Hi Andre,
while most of the ide code seems to be carefully designed to handle
jiffies wrap correctly, for ease of audit as well as future
maintainability I have changed all comparisons to use the
time_{before,after} macros. Also, a few places actually seem to get
the wrap wrong.
I did not yet CC Linus and Alan on this patch as I did on the others,
since it is a little bit larger, and some of the jiffies uses are
a bit tricky.
Btw.: I cannot figure out what read_timer in ide.c is supposed to do,
but it's use of jiffies is probably broken if it is intended to be
anything else than a random number generator.
Tim
--- /usr/src/linux-2.4.14-pre6/drivers/ide/ide-cd.c Wed Oct 31 23:06:19 2001
+++ drivers/ide/ide-cd.c Tue Nov 6 21:10:57 2001
@@ -1147,7 +1147,7 @@
return startstop;
CDROM_CONFIG_FLAGS(drive)->seeking = 1;
- if (retry && jiffies - info->start_seek > IDECD_SEEK_TIMER) {
+ if (retry && time_after(jiffies, info->start_seek + IDECD_SEEK_TIMER)) {
if (--retry == 0) {
/*
* this condition is far too common, to bother
@@ -1700,11 +1700,10 @@
case WRITE:
case READ: {
if (CDROM_CONFIG_FLAGS(drive)->seeking) {
- unsigned long elpased = jiffies - info->start_seek;
int stat = GET_STAT();
if ((stat & SEEK_STAT) != SEEK_STAT) {
- if (elpased < IDECD_SEEK_TIMEOUT) {
+ if (time_before(jiffies, info->start_seek + IDECD_SEEK_TIMEOUT) {
ide_stall_queue(drive, IDECD_SEEK_TIMER);
return ide_stopped;
}
--- /usr/src/linux-2.4.14-pre6/drivers/ide/ide-features.c Fri Feb 9 20:40:02 2001
+++ drivers/ide/ide-features.c Tue Nov 6 21:13:29 2001
@@ -173,7 +173,7 @@
OUT_BYTE(WIN_IDENTIFY, IDE_COMMAND_REG);
timeout = jiffies + WAIT_WORSTCASE;
do {
- if (0 < (signed long)(jiffies - timeout)) {
+ if (time_after(jiffies, timeout)) {
SELECT_MASK(HWIF(drive), drive, 0);
return 0; /* drive timed-out */
}
@@ -321,7 +321,7 @@
ide__sti(); /* local CPU only -- for jiffies */
timeout = jiffies + WAIT_CMD;
while ((stat = GET_STAT()) & BUSY_STAT) {
- if (0 < (signed long)(jiffies - timeout))
+ if (time_after(jiffies, timeout))
break;
}
__restore_flags(flags); /* local CPU only */
--- /usr/src/linux-2.4.14-pre6/drivers/ide/ide-probe.c Thu Oct 11 18:14:32 2001
+++ drivers/ide/ide-probe.c Tue Nov 6 21:15:57 2001
@@ -226,7 +226,7 @@
timeout = ((cmd == WIN_IDENTIFY) ? WAIT_WORSTCASE : WAIT_PIDENTIFY) / 2;
timeout += jiffies;
do {
- if (0 < (signed long)(jiffies - timeout)) {
+ if (time_after(jiffies, timeout)) {
return 1; /* drive timed-out */
}
ide_delay_50ms(); /* give drive a breather */
@@ -370,7 +370,7 @@
OUT_BYTE(EXABYTE_ENABLE_NEST, IDE_COMMAND_REG);
timeout = jiffies + WAIT_WORSTCASE;
do {
- if (jiffies > timeout) {
+ if (time_after(jiffies, timeout)) {
printk("failed (timeout)\n");
return;
}
@@ -548,7 +548,7 @@
do {
ide_delay_50ms();
stat = IN_BYTE(hwif->io_ports[IDE_STATUS_OFFSET]);
- } while ((stat & BUSY_STAT) && 0 < (signed long)(timeout - jiffies));
+ } while ((stat & BUSY_STAT) && time_after(timeout, jiffies));
}
__restore_flags(flags); /* local CPU only */
--- /usr/src/linux-2.4.14-pre6/drivers/ide/ide-proc.c Fri Sep 7 18:28:38 2001
+++ drivers/ide/ide-proc.c Tue Nov 6 21:17:07 2001
@@ -192,7 +192,7 @@
cli(); /* all CPUs; ensure all writes are done together */
while (mygroup->busy || (mategroup && mategroup->busy)) {
sti(); /* all CPUs */
- if (0 < (signed long)(jiffies - timeout)) {
+ if (time_after(jiffies, timeout)) {
printk("/proc/ide/%s/config: channel(s) busy, cannot write\n", hwif->name);
restore_flags(flags); /* all CPUs */
return -EBUSY;
--- /usr/src/linux-2.4.14-pre6/drivers/ide/ide-tape.c Mon Aug 13 23:56:19 2001
