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Diffstat (limited to 'kernel/bpf/btf.c')
-rw-r--r--kernel/bpf/btf.c117
1 files changed, 80 insertions, 37 deletions
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 72b32b7cd9cd..1095bbe29859 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -29,6 +29,7 @@
#include <net/netfilter/nf_bpf_link.h>
#include <net/sock.h>
+#include <net/xdp.h>
#include "../tools/lib/bpf/relo_core.h"
/* BTF (BPF Type Format) is the meta data format which describes
@@ -222,10 +223,17 @@ enum btf_kfunc_hook {
enum {
BTF_KFUNC_SET_MAX_CNT = 256,
BTF_DTOR_KFUNC_MAX_CNT = 256,
+ BTF_KFUNC_FILTER_MAX_CNT = 16,
+};
+
+struct btf_kfunc_hook_filter {
+ btf_kfunc_filter_t filters[BTF_KFUNC_FILTER_MAX_CNT];
+ u32 nr_filters;
};
struct btf_kfunc_set_tab {
struct btf_id_set8 *sets[BTF_KFUNC_HOOK_MAX];
+ struct btf_kfunc_hook_filter hook_filters[BTF_KFUNC_HOOK_MAX];
};
struct btf_id_dtor_kfunc_tab {
@@ -485,25 +493,26 @@ static bool btf_type_is_fwd(const struct btf_type *t)
return BTF_INFO_KIND(t->info) == BTF_KIND_FWD;
}
-static bool btf_type_nosize(const struct btf_type *t)
+static bool btf_type_is_datasec(const struct btf_type *t)
{
- return btf_type_is_void(t) || btf_type_is_fwd(t) ||
- btf_type_is_func(t) || btf_type_is_func_proto(t);
+ return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC;
}
-static bool btf_type_nosize_or_null(const struct btf_type *t)
+static bool btf_type_is_decl_tag(const struct btf_type *t)
{
- return !t || btf_type_nosize(t);
+ return BTF_INFO_KIND(t->info) == BTF_KIND_DECL_TAG;
}
-static bool btf_type_is_datasec(const struct btf_type *t)
+static bool btf_type_nosize(const struct btf_type *t)
{
- return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC;
+ return btf_type_is_void(t) || btf_type_is_fwd(t) ||
+ btf_type_is_func(t) || btf_type_is_func_proto(t) ||
+ btf_type_is_decl_tag(t);
}
-static bool btf_type_is_decl_tag(const struct btf_type *t)
+static bool btf_type_nosize_or_null(const struct btf_type *t)
{
- return BTF_INFO_KIND(t->info) == BTF_KIND_DECL_TAG;
+ return !t || btf_type_nosize(t);
}
static bool btf_type_is_decl_tag_target(const struct btf_type *t)
@@ -544,7 +553,7 @@ s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind)
return -ENOENT;
}
-static s32 bpf_find_btf_id(const char *name, u32 kind, struct btf **btf_p)
+s32 bpf_find_btf_id(const char *name, u32 kind, struct btf **btf_p)
{
struct btf *btf;
s32 ret;
@@ -6125,8 +6134,9 @@ static int btf_struct_walk(struct bpf_verifier_log *log, const struct btf *btf,
const char *tname, *mname, *tag_value;
u32 vlen, elem_id, mid;
- *flag = 0;
again:
+ if (btf_type_is_modifier(t))
+ t = btf_type_skip_modifiers(btf, t->type, NULL);
tname = __btf_name_by_offset(btf, t->name_off);
if (!btf_type_is_struct(t)) {
bpf_log(log, "Type '%s' is not a struct\n", tname);
@@ -6134,6 +6144,14 @@ again:
}
vlen = btf_type_vlen(t);
+ if (BTF_INFO_KIND(t->info) == BTF_KIND_UNION && vlen != 1 && !(*flag & PTR_UNTRUSTED))
+ /*
+ * walking unions yields untrusted pointers
+ * with exception of __bpf_md_ptr and other
+ * unions with a single member
+ */
+ *flag |= PTR_UNTRUSTED;
+
if (off + size > t->size) {
/* If the last element is a variable size array, we may
* need to relax the rule.
@@ -6294,15 +6312,6 @@ error:
* of this field or inside of this struct
*/
if (btf_type_is_struct(mtype)) {
- if (BTF_INFO_KIND(mtype->info) == BTF_KIND_UNION &&
- btf_type_vlen(mtype) != 1)
- /*
- * walking unions yields untrusted pointers
- * with exception of __bpf_md_ptr and other
- * unions with a single member
- */
- *flag |= PTR_UNTRUSTED;
-
/* our field must be inside that union or struct */
t = mtype;
@@ -6360,7 +6369,7 @@ error:
* that also allows using an array of int as a scratch
* space. e.g. skb->cb[].
