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-rw-r--r--tools/lib/bpf/bpf.c8
-rw-r--r--tools/lib/bpf/bpf.h6
-rw-r--r--tools/lib/bpf/hashmap.h10
-rw-r--r--tools/lib/bpf/libbpf.c258
-rw-r--r--tools/lib/bpf/libbpf.h15
-rw-r--r--tools/lib/bpf/libbpf.map1
-rw-r--r--tools/lib/bpf/usdt.c5
7 files changed, 268 insertions, 35 deletions
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index ed86b37d8024..3b0da19715e1 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -741,6 +741,14 @@ int bpf_link_create(int prog_fd, int target_fd,
if (!OPTS_ZEROED(opts, tracing))
return libbpf_err(-EINVAL);
break;
+ case BPF_NETFILTER:
+ attr.link_create.netfilter.pf = OPTS_GET(opts, netfilter.pf, 0);
+ attr.link_create.netfilter.hooknum = OPTS_GET(opts, netfilter.hooknum, 0);
+ attr.link_create.netfilter.priority = OPTS_GET(opts, netfilter.priority, 0);
+ attr.link_create.netfilter.flags = OPTS_GET(opts, netfilter.flags, 0);
+ if (!OPTS_ZEROED(opts, netfilter))
+ return libbpf_err(-EINVAL);
+ break;
default:
if (!OPTS_ZEROED(opts, flags))
return libbpf_err(-EINVAL);
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 9aa0ee473754..c676295ab9bf 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -349,6 +349,12 @@ struct bpf_link_create_opts {
struct {
__u64 cookie;
} tracing;
+ struct {
+ __u32 pf;
+ __u32 hooknum;
+ __s32 priority;
+ __u32 flags;
+ } netfilter;
};
size_t :0;
};
diff --git a/tools/lib/bpf/hashmap.h b/tools/lib/bpf/hashmap.h
index 0a5bf1937a7c..c12f8320e668 100644
--- a/tools/lib/bpf/hashmap.h
+++ b/tools/lib/bpf/hashmap.h
@@ -80,16 +80,6 @@ struct hashmap {
size_t sz;
};
-#define HASHMAP_INIT(hash_fn, equal_fn, ctx) { \
- .hash_fn = (hash_fn), \
- .equal_fn = (equal_fn), \
- .ctx = (ctx), \
- .buckets = NULL, \
- .cap = 0, \
- .cap_bits = 0, \
- .sz = 0, \
-}
-
void hashmap__init(struct hashmap *map, hashmap_hash_fn hash_fn,
hashmap_equal_fn equal_fn, void *ctx);
struct hashmap *hashmap__new(hashmap_hash_fn hash_fn,
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 214f828ece6b..63311a73c16d 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -5471,6 +5471,10 @@ static int load_module_btfs(struct bpf_object *obj)
err = bpf_btf_get_next_id(id, &id);
if (err && errno == ENOENT)
return 0;
+ if (err && errno == EPERM) {
+ pr_debug("skipping module BTFs loading, missing privileges\n");
+ return 0;
+ }
if (err) {
err = -errno;
pr_warn("failed to iterate BTF objects: %d\n", err);
@@ -6157,7 +6161,11 @@ static int append_subprog_relos(struct bpf_program *main_prog, struct bpf_progra
if (main_prog == subprog)
return 0;
relos = libbpf_reallocarray(main_prog->reloc_desc, new_cnt, sizeof(*relos));
- if (!relos)
+ /* if new count is zero, reallocarray can return a valid NULL result;
+ * in this case the previous pointer will be freed, so we *have to*
+ * reassign old pointer to the new value (even if it's NULL)
+ */
+ if (!relos && new_cnt)
return -ENOMEM;
if (subprog->nr_reloc)
memcpy(relos + main_prog->nr_reloc, subprog->reloc_desc,
@@ -8528,7 +8536,8 @@ int bpf_program__set_insns(struct bpf_program *prog,
return -EBUSY;
insns = libbpf_reallocarray(prog->insns, new_insn_cnt, sizeof(*insns));
- if (!insns) {
+ /* NULL is a valid return from reallocarray if the new count is zero */
+ if (!insns && new_insn_cnt) {
pr_warn("prog '%s': failed to realloc prog code\n", prog->name);
return -ENOMEM;
}
@@ -8558,13 +8567,31 @@ enum bpf_prog_type bpf_program__type(const struct bpf_program *prog)
return prog->type;
}
+static size_t custom_sec_def_cnt;
+static struct bpf_sec_def *custom_sec_defs;
+static struct bpf_sec_def custom_fallback_def;
+static bool has_custom_fallback_def;
+static int last_custom_sec_def_handler_id;
+
int bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type)
{
if (prog->obj->loaded)
return libbpf_err(-EBUSY);
+ /* if type is not changed, do nothing */
+ if (prog->type == type)
+ return 0;
+
prog->type = type;
- prog->sec_def = NULL;
+
+ /* If a program type was changed, we need to reset associated SEC()
+ * handler, as it will be invalid now. The only exception is a generic
+ * fallback handler, which by definition is program type-agnostic and
+ * is a catch-all custom handler, optionally set by the application,
+ * so should be able to handle any type of BPF program.
