From: Tejun Heo <tj@kernel.org>
Date: Fri, 22 May 2026 17:22:14 +0000 (-1000)
Subject: bpf: Add sleepable variant of bpf_arena_alloc_pages for kernel callers
X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=f211c81ddc368e5cc6ad69d171bca0fa52e71ad7;p=thirdparty%2Fkernel%2Flinux.git

bpf: Add sleepable variant of bpf_arena_alloc_pages for kernel callers

The existing kernel-side export of bpf_arena_alloc_pages is _non_sleepable
only - it's used by the verifier to inline the kfunc when the call site is
non-sleepable. There is no sleepable equivalent for kernel callers. The
kfunc bpf_arena_alloc_pages itself is BPF-only.

sched_ext needs sleepable kernel-side allocs for its arena pool init/grow
paths. Add bpf_arena_alloc_pages_sleepable() mirroring the _non_sleepable
wrapper but passing sleepable=true to arena_alloc_pages().

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Link: https://lore.kernel.org/r/20260522172219.1423324-4-tj@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index bb4261a5df64..c00be24e7244 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -679,6 +679,8 @@ int bpf_dynptr_from_file_sleepable(struct file *file, u32 flags,
 void *bpf_arena_alloc_pages_non_sleepable(void *p__map, void *addr__ign, u32 page_cnt, int node_id,
 					  u64 flags);
 void bpf_arena_free_pages_non_sleepable(void *p__map, void *ptr__ign, u32 page_cnt);
+void *bpf_arena_alloc_pages_sleepable(void *p__map, void *addr__ign, u32 page_cnt, int node_id,
+				      u64 flags);
 #else
 static inline void *bpf_arena_alloc_pages_non_sleepable(void *p__map, void *addr__ign, u32 page_cnt,
 							int node_id, u64 flags)
@@ -689,6 +691,12 @@ static inline void *bpf_arena_alloc_pages_non_sleepable(void *p__map, void *addr
 static inline void bpf_arena_free_pages_non_sleepable(void *p__map, void *ptr__ign, u32 page_cnt)
 {
 }
+
+static inline void *bpf_arena_alloc_pages_sleepable(void *p__map, void *addr__ign, u32 page_cnt,
+						    int node_id, u64 flags)
+{
+	return NULL;
+}
 #endif
 
 extern const struct bpf_map_ops bpf_map_offload_ops;
diff --git a/kernel/bpf/arena.c b/kernel/bpf/arena.c
index 2da2c275cff6..9e379ef27d41 100644
--- a/kernel/bpf/arena.c
+++ b/kernel/bpf/arena.c
@@ -951,6 +951,19 @@ void *bpf_arena_alloc_pages_non_sleepable(void *p__map, void *addr__ign, u32 pag
 
 	return (void *)arena_alloc_pages(arena, (long)addr__ign, page_cnt, node_id, false);
 }
+
+void *bpf_arena_alloc_pages_sleepable(void *p__map, void *addr__ign, u32 page_cnt,
+				      int node_id, u64 flags)
+{
+	struct bpf_map *map = p__map;
+	struct bpf_arena *arena = container_of(map, struct bpf_arena, map);
+
+	if (map->map_type != BPF_MAP_TYPE_ARENA || flags || !page_cnt)
+		return NULL;
+
+	return (void *)arena_alloc_pages(arena, (long)addr__ign, page_cnt, node_id, true);
+}
+
 __bpf_kfunc void bpf_arena_free_pages(void *p__map, void *ptr__ign, u32 page_cnt)
 {
 	struct bpf_map *map = p__map;