The patch titled
ntp: fix ADJ_OFFSET_SS_READ bug and do_adjtimex() cleanup
has been added to the -mm tree. Its filename is
ntp-fix-adj_offset_ss_read-bug-and-do_adjtimex-cleanup.patch
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------------------------------------------------------
Subject: ntp: fix ADJ_OFFSET_SS_READ bug and do_adjtimex() cleanup
From: Roman Zippel <zippel@xxxxxxxxxxxxxx>
Thanks to the review by Michael Kerrisk a bug in the recent
ADJ_OFFSET_SS_READ option was discovered, where the ntp time_offset was
inadvertently set by it. This fixes this by making the adjtime code
more separate from the ntp_adjtime code (both of which really want to
be separate syscalls).
Signed-off-by: Roman Zippel <zippel@xxxxxxxxxxxxxx>
Cc: Michael Kerrisk <mtk.manpages@xxxxxxxxxxxxxx>
Cc: john stultz <johnstul@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/timex.h | 9 ++++
kernel/time/ntp.c | 76 +++++++++++++++++++++-------------------
2 files changed, 48 insertions(+), 37 deletions(-)
diff -puN include/linux/timex.h~ntp-fix-adj_offset_ss_read-bug-and-do_adjtimex-cleanup include/linux/timex.h
--- a/include/linux/timex.h~ntp-fix-adj_offset_ss_read-bug-and-do_adjtimex-cleanup
+++ a/include/linux/timex.h
@@ -141,8 +141,15 @@ struct timex {
#define ADJ_MICRO 0x1000 /* select microsecond resolution */
#define ADJ_NANO 0x2000 /* select nanosecond resolution */
#define ADJ_TICK 0x4000 /* tick value */
+
+#ifdef __KERNEL__
+#define ADJ_ADJTIME 0x8000 /* switch between adjtime/adjtimex modes */
+#define ADJ_OFFSET_SINGLESHOT 0x0001 /* old-fashioned adjtime */
+#define ADJ_OFFSET_READONLY 0x2000 /* read-only adjtime */
+#else
#define ADJ_OFFSET_SINGLESHOT 0x8001 /* old-fashioned adjtime */
-#define ADJ_OFFSET_SS_READ 0xa001 /* read-only adjtime */
+#define ADJ_OFFSET_SS_READ 0xa001 /* read-only adjtime */
+#endif
/* xntp 3.4 compatibility names */
#define MOD_OFFSET ADJ_OFFSET
diff -puN kernel/time/ntp.c~ntp-fix-adj_offset_ss_read-bug-and-do_adjtimex-cleanup kernel/time/ntp.c
--- a/kernel/time/ntp.c~ntp-fix-adj_offset_ss_read-bug-and-do_adjtimex-cleanup
+++ a/kernel/time/ntp.c
@@ -277,38 +277,50 @@ static inline void notify_cmos_timer(voi
int do_adjtimex(struct timex *txc)
{
struct timespec ts;
- long save_adjust, sec;
int result;
- /* In order to modify anything, you gotta be super-user! */
- if (txc->modes && !capable(CAP_SYS_TIME))
- return -EPERM;
-
- /* Now we validate the data before disabling interrupts */
-
- if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT) {
+ /* Validate the data before disabling interrupts */
+ if (txc->modes & ADJ_ADJTIME) {
/* singleshot must not be used with any other mode bits */
- if (txc->modes & ~ADJ_OFFSET_SS_READ)
+ if (!(txc->modes & ADJ_OFFSET_SINGLESHOT))
return -EINVAL;
- }
+ if (!(txc->modes & ADJ_OFFSET_READONLY) &&
+ !capable(CAP_SYS_TIME))
+ return -EPERM;
+ } else {
+ /* In order to modify anything, you gotta be super-user! */
+ if (txc->modes && !capable(CAP_SYS_TIME))