+ */
+ if (prog->sec_def != &custom_fallback_def)
+ prog->sec_def = NULL;
return 0;
}
@@ -8740,13 +8767,6 @@ static const struct bpf_sec_def section_defs[] = {
SEC_DEF("netfilter", NETFILTER, BPF_NETFILTER, SEC_NONE),
};
-static size_t custom_sec_def_cnt;
-static struct bpf_sec_def *custom_sec_defs;
-static struct bpf_sec_def custom_fallback_def;
-static bool has_custom_fallback_def;
-
-static int last_custom_sec_def_handler_id;
-
int libbpf_register_prog_handler(const char *sec,
enum bpf_prog_type prog_type,
enum bpf_attach_type exp_attach_type,
@@ -8826,7 +8846,11 @@ int libbpf_unregister_prog_handler(int handler_id)
/* try to shrink the array, but it's ok if we couldn't */
sec_defs = libbpf_reallocarray(custom_sec_defs, custom_sec_def_cnt, sizeof(*sec_defs));
- if (sec_defs)
+ /* if new count is zero, reallocarray can return a valid NULL result;
+ * in this case the previous pointer will be freed, so we *have to*
+ * reassign old pointer to the new value (even if it's NULL)
+ */
+ if (sec_defs || custom_sec_def_cnt == 0)
custom_sec_defs = sec_defs;
return 0;
@@ -10224,6 +10248,18 @@ static const char *tracefs_uprobe_events(void)
return use_debugfs() ? DEBUGFS"/uprobe_events" : TRACEFS"/uprobe_events";
}
+static const char *tracefs_available_filter_functions(void)
+{
+ return use_debugfs() ? DEBUGFS"/available_filter_functions"
+ : TRACEFS"/available_filter_functions";
+}
+
+static const char *tracefs_available_filter_functions_addrs(void)
+{
+ return use_debugfs() ? DEBUGFS"/available_filter_functions_addrs"
+ : TRACEFS"/available_filter_functions_addrs";
+}
+
static void gen_kprobe_legacy_event_name(char *buf, size_t buf_sz,
const char *kfunc_name, size_t offset)
{
@@ -10539,25 +10575,158 @@ struct kprobe_multi_resolve {
size_t cnt;
};
-static int
-resolve_kprobe_multi_cb(unsigned long long sym_addr, char sym_type,
- const char *sym_name, void *ctx)
+struct avail_kallsyms_data {
+ char **syms;
+ size_t cnt;
+ struct kprobe_multi_resolve *res;
+};
+
+static int avail_func_cmp(const void *a, const void *b)
{
- struct kprobe_multi_resolve *res = ctx;
+ return strcmp(*(const char **)a, *(const char **)b);
+}
+
+static int avail_kallsyms_cb(unsigned long long sym_addr, char sym_type,
+ const char *sym_name, void *ctx)
+{
+ struct avail_kallsyms_data *data = ctx;
+ struct kprobe_multi_resolve *res = data->res;
int err;
- if (!glob_match(sym_name, res->pattern))
+ if (!bsearch(&sym_name, data->syms, data->cnt, sizeof(*data->syms), avail_func_cmp))
return 0;
- err = libbpf_ensure_mem((void **) &res->addrs, &res->cap, sizeof(unsigned long),
- res->cnt + 1);
+ err = libbpf_ensure_mem((void **)&res->addrs, &res->cap, sizeof(*res->addrs), res->cnt + 1);
if (err)
return err;
- res->addrs[res->cnt++] = (unsigned long) sym_addr;
+ res->addrs[res->cnt++] = (unsigned long)sym_addr;
return 0;
}
+static int libbpf_available_kallsyms_parse(struct kprobe_multi_resolve *res)
+{
+ const char *available_functions_file = tracefs_available_filter_functions();
+ struct avail_kallsyms_data data;
