From: Song Liu <song@kernel.org>
Date: Thu, 10 Feb 2022 18:49:39 -0800
Subject: bpf: Fix bpf_prog_pack build for ppc64_defconfig
Patch-mainline: v5.18-rc1
Git-commit: 4cc0991abd3954609a6929234bbb8c0fe7a0298d
References: jsc#PED-1377
bpf_prog_pack causes build error with powerpc ppc64_defconfig:
kernel/bpf/core.c:830:23: error: variably modified 'bitmap' at file scope
830 | unsigned long bitmap[BITS_TO_LONGS(BPF_PROG_CHUNK_COUNT)];
| ^~~~~~
This is because the marco expands as:
unsigned long bitmap[((((((1UL) << (16 + __pte_index_size)) / (1 << 6))) \
+ ((sizeof(long) * 8)) - 1) / ((sizeof(long) * 8)))];
where __pte_index_size is a global variable.
Fix it by turning bitmap into a 0-length array.
Fixes: 57631054fae6 ("bpf: Introduce bpf_prog_pack allocator")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220211024939.2962537-1-song@kernel.org
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
kernel/bpf/core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -827,7 +827,7 @@ int bpf_jit_add_poke_descriptor(struct b
struct bpf_prog_pack {
struct list_head list;
void *ptr;
- unsigned long bitmap[BITS_TO_LONGS(BPF_PROG_CHUNK_COUNT)];
+ unsigned long bitmap[];
};
#define BPF_PROG_MAX_PACK_PROG_SIZE BPF_PROG_PACK_SIZE
@@ -840,7 +840,7 @@ static struct bpf_prog_pack *alloc_new_p
{
struct bpf_prog_pack *pack;
- pack = kzalloc(sizeof(*pack), GFP_KERNEL);
+ pack = kzalloc(sizeof(*pack) + BITS_TO_BYTES(BPF_PROG_CHUNK_COUNT), GFP_KERNEL);
if (!pack)
return NULL;
pack->ptr = module_alloc(BPF_PROG_PACK_SIZE);