+++ drivers/ide/ide-tape.c Tue Nov 6 21:38:02 2001
@@ -2418,26 +2418,26 @@
idetape_tape_t *tape = drive->driver_data;
int full = 125, empty = 75;
- if (jiffies > tape->controlled_pipeline_head_time + 120 * HZ) {
+ if (time_after(jiffies, tape->controlled_pipeline_head_time + 120 * HZ)) {
tape->controlled_previous_pipeline_head = tape->controlled_last_pipeline_head;
tape->controlled_previous_head_time = tape->controlled_pipeline_head_time;
tape->controlled_last_pipeline_head = tape->pipeline_head;
tape->controlled_pipeline_head_time = jiffies;
}
- if (jiffies > tape->controlled_pipeline_head_time + 60 * HZ)
+ if (time_after(jiffies, tape->controlled_pipeline_head_time + 60 * HZ))
tape->controlled_pipeline_head_speed = (tape->pipeline_head - tape->controlled_last_pipeline_head) * 32 * HZ / (jiffies - tape->controlled_pipeline_head_time);
- else if (jiffies > tape->controlled_previous_head_time)
+ else if (time_after(jiffies, tape->controlled_previous_head_time))
tape->controlled_pipeline_head_speed = (tape->pipeline_head - tape->controlled_previous_pipeline_head) * 32 * HZ / (jiffies - tape->controlled_previous_head_time);
if (tape->nr_pending_stages < tape->max_stages /*- 1 */) { /* -1 for read mode error recovery */
- if (jiffies > tape->uncontrolled_previous_head_time + 10 * HZ) {
+ if (time_after(jiffies, tape->uncontrolled_previous_head_time + 10 * HZ)) {
tape->uncontrolled_pipeline_head_time = jiffies;
tape->uncontrolled_pipeline_head_speed = (tape->pipeline_head - tape->uncontrolled_previous_pipeline_head) * 32 * HZ / (jiffies - tape->uncontrolled_previous_head_time);
}
} else {
tape->uncontrolled_previous_head_time = jiffies;
tape->uncontrolled_previous_pipeline_head = tape->pipeline_head;
- if (jiffies > tape->uncontrolled_pipeline_head_time + 30 * HZ) {
+ if (time_after(jiffies, tape->uncontrolled_pipeline_head_time + 30 * HZ)) {
tape->uncontrolled_pipeline_head_time = jiffies;
}
}
@@ -2500,9 +2500,9 @@
tape->insert_time = jiffies;
tape->insert_size = 0;
}
- if (jiffies > tape->insert_time)
+ if (time_after(jiffies, tape->insert_time))
tape->insert_speed = tape->insert_size / 1024 * HZ / (jiffies - tape->insert_time);
- if (jiffies - tape->avg_time >= HZ) {
+ if (time_after_eq(jiffies, tape->avg_time + HZ)) {
tape->avg_speed = tape->avg_size * HZ / (jiffies - tape->avg_time) / 1024;
tape->avg_size = 0;
tape->avg_time = jiffies;
@@ -2680,11 +2680,11 @@
tape->reads_since_buffer_fill = 0;
tape->last_buffer_fill = jiffies;
idetape_queue_onstream_buffer_fill(drive);
- if (jiffies > tape->insert_time)
+ if (time_after(jiffies, tape->insert_time))
tape->insert_speed = tape->insert_size / 1024 * HZ / (jiffies - tape->insert_time);
return ide_stopped;
}
- if (jiffies > tape->insert_time)
+ if (time_after(jiffies, tape->insert_time))
tape->insert_speed = tape->insert_size / 1024 * HZ / (jiffies - tape->insert_time);
calculate_speeds(drive);
if (tape->onstream && tape->max_frames &&
@@ -2716,7 +2716,7 @@
tape->dsc_polling_start = jiffies;
tape->dsc_polling_frequency = tape->best_dsc_rw_frequency;
tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
- } else if ((signed long) (jiffies - tape->dsc_timeout) > 0) {
+ } else if (time_after(jiffies, tape->dsc_timeout)) {
printk (KERN_ERR "ide-tape: %s: DSC timeout\n", tape->name);
if (rq->cmd == IDETAPE_PC_RQ2) {
idetape_media_access_finished (drive);
@@ -2724,7 +2724,7 @@
} else {
return ide_do_reset (drive);
}
- } else if (jiffies - tape->dsc_polling_start > IDETAPE_DSC_MA_THRESHOLD)
+ } else if (time_after(jiffies, tape->dsc_polling_start + IDETAPE_DSC_MA_THRESHOLD))
