Y2038

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1143 discussions

[PATCH] firewire: ohci: stop using get_seconds() for BUS_TIME

by Arnd Bergmann

The ohci driver uses the get_seconds() function to implement the 32-bit CSR_BUS_TIME register. This was added in 2010 commit a48777e03ad5 ("firewire: add CSR BUS_TIME support"). As get_seconds() returns a 32-bit value (on 32-bit architectures), it seems like a good fit for that register, but it is also deprecated because of the y2038/y2106 overflow problem, and should be replaced throughout the kernel with either ktime_get_real_seconds() or ktime_get_seconds(). I'm using the latter here, which uses monotonic time. This has the advantage of behaving better during concurrent settimeofday() updates or leap second adjustments and won't overflow a 32-bit integer, but the downside of using CLOCK_MONOTONIC instead of CLOCK_REALTIME is that the observed values are not related to external clocks. If we instead need UTC but can live with clock jumps or overflows, then we should use ktime_get_real_seconds() instead, retaining the existing behavior. Signed-off-by: Arnd Bergmann <arnd(a)arndb.de> --- drivers/firewire/ohci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c index 45c048751f3b..5125841ea338 100644 --- a/drivers/firewire/ohci.c +++ b/drivers/firewire/ohci.c @@ -1765,7 +1765,7 @@ static u32 update_bus_time(struct fw_ohci *ohci) if (unlikely(!ohci->bus_time_running)) { reg_write(ohci, OHCI1394_IntMaskSet, OHCI1394_cycle64Seconds); - ohci->bus_time = (lower_32_bits(get_seconds()) & ~0x7f) | + ohci->bus_time = (lower_32_bits(ktime_get_seconds()) & ~0x7f) | (cycle_time_seconds & 0x40); ohci->bus_time_running = true; } -- 2.9.0

7 years, 7 months

+ sysinfo-remove-get_monotonic_boottime.patch added to -mm tree

by akpm＠linux-foundation.org

The patch titled Subject: kernel/sys.c: remove get_monotonic_boottime() has been added to the -mm tree. Its filename is sysinfo-remove-get_monotonic_boottime.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/sysinfo-remove-get_monotonic_boott… and later at http://ozlabs.org/~akpm/mmotm/broken-out/sysinfo-remove-get_monotonic_boott… Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Arnd Bergmann <arnd(a)arndb.de> Subject: kernel/sys.c: remove get_monotonic_boottime() get_monotonic_boottime() is deprecated because it uses the old 'timespec' structure. This replaces one of the last callers with a call to ktime_get_boottime. Link: http://lkml.kernel.org/r/20180618150114.849216-1-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd(a)arndb.de> Reviewed-by: Cyrill Gorcunov <gorcunov(a)gmail.com> Reviewed-by: Andrew Morton <akpm(a)linux-foundation.org> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: <y2038(a)lists.linaro.org> Cc: Dominik Brodowski <linux(a)dominikbrodowski.net> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- kernel/sys.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff -puN kernel/sys.c~sysinfo-remove-get_monotonic_boottime kernel/sys.c --- a/kernel/sys.c~sysinfo-remove-get_monotonic_boottime +++ a/kernel/sys.c @@ -2523,11 +2523,11 @@ static int do_sysinfo(struct sysinfo *in { unsigned long mem_total, sav_total; unsigned int mem_unit, bitcount; - struct timespec tp; + struct timespec64 tp; memset(info, 0, sizeof(struct sysinfo)); - get_monotonic_boottime(&tp); + ktime_get_boottime_ts64(&tp); info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0); get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT); _ Patches currently in -mm which might be from arnd(a)arndb.de are crash-print-timestamp-using-time64_t.patch sysinfo-remove-get_monotonic_boottime.patch

7 years, 7 months

[PATCH net-next] nfp: avoid using getnstimeofday64()

