Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753930AbZK0XG4 (ORCPT ); Fri, 27 Nov 2009 18:06:56 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753824AbZK0XGM (ORCPT ); Fri, 27 Nov 2009 18:06:12 -0500 Received: from server1.wserver.cz ([82.113.45.157]:60454 "EHLO server1.wserver.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753231AbZK0XGE (ORCPT ); Fri, 27 Nov 2009 18:06:04 -0500 From: Jiri Slaby To: jirislaby@gmail.com Cc: mingo@elte.hu, nhorman@tuxdriver.com, sfr@canb.auug.org.au, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, marcin.slusarz@gmail.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, torvalds@linux-foundation.org, oleg@redhat.com Subject: [PATCH v3 06/27] core: allow setrlimit to non-current tasks Date: Sat, 28 Nov 2009 00:05:46 +0100 Message-Id: <1259363167-9347-6-git-send-email-jslaby@suse.cz> X-Mailer: git-send-email 1.6.5.3 In-Reply-To: <1259363167-9347-1-git-send-email-jslaby@suse.cz> References: <1259363167-9347-1-git-send-email-jslaby@suse.cz> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1760 Lines: 61 From: Jiri Slaby Add locking to allow setrlimit accept task parameter other than current. Namely, lock tasklist_lock for read and check whether the task structure has sighand non-null. Do all the signal processing under that lock still held. Signed-off-by: Jiri Slaby Cc: Oleg Nesterov --- kernel/sys.c | 11 ++++++++++- 1 files changed, 10 insertions(+), 1 deletions(-) diff --git a/kernel/sys.c b/kernel/sys.c index 398f9e1..3082eaf 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1238,6 +1238,7 @@ SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, #endif +/* make sure you are allowed to change @tsk limits before calling this */ int setrlimit(struct task_struct *tsk, unsigned int resource, struct rlimit *new_rlim) { @@ -1249,9 +1250,16 @@ int setrlimit(struct task_struct *tsk, unsigned int resource, if (resource == RLIMIT_NOFILE && new_rlim->rlim_max > sysctl_nr_open) return -EPERM; + /* protect tsk->signal and tsk->sighand from disappearing */ + read_lock(&tasklist_lock); + if (!tsk->sighand) { + retval = -ESRCH; + goto out; + } + retval = security_task_setrlimit(tsk, resource, new_rlim); if (retval) - return retval; + goto out; if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) { /* @@ -1286,6 +1294,7 @@ int setrlimit(struct task_struct *tsk, unsigned int resource, update_rlimit_cpu(tsk, new_rlim->rlim_cur); out: + read_unlock(&tasklist_lock); return retval; } -- 1.6.5.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/