Commit fc9702273e2e ("bpf: Add mmap() support for BPF_MAP_TYPE_ARRAY")
added code that calls vmalloc_user_node_flags() and therefore requires
mm/vmalloc.c. However, that file is not built for the !CONFIG_MMU case.
This leads to a build failure when using ARM with the config provided
by at least one particular kbuild test robot report [1].
[1] https://lore/kernel.org/r/201911251639.UWS3hE3Y%lkp@xxxxxxxxx
Fix the build by providing a stub function for __bpf_map_area_alloc().
Fixes: fc9702273e2e ("bpf: Add mmap() support for BPF_MAP_TYPE_ARRAY")
Reported-by: kbuild test robot <lkp@xxxxxxxxx>
Cc: Andrii Nakryiko <andriin@xxxxxx>
Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Cc: Song Liu <songliubraving@xxxxxx>
Cc: John Fastabend <john.fastabend@xxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>
---
kernel/bpf/syscall.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index e3461ec59570..cb3e13ee4123 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -128,6 +128,7 @@ static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
return map;
}
+#ifdef CONFIG_MMU
static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable)
{
/* We really just want to fail instead of triggering OOM killer
@@ -162,6 +163,12 @@ static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable)
GFP_KERNEL | __GFP_RETRY_MAYFAIL |
flags, __builtin_return_address(0));
}
+#else /* CONFIG_MMU */
+static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable)
+{
+ return NULL;
+}
+#endif /* !CONFIG_MMU */
void *bpf_map_area_alloc(u64 size, int numa_node)
{
--
2.24.0
