Commit ab4dc30c authored by Viktor Malik's avatar Viktor Malik Committed by Alexei Starovoitov
Browse files

bpf: Do not alloc arena on unsupported arches 

Do not allocate BPF arena on arches that do not support it, instead
return EOPNOTSUPP. This is useful to prevent bugs such as soft lockups
while trying to free the arena which we have witnessed on ppc64le [1].

[1] https://lore.kernel.org/bpf/4afdcb50-13f2-4772-8db1-3fd02bd985b3@redhat.com/



Signed-off-by: default avatarViktor Malik <vmalik@redhat.com>
Link: https://lore.kernel.org/r/20241115082548.74972-1-vmalik@redhat.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent f01750ae

kernel/bpf/arena.c

+4 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
#include <linux/bpf.h>

#include <linux/btf.h>

#include <linux/err.h>

#include "linux/filter.h"

#include <linux/btf_ids.h>

#include <linux/vmalloc.h>

#include <linux/pagemap.h>
@@ -99,6 +100,9 @@ static struct bpf_map *arena_map_alloc(union bpf_attr *attr) 
	u64 vm_range;

	int err = -ENOMEM;



	if (!bpf_jit_supports_arena())

		return ERR_PTR(-EOPNOTSUPP);



	if (attr->key_size || attr->value_size || attr->max_entries == 0 ||

	    /* BPF_F_MMAPABLE must be set */

	    !(attr->map_flags & BPF_F_MMAPABLE) ||