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54b909436e
The scnprintf() function silently truncates the printf() and returns
the number bytes that it was able to copy (not counting the NUL
terminator). Thus, the highest value it can return here is
"NAME_SIZE - 1" and the overflow check is dead code. Fix this by
using the snprintf() function which returns the number of bytes that
would have been copied if there was enough space and changing the
condition from "> NAME_SIZE" to ">= NAME_SIZE".
Fixes: 92589c986b ("rtc-proc: permit the /proc/driver/rtc device to use other devices")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/YJov/pcGmhLi2pEl@mwanda
92 lines
2.1 KiB
C
92 lines
2.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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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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#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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#define NAME_SIZE 10
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#if defined(CONFIG_RTC_HCTOSYS_DEVICE)
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static bool is_rtc_hctosys(struct rtc_device *rtc)
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{
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int size;
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char name[NAME_SIZE];
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size = snprintf(name, NAME_SIZE, "rtc%d", rtc->id);
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if (size >= NAME_SIZE)
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return false;
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return !strncmp(name, CONFIG_RTC_HCTOSYS_DEVICE, NAME_SIZE);
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}
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#else
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static bool is_rtc_hctosys(struct rtc_device *rtc)
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{
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return (rtc->id == 0);
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}
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#endif
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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: %ptRt\n"
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"rtc_date\t: %ptRd\n",
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&tm, &tm);
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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: %ptRt\n", &alrm.time);
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seq_printf(seq, "alrm_date\t: %ptRd\n", &alrm.time);
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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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seq_printf(seq, "update IRQ enabled\t: %s\n",
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(rtc->uie_rtctimer.enabled) ? "yes" : "no");
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seq_printf(seq, "periodic IRQ enabled\t: %s\n",
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(rtc->pie_enabled) ? "yes" : "no");
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seq_printf(seq, "periodic IRQ frequency\t: %d\n",
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rtc->irq_freq);
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seq_printf(seq, "max user IRQ frequency\t: %d\n",
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rtc->max_user_freq);
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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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void rtc_proc_add_device(struct rtc_device *rtc)
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{
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if (is_rtc_hctosys(rtc))
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proc_create_single_data("driver/rtc", 0, NULL, rtc_proc_show,
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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 (is_rtc_hctosys(rtc))
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remove_proc_entry("driver/rtc", NULL);
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}
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