From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47304) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aQbXG-000234-OZ for qemu-devel@nongnu.org; Tue, 02 Feb 2016 09:02:27 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aQbXA-0001qF-NE for qemu-devel@nongnu.org; Tue, 02 Feb 2016 09:02:26 -0500 Received: from e06smtp11.uk.ibm.com ([195.75.94.107]:42362) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aQbXA-0001q5-Dp for qemu-devel@nongnu.org; Tue, 02 Feb 2016 09:02:20 -0500 Received: from localhost by e06smtp11.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 2 Feb 2016 14:02:16 -0000 Received: from b06cxnps4076.portsmouth.uk.ibm.com (d06relay13.portsmouth.uk.ibm.com [9.149.109.198]) by d06dlp02.portsmouth.uk.ibm.com (Postfix) with ESMTP id A46B32190019 for ; Tue, 2 Feb 2016 14:02:01 +0000 (GMT) Received: from d06av08.portsmouth.uk.ibm.com (d06av08.portsmouth.uk.ibm.com [9.149.37.249]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u12E2EXD55509160 for ; Tue, 2 Feb 2016 14:02:14 GMT Received: from d06av08.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av08.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u12E2ELM032663 for ; Tue, 2 Feb 2016 07:02:14 -0700 References: <1453816041-36362-1-git-send-email-pbonzini@redhat.com> <1453816041-36362-15-git-send-email-pbonzini@redhat.com> From: Christian Borntraeger Message-ID: <56B0B6E6.9000306@de.ibm.com> Date: Tue, 2 Feb 2016 15:02:14 +0100 MIME-Version: 1.0 In-Reply-To: <1453816041-36362-15-git-send-email-pbonzini@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PULL 14/49] scripts/kvm/kvm_stat: Improve debugfs access checking List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini , qemu-devel@nongnu.org Cc: Janosch Frank On 01/26/2016 02:46 PM, Paolo Bonzini wrote: > From: Janosch Frank > > Access checking with F_OK was replaced with the better readable > os.path.exists(). > > On Linux exists() returns False when the user doesn't have sufficient > permissions for statting the directory. Therefore the error message > now states that sufficient rights are needed when the check fails. > > Also added check for /sys/kernel/debug/tracing/. > > Signed-off-by: Janosch Frank > Message-Id: <1452525484-32309-9-git-send-email-frankja@linux.vnet.ibm.com> > Signed-off-by: Paolo Bonzini > --- > scripts/kvm/kvm_stat | 16 +++++++++++----- > 1 file changed, 11 insertions(+), 5 deletions(-) > > diff --git a/scripts/kvm/kvm_stat b/scripts/kvm/kvm_stat > index 5ca09f4..6f0692d 100755 > --- a/scripts/kvm/kvm_stat > +++ b/scripts/kvm/kvm_stat > @@ -473,12 +473,18 @@ class Stats: > self.values[key] = (newval, newdelta) > return self.values > > -if not os.access('/sys/kernel/debug', os.F_OK): > - print 'Please enable CONFIG_DEBUG_FS in your kernel' > +if not os.path.exists('/sys/kernel/debug'): > + sys.stderr.write('Please enable CONFIG_DEBUG_FS in your kernel.') > sys.exit(1) > -if not os.access(PATH_DEBUGFS_KVM, os.F_OK): > - print "Please mount debugfs ('mount -t debugfs debugfs /sys/kernel/debug')" > - print "and ensure the kvm modules are loaded" > +if not os.path.exists(PATH_DEBUGFS_KVM): > + sys.stderr.write("Please make sure, that debugfs is mounted and " > + "readable by the current user:\n" > + "('mount -t debugfs debugfs /sys/kernel/debug')\n" > + "Also ensure, that the kvm modules are loaded.\n") > + sys.exit(1) > +if not os.path.exists(PATH_DEBUGFS_TRACING): > + sys.stderr.write("Please make {0} readable by the current user.\n" > + .format(PATH_DEBUGFS_TRACING)) > sys.exit(1) Hmmm, this now bails out on kernels without CONFIG_TRACING. It could still fall back to the normal kvm_stat values. What about just removing the last sys.exit(1) and make this a warning that stays for a second or so?