+ return -EPERM;
+
+ /* if the quartz is off by more than 10% something is VERY wrong! */
+ if (txc->modes & ADJ_TICK &&
+ (txc->tick < 900000/USER_HZ ||
+ txc->tick > 1100000/USER_HZ))
+ return -EINVAL;
- /* if the quartz is off by more than 10% something is VERY wrong ! */
- if (txc->modes & ADJ_TICK)
- if (txc->tick < 900000/USER_HZ ||
- txc->tick > 1100000/USER_HZ)
- return -EINVAL;
+ if (txc->modes & ADJ_STATUS && time_state != TIME_OK)
+ hrtimer_cancel(&leap_timer);
+ }
- if (time_state != TIME_OK && txc->modes & ADJ_STATUS)
- hrtimer_cancel(&leap_timer);
getnstimeofday(&ts);
write_seqlock_irq(&xtime_lock);
- /* Save for later - semantics of adjtime is to return old value */
- save_adjust = time_adjust;
-
/* If there are input parameters, then process them */
+ if (txc->modes & ADJ_ADJTIME) {
+ long save_adjust = time_adjust;
+
+ if (!(txc->modes & ADJ_OFFSET_READONLY)) {
+ /* adjtime() is independent from ntp_adjtime() */
+ time_adjust = txc->offset;
+ ntp_update_frequency();
+ }
+ txc->offset = save_adjust;
+ goto adj_done;
+ }
if (txc->modes) {
+ long sec;
+
if (txc->modes & ADJ_STATUS) {
if ((time_status & STA_PLL) &&
!(txc->status & STA_PLL)) {
@@ -375,13 +387,8 @@ int do_adjtimex(struct timex *txc)
if (txc->modes & ADJ_TAI && txc->constant > 0)
time_tai = txc->constant;
- if (txc->modes & ADJ_OFFSET) {
- if (txc->modes == ADJ_OFFSET_SINGLESHOT)
- /* adjtime() is independent from ntp_adjtime() */
- time_adjust = txc->offset;
- else
- ntp_update_offset(txc->offset);
- }
+ if (txc->modes & ADJ_OFFSET)
+ ntp_update_offset(txc->offset);
if (txc->modes & ADJ_TICK)
tick_usec = txc->tick;
@@ -389,19 +396,16 @@ int do_adjtimex(struct timex *txc)
ntp_update_frequency();
}
+ txc->offset = shift_right(time_offset * NTP_INTERVAL_FREQ,
+ NTP_SCALE_SHIFT);
+ if (!(time_status & STA_NANO))
+ txc->offset /= NSEC_PER_USEC;
+
+adj_done:
result = time_state; /* mostly `TIME_OK' */
if (time_status & (STA_UNSYNC|STA_CLOCKERR))
result = TIME_ERROR;
- if ((txc->modes == ADJ_OFFSET_SINGLESHOT) ||
- (txc->modes == ADJ_OFFSET_SS_READ))
- txc->offset = save_adjust;
- else {
- txc->offset = shift_right(time_offset * NTP_INTERVAL_FREQ,
- NTP_SCALE_SHIFT);
- if (!(time_status & STA_NANO))
- txc->offset /= NSEC_PER_USEC;
- }
txc->freq = shift_right((s32)(time_freq >> PPM_SCALE_INV_SHIFT) *
(s64)PPM_SCALE_INV,
NTP_SCALE_SHIFT);
_
Patches currently in -mm which might be from zippel@xxxxxxxxxxxxxx are
ntp-let-update_persistent_clock-sleep.patch
timekeeping-fix-rounding-problem-during-clock-update.patch
ntp-fix-adj_offset_ss_read-bug-and-do_adjtimex-cleanup.patch
ntp-fix-calculation-of-the-next-jiffie-to-trigger-rtc-sync.patch
clocksource-keep-track-of-original-clocksource-frequency.patch
clocksource-introduce-clocksource_forward_now.patch
clocksource-introduce-clock_monotonic_raw.patch
hfsplus-quieten-down-mounting-hfsplus-journaled-fs-read-only.patch
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