+ char sym_name[500];
+ FILE *f;
+ int err = 0, ret, i;
+ char **syms = NULL;
+ size_t cap = 0, cnt = 0;
+
+ f = fopen(available_functions_file, "re");
+ if (!f) {
+ err = -errno;
+ pr_warn("failed to open %s: %d\n", available_functions_file, err);
+ return err;
+ }
+
+ while (true) {
+ char *name;
+
+ ret = fscanf(f, "%499s%*[^\n]\n", sym_name);
+ if (ret == EOF && feof(f))
+ break;
+
+ if (ret != 1) {
+ pr_warn("failed to parse available_filter_functions entry: %d\n", ret);
+ err = -EINVAL;
+ goto cleanup;
+ }
+
+ if (!glob_match(sym_name, res->pattern))
+ continue;
+
+ err = libbpf_ensure_mem((void **)&syms, &cap, sizeof(*syms), cnt + 1);
+ if (err)
+ goto cleanup;
+
+ name = strdup(sym_name);
+ if (!name) {
+ err = -errno;
+ goto cleanup;
+ }
+
+ syms[cnt++] = name;
+ }
+
+ /* no entries found, bail out */
+ if (cnt == 0) {
+ err = -ENOENT;
+ goto cleanup;
+ }
+
+ /* sort available functions */
+ qsort(syms, cnt, sizeof(*syms), avail_func_cmp);
+
+ data.syms = syms;
+ data.res = res;
+ data.cnt = cnt;
+ libbpf_kallsyms_parse(avail_kallsyms_cb, &data);
+
+ if (res->cnt == 0)
+ err = -ENOENT;
+
+cleanup:
+ for (i = 0; i < cnt; i++)
+ free((char *)syms[i]);
+ free(syms);
+
+ fclose(f);
+ return err;
+}
+
+static bool has_available_filter_functions_addrs(void)
+{
+ return access(tracefs_available_filter_functions_addrs(), R_OK) != -1;
+}
+
+static int libbpf_available_kprobes_parse(struct kprobe_multi_resolve *res)
+{
+ const char *available_path = tracefs_available_filter_functions_addrs();
+ char sym_name[500];
+ FILE *f;
+ int ret, err = 0;
+ unsigned long long sym_addr;
+
+ f = fopen(available_path, "re");
+ if (!f) {
+ err = -errno;
+ pr_warn("failed to open %s: %d\n", available_path, err);
+ return err;
+ }
+
+ while (true) {
+ ret = fscanf(f, "%llx %499s%*[^\n]\n", &sym_addr, sym_name);
+ if (ret == EOF && feof(f))
+ break;
+
+ if (ret != 2) {
+ pr_warn("failed to parse available_filter_functions_addrs entry: %d\n",
+ ret);
+ err = -EINVAL;
+ goto cleanup;
+ }
+
+ if (!glob_match(sym_name, res->pattern))
+ continue;
+
+ err = libbpf_ensure_mem((void **)&res->addrs, &res->cap,
+ sizeof(*res->addrs), res->cnt + 1);
+ if (err)
+ goto cleanup;
+
+ res->addrs[res->cnt++] = (unsigned long)sym_addr;
+ }
+
+ if (res->cnt == 0)
+ err = -ENOENT;
+
+cleanup:
+ fclose(f);
+ return err;
+}
+
struct bpf_link *
bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog,
const char *pattern,
@@ -10594,13 +10763,12 @@ bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog,
return libbpf_err_ptr(-EINVAL);
if (pattern) {
- err = libbpf_kallsyms_parse(resolve_kprobe_multi_cb, &res);
+ if (has_available_filter_functions_addrs())
+ err = libbpf_available_kprobes_parse(&res);
+ else
+ err = libbpf_available_kallsyms_parse(&res);
if (err)
goto error;
- if (!res.cnt) {
- err = -ENOENT;
- goto error;
- }
addrs = res.addrs;
cnt = res.cnt;
}
@@ -11811,6 +11979,48 @@ static int attach_iter(const struct bpf_program *prog, long cookie, struct bpf_l
return libbpf_get_error(*link);
}
