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: Viktor Malik <vmalik@redhat.com>
Link: https://lore.kernel.org/r/20241115082548.74972-1-vmalik@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Viktor Malik 2024-11-15 09:25:48 +01:00 committed by Alexei Starovoitov
parent f01750aecd
commit ab4dc30c53

View File

@ -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) ||