From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35401) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aO3yp-0000sz-PE for qemu-devel@nongnu.org; Tue, 26 Jan 2016 08:48:24 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aO3yo-0004Dj-TE for qemu-devel@nongnu.org; Tue, 26 Jan 2016 08:48:23 -0500 Received: from mx1.redhat.com ([209.132.183.28]:32818) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aO3yo-0004De-Nu for qemu-devel@nongnu.org; Tue, 26 Jan 2016 08:48:22 -0500 From: Paolo Bonzini Date: Tue, 26 Jan 2016 14:47:09 +0100 Message-Id: <1453816041-36362-38-git-send-email-pbonzini@redhat.com> In-Reply-To: <1453816041-36362-1-git-send-email-pbonzini@redhat.com> References: <1453816041-36362-1-git-send-email-pbonzini@redhat.com> Subject: [Qemu-devel] [PULL 37/49] scripts/kvm/kvm_stat: Fix rlimit for unprivileged users List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Janosch Frank From: Janosch Frank Setting the hard limit as a unprivileged user either returns an error when it is higher than the current one or irreversibly sets it lower. Therefore we leave the hardlimit untouched as long as we don't need to raise it as this needs CAP_SYS_RESOURCE. This gives admins the possibility to run the script as an unprivileged user to increase security. Signed-off-by: Janosch Frank Message-Id: <1452525484-32309-32-git-send-email-frankja@linux.vnet.ibm.com> Signed-off-by: Paolo Bonzini --- scripts/kvm/kvm_stat | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/scripts/kvm/kvm_stat b/scripts/kvm/kvm_stat index 611f82a..2a1842e 100755 --- a/scripts/kvm/kvm_stat +++ b/scripts/kvm/kvm_stat @@ -434,11 +434,19 @@ class TracepointProvider(object): # The constant is needed as a buffer for python libs, std # streams and other files that the script opens. - rlimit = len(cpus) * len(self._fields) + 50 + newlim = len(cpus) * len(self._fields) + 50 try: - resource.setrlimit(resource.RLIMIT_NOFILE, (rlimit, rlimit)) + softlim_, hardlim = resource.getrlimit(resource.RLIMIT_NOFILE) + + if hardlim < newlim: + # Now we need CAP_SYS_RESOURCE, to increase the hard limit. + resource.setrlimit(resource.RLIMIT_NOFILE, (newlim, newlim)) + else: + # Raising the soft limit is sufficient. + resource.setrlimit(resource.RLIMIT_NOFILE, (newlim, hardlim)) + except ValueError: - sys.exit("NOFILE rlimit could not be raised to {0}".format(rlimit)) + sys.exit("NOFILE rlimit could not be raised to {0}".format(newlim)) for cpu in cpus: group = Group() -- 1.8.3.1