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Diffstat (limited to 'kernel/bpf/btf.c')
-rw-r--r--kernel/bpf/btf.c323
1 files changed, 177 insertions, 146 deletions
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 8391a77138ee..3dad828db13c 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -3205,16 +3205,20 @@ enum {
struct btf_field_info {
enum btf_field_type type;
u32 off;
- u32 type_id;
+ struct {
+ u32 type_id;
+ } kptr;
};
static int btf_find_struct(const struct btf *btf, const struct btf_type *t,
- u32 off, int sz, struct btf_field_info *info)
+ u32 off, int sz, enum btf_field_type field_type,
+ struct btf_field_info *info)
{
if (!__btf_type_is_struct(t))
return BTF_FIELD_IGNORE;
if (t->size != sz)
return BTF_FIELD_IGNORE;
+ info->type = field_type;
info->off = off;
return BTF_FIELD_FOUND;
}
@@ -3251,28 +3255,66 @@ static int btf_find_kptr(const struct btf *btf, const struct btf_type *t,
if (!__btf_type_is_struct(t))
return -EINVAL;
- info->type_id = res_id;
- info->off = off;
info->type = type;
+ info->off = off;
+ info->kptr.type_id = res_id;
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_info_type field_type,
+static int btf_get_field_type(const char *name, u32 field_mask, u32 *seen_mask,
+ int *align, int *sz)
+{
+ int type = 0;
+
+ if (field_mask & BPF_SPIN_LOCK) {
+ if (!strcmp(name, "bpf_spin_lock")) {
+ if (*seen_mask & BPF_SPIN_LOCK)
+ return -E2BIG;
+ *seen_mask |= BPF_SPIN_LOCK;
+ type = BPF_SPIN_LOCK;
+ goto end;
+ }
+ }
+ if (field_mask & BPF_TIMER) {
+ if (!strcmp(name, "bpf_timer")) {
+ if (*seen_mask & BPF_TIMER)
+ return -E2BIG;
+ *seen_mask |= BPF_TIMER;
+ type = BPF_TIMER;
+ goto end;
+ }
+ }
+ /* Only return BPF_KPTR when all other types with matchable names fail */
+ if (field_mask & BPF_KPTR) {
+ type = BPF_KPTR_REF;
+ goto end;
+ }
+ return 0;
+end:
+ *sz = btf_field_type_size(type);
+ *align = btf_field_type_align(type);
+ return type;
+}
+
+static int btf_find_struct_field(const struct btf *btf,
+ const struct btf_type *t, u32 field_mask,
struct btf_field_info *info, int info_cnt)
{
+ int ret, idx = 0, align, sz, field_type;
const struct btf_member *member;
struct btf_field_info tmp;
- int ret, idx = 0;
- u32 i, off;
+ u32 i, off, seen_mask = 0;
for_each_member(i, t, member) {
const struct btf_type *member_type = btf_type_by_id(btf,
member->type);
- if (name && strcmp(__btf_name_by_offset(btf, member_type->name_off), name))
+ field_type = btf_get_field_type(__btf_name_by_offset(btf, member_type->name_off),
+ field_mask, &seen_mask, &align, &sz);
+ if (field_type == 0)
continue;
+ if (field_type < 0)
+ return field_type;
off = __btf_member_bit_offset(t, member);
if (off % 8)
@@ -3280,17 +3322,18 @@ static int btf_find_struct_field(const struct btf *btf, const struct btf_type *t
return -EINVAL;
off /= 8;
if (off % align)
- return -EINVAL;
+ continue;
switch (field_type) {
- case BTF_FIELD_SPIN_LOCK:
- case BTF_FIELD_TIMER:
- ret = btf_find_struct(btf, member_type, off, sz,
+ case BPF_SPIN_LOCK:
+ case BPF_TIMER:
+ ret = btf_find_struct(btf, member_type, off, sz, field_type,
idx < info_cnt ? &info[idx] : &tmp);
if (ret < 0)
return ret;
break;
- case BTF_FIELD_KPTR:
+ case BPF_KPTR_UNREF:
+ case BPF_KPTR_REF:
ret = btf_find_kptr(btf, member_type, off, sz,
idx < info_cnt ? &info[idx] : &tmp);
if (ret < 0)
@@ -3310,37 +3353,41 @@ static int btf_find_struct_field(const struct btf *btf, const struct btf_type *t
}
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_info_type field_type,
- struct btf_field_info *info, int info_cnt)
+ u32 field_mask, struct btf_field_info *info,
+ int info_cnt)
{
+ int ret, idx = 0, align, sz, field_type;
const struct btf_var_secinfo *vsi;
struct btf_field_info tmp;
- int ret, idx = 0;
- u32 i, off;
+ u32 i, off, seen_mask = 0;
