On 11/23/19 9:56 PM, Andrii Nakryiko wrote:
mmap() support for BPF array depends on vmalloc_user_node_flags, which is
available only on CONFIG_MMU configurations. Fail mmap-able allocations if no
CONFIG_MMU is set.
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Reported-by: kbuild test robot <lkp@xxxxxxxxx>
Signed-off-by: Andrii Nakryiko <andriin@xxxxxx>
---
kernel/bpf/syscall.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index bb002f15b32a..242a06fbdf18 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -156,8 +156,12 @@ static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable)
}
if (mmapable) {
BUG_ON(!PAGE_ALIGNED(size));
+#ifndef CONFIG_MMU
+ return NULL;
+#else
return vmalloc_user_node_flags(size, numa_node, GFP_KERNEL |
__GFP_RETRY_MAYFAIL | flags);
Hmm, this should rather live in include/linux/vmalloc.h, otherwise every future
user of vmalloc_user_node_flags() would need to add this ifdef? vmalloc.h has
the below, so perhaps this could be added there instead:
[..]
#ifndef CONFIG_MMU
extern void *__vmalloc_node_flags(unsigned long size, int node, gfp_t flags);
static inline void *__vmalloc_node_flags_caller(unsigned long size, int node,
gfp_t flags, void *caller)
{
return __vmalloc_node_flags(size, node, flags);
}
#else
extern void *__vmalloc_node_flags_caller(unsigned long size,
int node, gfp_t flags, void *caller);
#endif
[..]
+#endif
}
return __vmalloc_node_flags_caller(size, numa_node,
GFP_KERNEL | __GFP_RETRY_MAYFAIL |
