(strs)));
-}
-
-static int probe_kern_btf_float(void)
-{
- static const char strs[] = "\0float";
- __u32 types[] = {
- /* float */
- BTF_TYPE_FLOAT_ENC(1, 4),
- };
-
- return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
- strs, sizeof(strs)));
-}
-
-static int probe_kern_btf_decl_tag(void)
-{
- static const char strs[] = "\0tag";
- __u32 types[] = {
- /* int */
- BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */
- /* VAR x */ /* [2] */
- BTF_TYPE_ENC(1, BTF_INFO_ENC(BTF_KIND_VAR, 0, 0), 1),
- BTF_VAR_STATIC,
- /* attr */
- BTF_TYPE_DECL_TAG_ENC(1, 2, -1),
- };
-
- return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
- strs, sizeof(strs)));
-}
-
-static int probe_kern_btf_type_tag(void)
-{
- static const char strs[] = "\0tag";
- __u32 types[] = {
- /* int */
- BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */
- /* attr */
- BTF_TYPE_TYPE_TAG_ENC(1, 1), /* [2] */
- /* ptr */
- BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_PTR, 0, 0), 2), /* [3] */
- };
-
- return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
- strs, sizeof(strs)));
-}
-
-static int probe_kern_array_mmap(void)
-{
- LIBBPF_OPTS(bpf_map_create_opts, opts, .map_flags = BPF_F_MMAPABLE);
- int fd;
-
- fd = bpf_map_create(BPF_MAP_TYPE_ARRAY, "libbpf_mmap", sizeof(int), sizeof(int), 1, &opts);
- return probe_fd(fd);
-}
-
-static int probe_kern_exp_attach_type(void)
-{
- LIBBPF_OPTS(bpf_prog_load_opts, opts, .expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE);
- struct bpf_insn insns[] = {
- BPF_MOV64_IMM(BPF_REG_0, 0),
- BPF_EXIT_INSN(),
- };
- int fd, insn_cnt = ARRAY_SIZE(insns);
-
- /* use any valid combination of program type and (optional)
- * non-zero expected attach type (i.e., not a BPF_CGROUP_INET_INGRESS)
- * to see if kernel supports expected_attach_type field for
- * BPF_PROG_LOAD command
- */
- fd = bpf_prog_load(BPF_PROG_TYPE_CGROUP_SOCK, NULL, "GPL", insns, insn_cnt, &opts);
- return probe_fd(fd);
-}
-
-static int probe_kern_probe_read_kernel(void)
-{
- struct bpf_insn insns[] = {
- BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), /* r1 = r10 (fp) */
- BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8), /* r1 += -8 */
- BPF_MOV64_IMM(BPF_REG_2, 8), /* r2 = 8 */
- BPF_MOV64_IMM(BPF_REG_3, 0), /* r3 = 0 */
- BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_probe_read_kernel),
- BPF_EXIT_INSN(),
- };
- int fd, insn_cnt = ARRAY_SIZE(insns);
-
- fd = bpf_prog_load(BPF_PROG_TYPE_TRACEPOINT, NULL, "GPL", insns, insn_cnt, NULL);
- return probe_fd(fd);
-}
-
-static int probe_prog_bind_map(void)
-{
- char *cp, errmsg[STRERR_BUFSIZE];
- struct bpf_insn insns[] = {
- BPF_MOV64_IMM(BPF_REG_0, 0),
- BPF_EXIT_INSN(),
- };
- int ret, map, prog, insn_cnt = ARRAY_SIZE(insns);
-
- map = bpf_map_create(BPF_MAP_TYPE_ARRAY, "libbpf_det_bind", sizeof(int), 32, 1, NULL);