by Arnd Bergmann

getnstimeofday64 is deprecated in favor of the ktime_get() family of functions. The direct replacement would be ktime_get_real_ts64(), but I'm picking the basic ktime_get() instead: - using a ktime_t simplifies the code compared to timespec64 - using monotonic time instead of real time avoids issues caused by a concurrent settimeofday() or during a leap second adjustment. Signed-off-by: Arnd Bergmann <arnd(a)arndb.de> --- drivers/net/ethernet/netronome/nfp/flower/main.h | 2 +- drivers/net/ethernet/netronome/nfp/flower/metadata.c | 12 +++++------- 2 files changed, 6 insertions(+), 8 deletions(-) diff --git a/drivers/net/ethernet/netronome/nfp/flower/main.h b/drivers/net/ethernet/netronome/nfp/flower/main.h index bbe5764d26cb..ef2114d13387 100644 --- a/drivers/net/ethernet/netronome/nfp/flower/main.h +++ b/drivers/net/ethernet/netronome/nfp/flower/main.h @@ -73,7 +73,7 @@ struct nfp_app; struct nfp_fl_mask_id { struct circ_buf mask_id_free_list; - struct timespec64 *last_used; + ktime_t *last_used; u8 init_unallocated; }; diff --git a/drivers/net/ethernet/netronome/nfp/flower/metadata.c b/drivers/net/ethernet/netronome/nfp/flower/metadata.c index 93fb809f50d1..c098730544b7 100644 --- a/drivers/net/ethernet/netronome/nfp/flower/metadata.c +++ b/drivers/net/ethernet/netronome/nfp/flower/metadata.c @@ -158,7 +158,6 @@ static int nfp_release_mask_id(struct nfp_app *app, u8 mask_id) { struct nfp_flower_priv *priv = app->priv; struct circ_buf *ring; - struct timespec64 now; ring = &priv->mask_ids.mask_id_free_list; /* Checking if buffer is full. */ @@ -169,8 +168,7 @@ static int nfp_release_mask_id(struct nfp_app *app, u8 mask_id) ring->head = (ring->head + NFP_FLOWER_MASK_ELEMENT_RS) % (NFP_FLOWER_MASK_ENTRY_RS * NFP_FLOWER_MASK_ELEMENT_RS); - getnstimeofday64(&now); - priv->mask_ids.last_used[mask_id] = now; + priv->mask_ids.last_used[mask_id] = ktime_get(); return 0; } @@ -178,7 +176,7 @@ static int nfp_release_mask_id(struct nfp_app *app, u8 mask_id) static int nfp_mask_alloc(struct nfp_app *app, u8 *mask_id) { struct nfp_flower_priv *priv = app->priv; - struct timespec64 delta, now; + ktime_t reuse_timeout; struct circ_buf *ring; u8 temp_id, freed_id; @@ -198,10 +196,10 @@ static int nfp_mask_alloc(struct nfp_app *app, u8 *mask_id) memcpy(&temp_id, &ring->buf[ring->tail], NFP_FLOWER_MASK_ELEMENT_RS); *mask_id = temp_id; - getnstimeofday64(&now); - delta = timespec64_sub(now, priv->mask_ids.last_used[*mask_id]); + reuse_timeout = ktime_add_ns(priv->mask_ids.last_used[*mask_id], + NFP_FL_MASK_REUSE_TIME_NS); - if (timespec64_to_ns(&delta) < NFP_FL_MASK_REUSE_TIME_NS) + if (ktime_before(ktime_get(), reuse_timeout)) goto err_not_found; memcpy(&ring->buf[ring->tail], &freed_id, NFP_FLOWER_MASK_ELEMENT_RS); -- 2.9.0

7 years, 7 months

Re: [Y2038] [PATCH] leds: ledtrig-activity: use ktime_get_boot_ns()

by Arnd Bergmann

On Mon, Jun 18, 2018 at 5:07 PM, Pavel Machek <pavel(a)ucw.cz> wrote: > Hi! > >> get_monotonic_boottime() is deprecated, so let's convert this to >> the simpler ktime_get_boot_ns(). >> >> Signed-off-by: Arnd Bergmann <arnd(a)arndb.de> > > Have you tested it? No, only build-tested. >> diff --git a/drivers/leds/trigger/ledtrig-activity.c b/drivers/leds/trigger/ledtrig-activity.c >> index 5081894082bd..589c1bc4d0b9 100644 >> --- a/drivers/leds/trigger/ledtrig-activity.c >> +++ b/drivers/leds/trigger/ledtrig-activity.c >> @@ -37,7 +37,6 @@ static void led_activity_function(struct timer_list *t) >> struct activity_data *activity_data = from_timer(activity_data, t, >> timer); >> struct led_classdev *led_cdev = activity_data->led_cdev; >> - struct timespec boot_time; >> unsigned int target; >> unsigned int usage; >> int delay; >> @@ -57,7 +56,7 @@ static void led_activity_function(struct timer_list *t) >> return; >> } >> >> - get_monotonic_boottime(&boot_time); >> + curr_boot = ktime_get_boot_ns(); >> >> cpus = 0; >> curr_used = 0; >> @@ -76,7 +75,6 @@ static void led_activity_function(struct timer_list *t) >> * down to 16us, ensuring we won't overflow 32-bit computations below >> * even up to 3k CPUs, while keeping divides cheap on smaller systems. >> */ >> - curr_boot = timespec_to_ns(&boot_time) * cpus; > > Original code is pretty weird (notice the * cpus), so I'm > double-checking. Ok, dropping the *cpus was not intentional, I'll repost a version that puts it that back. Thanks for pointing this out! Arnd

