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2020-03-21linux/time.h: Extract common header for vDSOVincenzo Frascino1-4/+1
The vDSO library should only include the necessary headers required for a userspace library (UAPI and a minimal set of kernel headers). To make this possible it is necessary to isolate from the kernel headers the common parts that are strictly necessary to build the library. Split time.h into linux and common headers to make the latter suitable for inclusion in the vDSO library. Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200320145351.32292-11-vincenzo.frascino@arm.com
2020-01-14lib/vdso: Prepare for time namespace supportThomas Gleixner1-0/+6
To support time namespaces in the vdso with a minimal impact on regular non time namespace affected tasks, the namespace handling needs to be hidden in a slow path. The most obvious place is vdso_seq_begin(). If a task belongs to a time namespace then the VVAR page which contains the system wide vdso data is replaced with a namespace specific page which has the same layout as the VVAR page. That page has vdso_data->seq set to 1 to enforce the slow path and vdso_data->clock_mode set to VCLOCK_TIMENS to enforce the time namespace handling path. The extra check in the case that vdso_data->seq is odd, e.g. a concurrent update of the vdso data is in progress, is not really affecting regular tasks which are not part of a time namespace as the task is spin waiting for the update to finish and vdso_data->seq to become even again. If a time namespace task hits that code path, it invokes the corresponding time getter function which retrieves the real VVAR page, reads host time and then adds the offset for the requested clock which is stored in the special VVAR page. If VDSO time namespace support is disabled the whole magic is compiled out. Initial testing shows that the disabled case is almost identical to the host case which does not take the slow timens path. With the special timens page installed the performance hit is constant time and in the range of 5-7%. For the vdso functions which are not using the sequence count an unconditional check for vdso_data->clock_mode is added which switches to the real vdso when the clock_mode is VCLOCK_TIMENS. [avagin: Make do_hres_timens() work with raw clocks too: choose vdso_data pointer by CS_RAW offset.] Suggested-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20191112012724.250792-21-dima@arista.com
2019-12-06tcp: fix rejected syncookies due to stale timestampsGuillaume Nault1-0/+13
If no synflood happens for a long enough period of time, then the synflood timestamp isn't refreshed and jiffies can advance so much that time_after32() can't accurately compare them any more. Therefore, we can end up in a situation where time_after32(now, last_overflow + HZ) returns false, just because these two values are too far apart. In that case, the synflood timestamp isn't updated as it should be, which can trick tcp_synq_no_recent_overflow() into rejecting valid syncookies. For example, let's consider the following scenario on a system with HZ=1000: * The synflood timestamp is 0, either because that's the timestamp of the last synflood or, more commonly, because we're working with a freshly created socket. * We receive a new SYN, which triggers synflood protection. Let's say that this happens when jiffies == 2147484649 (that is, 'synflood timestamp' + HZ + 2^31 + 1). * Then tcp_synq_overflow() doesn't update the synflood timestamp, because time_after32(2147484649, 1000) returns false. With: - 2147484649: the value of jiffies, aka. 'now'. - 1000: the value of 'last_overflow' + HZ. * A bit later, we receive the ACK completing the 3WHS. But cookie_v[46]_check() rejects it because tcp_synq_no_recent_overflow() says that we're not under synflood. That's because time_after32(2147484649, 120000) returns false. With: - 2147484649: the value of jiffies, aka. 'now'. - 120000: the value of 'last_overflow' + TCP_SYNCOOKIE_VALID. Of course, in reality jiffies would have increased a bit, but this condition will last for the next 119 seconds, which is far enough to accommodate for jiffie's growth. Fix this by updating the overflow timestamp whenever jiffies isn't within the [last_overflow, last_overflow + HZ] range. That shouldn't have any performance impact since the update still happens at most once per second. Now we're guaranteed to have fresh timestamps while under synflood, so tcp_synq_no_recent_overflow() can safely use it with time_after32() in such situations. Stale timestamps can still make tcp_synq_no_recent_overflow() return the wrong verdict when not under synflood. This will be handled in the next patch. For 64 bits architectures, the problem was introduced with the conversion of ->tw_ts_recent_stamp to 32 bits integer by commit cca9bab1b72c ("tcp: use monotonic timestamps for PAWS"). The problem has always been there on 32 bits architectures. Fixes: cca9bab1b72c ("tcp: use monotonic timestamps for PAWS") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-15y2038: move itimer reset into itimer.cArnd Bergmann1-4/+5
