Revision 0a4c56c80f90797e9b9f8426c6aae4c0cf1c9785 authored by Linus Torvalds on 29 August 2020, 20:50:56 UTC, committed by Linus Torvalds on 29 August 2020, 20:50:56 UTC
Commit ef91bb196b0d ("kernel.h: Silence sparse warning in lower_32_bits") caused new warnings to show in the fsldma driver, but that commit was not to blame: it only exposed some very incorrect code that tried to take the low 32 bits of an address. That made no sense for multiple reasons, the most notable one being that that code was intentionally limited to only 32-bit ppc builds, so "only low 32 bits of an address" was completely nonsensical. There were no high bits to mask off to begin with. But even more importantly fropm a correctness standpoint, turning the address into an integer then caused the subsequent address arithmetic to be completely wrong too, and the "+1" actually incremented the address by one, rather than by four. Which again was incorrect, since the code was reading two 32-bit values and trying to make a 64-bit end result of it all. Surprisingly, the iowrite64() did not suffer from the same odd and incorrect model. This code has never worked, but it's questionable whether anybody cared: of the two users that actually read the 64-bit value (by way of some C preprocessor hackery and eventually the 'get_cdar()' inline function), one of them explicitly ignored the value, and the other one might just happen to work despite the incorrect value being read. This patch at least makes it not fail the build any more, and makes the logic superficially sane. Whether it makes any difference to the code _working_ or not shall remain a mystery. Compile-tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent e77aee1
misc.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Written 1992,1993 by Werner Almesberger
* 22/11/2000 - Fixed fat_date_unix2dos for dates earlier than 01/01/1980
* and date_dos2unix for date==0 by Igor Zhbanov(bsg@uniyar.ac.ru)
* Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
*/
#include <linux/time.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/buffer_head.h>
#include "exfat_raw.h"
#include "exfat_fs.h"
/*
* exfat_fs_error reports a file system problem that might indicate fa data
* corruption/inconsistency. Depending on 'errors' mount option the
* panic() is called, or error message is printed FAT and nothing is done,
* or filesystem is remounted read-only (default behavior).
* In case the file system is remounted read-only, it can be made writable
* again by remounting it.
*/
void __exfat_fs_error(struct super_block *sb, int report, const char *fmt, ...)
{
struct exfat_mount_options *opts = &EXFAT_SB(sb)->options;
va_list args;
struct va_format vaf;
if (report) {
va_start(args, fmt);
vaf.fmt = fmt;
vaf.va = &args;
exfat_err(sb, "error, %pV", &vaf);
va_end(args);
}
if (opts->errors == EXFAT_ERRORS_PANIC) {
panic("exFAT-fs (%s): fs panic from previous error\n",
sb->s_id);
} else if (opts->errors == EXFAT_ERRORS_RO && !sb_rdonly(sb)) {
sb->s_flags |= SB_RDONLY;
exfat_err(sb, "Filesystem has been set read-only");
}
}
/*
* exfat_msg() - print preformated EXFAT specific messages.
* All logs except what uses exfat_fs_error() should be written by exfat_msg()
*/
void exfat_msg(struct super_block *sb, const char *level, const char *fmt, ...)
