Re: [RFC PATCH] arm64: bpf: fix endianness conversion bugs

From: Alexei Starovoitov
Date: Fri Jun 26 2015 - 04:26:14 EST


On 6/25/15 6:39 PM, Xi Wang wrote:
Upper bits should be zeroed in endianness conversion:

- even when there's no need to change endianness (i.e., BPF_FROM_BE
on big endian or BPF_FROM_LE on little endian);

- after rev16.

This patch fixes such bugs by emitting extra instructions to clear
upper bits.

Cc: Zi Shen Lim<zlim.lnx@xxxxxxxxx>
Cc: Alexei Starovoitov<ast@xxxxxxxxxxxx>
Fixes: e54bcde3d69d ("arm64: eBPF JIT compiler")
Signed-off-by: Xi Wang<xi.wang@xxxxxxxxx>

Acked-by: Alexei Starovoitov <ast@xxxxxxxxxxxx>

The current testsuite catches the 16-bit bugs. I'll send a separate
patch that extends test_bpf to catch the 32-bit ones.

looking forward to it. Thanks.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/