From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752784AbbGOHjn (ORCPT ); Wed, 15 Jul 2015 03:39:43 -0400 Received: from ozlabs.org ([103.22.144.67]:40328 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751598AbbGOHhZ (ORCPT ); Wed, 15 Jul 2015 03:37:25 -0400 From: Michael Ellerman To: Cc: , keescook@chromium.org, luto@amacapital.net, wad@chromium.org, strosake@linux.vnet.ibm.com, bogdan.purcareata@freescale.com Subject: [RFC PATCH 05/12] powerpc: Don't negate error in syscall_set_return_value() Date: Wed, 15 Jul 2015 17:37:07 +1000 Message-Id: <1436945834-26660-5-git-send-email-mpe@ellerman.id.au> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1436945834-26660-1-git-send-email-mpe@ellerman.id.au> References: <1436945834-26660-1-git-send-email-mpe@ellerman.id.au> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently the only caller of syscall_set_return_value() is seccomp filter, which is not enabled on powerpc. This means we have not noticed that our implementation of syscall_set_return_value() negates error, even though the value passed in is already negative. So remove the negation in syscall_set_return_value(), and expect the caller to do it like all other implementations do. Also add a comment about the ccr handling. Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/syscall.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/syscall.h b/arch/powerpc/include/asm/syscall.h index c6239dabcfb1..cabe90133e69 100644 --- a/arch/powerpc/include/asm/syscall.h +++ b/arch/powerpc/include/asm/syscall.h @@ -44,9 +44,15 @@ static inline void syscall_set_return_value(struct task_struct *task, struct pt_regs *regs, int error, long val) { + /* + * In the general case it's not obvious that we must deal with CCR + * here, as the syscall exit path will also do that for us. However + * there are some places, eg. the signal code, which check ccr to + * decide if the value in r3 is actually an error. + */ if (error) { regs->ccr |= 0x10000000L; - regs->gpr[3] = -error; + regs->gpr[3] = error; } else { regs->ccr &= ~0x10000000L; regs->gpr[3] = val; -- 2.1.0