| Message ID | 20220211024939.2962537-1-song@kernel.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 4cc0991abd3954609a6929234bbb8c0fe7a0298d |
| Delegated to: | BPF |
| Headers | show |
| Series | [v2,bpf-next] bpf: fix bpf_prog_pack build for ppc64_defconfig | expand |
Hello: This patch was applied to bpf/bpf-next.git (master) by Alexei Starovoitov <ast@kernel.org>: On Thu, 10 Feb 2022 18:49:39 -0800 you wrote: > 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: > > [...] Here is the summary with links: - [v2,bpf-next] bpf: fix bpf_prog_pack build for ppc64_defconfig https://git.kernel.org/bpf/bpf-next/c/4cc0991abd39 You are awesome, thank you!
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 42d96549a804..44623c9b5bb1 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -827,7 +827,7 @@ int bpf_jit_add_poke_descriptor(struct bpf_prog *prog, 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_pack(void) { 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);
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> --- v2: add information about the build failure. --- kernel/bpf/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)