Preparing for a change to the itimer internals, stop using the do_setitimer() symbol and instead use a new higher-level interface. The do_getitimer()/do_setitimer functions can now be made static, allowing the compiler to potentially produce better object code. Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-06-24time: Introduce struct __kernel_itimerspecDeepa Dinamani1-2/+2
struct itimerspec is not y2038-safe. Introduce a new struct __kernel_itimerspec based on the kernel internal y2038-safe struct itimerspec64. The definition of struct __kernel_itimerspec includes two struct __kernel_timespec. Since struct __kernel_timespec has the same representation in native and compat modes, so does struct __kernel_itimerspec. This helps have a common entry point for syscalls using struct __kernel_itimerspec. New y2038-safe syscalls will use this new type. Since most of the new syscalls are just an update to the native syscalls with the type update, place the new definition under CONFIG_64BIT_TIME. This helps architectures that do not support the above config to keep using the old definition of struct itimerspec. Also change the get/put_itimerspec64 to use struct__kernel_itimerspec. This will help 32 bit architectures to use the new syscalls when architectures select CONFIG_64BIT_TIME. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: arnd@arndb.de Cc: viro@zeniv.linux.org.uk Cc: linux-fsdevel@vger.kernel.org Cc: linux-api@vger.kernel.org Cc: y2038@lists.linaro.org Link: https://lkml.kernel.org/r/20180617051144.29756-2-deepa.kernel@gmail.com
2018-04-19time: Fix get_timespec64() for y2038 safe compat interfacesDeepa Dinamani1-2/+2
get/put_timespec64() interfaces will eventually be used for conversions between the new y2038 safe struct __kernel_timespec and struct timespec64. The new y2038 safe syscalls have a common entry for native and compat interfaces. On compat interfaces, the high order bits of nanoseconds should be zeroed out. This is because the application code or the libc do not guarantee zeroing of these. If used without zeroing, kernel might be at risk of using timespec values incorrectly. Note that clearing of bits is dependent on CONFIG_64BIT_TIME for now. This is until COMPAT_USE_64BIT_TIME has been handled correctly. x86 will be the first architecture that will use the CONFIG_64BIT_TIME. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2017-11-13Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-206/+1
Pull timer updates from Thomas Gleixner: "Yet another big pile of changes: - More year 2038 work from Arnd slowly reaching the point where we need to think about the syscalls themself. - A new timer function which allows to conditionally (re)arm a timer only when it's either not running or the new expiry time is sooner than the armed expiry time. This allows to use a single timer for multiple timeout requirements w/o caring about the first expiry time at the call site. - A new NMI safe accessor to clock real time for the printk timestamp work. Can be used by tracing, perf as well if required. - A large number of timer setup conversions from Kees which got collected here because either maintainers requested so or they simply got ignored. As Kees pointed out already there are a few trivial merge conflicts and some redundant commits which was unavoidable due to the size of this conversion effort. - Avoid a redundant iteration in the timer wheel softirq processing. - Provide a mechanism to treat RTC implementations depending on their hardware properties, i.e. don't inflict the write at the 0.5 seconds boundary which originates from the PC CMOS RTC to all RTCs. No functional change as drivers need to be updated separately. - The usual small updates to core code clocksource drivers. Nothing really exciting" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (111 commits) timers: Add a function to start/reduce a timer pstore: Use ktime_get_real_fast_ns() instead of __getnstimeofday() timer: Prepare to change all DEFINE_TIMER() callbacks netfilter: ipvs: Convert timers to use timer_setup() scsi: qla2xxx: Convert timers to use timer_setup() block/aoe: discover_timer: Convert timers to use timer_setup() ide: Convert timers to use timer_setup() drbd: Convert timers to use timer_setup() mailbox: Convert timers to use timer_setup() crypto: Convert timers to use timer_setup() drivers/pcmcia: omap1: Fix error in automated timer conversion ARM: footbridge: Fix typo in timer conversion drivers/sgi-xp: Convert timers to use timer_setup() drivers/pcmcia: Convert timers to use timer_setup() drivers/memstick: Convert timers to use timer_setup() drivers/macintosh: Convert timers to use timer_setup() hwrng/xgene-rng: Convert timers to use timer_setup() auxdisplay: Convert timers to use timer_setup() sparc/led: Convert timers to use timer_setup() mips: ip22/32: Convert timers to use timer_setup() ...
