From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34320) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YuOVi-0000pN-ML for qemu-devel@nongnu.org; Mon, 18 May 2015 13:07:28 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YuOVf-0008HH-Ej for qemu-devel@nongnu.org; Mon, 18 May 2015 13:07:26 -0400 Received: from cantor2.suse.de ([195.135.220.15]:58572 helo=mx2.suse.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YuOVf-0008GM-82 for qemu-devel@nongnu.org; Mon, 18 May 2015 13:07:23 -0400 Message-ID: <555A1C49.4030303@suse.de> Date: Mon, 18 May 2015 19:07:21 +0200 From: Alexander Graf MIME-Version: 1.0 References: <1431818883-14944-1-git-send-email-aurelien@aurel32.net> <555A06DC.7030608@twiddle.net> In-Reply-To: <555A06DC.7030608@twiddle.net> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] target-s390x: fix CC computation for EX instruction List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Richard Henderson , Aurelien Jarno , qemu-devel@nongnu.org On 05/18/2015 05:35 PM, Richard Henderson wrote: > On 05/16/2015 04:28 PM, Aurelien Jarno wrote: >> Commit 7a6c7067f optimized CC computation by only saving cc_op before >> calling helpers as they either don't touch the CC or generate a new >> static value. This however doesn't work for the EX instruction as the >> helper changes or not the CC value depending on the actual executed >> instruction (e.g. MVC vs CLC). >> >> This patches force a CC computation before calling the helper. This >> fixes random memory corruption occuring in guests. >> >> Cc: Richard Henderson >> Cc: Alexander Graf >> Signed-off-by: Aurelien Jarno >> --- >> target-s390x/translate.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/target-s390x/translate.c b/target-s390x/translate.c >> index 80e3a54..10522df 100644 >> --- a/target-s390x/translate.c >> +++ b/target-s390x/translate.c >> @@ -2095,7 +2095,7 @@ static ExitStatus op_ex(DisasContext *s, DisasOps *o) >> TCGv_i64 tmp; >> >> update_psw_addr(s); >> - update_cc_op(s); >> + gen_op_calc_cc(s); >> >> tmp = tcg_const_i64(s->next_pc); >> gen_helper_ex(cc_op, cpu_env, cc_op, o->in1, o->in2, tmp); > I agree this is a bug, and the right fix. > > You can also remove the set_cc_static at the end of op_ex, since that's done by > gen_op_calc_cc. Thanks, I applied the patch and did the change to remove set_cc_static from op_ex locally. Alex