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Diffstat (limited to 'kernel')
-rw-r--r--kernel/bpf/btf.c143
-rw-r--r--kernel/bpf/inode.c42
-rw-r--r--kernel/bpf/verifier.c7
3 files changed, 148 insertions, 44 deletions
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 2c6076fc29b9..364dd84bfc5a 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -259,6 +259,7 @@ struct btf {
void *nohdr_data;
struct btf_header hdr;
u32 nr_types; /* includes VOID for base BTF */
+ u32 named_start_id;
u32 types_size;
u32 data_size;
refcount_t refcnt;
@@ -494,6 +495,11 @@ static bool btf_type_is_modifier(const struct btf_type *t)
return false;
}
+static int btf_start_id(const struct btf *btf)
+{
+ return btf->start_id + (btf->base_btf ? 0 : 1);
+}
+
bool btf_type_is_void(const struct btf_type *t)
{
return t == &btf_void;
@@ -544,21 +550,125 @@ u32 btf_nr_types(const struct btf *btf)
return total;
}
+/*
+ * Note that vmlinux and kernel module BTFs are always sorted
+ * during the building phase.
+ */
+static void btf_check_sorted(struct btf *btf)
+{
+ u32 i, n, named_start_id = 0;
+
+ n = btf_nr_types(btf);
+ if (btf_is_vmlinux(btf)) {
+ for (i = btf_start_id(btf); i < n; i++) {
+ const struct btf_type *t = btf_type_by_id(btf, i);
+ const char *n = btf_name_by_offset(btf, t->name_off);
+
+ if (n[0] != '\0') {
+ btf->named_start_id = i;
+ return;
+ }
+ }
+ return;
+ }
+
+ for (i = btf_start_id(btf) + 1; i < n; i++) {
+ const struct btf_type *ta = btf_type_by_id(btf, i - 1);
+ const struct btf_type *tb = btf_type_by_id(btf, i);
+ const char *na = btf_name_by_offset(btf, ta->name_off);
+ const char *nb = btf_name_by_offset(btf, tb->name_off);
+
+ if (strcmp(na, nb) > 0)
+ return;
+
+ if (named_start_id == 0 && na[0] != '\0')
+ named_start_id = i - 1;
+ if (named_start_id == 0 && nb[0] != '\0')
+ named_start_id = i;
+ }
+
+ if (named_start_id)
+ btf->named_start_id = named_start_id;
+}
+
+/*
+ * btf_named_start_id - Get the named starting ID for the BTF
+ * @btf: Pointer to the target BTF object
+ * @own: Flag indicating whether to query only the current BTF (true = current BTF only,
+ * false = recursively traverse the base BTF chain)
+ *
+ * Return value rules:
+ * 1. For a sorted btf, return its named_start_id
+ * 2. Else for a split BTF, return its start_id
+ * 3. Else for a base BTF, return 1
+ */
+u32 btf_named_start_id(const struct btf *btf, bool own)
+{
+ const struct btf *base_btf = btf;
+
+ while (!own && base_btf->base_btf)
+ base_btf = base_btf->base_btf;
+
+ return base_btf->named_start_id ?: (base_btf->start_id ?: 1);
+}
+
+static s32 btf_find_by_name_kind_bsearch(const struct btf *btf, const char *name)
+{
+ const struct btf_type *t;
+ const char *tname;
+ s32 l, r, m;
+
+ l = btf_named_start_id(btf, true);
+ r = btf_nr_types(btf) - 1;
+ while (l <= r) {
+ m = l + (r - l) / 2;
+ t = btf_type_by_id(btf, m);
+ tname = btf_name_by_offset(btf, t->name_off);
+ if (strcmp(tname, name) >= 0) {
+ if (l == r)
+ return r;
+ r = m;