+struct bpf_link *bpf_program__attach_netfilter(const struct bpf_program *prog,
+ const struct bpf_netfilter_opts *opts)
+{
+ LIBBPF_OPTS(bpf_link_create_opts, lopts);
+ struct bpf_link *link;
+ int prog_fd, link_fd;
+
+ if (!OPTS_VALID(opts, bpf_netfilter_opts))
+ return libbpf_err_ptr(-EINVAL);
+
+ prog_fd = bpf_program__fd(prog);
+ if (prog_fd < 0) {
+ pr_warn("prog '%s': can't attach before loaded\n", prog->name);
+ return libbpf_err_ptr(-EINVAL);
+ }
+
+ link = calloc(1, sizeof(*link));
+ if (!link)
+ return libbpf_err_ptr(-ENOMEM);
+
+ link->detach = &bpf_link__detach_fd;
+
+ lopts.netfilter.pf = OPTS_GET(opts, pf, 0);
+ lopts.netfilter.hooknum = OPTS_GET(opts, hooknum, 0);
+ lopts.netfilter.priority = OPTS_GET(opts, priority, 0);
+ lopts.netfilter.flags = OPTS_GET(opts, flags, 0);
+
+ link_fd = bpf_link_create(prog_fd, 0, BPF_NETFILTER, &lopts);
+ if (link_fd < 0) {
+ char errmsg[STRERR_BUFSIZE];
+
+ link_fd = -errno;
+ free(link);
+ pr_warn("prog '%s': failed to attach to netfilter: %s\n",
+ prog->name, libbpf_strerror_r(link_fd, errmsg, sizeof(errmsg)));
+ return libbpf_err_ptr(link_fd);
+ }
+ link->fd = link_fd;
+
+ return link;
+}
+
struct bpf_link *bpf_program__attach(const struct bpf_program *prog)
{
struct bpf_link *link = NULL;
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 754da73c643b..10642ad69d76 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -718,6 +718,21 @@ LIBBPF_API struct bpf_link *
bpf_program__attach_freplace(const struct bpf_program *prog,
int target_fd, const char *attach_func_name);
+struct bpf_netfilter_opts {
+ /* size of this struct, for forward/backward compatibility */
+ size_t sz;
+
+ __u32 pf;
+ __u32 hooknum;
+ __s32 priority;
+ __u32 flags;
+};
+#define bpf_netfilter_opts__last_field flags
+
+LIBBPF_API struct bpf_link *
+bpf_program__attach_netfilter(const struct bpf_program *prog,
+ const struct bpf_netfilter_opts *opts);
+
struct bpf_map;
LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map);
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 7521a2fb7626..d9ec4407befa 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -395,4 +395,5 @@ LIBBPF_1.2.0 {
LIBBPF_1.3.0 {
global:
bpf_obj_pin_opts;
+ bpf_program__attach_netfilter;
} LIBBPF_1.2.0;
diff --git a/tools/lib/bpf/usdt.c b/tools/lib/bpf/usdt.c
index f1a141555f08..37455d00b239 100644
--- a/tools/lib/bpf/usdt.c
+++ b/tools/lib/bpf/usdt.c
@@ -852,8 +852,11 @@ static int bpf_link_usdt_detach(struct bpf_link *link)
* system is so exhausted on memory, it's the least of user's
* concerns, probably.
* So just do our best here to return those IDs to usdt_manager.
+ * Another edge case when we can legitimately get NULL is when
+ * new_cnt is zero, which can happen in some edge cases, so we
+ * need to be careful about that.
*/
- if (new_free_ids) {
+ if (new_free_ids || new_cnt == 0) {
memcpy(new_free_ids + man->free_spec_cnt, usdt_link->spec_ids,
usdt_link->spec_cnt * sizeof(*usdt_link->spec_ids));
man->free_spec_ids = new_free_ids;
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-17 02:34:58 +0300