From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e28smtp08.in.ibm.com (e28smtp08.in.ibm.com [122.248.162.8]) (using TLSv1 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 1994E1A0ADA for ; Thu, 29 Oct 2015 18:07:31 +1100 (AEDT) Received: from /spool/local by e28smtp08.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 29 Oct 2015 12:37:27 +0530 Received: from d28relay03.in.ibm.com (d28relay03.in.ibm.com [9.184.220.60]) by d28dlp03.in.ibm.com (Postfix) with ESMTP id ADE1B125805D for ; Thu, 29 Oct 2015 12:37:19 +0530 (IST) Received: from d28av04.in.ibm.com (d28av04.in.ibm.com [9.184.220.66]) by d28relay03.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t9T77LDY18808898 for ; Thu, 29 Oct 2015 12:37:22 +0530 Received: from d28av04.in.ibm.com (localhost [127.0.0.1]) by d28av04.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t9T77JAO016376 for ; Thu, 29 Oct 2015 12:37:20 +0530 Message-ID: <5631C5A6.4040101@linux.vnet.ibm.com> Date: Thu, 29 Oct 2015 12:37:18 +0530 From: Hemant Kumar MIME-Version: 1.0 To: Alexander Yarygin CC: David Ahern , linux-kernel@vger.kernel.org, srikar@linux.vnet.ibm.com, acme@kernel.org, borntraeger@de.ibm.com, mingo@redhat.com, paulus@samba.org, scottwood@freescale.com, naveen.n.rao@linux.vnet.ibm.com, sukadev@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH v9 1/4] perf, kvm/{x86, s390}: Remove dependency on uapi/kvm_perf.h References: <1444184711-8559-1-git-send-email-hemant@linux.vnet.ibm.com> <5615443F.7030909@gmail.com> <561639B8.8040407@linux.vnet.ibm.com> <8737wuk9g6.fsf@linux.vnet.ibm.com> In-Reply-To: <8737wuk9g6.fsf@linux.vnet.ibm.com> Content-Type: text/plain; charset=windows-1252; format=flowed List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 10/29/2015 02:17 AM, Alexander Yarygin wrote: > Hemant Kumar writes: > >> Hi David, >> >> >> On 10/07/2015 09:41 PM, David Ahern wrote: >>> On 10/6/15 8:25 PM, Hemant Kumar wrote: >>>> @@ -358,7 +357,12 @@ static bool handle_end_event(struct >>>> perf_kvm_stat *kvm, >>>> time_diff = sample->time - time_begin; >>>> >>>> if (kvm->duration && time_diff > kvm->duration) { >>>> - char decode[DECODE_STR_LEN]; >>>> + char *decode = zalloc(decode_str_len); >>> decode can still be a stack variable even with variable length. >>> >> Yeah, we can do that. But, I am not sure whether its a standard way. >> > Well, I also vote for making them variable length arrays. I guess that > wouldn't be a problem because the "variable" here is actually a constant > compile time value, even if it's extern. > > But if people are strongly against it, as an alternative I can suggest > to move the 'char *decode' variable to the perf_kvm_stat structure, > allocate it once e.g. in kvm_events_report() and just write to it via > decode_key(). If I'm not mistaken, we always write \0 trimmed strings, > so garbage after \0 shouldn't be a problem. I agree. We can do that. But, since this is a small change (making the variable a constant compile time value rather than the array being a run time value), we can do that subsequently. For now, we can go with the current patchset. > It's not a real problem anyway :) Yeah. > For s390 parts: > Acked-by: Alexander Yarygin Thanks a lot for testing and acking it. :) >>> -----8<----- >>> >>>> @@ -575,7 +581,7 @@ static void show_timeofday(void) >>>> >>>> static void print_result(struct perf_kvm_stat *kvm) >>>> { >>>> - char decode[DECODE_STR_LEN]; >>>> + char *decode; >>> and a stack variable here too. >>> >> Same here. >> >>> David >>> _______________________________________________ >>> Linuxppc-dev mailing list >>> Linuxppc-dev@lists.ozlabs.org >>> https://lists.ozlabs.org/listinfo/linuxppc-dev -- Thanks, Hemant Kumar