On 12/18/17 10:19 AM, Daniel Borkmann wrote:
On 12/18/2017 07:09 PM, Alexei Starovoitov wrote:
From: Alexei Starovoitov <a...@fb.com>
fix the following issue:
arch/arm64/net/bpf_jit_comp.c: In function 'bpf_int_jit_compile':
arch/arm64/net/bpf_jit_comp.c:982:18: error: 'image_size' may be used
uninitialized in this function [-Werror=maybe-uninitialized]
Fixes: db496944fdaa ("bpf: arm64: add JIT support for multi-function programs")
Reported-by: Arnd Bergmann <a...@arndb.de>
Signed-off-by: Alexei Starovoitov <a...@kernel.org>
---
arch/arm64/net/bpf_jit_comp.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index 396490cf7316..acaa935ed977 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -897,6 +897,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
image_ptr = jit_data->image;
header = jit_data->header;
extra_pass = true;
+ image_size = sizeof(u32) * ctx.idx;
goto skip_init_ctx;
}
memset(&ctx, 0, sizeof(ctx));
I don't really mind, but it feels more complex than it needs to be
imho, since in the initial pass you fetch 'image_size' in fake pass
from ctx.idx, then we set ctx.idx to 0 again, do another pass and
use the cached ctx.idx from that second pass instead of the first
one where we set 'image_size' originally, so we definitely need to
take that into consideration in future reviews at least.
not sure what you mean.
This check: ctx.idx != jit_data->ctx.idx matters the most.
After first alloc the 'image_size' variable used for dumping only.
That's why the JITing itself worked fine. We could have removed it
since it's computable from idx, but imo it's fine this way.