- if (map < 0) {
- ret = -errno;
- cp = libbpf_strerror_r(ret, errmsg, sizeof(errmsg));
- pr_warn("Error in %s():%s(%d). Couldn't create simple array map.\n",
- __func__, cp, -ret);
- return ret;
- }
-
- prog = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, NULL, "GPL", insns, insn_cnt, NULL);
- if (prog < 0) {
- close(map);
- return 0;
- }
-
- ret = bpf_prog_bind_map(prog, map, NULL);
-
- close(map);
- close(prog);
-
- return ret >= 0;
-}
-
-static int probe_module_btf(void)
-{
- static const char strs[] = "\0int";
- __u32 types[] = {
- /* int */
- BTF_TYPE_INT_ENC(1, BTF_INT_SIGNED, 0, 32, 4),
- };
- struct bpf_btf_info info;
- __u32 len = sizeof(info);
- char name[16];
- int fd, err;
-
- fd = libbpf__load_raw_btf((char *)types, sizeof(types), strs, sizeof(strs));
- if (fd < 0)
- return 0; /* BTF not supported at all */
-
- memset(&info, 0, sizeof(info));
- info.name = ptr_to_u64(name);
- info.name_len = sizeof(name);
-
- /* check that BPF_OBJ_GET_INFO_BY_FD supports specifying name pointer;
- * kernel's module BTF support coincides with support for
- * name/name_len fields in struct bpf_btf_info.
- */
- err = bpf_btf_get_info_by_fd(fd, &info, &len);
- close(fd);
- return !err;
-}
-
-static int probe_perf_link(void)
-{
- struct bpf_insn insns[] = {
- BPF_MOV64_IMM(BPF_REG_0, 0),
- BPF_EXIT_INSN(),
- };
- int prog_fd, link_fd, err;
-
- prog_fd = bpf_prog_load(BPF_PROG_TYPE_TRACEPOINT, NULL, "GPL",
- insns, ARRAY_SIZE(insns), NULL);
- if (prog_fd < 0)
- return -errno;
-
- /* use invalid perf_event FD to get EBADF, if link is supported;
- * otherwise EINVAL should be returned
- */
- link_fd = bpf_link_create(prog_fd, -1, BPF_PERF_EVENT, NULL);
- err = -errno; /* close() can clobber errno */
-
- if (link_fd >= 0)
- close(link_fd);
- close(prog_fd);
-
- return link_fd < 0 && err == -EBADF;
-}
-
-static int probe_uprobe_multi_link(void)
-{
- LIBBPF_OPTS(bpf_prog_load_opts, load_opts,
- .expected_attach_type = BPF_TRACE_UPROBE_MULTI,
- );
- LIBBPF_OPTS(bpf_link_create_opts, link_opts);
- struct bpf_insn insns[] = {
- BPF_MOV64_IMM(BPF_REG_0, 0),
- BPF_EXIT_INSN(),
- };
- int prog_fd, link_fd, err;
- unsigned long offset = 0;
-
- prog_fd = bpf_prog_load(BPF_PROG_TYPE_KPROBE, NULL, "GPL",
- insns, ARRAY_SIZE(insns), &load_opts);
- if (prog_fd < 0)
- return -errno;
-
- /* Creating uprobe in '/' binary should fail with -EBADF. */
- link_opts.uprobe_multi.path = "/";
- link_opts.uprobe_multi.offsets = &offset;
- link_opts.uprobe_multi.cnt = 1;
-
- link_fd = bpf_link_create(prog_fd, -1, BPF_TRACE_UPROBE_MULTI, &link_opts);
- err = -errno; /* close() can clobber errno */
-
- if (link_fd >= 0)
- close(link_fd);
- close(prog_fd);
-
- return link_fd < 0 && err == -EBADF;
-}
-
-static int probe_kern_bpf_cookie(void)
-{
