From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42266) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YuOuL-0001Wt-IT for qemu-devel@nongnu.org; Mon, 18 May 2015 13:32:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YuOuK-0003Rr-ID for qemu-devel@nongnu.org; Mon, 18 May 2015 13:32:53 -0400 Received: from hall.aurel32.net ([2001:bc8:30d7:101::1]:32780) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YuOuK-0003Rj-CZ for qemu-devel@nongnu.org; Mon, 18 May 2015 13:32:52 -0400 Date: Mon, 18 May 2015 19:32:49 +0200 From: Aurelien Jarno Message-ID: <20150518173249.GC28272@aurel32.net> References: <1431818883-14944-1-git-send-email-aurelien@aurel32.net> <555A06DC.7030608@twiddle.net> <555A1C49.4030303@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <555A1C49.4030303@suse.de> Sender: Aurelien Jarno 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: Alexander Graf Cc: qemu-devel@nongnu.org, Richard Henderson On 2015-05-18 19:07, Alexander Graf wrote: > 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. Thanks! Aurelien -- Aurelien Jarno GPG: 4096R/1DDD8C9B aurelien@aurel32.net http://www.aurel32.net