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-30time: Move time_t based interfaces to time32.hArnd Bergmann1-162/+1
Interfaces based on 'struct timespec' or 'struct timeval' should no longer be used for new code, which can use either ktime_t or 'struct timespec64' instead. To make this a little clearer, this moves the various helpers into a new time32.h header. For the moment, this gets included by the normal time.h, but we may be able to separate it entirely when most users of time32.h are gone. Individual helpers in the new file can get removed once they become unused in the future. Since the contents of time32.h look a lot like what's in time64.h, I'm reordering them during the move to make them more similar, and to allow a follow-up patch to redirect the 'timespec' based functions to thei 'timespec64' based counterparts on 64-bit architectures later. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Miroslav Lichvar <mlichvar@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Stephen Boyd <stephen.boyd@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> [jstultz: Whitespace & checkpatch fixups] Signed-off-by: John Stultz <john.stultz@linaro.org>
2017-10-30time: Remove unused functionsArnd Bergmann1-18/+0
The (slow but) ongoing work on conversion from timespec to timespec64 has led some timespec based helper functions to become unused. No new code should use them, so we can remove the functions entirely. I'm planning to obsolete additional interfaces next and remove more of these. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Miroslav Lichvar <mlichvar@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Stephen Boyd <stephen.boyd@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
2017-10-30timekeeping: Consolidate timekeeping_inject_offset codeArnd Bergmann1-26/+0
The code to check the adjtimex() or clock_adjtime() arguments is spread out across multiple files for presumably only historic reasons. As a preparatation for a rework to get rid of the use of 'struct timeval' and 'struct timespec' in there, this moves all the portions into kernel/time/timekeeping.c and marks them as 'static'. The warp_clock() function here is not as closely related as the others, but I feel it still makes sense to move it here in order to consolidate all callers of timekeeping_inject_offset(). Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Miroslav Lichvar <mlichvar@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Stephen Boyd <stephen.boyd@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> [jstultz: Whitespace fixup] Signed-off-by: John Stultz <john.stultz@linaro.org>
2017-09-14Merge branch 'work.ipc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds1-1/+1
Pull ipc compat cleanup and 64-bit time_t from Al Viro: "IPC copyin/copyout sanitizing, including 64bit time_t work from Deepa Dinamani" * 'work.ipc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: utimes: Make utimes y2038 safe ipc: shm: Make shmid_kernel timestamps y2038 safe ipc: sem: Make sem_array timestamps y2038 safe ipc: msg: Make msg_queue timestamps y2038 safe ipc: mqueue: Replace timespec with timespec64 ipc: Make sys_semtimedop() y2038 safe get rid of SYSVIPC_COMPAT on ia64 semtimedop(): move compat to native shmat(2): move compat to native msgrcv(2), msgsnd(2): move compat to native ipc(2): move compat to native ipc: make use of compat ipc_perm helpers semctl(): move compat to native semctl(): separate all layout-dependent copyin/copyout msgctl(): move compat to native msgctl(): split the actual work from copyin/copyout ipc: move compat shmctl to native shmctl: split the work from copyin/copyout
2017-09-03utimes: Make utimes y2038 safeDeepa Dinamani1-1/+1
struct timespec is not y2038 safe on 32 bit machines. Replace timespec with y2038 safe struct timespec64. Note that the patch only changes the internals without modifying the syscall interfaces. This will be part of a separate series. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-08-31ext4: avoid Y2038 overflow in recently_deleted()Andreas Dilger1-0/+15