- struct bpf_insn insns[] = {
- BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_get_attach_cookie),
- BPF_EXIT_INSN(),
- };
- int ret, insn_cnt = ARRAY_SIZE(insns);
-
- ret = bpf_prog_load(BPF_PROG_TYPE_KPROBE, NULL, "GPL", insns, insn_cnt, NULL);
- return probe_fd(ret);
-}
-
-static int probe_kern_btf_enum64(void)
-{
- static const char strs[] = "\0enum64";
- __u32 types[] = {
- BTF_TYPE_ENC(1, BTF_INFO_ENC(BTF_KIND_ENUM64, 0, 0), 8),
- };
-
- return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
- strs, sizeof(strs)));
-}
-
-static int probe_kern_syscall_wrapper(void);
-
-enum kern_feature_result {
- FEAT_UNKNOWN = 0,
- FEAT_SUPPORTED = 1,
- FEAT_MISSING = 2,
-};
-
-typedef int (*feature_probe_fn)(void);
-
-static struct kern_feature_desc {
- const char *desc;
- feature_probe_fn probe;
- enum kern_feature_result res;
-} feature_probes[__FEAT_CNT] = {
- [FEAT_PROG_NAME] = {
- "BPF program name", probe_kern_prog_name,
- },
- [FEAT_GLOBAL_DATA] = {
- "global variables", probe_kern_global_data,
- },
- [FEAT_BTF] = {
- "minimal BTF", probe_kern_btf,
- },
- [FEAT_BTF_FUNC] = {
- "BTF functions", probe_kern_btf_func,
- },
- [FEAT_BTF_GLOBAL_FUNC] = {
- "BTF global function", probe_kern_btf_func_global,
- },
- [FEAT_BTF_DATASEC] = {
- "BTF data section and variable", probe_kern_btf_datasec,
- },
- [FEAT_ARRAY_MMAP] = {
- "ARRAY map mmap()", probe_kern_array_mmap,
- },
- [FEAT_EXP_ATTACH_TYPE] = {
- "BPF_PROG_LOAD expected_attach_type attribute",
- probe_kern_exp_attach_type,
- },
- [FEAT_PROBE_READ_KERN] = {
- "bpf_probe_read_kernel() helper", probe_kern_probe_read_kernel,
- },
- [FEAT_PROG_BIND_MAP] = {
- "BPF_PROG_BIND_MAP support", probe_prog_bind_map,
- },
- [FEAT_MODULE_BTF] = {
- "module BTF support", probe_module_btf,
- },
- [FEAT_BTF_FLOAT] = {
- "BTF_KIND_FLOAT support", probe_kern_btf_float,
- },
- [FEAT_PERF_LINK] = {
- "BPF perf link support", probe_perf_link,
- },
- [FEAT_BTF_DECL_TAG] = {
- "BTF_KIND_DECL_TAG support", probe_kern_btf_decl_tag,
- },
- [FEAT_BTF_TYPE_TAG] = {
- "BTF_KIND_TYPE_TAG support", probe_kern_btf_type_tag,
- },
- [FEAT_MEMCG_ACCOUNT] = {
- "memcg-based memory accounting", probe_memcg_account,
- },
- [FEAT_BPF_COOKIE] = {
- "BPF cookie support", probe_kern_bpf_cookie,
- },
- [FEAT_BTF_ENUM64] = {
- "BTF_KIND_ENUM64 support", probe_kern_btf_enum64,
- },
- [FEAT_SYSCALL_WRAPPER] = {
- "Kernel using syscall wrapper", probe_kern_syscall_wrapper,
- },
- [FEAT_UPROBE_MULTI_LINK] = {
- "BPF multi-uprobe link support", probe_uprobe_multi_link,
- },
-};
-
bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id)
{
- struct kern_feature_desc *feat = &feature_probes[feat_id];
- int ret;
-
if (obj && obj->gen_loader)
/* To generate loader program assume the latest kernel
* to avoid doing extra prog_load, map_create syscalls.
