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Diffstat (limited to 'kernel/bpf/btf.c')
-rw-r--r--kernel/bpf/btf.c167
1 files changed, 146 insertions, 21 deletions
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 0493310d981f..563ac61e6d6b 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -3166,9 +3166,16 @@ static void btf_struct_log(struct btf_verifier_env *env,
enum btf_field_type {
BTF_FIELD_SPIN_LOCK,
BTF_FIELD_TIMER,
+ BTF_FIELD_KPTR,
+};
+
+enum {
+ BTF_FIELD_IGNORE = 0,
+ BTF_FIELD_FOUND = 1,
};
struct btf_field_info {
+ u32 type_id;
u32 off;
};
@@ -3176,29 +3183,57 @@ static int btf_find_struct(const struct btf *btf, const struct btf_type *t,
u32 off, int sz, struct btf_field_info *info)
{
if (!__btf_type_is_struct(t))
- return 0;
+ return BTF_FIELD_IGNORE;
if (t->size != sz)
- return 0;
- if (info->off != -ENOENT)
- /* only one such field is allowed */
- return -E2BIG;
+ return BTF_FIELD_IGNORE;
info->off = off;
- return 0;
+ return BTF_FIELD_FOUND;
+}
+
+static int btf_find_kptr(const struct btf *btf, const struct btf_type *t,
+ u32 off, int sz, struct btf_field_info *info)
+{
+ u32 res_id;
+
+ /* For PTR, sz is always == 8 */
+ if (!btf_type_is_ptr(t))
+ return BTF_FIELD_IGNORE;
+ t = btf_type_by_id(btf, t->type);
+
+ if (!btf_type_is_type_tag(t))
+ return BTF_FIELD_IGNORE;
+ /* Reject extra tags */
+ if (btf_type_is_type_tag(btf_type_by_id(btf, t->type)))
+ return -EINVAL;
+ if (strcmp("kptr", __btf_name_by_offset(btf, t->name_off)))
+ return -EINVAL;
+
+ /* Get the base type */
+ t = btf_type_skip_modifiers(btf, t->type, &res_id);
+ /* Only pointer to struct is allowed */
+ if (!__btf_type_is_struct(t))
+ return -EINVAL;
+
+ info->type_id = res_id;
+ info->off = off;
+ return BTF_FIELD_FOUND;
}
static int btf_find_struct_field(const struct btf *btf, const struct btf_type *t,
const char *name, int sz, int align,
enum btf_field_type field_type,
- struct btf_field_info *info)
+ struct btf_field_info *info, int info_cnt)
{
const struct btf_member *member;
+ struct btf_field_info tmp;
+ int ret, idx = 0;
u32 i, off;
for_each_member(i, t, member) {
const struct btf_type *member_type = btf_type_by_id(btf,
member->type);
- if (strcmp(__btf_name_by_offset(btf, member_type->name_off), name))
+ if (name && strcmp(__btf_name_by_offset(btf, member_type->name_off), name))
continue;
off = __btf_member_bit_offset(t, member);
@@ -3212,20 +3247,38 @@ static int btf_find_struct_field(const struct btf *btf, const struct btf_type *t
switch (field_type) {
case BTF_FIELD_SPIN_LOCK:
case BTF_FIELD_TIMER:
- return btf_find_struct(btf, member_type, off, sz, info);
+ ret = btf_find_struct(btf, member_type, off, sz,
+ idx < info_cnt ? &info[idx] : &tmp);
+ if (ret < 0)
+ return ret;
+ break;
+ case BTF_FIELD_KPTR:
+ ret = btf_find_kptr(btf, member_type, off, sz,
+ idx < info_cnt ? &info[idx] : &tmp);
+ if (ret < 0)
+ return ret;
+ break;
default:
return -EFAULT;
}
+
+ if (ret == BTF_FIELD_IGNORE)
+ continue;
+ if (idx >= info_cnt)
+ return -E2BIG;
+ ++idx;
}
- return 0;
+ return idx;
}
static int btf_find_datasec_var(const struct btf *btf, const struct btf_type *t,
const char *name, int sz, int align,
enum btf_field_type field_type,
- struct btf_field_info *info)
+ struct btf_field_info *info, int info_cnt)
{
const struct btf_var_secinfo *vsi;
+ struct btf_field_info tmp;
+ int ret, idx = 0;
u32 i, off;
for_each_vsi(i, t, vsi) {
@@ -3234,7 +3287,7 @@ static int btf_find_datasec_var(const struct btf *btf, const struct btf_type *t,
off = vsi->offset;
- if (strcmp(__btf_name_by_offset(btf, var_type->name_off), name))
+ if (name && strcmp(__btf_name_by_offset(btf, var_type->name_off), name))
continue;
if (vsi->size != sz)
continue;