Avoid a 32-bit time overflow in recently_deleted() since i_dtime (inode deletion time) is stored only as a 32-bit value on disk. Since i_dtime isn't used for much beyond a boolean value in e2fsck and is otherwise only used in this function in the kernel, there is no benefit to use more space in the inode for this field on disk. Instead, compare only the relative deletion time with the low 32 bits of the time using the newly-added time_before32() helper, which is similar to time_before() and time_after() for jiffies. Increase RECENTCY_DIRTY to 300s based on Ted's comments about usage experience at Google. Signed-off-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
2017-07-06Merge branch 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds1-3/+0
Pull misc compat stuff updates from Al Viro: "This part is basically untangling various compat stuff. Compat syscalls moved to their native counterparts, getting rid of quite a bit of double-copying and/or set_fs() uses. A lot of field-by-field copyin/copyout killed off. - kernel/compat.c is much closer to containing just the copyin/copyout of compat structs. Not all compat syscalls are gone from it yet, but it's getting there. - ipc/compat_mq.c killed off completely. - block/compat_ioctl.c cleaned up; floppy compat ioctls moved to drivers/block/floppy.c where they belong. Yes, there are several drivers that implement some of the same ioctls. Some are m68k and one is 32bit-only pmac. drivers/block/floppy.c is the only one in that bunch that can be built on biarch" * 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: mqueue: move compat syscalls to native ones usbdevfs: get rid of field-by-field copyin compat_hdio_ioctl: get rid of set_fs() take floppy compat ioctls to sodding floppy.c ipmi: get rid of field-by-field __get_user() ipmi: get COMPAT_IPMICTL_RECEIVE_MSG in sync with the native one rt_sigtimedwait(): move compat to native select: switch compat_{get,put}_fd_set() to compat_{get,put}_bitmap() put_compat_rusage(): switch to copy_to_user() sigpending(): move compat to native getrlimit()/setrlimit(): move compat to native times(2): move compat to native compat_{get,put}_bitmap(): use unsafe_{get,put}_user() fb_get_fscreeninfo(): don't bother with do_fb_ioctl() do_sigaltstack(): lift copying to/from userland into callers take compat_sys_old_getrlimit() to native syscall trim __ARCH_WANT_SYS_OLD_GETRLIMIT
2017-06-25time: introduce {get,put}_itimerspec64Deepa Dinamani1-0/+13
As we change the user space type for the timerfd and posix timer functions to newer data types, we need some form of conversion helpers to avoid duplicating that logic. Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-25time: add get_timespec64 and put_timespec64Deepa Dinamani1-0/+5
Add helper functions to convert between struct timespec64 and struct timespec at userspace boundaries. This is a preparatory patch to use timespec64 as the basic type internally in the kernel as timespec is not y2038 safe on 32 bit systems. The patch helps the cause by containing all data conversions at the userspace boundaries within these functions. Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-09times(2): move compat to nativeAl Viro1-3/+0
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-05-08time: delete CURRENT_TIME_SEC and CURRENT_TIMEDeepa Dinamani1-3/+0
All uses of CURRENT_TIME_SEC and CURRENT_TIME macros have been replaced by other time functions. These macros are also not y2038 safe. And, all their use cases can be fulfilled by y2038 safe ktime_get_* variants. Link: http://lkml.kernel.org/r/1491613030-11599-12-git-send-email-deepa.kernel@gmail.com Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-11-16timer: Move sys_alarm from timer.c to itimer.cNicolas Pitre1-2/+0
Move the only user of alarm_setitimer to itimer.c where it is defined. This allows for making alarm_setitimer static, and dropping it from the build when __ARCH_WANT_SYS_ALARM is not defined. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: John Stultz <john.stultz@linaro.org> Cc: Paul Bolle <pebolle@tiscali.nl> Cc: linux-kbuild@vger.kernel.org Cc: netdev@vger.kernel.org Cc: Richard Cochran <richardcochran@gmail.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Michal Marek <mmarek@suse.com> Cc: Edward Cree <ecree@solarflare.com> Link: http://lkml.kernel.org/r/1478841010-28605-5-git-send-email-nicolas.pitre@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-06-20time: Add time64_to_tm()Deepa Dinamani1-1/+14