*/
return true;
- if (READ_ONCE(feat->res) == FEAT_UNKNOWN) {
- ret = feat->probe();
- if (ret > 0) {
- WRITE_ONCE(feat->res, FEAT_SUPPORTED);
- } else if (ret == 0) {
- WRITE_ONCE(feat->res, FEAT_MISSING);
- } else {
- pr_warn("Detection of kernel %s support failed: %d\n", feat->desc, ret);
- WRITE_ONCE(feat->res, FEAT_MISSING);
- }
- }
+ if (obj->token_fd)
+ return feat_supported(obj->feat_cache, feat_id);
- return READ_ONCE(feat->res) == FEAT_SUPPORTED;
+ return feat_supported(NULL, feat_id);
}
static bool map_is_reuse_compat(const struct bpf_map *map, int map_fd)
@@ -5200,6 +4831,7 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b
create_attr.map_flags = def->map_flags;
create_attr.numa_node = map->numa_node;
create_attr.map_extra = map->map_extra;
+ create_attr.token_fd = obj->token_fd;
if (bpf_map__is_struct_ops(map))
create_attr.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
@@ -7035,6 +6667,7 @@ static int bpf_object_load_prog(struct bpf_object *obj, struct bpf_program *prog
load_attr.attach_btf_id = prog->attach_btf_id;
load_attr.kern_version = kern_version;
load_attr.prog_ifindex = prog->prog_ifindex;
+ load_attr.token_fd = obj->token_fd;
/* specify func_info/line_info only if kernel supports them */
btf_fd = bpf_object__btf_fd(obj);
@@ -7496,10 +7129,10 @@ static int bpf_object_init_progs(struct bpf_object *obj, const struct bpf_object
static struct bpf_object *bpf_object_open(const char *path, const void *obj_buf, size_t obj_buf_sz,
const struct bpf_object_open_opts *opts)
{
- const char *obj_name, *kconfig, *btf_tmp_path;
+ const char *obj_name, *kconfig, *btf_tmp_path, *token_path;
struct bpf_object *obj;
char tmp_name[64];
- int err;
+ int err, token_fd;
char *log_buf;
size_t log_size;
__u32 log_level;
@@ -7533,6 +7166,28 @@ static struct bpf_object *bpf_object_open(const char *path, const void *obj_buf,
if (log_size && !log_buf)
return ERR_PTR(-EINVAL);
+ token_path = OPTS_GET(opts, bpf_token_path, NULL);
+ token_fd = OPTS_GET(opts, bpf_token_fd, -1);
+ /* non-empty token path can't be combined with invalid token FD */
+ if (token_path && token_path[0] != '\0' && token_fd < 0)
+ return ERR_PTR(-EINVAL);
+ /* empty token path can't be combined with valid token FD */
+ if (token_path && token_path[0] == '\0' && token_fd > 0)
+ return ERR_PTR(-EINVAL);
+ /* if user didn't specify bpf_token_path/bpf_token_fd explicitly,
+ * check if LIBBPF_BPF_TOKEN_PATH envvar was set and treat it as
+ * bpf_token_path option
+ */
+ if (token_fd == 0 && !token_path)
+ token_path = getenv("LIBBPF_BPF_TOKEN_PATH");
+ /* empty token_path is equivalent to invalid token_fd */
+ if (token_path && token_path[0] == '\0') {
+ token_path = NULL;
+ token_fd = -1;
+ }
+ if (token_path && strlen(token_path) >= PATH_MAX)
+ return ERR_PTR(-ENAMETOOLONG);
+
obj = bpf_object__new(path, obj_buf, obj_buf_sz, obj_name);
if (IS_ERR(obj))
return obj;
@@ -7541,6 +7196,19 @@ static struct bpf_object *bpf_object_open(const char *path, const void *obj_buf,
obj->log_size = log_size;
obj->log_level = log_level;
+ obj->token_fd = token_fd <= 0 ? token_fd : dup_good_fd(token_fd);
