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Diffstat (limited to 'kernel/bpf/syscall.c')
-rw-r--r--kernel/bpf/syscall.c124
1 files changed, 115 insertions, 9 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index c5aa127ed4cc..58190ca724a2 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -155,6 +155,89 @@ static void maybe_wait_bpf_programs(struct bpf_map *map)
synchronize_rcu();
}
+static void unpin_uptr_kaddr(void *kaddr)
+{
+ if (kaddr)
+ unpin_user_page(virt_to_page(kaddr));
+}
+
+static void __bpf_obj_unpin_uptrs(struct btf_record *rec, u32 cnt, void *obj)
+{
+ const struct btf_field *field;
+ void **uptr_addr;
+ int i;
+
+ for (i = 0, field = rec->fields; i < cnt; i++, field++) {
+ if (field->type != BPF_UPTR)
+ continue;
+
+ uptr_addr = obj + field->offset;
+ unpin_uptr_kaddr(*uptr_addr);
+ }
+}
+
+static void bpf_obj_unpin_uptrs(struct btf_record *rec, void *obj)
+{
+ if (!btf_record_has_field(rec, BPF_UPTR))
+ return;
+
+ __bpf_obj_unpin_uptrs(rec, rec->cnt, obj);
+}
+
+static int bpf_obj_pin_uptrs(struct btf_record *rec, void *obj)
+{
+ const struct btf_field *field;
+ const struct btf_type *t;
+ unsigned long start, end;
+ struct page *page;
+ void **uptr_addr;
+ int i, err;
+
+ if (!btf_record_has_field(rec, BPF_UPTR))
+ return 0;
+
+ for (i = 0, field = rec->fields; i < rec->cnt; i++, field++) {
+ if (field->type != BPF_UPTR)
+ continue;
+
+ uptr_addr = obj + field->offset;
+ start = *(unsigned long *)uptr_addr;
+ if (!start)
+ continue;
+
+ t = btf_type_by_id(field->kptr.btf, field->kptr.btf_id);
+ /* t->size was checked for zero before */
+ if (check_add_overflow(start, t->size - 1, &end)) {
+ err = -EFAULT;
+ goto unpin_all;
+ }
+
+ /* The uptr's struct cannot span across two pages */
+ if ((start & PAGE_MASK) != (end & PAGE_MASK)) {
+ err = -EOPNOTSUPP;
+ goto unpin_all;
+ }
+
+ err = pin_user_pages_fast(start, 1, FOLL_LONGTERM | FOLL_WRITE, &page);
+ if (err != 1)
+ goto unpin_all;
+
+ if (PageHighMem(page)) {
+ err = -EOPNOTSUPP;
+ unpin_user_page(page);
+ goto unpin_all;
+ }
+
+ *uptr_addr = page_address(page) + offset_in_page(start);
+ }
+
+ return 0;
+
+unpin_all:
+ __bpf_obj_unpin_uptrs(rec, i, obj);
+ return err;
+}
+
static int bpf_map_update_value(struct bpf_map *map, struct file *map_file,
void *key, void *value, __u64 flags)
{
@@ -199,9 +282,14 @@ static int bpf_map_update_value(struct bpf_map *map, struct file *map_file,
map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
err = map->ops->map_push_elem(map, value, flags);
} else {
- rcu_read_lock();
- err = map->ops->map_update_elem(map, key, value, flags);
- rcu_read_unlock();
+ err = bpf_obj_pin_uptrs(map->record, value);
+ if (!err) {
+ rcu_read_lock();
+ err = map->ops->map_update_elem(map, key, value, flags);
+ rcu_read_unlock();
+ if (err)
+ bpf_obj_unpin_uptrs(map->record, value);
+ }
}
bpf_enable_instrumentation();
@@ -548,6 +636,7 @@ void btf_record_free(struct btf_record *rec)
case BPF_KPTR_UNREF:
case BPF_KPTR_REF:
case BPF_KPTR_PERCPU:
+ case BPF_UPTR:
if (rec->fields[i].kptr.module)
module_put(rec->fields[i].kptr.module);
if (btf_is_kernel(rec->fields[i].kptr.btf))
@@ -597,6 +686,7 @@ struct btf_record *btf_record_dup(const struct btf_record *rec)
case BPF_KPTR_UNREF:
case BPF_KPTR_REF:
case BPF_KPTR_PERCPU:
+ case BPF_UPTR:
if (btf_is_kernel(fields[i].kptr.btf))
btf_get(fields[i].kptr.btf);
if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) {
@@ -714,6 +804,10 @@ void bpf_obj_free_fields(const struct btf_record *rec, void *obj)
field->kptr.dtor(xchgd_field);
}
break;
+ case BPF_UPTR:
+ /* The caller ensured that no one is using the uptr */
+ unpin_uptr_kaddr(*(void **)field_ptr);
+ break;
case BPF_LIST_HEAD:
if (WARN_ON_ONCE(rec->spin_lock_off < 0))
continue;
@@ -1105,7 +1199,7 @@ static int map_check_btf(struct bpf_map *map, struct bpf_token *token,
map->record = btf_parse_fields(btf, value_type,
BPF_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD |
- BPF_RB_ROOT | BPF_REFCOUNT | BPF_WORKQUEUE,
+ BPF_RB_ROOT | BPF_REFCOUNT | BPF_WORKQUEUE | BPF_UPTR,
map->value_size);
if (!IS_ERR_OR_NULL(map->record)) {
int i;
@@ -1161,6 +1255,12 @@ static int map_check_btf(struct bpf_map *map, struct bpf_token *token,
goto free_map_tab;
}
break;
+ case BPF_UPTR:
+ if (map->map_type != BPF_MAP_TYPE_TASK_STORAGE) {
+ ret = -EOPNOTSUPP;
+ goto free_map_tab;
+ }
+ break;
case BPF_LIST_HEAD:
case BPF_RB_ROOT:
if (map->map_type != BPF_MAP_TYPE_HASH &&
@@ -3218,7 +3318,8 @@ static void bpf_tracing_link_release(struct bpf_link *link)
container_of(link, struct bpf_tracing_link, link.link);
WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link,
- tr_link->trampoline));
+ tr_link->trampoline,
+ tr_link->tgt_prog));
bpf_trampoline_put(tr_link->trampoline);
@@ -3358,7 +3459,7 @@ static int bpf_tracing_prog_attach(struct bpf_prog *prog,
* in prog->aux
*
* - if prog->aux->dst_trampoline is NULL, the program has already been
- * attached to a target and its initial target was cleared (below)
+ * attached to a target and its initial target was cleared (below)
*
* - if tgt_prog != NULL, the caller specified tgt_prog_fd +
* target_btf_id using the link_create API.
@@ -3433,7 +3534,7 @@ static int bpf_tracing_prog_attach(struct bpf_prog *prog,
if (err)
goto out_unlock;
- err = bpf_trampoline_link_prog(&link->link, tr);
+ err = bpf_trampoline_link_prog(&link->link, tr, tgt_prog);
if (err) {
bpf_link_cleanup(&link_primer);
link = NULL;
@@ -4002,10 +4103,14 @@ static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI &&
attach_type != BPF_TRACE_UPROBE_MULTI)
return -EINVAL;
+ if (prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION &&
+ attach_type != BPF_TRACE_UPROBE_SESSION)
+ return -EINVAL;
if (attach_type != BPF_PERF_EVENT &&
attach_type != BPF_TRACE_KPROBE_MULTI &&
attach_type != BPF_TRACE_KPROBE_SESSION &&
- attach_type != BPF_TRACE_UPROBE_MULTI)
+ attach_type != BPF_TRACE_UPROBE_MULTI &&
+ attach_type != BPF_TRACE_UPROBE_SESSION)
return -EINVAL;
return 0;
case BPF_PROG_TYPE_SCHED_CLS:
@@ -5258,7 +5363,8 @@ static int link_create(union bpf_attr *attr, bpfptr_t uattr)
else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI ||
attr->link_create.attach_type == BPF_TRACE_KPROBE_SESSION)
ret = bpf_kprobe_multi_link_attach(attr, prog);
- else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI)
+ else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI ||
+ attr->link_create.attach_type == BPF_TRACE_UPROBE_SESSION)
ret = bpf_uprobe_multi_link_attach(attr, prog);
break;
default:
generated by cgit (git 2.34.1) at 2025-03-16 22:40:18 +0000