for_each_vsi(i, t, vsi) {
const struct btf_type *var = btf_type_by_id(btf, vsi->type);
const struct btf_type *var_type = btf_type_by_id(btf, var->type);
- off = vsi->offset;
-
- if (name && strcmp(__btf_name_by_offset(btf, var_type->name_off), name))
+ field_type = btf_get_field_type(__btf_name_by_offset(btf, var_type->name_off),
+ field_mask, &seen_mask, &align, &sz);
+ if (field_type == 0)
continue;
+ if (field_type < 0)
+ return field_type;
+
+ off = vsi->offset;
if (vsi->size != sz)
continue;
if (off % align)
- return -EINVAL;
+ continue;
switch (field_type) {
- case BTF_FIELD_SPIN_LOCK:
- case BTF_FIELD_TIMER:
- ret = btf_find_struct(btf, var_type, off, sz,
+ case BPF_SPIN_LOCK:
+ case BPF_TIMER:
+ ret = btf_find_struct(btf, var_type, off, sz, field_type,
idx < info_cnt ? &info[idx] : &tmp);
if (ret < 0)
return ret;
break;
- case BTF_FIELD_KPTR:
+ case BPF_KPTR_UNREF:
+ case BPF_KPTR_REF:
ret = btf_find_kptr(btf, var_type, off, sz,
idx < info_cnt ? &info[idx] : &tmp);
if (ret < 0)
@@ -3360,78 +3407,98 @@ static int btf_find_datasec_var(const struct btf *btf, const struct btf_type *t,
}
static int btf_find_field(const struct btf *btf, const struct btf_type *t,
- enum btf_field_info_type field_type,
- struct btf_field_info *info, int info_cnt)
+ u32 field_mask, struct btf_field_info *info,
+ int info_cnt)
{
- const char *name;
- int sz, align;
-
- switch (field_type) {
- case BTF_FIELD_SPIN_LOCK:
- name = "bpf_spin_lock";
- sz = sizeof(struct bpf_spin_lock);
- align = __alignof__(struct bpf_spin_lock);
- break;
- case BTF_FIELD_TIMER:
- name = "bpf_timer";
- 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, info_cnt);
+ return btf_find_struct_field(btf, t, field_mask, info, info_cnt);
else if (btf_type_is_datasec(t))
- return btf_find_datasec_var(btf, t, name, sz, align, field_type, info, info_cnt);
+ return btf_find_datasec_var(btf, t, field_mask, info, info_cnt);
return -EINVAL;
}
-/* find 'struct bpf_spin_lock' in map value.
- * return >= 0 offset if found
- * and < 0 in case of error
- */
-int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t)
+static int btf_parse_kptr(const struct btf *btf, struct btf_field *field,
+ struct btf_field_info *info)
{
- struct btf_field_info info;
+ struct module *mod = NULL;
+ const struct btf_type *t;
+ struct btf *kernel_btf;
int ret;
+ s32 id;
- ret = btf_find_field(btf, t, BTF_FIELD_SPIN_LOCK, &info, 1);
- if (ret < 0)
- return ret;
- if (!ret)
- return -ENOENT;
- return info.off;
-}
+ /* 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->kptr.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)
+ return id;
+
+ /* Find and stash the function pointer for the destruction function that
+ * needs to be eventually invoked from the map free path.
+ */
+ if (info->type == BPF_KPTR_REF) {
+ const struct btf_type *dtor_func;
+ const char *dtor_func_name;
+ unsigned long addr;
+ s32 dtor_btf_id;
+
+ /* This call also serves as a whitelist of allowed objects that
+ * can be used as a referenced pointer and be stored in a map at
+ * the same time.
+ */
+ dtor_btf_id = btf_find_dtor_kfunc(kernel_btf, id);
+ if (dtor_btf_id < 0) {
+ ret = dtor_btf_id;
+ goto end_btf;
+ }
-int btf_find_timer(const struct btf *btf, const struct btf_type *t)
-{
- struct btf_field_info info;
- int ret;
+ dtor_func = btf_type_by_id(kernel_btf, dtor_btf_id);
+ if (!dtor_func) {
+ ret = -ENOENT;
+ goto end_btf;
+ }
- ret = btf_find_field(btf, t, BTF_FIELD_TIMER, &info, 1);
- if (ret < 0)
- return ret;
- if (!ret)
- return -ENOENT;
- return info.off;
+ if (btf_is_module(kernel_btf)) {
+ mod = btf_try_get_module(kernel_btf);
+ if (!mod) {
+ ret = -ENXIO;
+ goto end_btf;
+ }
+ }
+
+ /* We already verified dtor_func to be btf_type_is_func
+ * in register_btf_id_dtor_kfuncs.