+ if (token_fd > 0 && obj->token_fd < 0) {
+ err = -errno;
+ goto out;
+ }
+ if (token_path) {
+ obj->token_path = strdup(token_path);
+ if (!obj->token_path) {
+ err = -ENOMEM;
+ goto out;
+ }
+ }
+
btf_tmp_path = OPTS_GET(opts, btf_custom_path, NULL);
if (btf_tmp_path) {
if (strlen(btf_tmp_path) >= PATH_MAX) {
@@ -8051,7 +7719,8 @@ static int bpf_object_load(struct bpf_object *obj, int extra_log_level, const ch
if (obj->gen_loader)
bpf_gen__init(obj->gen_loader, extra_log_level, obj->nr_programs, obj->nr_maps);
- err = bpf_object__probe_loading(obj);
+ err = bpf_object_prepare_token(obj);
+ err = err ? : bpf_object__probe_loading(obj);
err = err ? : bpf_object__load_vmlinux_btf(obj, false);
err = err ? : bpf_object__resolve_externs(obj, obj->kconfig);
err = err ? : bpf_object__sanitize_and_load_btf(obj);
@@ -8588,6 +8257,11 @@ void bpf_object__close(struct bpf_object *obj)
}
zfree(&obj->programs);
+ zfree(&obj->feat_cache);
+ zfree(&obj->token_path);
+ if (obj->token_fd > 0)
+ close(obj->token_fd);
+
free(obj);
}
@@ -10601,7 +10275,7 @@ static const char *arch_specific_syscall_pfx(void)
#endif
}
-static int probe_kern_syscall_wrapper(void)
+int probe_kern_syscall_wrapper(int token_fd)
{
char syscall_name[64];
const char *ksys_pfx;
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 6cd9c501624f..916904bd2a7a 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -177,10 +177,45 @@ struct bpf_object_open_opts {
* logs through its print callback.
*/
__u32 kernel_log_level;
+ /* FD of a BPF token instantiated by user through bpf_token_create()
+ * API. BPF object will keep dup()'ed FD internally, so passed token
+ * FD can be closed after BPF object/skeleton open step.
+ *
+ * Setting bpf_token_fd to negative value disables libbpf's automatic
+ * attempt to create BPF token from default BPF FS mount point
+ * (/sys/fs/bpf), in case this default behavior is undesirable.
+ *
+ * If bpf_token_path and bpf_token_fd are not specified, libbpf will
+ * consult LIBBPF_BPF_TOKEN_PATH environment variable. If set, it will
+ * be taken as a value of bpf_token_path option and will force libbpf
+ * to either create BPF token from provided custom BPF FS path, or
+ * will disable implicit BPF token creation, if envvar value is an
+ * empty string.
+ *
+ * bpf_token_path and bpf_token_fd are mutually exclusive and only one
+ * of those options should be set. Either of them overrides
+ * LIBBPF_BPF_TOKEN_PATH envvar.
+ */
+ int bpf_token_fd;
+ /* Path to BPF FS mount point to derive BPF token from.
+ *
+ * Created BPF token will be used for all bpf() syscall operations
+ * that accept BPF token (e.g., map creation, BTF and program loads,
+ * etc) automatically within instantiated BPF object.
+ *
+ * Setting bpf_token_path option to empty string disables libbpf's
+ * automatic attempt to create BPF token from default BPF FS mount
+ * point (/sys/fs/bpf), in case this default behavior is undesirable.
+ *
+ * bpf_token_path and bpf_token_fd are mutually exclusive and only one
+ * of those options should be set. Either of them overrides
+ * LIBBPF_BPF_TOKEN_PATH envvar.