@@ -3244,17 +3297,33 @@ static int btf_find_datasec_var(const struct btf *btf, const struct btf_type *t,
switch (field_type) {
case BTF_FIELD_SPIN_LOCK:
case BTF_FIELD_TIMER:
- return btf_find_struct(btf, var_type, off, sz, info);
+ ret = btf_find_struct(btf, var_type, off, sz,
+ idx < info_cnt ? &info[idx] : &tmp);
+ if (ret < 0)
+ return ret;
+ break;
+ case BTF_FIELD_KPTR:
+ ret = btf_find_kptr(btf, var_type, off, sz,
+ idx < info_cnt ? &info[idx] : &tmp);
+ if (ret < 0)
+ return ret;
+ break;
default:
return -EFAULT;
}
+
+ if (ret == BTF_FIELD_IGNORE)
+ continue;
+ if (idx >= info_cnt)
+ return -E2BIG;
+ ++idx;
}
- return 0;
+ return idx;
}
static int btf_find_field(const struct btf *btf, const struct btf_type *t,
enum btf_field_type field_type,
- struct btf_field_info *info)
+ struct btf_field_info *info, int info_cnt)
{
const char *name;
int sz, align;
@@ -3270,14 +3339,19 @@ static int btf_find_field(const struct btf *btf, const struct btf_type *t,
sz = sizeof(struct bpf_timer);
align = __alignof__(struct bpf_timer);
break;
+ case BTF_FIELD_KPTR:
+ name = NULL;
+ sz = sizeof(u64);
+ align = 8;
+ break;
default:
return -EFAULT;
}
if (__btf_type_is_struct(t))
- return btf_find_struct_field(btf, t, name, sz, align, field_type, info);
+ return btf_find_struct_field(btf, t, name, sz, align, field_type, info, info_cnt);
else if (btf_type_is_datasec(t))
- return btf_find_datasec_var(btf, t, name, sz, align, field_type, info);
+ return btf_find_datasec_var(btf, t, name, sz, align, field_type, info, info_cnt);
return -EINVAL;
}
@@ -3287,26 +3361,77 @@ static int btf_find_field(const struct btf *btf, const struct btf_type *t,
*/
int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t)
{
- struct btf_field_info info = { .off = -ENOENT };
+ struct btf_field_info info;
int ret;
- ret = btf_find_field(btf, t, BTF_FIELD_SPIN_LOCK, &info);
+ ret = btf_find_field(btf, t, BTF_FIELD_SPIN_LOCK, &info, 1);
if (ret < 0)
return ret;
+ if (!ret)
+ return -ENOENT;
return info.off;
}
int btf_find_timer(const struct btf *btf, const struct btf_type *t)
{
- struct btf_field_info info = { .off = -ENOENT };
+ struct btf_field_info info;
int ret;
- ret = btf_find_field(btf, t, BTF_FIELD_TIMER, &info);
+ ret = btf_find_field(btf, t, BTF_FIELD_TIMER, &info, 1);
if (ret < 0)
return ret;
+ if (!ret)
+ return -ENOENT;
return info.off;
}
+struct bpf_map_value_off *btf_parse_kptrs(const struct btf *btf,
+ const struct btf_type *t)
+{
+ struct btf_field_info info_arr[BPF_MAP_VALUE_OFF_MAX];
+ struct bpf_map_value_off *tab;
+ struct btf *kernel_btf = NULL;
+ int ret, i, nr_off;
+
+ ret = btf_find_field(btf, t, BTF_FIELD_KPTR, info_arr, ARRAY_SIZE(info_arr));
+ if (ret < 0)
+ return ERR_PTR(ret);
+ if (!ret)
+ return NULL;
+
+ nr_off = ret;
+ tab = kzalloc(offsetof(struct bpf_map_value_off, off[nr_off]), GFP_KERNEL | __GFP_NOWARN);
+ if (!tab)
+ return ERR_PTR(-ENOMEM);
+
+ for (i = 0; i < nr_off; i++) {
+ const struct btf_type *t;
+ s32 id;
+
+ /* Find type in map BTF, and use it to look up the matching type
+ * in vmlinux or module BTFs, by name and kind.
+ */
+ t = btf_type_by_id(btf, info_arr[i].type_id);
+ id = bpf_find_btf_id(__btf_name_by_offset(btf, t->name_off), BTF_INFO_KIND(t->info),
+ &kernel_btf);
+ if (id < 0) {
+ ret = id;
+ goto end;
+ }
+
+ tab->off[i].offset = info_arr[i].off;
+ tab->off[i].kptr.btf_id = id;
+ tab->off[i].kptr.btf = kernel_btf;
+ }
+ tab->nr_off = nr_off;
+ return tab;
+end:
+ while (i--)
+ btf_put(tab->off[i].kptr.btf);
+ kfree(tab);
+ return ERR_PTR(ret);
+}
+
static void __btf_struct_show(const struct btf *btf, const struct btf_type *t,
u32 type_id, void *data, u8 bits_offset,
struct btf_show *show)
generated by cgit v1.2.3 (git 2.39.0) at 2024-09-12 17:19:52 +0300