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![Alexey Dobriyan](/assets/img/avatar_default.png)
Setting ->owner as done currently (pde->owner = THIS_MODULE) is racy as correctly noted at bug #12454. Someone can lookup entry with NULL ->owner, thus not pinning enything, and release it later resulting in module refcount underflow. We can keep ->owner and supply it at registration time like ->proc_fops and ->data. But this leaves ->owner as easy-manipulative field (just one C assignment) and somebody will forget to unpin previous/pin current module when switching ->owner. ->proc_fops is declared as "const" which should give some thoughts. ->read_proc/->write_proc were just fixed to not require ->owner for protection. rmmod'ed directories will be empty and return "." and ".." -- no harm. And directories with tricky enough readdir and lookup shouldn't be modular. We definitely don't want such modular code. Removing ->owner will also make PDE smaller. So, let's nuke it. Kudos to Jeff Layton for reminding about this, let's say, oversight. http://bugzilla.kernel.org/show_bug.cgi?id=12454 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
116 lines
2.8 KiB
C
116 lines
2.8 KiB
C
/*
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* RTC subsystem, proc interface
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*
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* Copyright (C) 2005-06 Tower Technologies
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* Author: Alessandro Zummo <a.zummo@towertech.it>
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*
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* based on arch/arm/common/rtctime.c
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/rtc.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include "rtc-core.h"
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static int rtc_proc_show(struct seq_file *seq, void *offset)
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{
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int err;
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struct rtc_device *rtc = seq->private;
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const struct rtc_class_ops *ops = rtc->ops;
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struct rtc_wkalrm alrm;
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struct rtc_time tm;
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err = rtc_read_time(rtc, &tm);
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if (err == 0) {
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seq_printf(seq,
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"rtc_time\t: %02d:%02d:%02d\n"
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"rtc_date\t: %04d-%02d-%02d\n",
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tm.tm_hour, tm.tm_min, tm.tm_sec,
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tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);
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}
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err = rtc_read_alarm(rtc, &alrm);
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if (err == 0) {
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seq_printf(seq, "alrm_time\t: ");
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if ((unsigned int)alrm.time.tm_hour <= 24)
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seq_printf(seq, "%02d:", alrm.time.tm_hour);
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else
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seq_printf(seq, "**:");
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if ((unsigned int)alrm.time.tm_min <= 59)
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seq_printf(seq, "%02d:", alrm.time.tm_min);
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else
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seq_printf(seq, "**:");
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if ((unsigned int)alrm.time.tm_sec <= 59)
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seq_printf(seq, "%02d\n", alrm.time.tm_sec);
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else
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seq_printf(seq, "**\n");
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seq_printf(seq, "alrm_date\t: ");
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if ((unsigned int)alrm.time.tm_year <= 200)
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seq_printf(seq, "%04d-", alrm.time.tm_year + 1900);
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else
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seq_printf(seq, "****-");
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if ((unsigned int)alrm.time.tm_mon <= 11)
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seq_printf(seq, "%02d-", alrm.time.tm_mon + 1);
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else
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seq_printf(seq, "**-");
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if (alrm.time.tm_mday && (unsigned int)alrm.time.tm_mday <= 31)
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seq_printf(seq, "%02d\n", alrm.time.tm_mday);
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else
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seq_printf(seq, "**\n");
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seq_printf(seq, "alarm_IRQ\t: %s\n",
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alrm.enabled ? "yes" : "no");
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seq_printf(seq, "alrm_pending\t: %s\n",
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alrm.pending ? "yes" : "no");
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}
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seq_printf(seq, "24hr\t\t: yes\n");
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if (ops->proc)
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ops->proc(rtc->dev.parent, seq);
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return 0;
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}
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static int rtc_proc_open(struct inode *inode, struct file *file)
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{
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struct rtc_device *rtc = PDE(inode)->data;
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if (!try_module_get(THIS_MODULE))
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return -ENODEV;
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return single_open(file, rtc_proc_show, rtc);
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}
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static int rtc_proc_release(struct inode *inode, struct file *file)
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{
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int res = single_release(inode, file);
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module_put(THIS_MODULE);
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return res;
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}
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static const struct file_operations rtc_proc_fops = {
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.open = rtc_proc_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = rtc_proc_release,
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};
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void rtc_proc_add_device(struct rtc_device *rtc)
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{
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if (rtc->id == 0)
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proc_create_data("driver/rtc", 0, NULL, &rtc_proc_fops, rtc);
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}
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void rtc_proc_del_device(struct rtc_device *rtc)
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{
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if (rtc->id == 0)
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remove_proc_entry("driver/rtc", NULL);
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}
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