*/
- if (off + size > mtrue_end) {
+ if (off + size > mtrue_end && !(*flag & PTR_UNTRUSTED)) {
bpf_log(log,
"access beyond the end of member %s (mend:%u) in struct %s with off %u size %u\n",
mname, mtrue_end, tname, off, size);
@@ -6468,7 +6477,7 @@ bool btf_struct_ids_match(struct bpf_verifier_log *log,
bool strict)
{
const struct btf_type *type;
- enum bpf_type_flag flag;
+ enum bpf_type_flag flag = 0;
int err;
/* Are we already done? */
@@ -7665,9 +7674,12 @@ static int btf_check_kfunc_protos(struct btf *btf, u32 func_id, u32 func_flags)
/* Kernel Function (kfunc) BTF ID set registration API */
static int btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook,
- struct btf_id_set8 *add_set)
+ const struct btf_kfunc_id_set *kset)
{
+ struct btf_kfunc_hook_filter *hook_filter;
+ struct btf_id_set8 *add_set = kset->set;
bool vmlinux_set = !btf_is_module(btf);
+ bool add_filter = !!kset->filter;
struct btf_kfunc_set_tab *tab;
struct btf_id_set8 *set;
u32 set_cnt;
@@ -7682,6 +7694,24 @@ static int btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook,
return 0;
tab = btf->kfunc_set_tab;
+
+ if (tab && add_filter) {
+ u32 i;
+
+ hook_filter = &tab->hook_filters[hook];
+ for (i = 0; i < hook_filter->nr_filters; i++) {
+ if (hook_filter->filters[i] == kset->filter) {
+ add_filter = false;
+ break;
+ }
+ }
+
+ if (add_filter && hook_filter->nr_filters == BTF_KFUNC_FILTER_MAX_CNT) {
+ ret = -E2BIG;
+ goto end;
+ }
+ }
+
if (!tab) {
tab = kzalloc(sizeof(*tab), GFP_KERNEL | __GFP_NOWARN);
if (!tab)
@@ -7704,7 +7734,7 @@ static int btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook,
*/
if (!vmlinux_set) {
tab->sets[hook] = add_set;
- return 0;
+ goto do_add_filter;
}
/* In case of vmlinux sets, there may be more than one set being
@@ -7746,6 +7776,11 @@ static int btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook,
sort(set->pairs, set->cnt, sizeof(set->pairs[0]), btf_id_cmp_func, NULL);
+do_add_filter:
+ if (add_filter) {
+ hook_filter = &tab->hook_filters[hook];
+ hook_filter->filters[hook_filter->nr_filters++] = kset->filter;
+ }
return 0;
end:
btf_free_kfunc_set_tab(btf);
@@ -7754,15 +7789,22 @@ end:
static u32 *__btf_kfunc_id_set_contains(const struct btf *btf,
enum btf_kfunc_hook hook,
- u32 kfunc_btf_id)
+ u32 kfunc_btf_id,
+ const struct bpf_prog *prog)
{
+ struct btf_kfunc_hook_filter *hook_filter;
struct btf_id_set8 *set;
- u32 *id;
+ u32 *id, i;
if (hook >= BTF_KFUNC_HOOK_MAX)
return NULL;
if (!btf->kfunc_set_tab)
return NULL;
+ hook_filter = &btf->kfunc_set_tab->hook_filters[hook];
+ for (i = 0; i < hook_filter->nr_filters; i++) {
+ if (hook_filter->filters[i](prog, kfunc_btf_id))
+ return NULL;
+ }
set = btf->kfunc_set_tab->sets[hook];
if (!set)
return NULL;
@@ -7817,23 +7859,25 @@ static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type)
* protection for looking up a well-formed btf->kfunc_set_tab.
*/
u32 *btf_kfunc_id_set_contains(const struct btf *btf,
- enum bpf_prog_type prog_type,
- u32 kfunc_btf_id)
+ u32 kfunc_btf_id,
+ const struct bpf_prog *prog)
{
+ enum bpf_prog_type prog_type = resolve_prog_type(prog);
enum btf_kfunc_hook hook;
u32 *kfunc_flags;
- kfunc_flags = __btf_kfunc_id_set_contains(btf, BTF_KFUNC_HOOK_COMMON, kfunc_btf_id);
+ kfunc_flags = __btf_kfunc_id_set_contains(btf, BTF_KFUNC_HOOK_COMMON, kfunc_btf_id, prog);
if (kfunc_flags)
return kfunc_flags;
hook = bpf_prog_type_to_kfunc_hook(prog_type);
- return __btf_kfunc_id_set_contains(btf, hook, kfunc_btf_id);
+ return __btf_kfunc_id_set_contains(btf, hook, kfunc_btf_id, prog);
}
-u32 *btf_kfunc_is_modify_return(const struct btf *btf, u32 kfunc_btf_id)
+u32 *btf_kfunc_is_modify_return(const struct btf *btf, u32 kfunc_btf_id,
+ const struct bpf_prog *prog)
{
- return __btf_kfunc_id_set_contains(btf, BTF_KFUNC_HOOK_FMODRET, kfunc_btf_id);
+ return __btf_kfunc_id_set_contains(btf, BTF_KFUNC_HOOK_FMODRET, kfunc_btf_id, prog);
}
static int __register_btf_kfunc_id_set(enum btf_kfunc_hook hook,
@@ -7848,10 +7892,8 @@ static int __register_btf_kfunc_id_set(enum btf_kfunc_hook hook,
pr_err("missing vmlinux BTF, cannot register kfuncs\n");
return -ENOENT;
}
- if (kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) {
- pr_err("missing module BTF, cannot register kfuncs\n");
- return -ENOENT;
- }
+ if (kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES))
+ pr_warn("missing module BTF, cannot register kfuncs\n");
return 0;
}
if (IS_ERR(btf))
@@ -7864,7 +7906,8 @@ static int __register_btf_kfunc_id_set(enum btf_kfunc_hook hook,
goto err_out;
}
- ret = btf_populate_kfunc_set(btf, hook, kset->set);
+ ret = btf_populate_kfunc_set(btf, hook, kset);
+
err_out:
btf_put(btf);
return ret;
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