bpf: cpumap: use GFP_KERNEL instead of GFP_ATOMIC in __cpu_map_entry_alloc()

There're several implications after commit 0bf7800f1799 ("ptr_ring:
try vmalloc() when kmalloc() fails") with the using of vmalloc() since
can't allow GFP_ATOMIC but mandate GFP_KERNEL. This will lead a WARN
since cpumap try to call with GFP_ATOMIC. Fortunately, entry
allocation of cpumap can only be done through syscall path which means
GFP_ATOMIC is not necessary, so fixing this by replacing GFP_ATOMIC
with GFP_KERNEL.

Reported-by: [email protected]
Fixes: 0bf7800f1799 ("ptr_ring: try vmalloc() when kmalloc() fails")
Cc: Michal Hocko <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Jesper Dangaard Brouer <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Jason Wang <[email protected]>
Acked-by: Jesper Dangaard Brouer <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>

1 files changed, 1 insertions, 1 deletions

diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
index fbfdada6caee..a4bb0b34375a 100644
--- a/kernel/bpf/cpumap.c
+++ b/kernel/bpf/cpumap.c
@@ -334,7 +334,7 @@ static int cpu_map_kthread_run(void *data)
 static struct bpf_cpu_map_entry *__cpu_map_entry_alloc(u32 qsize, u32 cpu,
 						       int map_id)
 {
-	gfp_t gfp = GFP_ATOMIC|__GFP_NOWARN;
+	gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;
 	struct bpf_cpu_map_entry *rcpu;
 	int numa, err;