1 files changed, 30 insertions, 22 deletions

diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c
index b7aef5b3416d..d5d96ceca105 100644
--- a/kernel/bpf/bpf_iter.c
+++ b/kernel/bpf/bpf_iter.c
@@ -5,6 +5,7 @@
 #include <linux/anon_inodes.h>
 #include <linux/filter.h>
 #include <linux/bpf.h>
+#include <linux/rcupdate_trace.h>
 
 struct bpf_iter_target_info {
 	struct list_head list;
@@ -329,35 +330,34 @@ static void cache_btf_id(struct bpf_iter_target_info *tinfo,
 bool bpf_iter_prog_supported(struct bpf_prog *prog)
 {
 	const char *attach_fname = prog->aux->attach_func_name;
+	struct bpf_iter_target_info *tinfo = NULL, *iter;
 	u32 prog_btf_id = prog->aux->attach_btf_id;
 	const char *prefix = BPF_ITER_FUNC_PREFIX;
-	struct bpf_iter_target_info *tinfo;
 	int prefix_len = strlen(prefix);
-	bool supported = false;
 
 	if (strncmp(attach_fname, prefix, prefix_len))
 		return false;
 
 	mutex_lock(&targets_mutex);
-	list_for_each_entry(tinfo, &targets, list) {
-		if (tinfo->btf_id && tinfo->btf_id == prog_btf_id) {
-			supported = true;
+	list_for_each_entry(iter, &targets, list) {
+		if (iter->btf_id && iter->btf_id == prog_btf_id) {
+			tinfo = iter;
 			break;
 		}
-		if (!strcmp(attach_fname + prefix_len, tinfo->reg_info->target)) {
-			cache_btf_id(tinfo, prog);
-			supported = true;
+		if (!strcmp(attach_fname + prefix_len, iter->reg_info->target)) {
+			cache_btf_id(iter, prog);
+			tinfo = iter;
 			break;
 		}
 	}
 	mutex_unlock(&targets_mutex);
 
-	if (supported) {
+	if (tinfo) {
 		prog->aux->ctx_arg_info_size = tinfo->reg_info->ctx_arg_info_size;
 		prog->aux->ctx_arg_info = tinfo->reg_info->ctx_arg_info;
 	}
 
-	return supported;
+	return tinfo != NULL;
 }
 
 const struct bpf_func_proto *
@@ -498,12 +498,11 @@ bool bpf_link_is_iter(struct bpf_link *link)
 int bpf_iter_link_attach(const union bpf_attr *attr, bpfptr_t uattr,
 			 struct bpf_prog *prog)
 {
+	struct bpf_iter_target_info *tinfo = NULL, *iter;
 	struct bpf_link_primer link_primer;
-	struct bpf_iter_target_info *tinfo;
 	union bpf_iter_link_info linfo;
 	struct bpf_iter_link *link;
 	u32 prog_btf_id, linfo_len;
-	bool existed = false;
 	bpfptr_t ulinfo;
 	int err;
 
@@ -529,14 +528,14 @@ int bpf_iter_link_attach(const union bpf_attr *attr, bpfptr_t uattr,
 
 	prog_btf_id = prog->aux->attach_btf_id;
 	mutex_lock(&targets_mutex);
-	list_for_each_entry(tinfo, &targets, list) {
-		if (tinfo->btf_id == prog_btf_id) {
-			existed = true;
+	list_for_each_entry(iter, &targets, list) {
+		if (iter->btf_id == prog_btf_id) {
+			tinfo = iter;
 			break;
 		}
 	}
 	mutex_unlock(&targets_mutex);
-	if (!existed)
+	if (!tinfo)
 		return -ENOENT;
 
 	link = kzalloc(sizeof(*link), GFP_USER | __GFP_NOWARN);
@@ -546,7 +545,7 @@ int bpf_iter_link_attach(const union bpf_attr *attr, bpfptr_t uattr,
 	bpf_link_init(&link->link, BPF_LINK_TYPE_ITER, &bpf_iter_link_lops, prog);
 	link->tinfo = tinfo;
 
-	err  = bpf_link_prime(&link->link, &link_primer);
+	err = bpf_link_prime(&link->link, &link_primer);
 	if (err) {
 		kfree(link);
 		return err;
@@ -684,11 +683,20 @@ int bpf_iter_run_prog(struct bpf_prog *prog, void *ctx)
 {
 	int ret;
 
-	rcu_read_lock();
-	migrate_disable();
-	ret = bpf_prog_run(prog, ctx);
-	migrate_enable();
-	rcu_read_unlock();
+	if (prog->aux->sleepable) {
+		rcu_read_lock_trace();
+		migrate_disable();
+		might_fault();
+		ret = bpf_prog_run(prog, ctx);
+		migrate_enable();
+		rcu_read_unlock_trace();
+	} else {
+		rcu_read_lock();
+		migrate_disable();
+		ret = bpf_prog_run(prog, ctx);
+		migrate_enable();
+		rcu_read_unlock();
+	}
 
 	/* bpf program can only return 0 or 1:
 	 *  0 : okay