+ */
+ const char *bpf_token_path;
size_t :0;
};
-#define bpf_object_open_opts__last_field kernel_log_level
+#define bpf_object_open_opts__last_field bpf_token_path
/**
* @brief **bpf_object__open()** creates a bpf_object by opening
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 91c5aef7dae7..df7657b65c47 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -401,6 +401,7 @@ LIBBPF_1.3.0 {
bpf_program__attach_netkit;
bpf_program__attach_tcx;
bpf_program__attach_uprobe_multi;
+ bpf_token_create;
ring__avail_data_size;
ring__consume;
ring__consumer_pos;
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index b5d334754e5d..4cda32298c49 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -360,15 +360,32 @@ enum kern_feature_id {
__FEAT_CNT,
};
-int probe_memcg_account(void);
+enum kern_feature_result {
+ FEAT_UNKNOWN = 0,
+ FEAT_SUPPORTED = 1,
+ FEAT_MISSING = 2,
+};
+
+struct kern_feature_cache {
+ enum kern_feature_result res[__FEAT_CNT];
+ int token_fd;
+};
+
+bool feat_supported(struct kern_feature_cache *cache, enum kern_feature_id feat_id);
bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id);
+
+int probe_kern_syscall_wrapper(int token_fd);
+int probe_memcg_account(int token_fd);
int bump_rlimit_memlock(void);
int parse_cpu_mask_str(const char *s, bool **mask, int *mask_sz);
int parse_cpu_mask_file(const char *fcpu, bool **mask, int *mask_sz);
int libbpf__load_raw_btf(const char *raw_types, size_t types_len,
- const char *str_sec, size_t str_len);
-int btf_load_into_kernel(struct btf *btf, char *log_buf, size_t log_sz, __u32 log_level);
+ const char *str_sec, size_t str_len,
+ int token_fd);
+int btf_load_into_kernel(struct btf *btf,
+ char *log_buf, size_t log_sz, __u32 log_level,
+ int token_fd);
struct btf *btf_get_from_fd(int btf_fd, struct btf *base_btf);
void btf_get_kernel_prefix_kind(enum bpf_attach_type attach_type,
@@ -532,6 +549,17 @@ static inline bool is_ldimm64_insn(struct bpf_insn *insn)
return insn->code == (BPF_LD | BPF_IMM | BPF_DW);
}
+/* Unconditionally dup FD, ensuring it doesn't use [0, 2] range.
+ * Original FD is not closed or altered in any other way.
+ * Preserves original FD value, if it's invalid (negative).
+ */
+static inline int dup_good_fd(int fd)
+{
+ if (fd < 0)
+ return fd;
+ return fcntl(fd, F_DUPFD_CLOEXEC, 3);
+}
+
/* if fd is stdin, stdout, or stderr, dup to a fd greater than 2
* Takes ownership of the fd passed in, and closes it if calling
* fcntl(fd, F_DUPFD_CLOEXEC, 3).
@@ -543,7 +571,7 @@ static inline int ensure_good_fd(int fd)
if (fd < 0)
return fd;
if (fd < 3) {
- fd = fcntl(fd, F_DUPFD_CLOEXEC, 3);
+ fd = dup_good_fd(fd);
saved_errno = errno;
close(old_fd);
errno = saved_errno;
diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c
index 9c4db90b92b6..8e7437006639 100644
--- a/tools/lib/bpf/libbpf_probes.c
+++ b/tools/lib/bpf/libbpf_probes.c
@@ -219,7 +219,8 @@ int libbpf_probe_bpf_prog_type(enum bpf_prog_type prog_type, const void *opts)
}
int libbpf__load_raw_btf(const char *raw_types, size_t types_len,
- const char *str_sec, size_t str_len)
