Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757864AbXIERB2 (ORCPT ); Wed, 5 Sep 2007 13:01:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753967AbXIERBU (ORCPT ); Wed, 5 Sep 2007 13:01:20 -0400 Received: from mpc-26.sohonet.co.uk ([193.203.82.251]:33514 "EHLO moving-picture.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753690AbXIERBT (ORCPT ); Wed, 5 Sep 2007 13:01:19 -0400 Message-ID: <46DEE0C9.1000402@moving-picture.com> Date: Wed, 05 Sep 2007 18:00:57 +0100 From: James Pearson User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040524 X-Accept-Language: en-us, en MIME-Version: 1.0 To: "H. Peter Anvin" CC: Anton Arapov , Guy Streeter , linux-kernel@vger.kernel.org Subject: Re: 4096 byte limit to /proc/PID/environ ? References: <4474B7DB.8000304@moving-picture.com> <200605242029.k4OKTn9C031700@terminus.zytor.com> <447EF58C.6000605@moving-picture.com> <52dd17640708150954q798d137cn1b07739785917c5b@mail.gmail.com> <46C33700.1060605@zytor.com> <46D6CBED.4040301@moving-picture.com> <46DE6196.3050605@zytor.com> In-Reply-To: <46DE6196.3050605@zytor.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Disclaimer: This email and any attachments are confidential, may be legally X-Disclaimer: privileged and intended solely for the use of addressee. If you X-Disclaimer: are not the intended recipient of this message, any disclosure, X-Disclaimer: copying, distribution or any action taken in reliance on it is X-Disclaimer: strictly prohibited and may be unlawful. If you have received X-Disclaimer: this message in error, please notify the sender and delete all X-Disclaimer: copies from your system. X-Disclaimer: X-Disclaimer: Email may be susceptible to data corruption, interception and X-Disclaimer: unauthorised amendment, and we do not accept liability for any X-Disclaimer: such corruption, interception or amendment or the consequences X-Disclaimer: thereof. Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5084 Lines: 167 H. Peter Anvin wrote: > Anton Arapov wrote: > >> Hey guys, the future of this patch is important for me. What do you >> think, has this patch any chances to be committed to upstream? >> >> James Pearson writes: >> >>> H. Peter Anvin wrote: >>> There isn't that much that is duplicated - and there are also bits of >>> the /proc/PID/mem code that are not needed in this case, so I'm not >>> really sure if it is worth doing. >>> >>> I did submit a patch a few months ago - see: >>> >>> >> >> > > Looks reasonable to me, except for the one overlong line. > OK, here is the patch (without the long line) against 2.6.23-rc5 - what else needs to be done to get it committed? James Pearson --- ./fs/proc/base.c.dist 2007-09-01 07:08:24.000000000 +0100 +++ ./fs/proc/base.c 2007-09-05 14:08:15.762518000 +0100 @@ -199,27 +199,6 @@ static int proc_root_link(struct inode * (task->state == TASK_STOPPED || task->state == TASK_TRACED) && \ security_ptrace(current,task) == 0)) -static int proc_pid_environ(struct task_struct *task, char * buffer) -{ - int res = 0; - struct mm_struct *mm = get_task_mm(task); - if (mm) { - unsigned int len; - - res = -ESRCH; - if (!ptrace_may_attach(task)) - goto out; - - len = mm->env_end - mm->env_start; - if (len > PAGE_SIZE) - len = PAGE_SIZE; - res = access_process_vm(task, mm->env_start, buffer, len, 0); -out: - mmput(mm); - } - return res; -} - static int proc_pid_cmdline(struct task_struct *task, char * buffer) { int res = 0; @@ -658,6 +637,85 @@ static const struct file_operations proc .open = mem_open, }; +static ssize_t environ_read(struct file * file, char __user * buf, + size_t count, loff_t *ppos) +{ + struct task_struct *task = get_proc_task(file->f_dentry->d_inode); + char *page; + unsigned long src = *ppos; + int ret = -ESRCH; + struct mm_struct *mm; + size_t max_len; + + if (!task) + goto out_no_task; + + if (!ptrace_may_attach(task)) + goto out; + + ret = -ENOMEM; + page = (char *)__get_free_page(GFP_USER); + if (!page) + goto out; + + ret = 0; + + mm = get_task_mm(task); + if (!mm) + goto out_free; + + max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; + + while (count > 0) { + int this_len, retval; + + this_len = mm->env_end - (mm->env_start + src); + + if (this_len <= 0) { + break; + } + + if (this_len > max_len) + this_len = max_len; + + retval = access_process_vm(task, (mm->env_start + src), + page, this_len, 0); + + if (!ptrace_may_attach(task)) { + ret = -ESRCH; + break; + } + + if (retval <= 0) { + ret = retval; + break; + } + + if (copy_to_user(buf, page, retval)) { + ret = -EFAULT; + break; + } + + ret += retval; + src += retval; + buf += retval; + count -= retval; + } + *ppos = src; + + mmput(mm); +out_free: + free_page((unsigned long) page); +out: + put_task_struct(task); +out_no_task: + return ret; +} + +static const struct file_operations proc_environ_operations = { + .read = environ_read, +}; + static ssize_t oom_adjust_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { @@ -2048,7 +2106,7 @@ static const struct pid_entry tgid_base_ DIR("task", S_IRUGO|S_IXUGO, task), DIR("fd", S_IRUSR|S_IXUSR, fd), DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo), - INF("environ", S_IRUSR, pid_environ), + REG("environ", S_IRUSR, environ), INF("auxv", S_IRUSR, pid_auxv), INF("status", S_IRUGO, pid_status), #ifdef CONFIG_SCHED_DEBUG @@ -2335,7 +2393,7 @@ out_no_task: static const struct pid_entry tid_base_stuff[] = { DIR("fd", S_IRUSR|S_IXUSR, fd), DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo), - INF("environ", S_IRUSR, pid_environ), + REG("environ", S_IRUSR, environ), INF("auxv", S_IRUSR, pid_auxv), INF("status", S_IRUGO, pid_status), #ifdef CONFIG_SCHED_DEBUG - 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/