tape->dsc_polling_frequency = IDETAPE_DSC_MA_SLOW;
idetape_postpone_request (drive);
return ide_stopped;
@@ -2740,7 +2740,7 @@
if (tape->onstream) {
if (tape->cur_frames - tape->reads_since_buffer_fill <= 0)
tape->req_buffer_fill = 1;
- if (jiffies > tape->last_buffer_fill + 5 * HZ / 100)
+ if (time_after(jiffies, tape->last_buffer_fill + 5 * HZ / 100))
tape->req_buffer_fill = 1;
}
pc = idetape_next_pc_storage (drive);
@@ -2756,7 +2756,7 @@
if (tape->onstream) {
if (tape->cur_frames + tape->writes_since_buffer_fill >= tape->max_frames)
tape->req_buffer_fill = 1;
- if (jiffies > tape->last_buffer_fill + 5 * HZ / 100)
+ if (time_after(jiffies, tape->last_buffer_fill + 5 * HZ / 100))
tape->req_buffer_fill = 1;
calculate_speeds(drive);
}
@@ -3214,7 +3214,7 @@
* Wait for the tape to become ready
*/
timeout += jiffies;
- while (jiffies < timeout) {
+ while (time_before(jiffies, timeout)) {
idetape_create_test_unit_ready_cmd(&pc);
if (!__idetape_queue_pc_tail(drive, &pc))
return 0;
--- /usr/src/linux-2.4.14-pre6/drivers/ide/ide.c Wed Oct 31 23:06:19 2001
+++ drivers/ide/ide.c Tue Nov 6 22:36:20 2001
@@ -654,7 +654,7 @@
if (OK_STAT(stat=GET_STAT(), 0, BUSY_STAT)) {
printk("%s: ATAPI reset complete\n", drive->name);
} else {
- if (0 < (signed long)(hwgroup->poll_timeout - jiffies)) {
+ if (time_before(jiffies, hwgroup->poll_timeout)) {
ide_set_handler (drive, &atapi_reset_pollfunc, HZ/20, NULL);
return ide_started; /* continue polling */
}
@@ -679,7 +679,7 @@
byte tmp;
if (!OK_STAT(tmp=GET_STAT(), 0, BUSY_STAT)) {
- if (0 < (signed long)(hwgroup->poll_timeout - jiffies)) {
+ if (time_before(jiffies, hwgroup->poll_timeout)) {
ide_set_handler (drive, &reset_pollfunc, HZ/20, NULL);
return ide_started; /* continue polling */
}
@@ -1111,7 +1111,7 @@
ide__sti(); /* local CPU only */
timeout += jiffies;
while ((stat = GET_STAT()) & BUSY_STAT) {
- if (0 < (signed long)(jiffies - timeout)) {
+ if (time_after(jiffies, timeout)) {
__restore_flags(flags); /* local CPU only */
*startstop = ide_error(drive, "status timeout", stat);
return 1;
@@ -1300,7 +1300,7 @@
best = NULL;
drive = hwgroup->drive;
do {
- if (!list_empty(&drive->queue.queue_head) && (!drive->sleep || 0 <= (signed long)(jiffies - drive->sleep))) {
+ if (!list_empty(&drive->queue.queue_head) && (!drive->sleep || time_after_eq(jiffies, drive->sleep))) {
if (!best
|| (drive->sleep && (!best->sleep || 0 < (signed long)(best->sleep - drive->sleep)))
|| (!best->sleep && 0 < (signed long)(WAKEUP(best) - WAKEUP(drive))))
@@ -1395,7 +1395,7 @@
* play fairly with us, just in case there are big differences
* in relative throughputs.. don't want to hog the cpu too much.
*/
- if (0 < (signed long)(jiffies + WAIT_MIN_SLEEP - sleep))
+ if (time_before(sleep, jiffies + WAIT_MIN_SLEEP))
sleep = jiffies + WAIT_MIN_SLEEP;
#if 1
if (timer_pending(&hwgroup->timer))
@@ -1634,7 +1634,7 @@
/* Try to not flood the console with msgs */
static unsigned long last_msgtime, count;
++count;
- if (0 < (signed long)(jiffies - (last_msgtime + HZ))) {
+ if (time_after(jiffies, last_msgtime + HZ)) {
last_msgtime = jiffies;
printk("%s%s: unexpected interrupt, status=0x%02x, count=%ld\n",
hwif->name, (hwif->next == hwgroup->hwif) ? "" : "(?)", stat, count);
@@ -2433,7 +2433,7 @@
spin_unlock_irq(&io_request_lock);
__save_flags(lflags); /* local CPU only */
__sti(); /* local CPU only; needed for jiffies */
- if (0 < (signed long)(jiffies - timeout)) {
+ if (time_after(jiffies, timeout)) {
__restore_flags(lflags); /* local CPU only */
printk("%s: channel busy\n", drive->name);
return -EBUSY;