+ const char *str_sec, size_t str_len,
+ int token_fd)
{
struct btf_header hdr = {
.magic = BTF_MAGIC,
@@ -229,6 +230,7 @@ int libbpf__load_raw_btf(const char *raw_types, size_t types_len,
.str_off = types_len,
.str_len = str_len,
};
+ LIBBPF_OPTS(bpf_btf_load_opts, opts, .token_fd = token_fd);
int btf_fd, btf_len;
__u8 *raw_btf;
@@ -241,7 +243,7 @@ int libbpf__load_raw_btf(const char *raw_types, size_t types_len,
memcpy(raw_btf + hdr.hdr_len, raw_types, hdr.type_len);
memcpy(raw_btf + hdr.hdr_len + hdr.type_len, str_sec, hdr.str_len);
- btf_fd = bpf_btf_load(raw_btf, btf_len, NULL);
+ btf_fd = bpf_btf_load(raw_btf, btf_len, &opts);
free(raw_btf);
return btf_fd;
@@ -271,7 +273,7 @@ static int load_local_storage_btf(void)
};
return libbpf__load_raw_btf((char *)types, sizeof(types),
- strs, sizeof(strs));
+ strs, sizeof(strs), 0);
}
static int probe_map_create(enum bpf_map_type map_type)
diff --git a/tools/lib/bpf/linker.c b/tools/lib/bpf/linker.c
index 5ced96d99f8c..52a2901e8bd0 100644
--- a/tools/lib/bpf/linker.c
+++ b/tools/lib/bpf/linker.c
@@ -719,13 +719,25 @@ static int linker_sanity_check_elf(struct src_obj *obj)
return -EINVAL;
}
- if (sec->shdr->sh_addralign && !is_pow_of_2(sec->shdr->sh_addralign))
+ if (sec->shdr->sh_addralign && !is_pow_of_2(sec->shdr->sh_addralign)) {
+ pr_warn("ELF section #%zu alignment %llu is non pow-of-2 alignment in %s\n",
+ sec->sec_idx, (long long unsigned)sec->shdr->sh_addralign,
+ obj->filename);
return -EINVAL;
- if (sec->shdr->sh_addralign != sec->data->d_align)
+ }
+ if (sec->shdr->sh_addralign != sec->data->d_align) {
+ pr_warn("ELF section #%zu has inconsistent alignment addr=%llu != d=%llu in %s\n",
+ sec->sec_idx, (long long unsigned)sec->shdr->sh_addralign,
+ (long long unsigned)sec->data->d_align, obj->filename);
return -EINVAL;
+ }
- if (sec->shdr->sh_size != sec->data->d_size)
+ if (sec->shdr->sh_size != sec->data->d_size) {
+ pr_warn("ELF section #%zu has inconsistent section size sh=%llu != d=%llu in %s\n",
+ sec->sec_idx, (long long unsigned)sec->shdr->sh_size,
+ (long long unsigned)sec->data->d_size, obj->filename);
return -EINVAL;
+ }
switch (sec->shdr->sh_type) {
case SHT_SYMTAB:
@@ -737,8 +749,12 @@ static int linker_sanity_check_elf(struct src_obj *obj)
break;
case SHT_PROGBITS:
if (sec->shdr->sh_flags & SHF_EXECINSTR) {
- if (sec->shdr->sh_size % sizeof(struct bpf_insn) != 0)
+ if (sec->shdr->sh_size % sizeof(struct bpf_insn) != 0) {
+ pr_warn("ELF section #%zu has unexpected size alignment %llu in %s\n",
+ sec->sec_idx, (long long unsigned)sec->shdr->sh_size,
+ obj->filename);
return -EINVAL;
+ }
}
break;
case SHT_NOBITS:
diff --git a/tools/lib/bpf/str_error.h b/tools/lib/bpf/str_error.h
index a139334d57b6..626d7ffb03d6 100644
--- a/tools/lib/bpf/str_error.h
+++ b/tools/lib/bpf/str_error.h
@@ -2,5 +2,8 @@
#ifndef __LIBBPF_STR_ERROR_H
#define __LIBBPF_STR_ERROR_H
+#define STRERR_BUFSIZE 128
+
char *libbpf_strerror_r(int err, char *dst, int len);
+
#endif /* __LIBBPF_STR_ERROR_H */
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