+ } else {
+ l = m + 1;
+ }
+ }
+
+ return btf_nr_types(btf);
+}
+
s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind)
{
+ const struct btf *base_btf = btf_base_btf(btf);
const struct btf_type *t;
const char *tname;
- u32 i, total;
+ s32 id, total;
- total = btf_nr_types(btf);
- for (i = 1; i < total; i++) {
- t = btf_type_by_id(btf, i);
- if (BTF_INFO_KIND(t->info) != kind)
- continue;
+ if (base_btf) {
+ id = btf_find_by_name_kind(base_btf, name, kind);
+ if (id > 0)
+ return id;
+ }
- tname = btf_name_by_offset(btf, t->name_off);
- if (!strcmp(tname, name))
- return i;
+ total = btf_nr_types(btf);
+ if (btf->named_start_id > 0 && name[0]) {
+ id = btf_find_by_name_kind_bsearch(btf, name);
+ for (; id < total; id++) {
+ t = btf_type_by_id(btf, id);
+ tname = btf_name_by_offset(btf, t->name_off);
+ if (strcmp(tname, name) != 0)
+ return -ENOENT;
+ if (BTF_INFO_KIND(t->info) == kind)
+ return id;
+ }
+ } else {
+ for (id = btf_start_id(btf); id < total; id++) {
+ t = btf_type_by_id(btf, id);
+ if (BTF_INFO_KIND(t->info) != kind)
+ continue;
+ tname = btf_name_by_offset(btf, t->name_off);
+ if (strcmp(tname, name) == 0)
+ return id;
+ }
}
return -ENOENT;
@@ -3424,7 +3534,8 @@ const char *btf_find_decl_tag_value(const struct btf *btf, const struct btf_type
const struct btf_type *t;
int len, id;
- id = btf_find_next_decl_tag(btf, pt, comp_idx, tag_key, 0);
+ id = btf_find_next_decl_tag(btf, pt, comp_idx, tag_key,
+ btf_named_start_id(btf, false) - 1);
if (id < 0)
return ERR_PTR(id);
@@ -5791,6 +5902,7 @@ static struct btf *btf_parse(const union bpf_attr *attr, bpfptr_t uattr, u32 uat
goto errout;
}
env->btf = btf;
+ btf->named_start_id = 0;
data = kvmalloc(attr->btf_size, GFP_KERNEL | __GFP_NOWARN);
if (!data) {
@@ -6210,6 +6322,7 @@ static struct btf *btf_parse_base(struct btf_verifier_env *env, const char *name
btf->data = data;
btf->data_size = data_size;
btf->kernel_btf = true;
+ btf->named_start_id = 0;
snprintf(btf->name, sizeof(btf->name), "%s", name);
err = btf_parse_hdr(env);
@@ -6230,6 +6343,7 @@ static struct btf *btf_parse_base(struct btf_verifier_env *env, const char *name
if (err)
goto errout;
+ btf_check_sorted(btf);
refcount_set(&btf->refcnt, 1);
return btf;
@@ -6327,6 +6441,7 @@ static struct btf *btf_parse_module(const char *module_name, const void *data,
btf->start_id = base_btf->nr_types;
btf->start_str_off = base_btf->hdr.str_len;
btf->kernel_btf = true;
+ btf->named_start_id = 0;
snprintf(btf->name, sizeof(btf->name), "%s", module_name);
btf->data = kvmemdup(data, data_size, GFP_KERNEL | __GFP_NOWARN);
@@ -6363,6 +6478,7 @@ static struct btf *btf_parse_module(const char *module_name, const void *data,
}
btf_verifier_env_free(env);
+ btf_check_sorted(btf);
refcount_set(&btf->refcnt, 1);
return btf;
@@ -7729,12 +7845,13 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog)
tname);
return -EINVAL;
}
+
/* Convert BTF function arguments into verifier types.
* Only PTR_TO_CTX and SCALAR are supported atm.
