From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756401AbZICUJP (ORCPT ); Thu, 3 Sep 2009 16:09:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756345AbZICUJN (ORCPT ); Thu, 3 Sep 2009 16:09:13 -0400 Received: from server1.wserver.cz ([82.113.45.157]:51036 "EHLO server1.wserver.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756322AbZICUIl (ORCPT ); Thu, 3 Sep 2009 16:08:41 -0400 From: Jiri Slaby To: oleg@redhat.com Cc: akpm@linux-foundation.org, mingo@redhat.com, linux-kernel@vger.kernel.org, Jiri Slaby Subject: [PATCH v2 8/8] FS: proc, make limits writable Date: Thu, 3 Sep 2009 22:08:44 +0200 Message-Id: <1252008524-5376-8-git-send-email-jirislaby@gmail.com> X-Mailer: git-send-email 1.6.3.3 In-Reply-To: <20090903174106.GC27161@redhat.com> References: <20090903174106.GC27161@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Allow writing strings such as Max core file size=0:unlimited to /proc//limits to change limits. Signed-off-by: Jiri Slaby --- fs/proc/base.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 files changed, 76 insertions(+), 2 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index ea71cae..0d9e3e9 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -129,6 +129,8 @@ struct pid_entry { NULL, &proc_single_file_operations, \ { .proc_show = show } ) +static ssize_t proc_info_read(struct file * file, char __user * buf, + size_t count, loff_t *ppos); /* * Count the number of hardlinks for the pid_entry table, excluding the . * and .. links. @@ -522,6 +524,74 @@ static int proc_pid_limits(struct task_struct *task, char *buffer) return count; } +static ssize_t limits_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); + char str[32 + 1 + 16 + 1 + 16 + 1], *delim, *next; + struct rlimit new_rlimit; + unsigned int i; + int ret; + + if (!task) { + count = -ESRCH; + goto out; + } + if (copy_from_user(str, buf, min(count, sizeof(str) - 1))) { + count = -EFAULT; + goto put_task; + } + + str[min(count, sizeof(str) - 1)] = 0; + + delim = strchr(str, '='); + if (!delim) { + count = -EINVAL; + goto put_task; + } + *delim++ = 0; /* for easy 'str' usage */ + new_rlimit.rlim_cur = simple_strtoul(delim, &next, 0); + if (*next != ':') { + if (strncmp(delim, "unlimited:", 10)) { + count = -EINVAL; + goto put_task; + } + new_rlimit.rlim_cur = RLIM_INFINITY; + next = delim + 9; /* move to ':' */ + } + delim = next + 1; + new_rlimit.rlim_max = simple_strtoul(delim, &next, 0); + if (*next != 0) { + if (strcmp(delim, "unlimited")) { + count = -EINVAL; + goto put_task; + } + new_rlimit.rlim_max = RLIM_INFINITY; + } + + for (i = 0; i < RLIM_NLIMITS; i++) + if (!strcmp(str, lnames[i].name)) + break; + if (i >= RLIM_NLIMITS) { + count = -EINVAL; + goto put_task; + } + + ret = setrlimit(task, i, &new_rlimit); + if (ret) + count = ret; + +put_task: + put_task_struct(task); +out: + return count; +} + +static const struct file_operations proc_pid_limits_operations = { + .read = proc_info_read, + .write = limits_write, +}; + #ifdef CONFIG_HAVE_ARCH_TRACEHOOK static int proc_pid_syscall(struct task_struct *task, char *buffer) { @@ -2501,7 +2571,9 @@ static const struct pid_entry tgid_base_stuff[] = { INF("auxv", S_IRUSR, proc_pid_auxv), ONE("status", S_IRUGO, proc_pid_status), ONE("personality", S_IRUSR, proc_pid_personality), - INF("limits", S_IRUSR, proc_pid_limits), + NOD("limits", S_IFREG|S_IRUSR|S_IWUSR, NULL, + &proc_pid_limits_operations, + { .proc_read = proc_pid_limits }), #ifdef CONFIG_SCHED_DEBUG REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), #endif @@ -2836,7 +2908,9 @@ static const struct pid_entry tid_base_stuff[] = { INF("auxv", S_IRUSR, proc_pid_auxv), ONE("status", S_IRUGO, proc_pid_status), ONE("personality", S_IRUSR, proc_pid_personality), - INF("limits", S_IRUSR, proc_pid_limits), + NOD("limits", S_IFREG|S_IRUSR|S_IWUSR, NULL, + &proc_pid_limits_operations, + { .proc_read = proc_pid_limits }), #ifdef CONFIG_SCHED_DEBUG REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), #endif -- 1.6.3.3