7 years, 7 months

[PATCH] ipmi: Change to ktime_get_ts64()

by Arnd Bergmann

getnstimeofday64() is deprecated because of the inconsistent naming, it is only a wrapper around ktime_get_real_ts64() now, which could be used as a direct replacement. However, it is generally better to use CLOCK_MONOTONIC timestamps where possible, to avoid glitches with a concurrent settimeofday() or leap second. The uses in ipmi are either for debugging prints or for comparing against a prior timestamp, so using a monotonic ktime_get_ts64() is probably best here. Signed-off-by: Arnd Bergmann <arnd(a)arndb.de> --- drivers/char/ipmi/ipmi_si_intf.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c index ad353be871bf..fb19c796f0fa 100644 --- a/drivers/char/ipmi/ipmi_si_intf.c +++ b/drivers/char/ipmi/ipmi_si_intf.c @@ -269,7 +269,7 @@ void debug_timestamp(char *msg) { struct timespec64 t; - getnstimeofday64(&t); + ktime_get_ts64(&t); pr_debug("**%s: %lld.%9.9ld\n", msg, (long long) t.tv_sec, t.tv_nsec); } #else @@ -961,12 +961,12 @@ static inline int ipmi_thread_busy_wait(enum si_sm_result smi_result, if (max_busy_us == 0 || smi_result != SI_SM_CALL_WITH_DELAY) ipmi_si_set_not_busy(busy_until); else if (!ipmi_si_is_busy(busy_until)) { - getnstimeofday64(busy_until); + ktime_get_ts64(busy_until); timespec64_add_ns(busy_until, max_busy_us*NSEC_PER_USEC); } else { struct timespec64 now; - getnstimeofday64(&now); + ktime_get_ts64(&now); if (unlikely(timespec64_compare(&now, busy_until) > 0)) { ipmi_si_set_not_busy(busy_until); return 0; -- 2.9.0

7 years, 7 months

[PATCH 1/2] amdgpu: display: use modern ktime accessors

by Arnd Bergmann

getrawmonotonic64() is deprecated because of the nonstandard naming. The replacement functions ktime_get_raw_ns() also simplifies the callers. Signed-off-by: Arnd Bergmann <arnd(a)arndb.de> --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_services.c | 8 -------- drivers/gpu/drm/amd/display/dc/dm_services.h | 5 ++++- 2 files changed, 4 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_services.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_services.c index 5a3346124a01..e861929dd981 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_services.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_services.c @@ -35,14 +35,6 @@ #include "amdgpu_dm_irq.h" #include "amdgpu_pm.h" -unsigned long long dm_get_timestamp(struct dc_context *ctx) -{ - struct timespec64 time; - - getrawmonotonic64(&time); - return timespec64_to_ns(&time); -} - unsigned long long dm_get_elapse_time_in_ns(struct dc_context *ctx, unsigned long long current_time_stamp, unsigned long long last_time_stamp) diff --git a/drivers/gpu/drm/amd/display/dc/dm_services.h b/drivers/gpu/drm/amd/display/dc/dm_services.h index 4ff9b2bba178..eb5ab3978e84 100644 --- a/drivers/gpu/drm/amd/display/dc/dm_services.h +++ b/drivers/gpu/drm/amd/display/dc/dm_services.h @@ -339,7 +339,10 @@ bool dm_dmcu_set_pipe(struct dc_context *ctx, unsigned int controller_id); #define dm_log_to_buffer(buffer, size, fmt, args)\ vsnprintf(buffer, size, fmt, args) -unsigned long long dm_get_timestamp(struct dc_context *ctx); +static inline unsigned long long dm_get_timestamp(struct dc_context *ctx) +{ + return ktime_get_raw_ns(); +} unsigned long long dm_get_elapse_time_in_ns(struct dc_context *ctx, unsigned long long current_time_stamp, -- 2.9.0

7 years, 7 months

[PATCH] i915: remove timespec_to_jiffies_timeout

by Arnd Bergmann

This function has been unused since commit 5ed0bdf21a85 ("drm: i915: Use nsec based interfaces"). Let's remove the definition as well now to help get rid of all uses of 'timespec'. Signed-off-by: Arnd Bergmann <arnd(a)arndb.de> --- drivers/gpu/drm/i915/i915_drv.h | 8 -------- 1 file changed, 8 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 34c125e2d90c..5f61676e8fb8 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -3673,14 +3673,6 @@ static inline unsigned long nsecs_to_jiffies_timeout(const u64 n) return min_t(u64, MAX_JIFFY_OFFSET, nsecs_to_jiffies64(n) + 1); } -static inline unsigned long -timespec_to_jiffies_timeout(const struct timespec *value) -{ - unsigned long j = timespec_to_jiffies(value); - - return min_t(unsigned long, MAX_JIFFY_OFFSET, j + 1); -} - /* * If you need to wait X milliseconds between events A and B, but event B * doesn't happen exactly after event A, you record the timestamp (jiffies) of -- 2.9.0