{
struct va_format vaf;
va_list args;
va_start(args, fmt);
vaf.fmt = fmt;
vaf.va = &args;
/* level means KERN_ pacility level */
printk("%sexFAT-fs (%s): %pV\n", level, sb->s_id, &vaf);
va_end(args);
}
#define SECS_PER_MIN (60)
#define TIMEZONE_SEC(x) ((x) * 15 * SECS_PER_MIN)
static void exfat_adjust_tz(struct timespec64 *ts, u8 tz_off)
{
if (tz_off <= 0x3F)
ts->tv_sec -= TIMEZONE_SEC(tz_off);
else /* 0x40 <= (tz_off & 0x7F) <=0x7F */
ts->tv_sec += TIMEZONE_SEC(0x80 - tz_off);
}
/* Convert a EXFAT time/date pair to a UNIX date (seconds since 1 1 70). */
void exfat_get_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
u8 tz, __le16 time, __le16 date, u8 time_cs)
{
u16 t = le16_to_cpu(time);
u16 d = le16_to_cpu(date);
ts->tv_sec = mktime64(1980 + (d >> 9), d >> 5 & 0x000F, d & 0x001F,
t >> 11, (t >> 5) & 0x003F, (t & 0x001F) << 1);
/* time_cs field represent 0 ~ 199cs(1990 ms) */
if (time_cs) {
ts->tv_sec += time_cs / 100;
ts->tv_nsec = (time_cs % 100) * 10 * NSEC_PER_MSEC;
} else
ts->tv_nsec = 0;
if (tz & EXFAT_TZ_VALID)
/* Adjust timezone to UTC0. */
exfat_adjust_tz(ts, tz & ~EXFAT_TZ_VALID);
else
/* Convert from local time to UTC using time_offset. */
ts->tv_sec -= sbi->options.time_offset * SECS_PER_MIN;
}
/* Convert linear UNIX date to a EXFAT time/date pair. */
void exfat_set_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
u8 *tz, __le16 *time, __le16 *date, u8 *time_cs)
{
struct tm tm;
u16 t, d;
time64_to_tm(ts->tv_sec, 0, &tm);
t = (tm.tm_hour << 11) | (tm.tm_min << 5) | (tm.tm_sec >> 1);
d = ((tm.tm_year - 80) << 9) | ((tm.tm_mon + 1) << 5) | tm.tm_mday;
*time = cpu_to_le16(t);
*date = cpu_to_le16(d);
/* time_cs field represent 0 ~ 199cs(1990 ms) */
if (time_cs)
*time_cs = (tm.tm_sec & 1) * 100 +
ts->tv_nsec / (10 * NSEC_PER_MSEC);
/*
* Record 00h value for OffsetFromUtc field and 1 value for OffsetValid
* to indicate that local time and UTC are the same.
*/
*tz = EXFAT_TZ_VALID;
}
/*
* The timestamp for access_time has double seconds granularity.
* (There is no 10msIncrement field for access_time unlike create/modify_time)
* atime also has only a 2-second resolution.
*/
void exfat_truncate_atime(struct timespec64 *ts)
{
ts->tv_sec = round_down(ts->tv_sec, 2);
ts->tv_nsec = 0;
}
u16 exfat_calc_chksum16(void *data, int len, u16 chksum, int type)
{
int i;
u8 *c = (u8 *)data;
for (i = 0; i < len; i++, c++) {
if (unlikely(type == CS_DIR_ENTRY && (i == 2 || i == 3)))
continue;
chksum = ((chksum << 15) | (chksum >> 1)) + *c;
}
return chksum;
}
u32 exfat_calc_chksum32(void *data, int len, u32 chksum, int type)
{
int i;
u8 *c = (u8 *)data;
for (i = 0; i < len; i++, c++) {
if (unlikely(type == CS_BOOT_SECTOR &&
(i == 106 || i == 107 || i == 112)))
continue;
chksum = ((chksum << 31) | (chksum >> 1)) + *c;
}
return chksum;
}
void exfat_update_bh(struct buffer_head *bh, int sync)
{
set_buffer_uptodate(bh);
mark_buffer_dirty(bh);
if (sync)
sync_dirty_buffer(bh);
}
int exfat_update_bhs(struct buffer_head **bhs, int nr_bhs, int sync)
{
int i, err = 0;
for (i = 0; i < nr_bhs; i++) {
set_buffer_uptodate(bhs[i]);
mark_buffer_dirty(bhs[i]);
if (sync)
write_dirty_buffer(bhs[i], 0);
}
for (i = 0; i < nr_bhs && sync; i++) {
wait_on_buffer(bhs[i]);
if (!err && !buffer_uptodate(bhs[i]))
err = -EIO;
}
return err;
}
void exfat_chain_set(struct exfat_chain *ec, unsigned int dir,
unsigned int size, unsigned char flags)
{
ec->dir = dir;
ec->size = size;
ec->flags = flags;
}
void exfat_chain_dup(struct exfat_chain *dup, struct exfat_chain *ec)
{
return exfat_chain_set(dup, ec->dir, ec->size, ec->flags);
}
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