From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754605AbaCaNbM (ORCPT ); Mon, 31 Mar 2014 09:31:12 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:35839 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754361AbaCaNYy (ORCPT ); Mon, 31 Mar 2014 09:24:54 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Alexei Starovoitov , Jan Seiffert , Eric Dumazet , "David S. Miller" , Luis Henriques Subject: [PATCH 3.5 62/71] x86: bpf_jit: support negative offsets Date: Mon, 31 Mar 2014 14:23:08 +0100 Message-Id: <1396272197-13394-63-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1396272197-13394-1-git-send-email-luis.henriques@canonical.com> References: <1396272197-13394-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.5.7.33 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexei Starovoitov commit fdfaf64e75397567257e1051931f9a3377360665 upstream. Commit a998d4342337 claimed to introduce negative offset support to x86 jit, but it couldn't be working, since at the time of the execution of LD+ABS or LD+IND instructions via call into bpf_internal_load_pointer_neg_helper() the %edx (3rd argument of this func) had junk value instead of access size in bytes (1 or 2 or 4). Store size into %edx instead of %ecx (what original commit intended to do) Fixes: a998d4342337 ("bpf jit: Let the x86 jit handle negative offsets") Signed-off-by: Alexei Starovoitov Cc: Jan Seiffert Cc: Eric Dumazet Acked-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Luis Henriques --- arch/x86/net/bpf_jit.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/net/bpf_jit.S b/arch/x86/net/bpf_jit.S index 877b9a1..0149575 100644 --- a/arch/x86/net/bpf_jit.S +++ b/arch/x86/net/bpf_jit.S @@ -140,7 +140,7 @@ bpf_slow_path_byte_msh: push %r9; \ push SKBDATA; \ /* rsi already has offset */ \ - mov $SIZE,%ecx; /* size */ \ + mov $SIZE,%edx; /* size */ \ call bpf_internal_load_pointer_neg_helper; \ test %rax,%rax; \ pop SKBDATA; \ -- 1.9.1