7 years, 7 months

[PATCH] efi: cper: avoid using get_seconds()

by Arnd Bergmann

get_seconds() is deprecated because of the 32-bit time overflow in y2038/y2106 on 32-bit architectures. The way it is used in cper_next_record_id() causes an overflow in 2106 when unsigned UTC seconds overflow, even on 64-bit architectures. This starts using ktime_get_real_seconds() to give us more than 32 bits of timestamp on all architectures, and then changes the algorithm to use 39 bits for the timestamp after the y2038 wrap date, plus an always-1 bit at the top. This gives us another 127 epochs of 136 years, with strictly monotonically increasing sequence numbers across boots. This is almost certainly overkill, but seems better than just extending the deadline from 2038 to 2106. Signed-off-by: Arnd Bergmann <arnd(a)arndb.de> --- drivers/firmware/efi/cper.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/firmware/efi/cper.c b/drivers/firmware/efi/cper.c index 3bf0dca378a6..b73fc4cab083 100644 --- a/drivers/firmware/efi/cper.c +++ b/drivers/firmware/efi/cper.c @@ -48,8 +48,21 @@ u64 cper_next_record_id(void) { static atomic64_t seq; - if (!atomic64_read(&seq)) - atomic64_set(&seq, ((u64)get_seconds()) << 32); + if (!atomic64_read(&seq)) { + time64_t time = ktime_get_real_seconds(); + + /* + * This code is unlikely to still be needed in year 2106, + * but just in case, let's use a few more bits for timestamps + * after y2038 to be sure they keep increasing monotonically + * for the next few hundred years... + */ + if (time < 0x80000000) + atomic64_set(&seq, (ktime_get_real_seconds()) << 32); + else + atomic64_set(&seq, 0x8000000000000000ull | + ktime_get_real_seconds() << 24); + } return atomic64_inc_return(&seq); } -- 2.9.0

7 years, 7 months

[PATCH 1/2] ALSA: use ktime_get_raw_ts64() instead of getrawmonotonic64()

by Arnd Bergmann

The API got renamed for consistency and the old name will be removed once the last users are gone. Signed-off-by: Arnd Bergmann <arnd(a)arndb.de> --- include/sound/pcm.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/sound/pcm.h b/include/sound/pcm.h index 5d5daa190b08..f566611f0fef 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -1187,7 +1187,7 @@ static inline void snd_pcm_gettime(struct snd_pcm_runtime *runtime, ktime_get_ts64(tv); break; case SNDRV_PCM_TSTAMP_TYPE_MONOTONIC_RAW: - getrawmonotonic64(tv); + ktime_get_raw_ts64(tv); break; default: #ifdef CONFIG_SND_TSTAMP_REALTIME -- 2.9.0

7 years, 7 months

[PATCH] firewire: use 64-bit time_t based interfaces

by Arnd Bergmann

32-bit CLOCK_REALTIME timestamps overflow in year 2038, so all such interfaces are deprecated now. For the FW_CDEV_IOC_GET_CYCLE_TIMER2 ioctl, we already support 64-bit timestamps, but the implementation still uses timespec. This changes the code to use timespec64 instead with the appropriate accessor functions. Signed-off-by: Arnd Bergmann <arnd(a)arndb.de> --- drivers/firewire/core-cdev.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c index f0587273940e..d8e185582642 100644 --- a/drivers/firewire/core-cdev.c +++ b/drivers/firewire/core-cdev.c @@ -1205,7 +1205,7 @@ static int ioctl_get_cycle_timer2(struct client *client, union ioctl_arg *arg) { struct fw_cdev_get_cycle_timer2 *a = &arg->get_cycle_timer2; struct fw_card *card = client->device->card; - struct timespec ts = {0, 0}; + struct timespec64 ts = {0, 0}; u32 cycle_time; int ret = 0; @@ -1214,9 +1214,9 @@ static int ioctl_get_cycle_timer2(struct client *client, union ioctl_arg *arg) cycle_time = card->driver->read_csr(card, CSR_CYCLE_TIME); switch (a->clk_id) { - case CLOCK_REALTIME: getnstimeofday(&ts); break; - case CLOCK_MONOTONIC: ktime_get_ts(&ts); break; - case CLOCK_MONOTONIC_RAW: getrawmonotonic(&ts); break; + case CLOCK_REALTIME: ktime_get_real_ts64(&ts); break; + case CLOCK_MONOTONIC: ktime_get_ts64(&ts); break; + case CLOCK_MONOTONIC_RAW: ktime_get_raw_ts64(&ts); break; default: ret = -EINVAL; } -- 2.9.0

7 years, 7 months

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