*/
for (i = 0; i < nargs; i++) {
u32 tags = 0;
- int id = 0;
+ int id = btf_named_start_id(btf, false) - 1;
/* 'arg:<tag>' decl_tag takes precedence over derivation of
* register type from BTF type itself
@@ -9223,7 +9340,7 @@ bpf_core_find_cands(struct bpf_core_ctx *ctx, u32 local_type_id)
}
/* Attempt to find target candidates in vmlinux BTF first */
- cands = bpf_core_add_cands(cands, main_btf, 1);
+ cands = bpf_core_add_cands(cands, main_btf, btf_named_start_id(main_btf, true));
if (IS_ERR(cands))
return ERR_CAST(cands);
@@ -9255,7 +9372,7 @@ check_modules:
*/
btf_get(mod_btf);
spin_unlock_bh(&btf_idr_lock);
- cands = bpf_core_add_cands(cands, mod_btf, btf_nr_types(main_btf));
+ cands = bpf_core_add_cands(cands, mod_btf, btf_named_start_id(mod_btf, true));
btf_put(mod_btf);
if (IS_ERR(cands))
return ERR_CAST(cands);
diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
index 9f866a010dad..005ea3a2cda7 100644
--- a/kernel/bpf/inode.c
+++ b/kernel/bpf/inode.c
@@ -600,10 +600,17 @@ struct bpffs_btf_enums {
static int find_bpffs_btf_enums(struct bpffs_btf_enums *info)
{
+ struct {
+ const struct btf_type **type;
+ const char *name;
+ } btf_enums[] = {
+ {&info->cmd_t, "bpf_cmd"},
+ {&info->map_t, "bpf_map_type"},
+ {&info->prog_t, "bpf_prog_type"},
+ {&info->attach_t, "bpf_attach_type"},
+ };
const struct btf *btf;
- const struct btf_type *t;
- const char *name;
- int i, n;
+ int i, id;
memset(info, 0, sizeof(*info));
@@ -615,31 +622,16 @@ static int find_bpffs_btf_enums(struct bpffs_btf_enums *info)
info->btf = btf;
- for (i = 1, n = btf_nr_types(btf); i < n; i++) {
- t = btf_type_by_id(btf, i);
- if (!btf_type_is_enum(t))
- continue;
-
- name = btf_name_by_offset(btf, t->name_off);
- if (!name)
- continue;
-
- if (strcmp(name, "bpf_cmd") == 0)
- info->cmd_t = t;
- else if (strcmp(name, "bpf_map_type") == 0)
- info->map_t = t;
- else if (strcmp(name, "bpf_prog_type") == 0)
- info->prog_t = t;
- else if (strcmp(name, "bpf_attach_type") == 0)
- info->attach_t = t;
- else
- continue;
+ for (i = 0; i < ARRAY_SIZE(btf_enums); i++) {
+ id = btf_find_by_name_kind(btf, btf_enums[i].name,
+ BTF_KIND_ENUM);
+ if (id < 0)
+ return -ESRCH;
- if (info->cmd_t && info->map_t && info->prog_t && info->attach_t)
- return 0;
+ *btf_enums[i].type = btf_type_by_id(btf, id);
}
- return -ESRCH;
+ return 0;
}
static bool find_btf_enum_const(const struct btf *btf, const struct btf_type *enum_t,
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 092003cc7841..45733bae271d 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -20687,12 +20687,7 @@ static int find_btf_percpu_datasec(struct btf *btf)
* types to look at only module's own BTF types.
*/
n = btf_nr_types(btf);
- if (btf_is_module(btf))
- i = btf_nr_types(btf_vmlinux);
- else
- i = 1;
-
- for(; i < n; i++) {
+ for (i = btf_named_start_id(btf, true); i < n; i++) {
t = btf_type_by_id(btf, i);
if (BTF_INFO_KIND(t->info) != BTF_KIND_DATASEC)
continue;
generated by cgit v1.2.3 (git 2.0.4) at 2026-02-24 01:04:32 +0000