+ */
+ dtor_func_name = __btf_name_by_offset(kernel_btf, dtor_func->name_off);
+ addr = kallsyms_lookup_name(dtor_func_name);
+ if (!addr) {
+ ret = -EINVAL;
+ goto end_mod;
+ }
+ field->kptr.dtor = (void *)addr;
+ }
+
+ field->kptr.btf_id = id;
+ field->kptr.btf = kernel_btf;
+ field->kptr.module = mod;
+ return 0;
+end_mod:
+ module_put(mod);
+end_btf:
+ btf_put(kernel_btf);
+ return ret;
}
-struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t)
+struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t,
+ u32 field_mask, u32 value_size)
{
struct btf_field_info info_arr[BTF_FIELDS_MAX];
- struct btf *kernel_btf = NULL;
- struct module *mod = NULL;
struct btf_record *rec;
int ret, i, cnt;
- ret = btf_find_field(btf, t, BTF_FIELD_KPTR, info_arr, ARRAY_SIZE(info_arr));
+ ret = btf_find_field(btf, t, field_mask, info_arr, ARRAY_SIZE(info_arr));
if (ret < 0)
return ERR_PTR(ret);
if (!ret)
@@ -3441,80 +3508,44 @@ struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type
rec = kzalloc(offsetof(struct btf_record, fields[cnt]), GFP_KERNEL | __GFP_NOWARN);
if (!rec)
return ERR_PTR(-ENOMEM);
- rec->cnt = 0;
- for (i = 0; i < cnt; 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;
+ rec->spin_lock_off = -EINVAL;
+ rec->timer_off = -EINVAL;
+ for (i = 0; i < cnt; i++) {
+ if (info_arr[i].off + btf_field_type_size(info_arr[i].type) > value_size) {
+ WARN_ONCE(1, "verifier bug off %d size %d", info_arr[i].off, value_size);
+ ret = -EFAULT;
goto end;
}
- /* Find and stash the function pointer for the destruction function that
- * needs to be eventually invoked from the map free path.
- */
- if (info_arr[i].type == BPF_KPTR_REF) {
- const struct btf_type *dtor_func;
- const char *dtor_func_name;
- unsigned long addr;
- s32 dtor_btf_id;
-
- /* This call also serves as a whitelist of allowed objects that
- * can be used as a referenced pointer and be stored in a map at
- * the same time.
- */
- dtor_btf_id = btf_find_dtor_kfunc(kernel_btf, id);
- if (dtor_btf_id < 0) {
- ret = dtor_btf_id;
- goto end_btf;
- }
-
- dtor_func = btf_type_by_id(kernel_btf, dtor_btf_id);
- if (!dtor_func) {
- ret = -ENOENT;
- goto end_btf;
- }
-
- if (btf_is_module(kernel_btf)) {
- mod = btf_try_get_module(kernel_btf);
- if (!mod) {
- ret = -ENXIO;
- goto end_btf;
- }
- }
-
- /* We already verified dtor_func to be btf_type_is_func
- * in register_btf_id_dtor_kfuncs.
- */
- dtor_func_name = __btf_name_by_offset(kernel_btf, dtor_func->name_off);
- addr = kallsyms_lookup_name(dtor_func_name);
- if (!addr) {
- ret = -EINVAL;
- goto end_mod;
- }
- rec->fields[i].kptr.dtor = (void *)addr;
- }
-
rec->field_mask |= info_arr[i].type;
rec->fields[i].offset = info_arr[i].off;
rec->fields[i].type = info_arr[i].type;
- rec->fields[i].kptr.btf_id = id;
- rec->fields[i].kptr.btf = kernel_btf;
- rec->fields[i].kptr.module = mod;
+
+ switch (info_arr[i].type) {
+ case BPF_SPIN_LOCK:
+ WARN_ON_ONCE(rec->spin_lock_off >= 0);
+ /* Cache offset for faster lookup at runtime */
+ rec->spin_lock_off = rec->fields[i].offset;
+ break;
+ case BPF_TIMER:
+ WARN_ON_ONCE(rec->timer_off >= 0);
+ /* Cache offset for faster lookup at runtime */
+ rec->timer_off = rec->fields[i].offset;
+ break;
+ case BPF_KPTR_UNREF:
+ case BPF_KPTR_REF:
+ ret = btf_parse_kptr(btf, &rec->fields[i], &info_arr[i]);
+ if (ret < 0)
+ goto end;
+ break;
+ default:
+ ret = -EFAULT;
+ goto end;
+ }
rec->cnt++;
}
return rec;
-end_mod:
- module_put(mod);
-end_btf:
- btf_put(kernel_btf);
end:
btf_record_free(rec);
return ERR_PTR(ret);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-23 09:45:01 +0100