time_to_tm() takes time_t as an argument. time_t is not y2038 safe. Add time64_to_tm() that takes time64_t as an argument which is y2038 safe. The plan is to eventually replace all calls to time_to_tm() by time64_to_tm(). Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-12-10time: Verify time values in adjtimex ADJ_SETOFFSET to avoid overflowJohn Stultz1-0/+26
For adjtimex()'s ADJ_SETOFFSET, make sure the tv_usec value is sane. We might multiply them later which can cause an overflow and undefined behavior. This patch introduces new helper functions to simplify the checking code and adds comments to clarify Orginally this patch was by Sasha Levin, but I've basically rewritten it, so he should get credit for finding the issue and I should get the blame for any mistakes made since. Also, credit to Richard Cochran for the phrasing used in the comment for what is considered valid here. Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-01-22Merge branch 'fortglx/3.19-stable/time' of https://git.linaro.org/people/john.stultz/linux into timers/urgentThomas Gleixner1-0/+13
Pull urgent fixes from John Stultz: Two urgent fixes for user triggerable time related overflow issues
2015-01-07time: settimeofday: Validate the values of tv from userSasha Levin1-0/+13
An unvalidated user input is multiplied by a constant, which can result in an undefined behaviour for large values. While this is validated later, we should avoid triggering undefined behaviour. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> [jstultz: include trivial milisecond->microsecond correction noticed by Andy] Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-11-21time: Provide y2038 safe mktime() replacementpang.xunlei1-3/+14
As part of addressing "y2038 problem" for in-kernel uses, this patch adds safe mktime64() using time64_t. After this patch, mktime() is deprecated and all its call sites will be fixed using mktime64(), after that it can be removed. Signed-off-by: pang.xunlei <pang.xunlei@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23time: Consolidate the time accessor prototypesThomas Gleixner1-41/+4
Right now we have time related prototypes in 3 different header files. Move it to a single timekeeping header file and move the core internal stuff into a core private header. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23time64: Add time64.h header and define struct timespec64John Stultz1-14/+1
Define the timespec64 structure and standard helper functions. [ tglx: Make it 32bit only. 64bit really can map timespec to timespec64 ] Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23ktime: Kill non-scalar ktime_t implementation for 2038John Stultz1-7/+4
The non-scalar ktime_t implementation is basically a timespec which has to be changed to support dates past 2038 on 32bit systems. This patch removes the non-scalar ktime_t implementation, forcing the scalar s64 nanosecond version on all architectures. This may have additional performance overhead on some 32bit systems when converting between ktime_t and timespec structures, however the majority of 32bit systems (arm and i386) were already using scalar ktime_t, so no performance regressions will be seen on those platforms. On affected platforms, I'm open to finding optimizations, including avoiding converting to timespecs where possible. [ tglx: We can now cleanup the ktime_t.tv64 mess, but thats a different issue and we can throw a coccinelle script at it ] Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23hrtimer: Cleanup hrtimer accessors to the timekepeing stateJohn Stultz1-2/+0
Rather then having two similar but totally different implementations that provide timekeeping state to the hrtimer code, try to unify the two implementations to be more simliar. Thus this clarifies ktime_get_update_offsets to ktime_get_update_offsets_now and changes get_xtime... to ktime_get_update_offsets_tick. Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-05-14time: Revert ALWAYS_USE_PERSISTENT_CLOCK compile time optimizaitonsJohn Stultz1-4/+0
Kay Sievers noted that the ALWAYS_USE_PERSISTENT_CLOCK config, which enables some minor compile time optimization to avoid uncessary code in mostly the suspend/resume path could cause problems for userland. In particular, the dependency for RTC_HCTOSYS on !ALWAYS_USE_PERSISTENT_CLOCK, which avoids setting the time twice and simplifies suspend/resume, has the side effect of causing the /sys/class/rtc/rtcN/hctosys flag to always be zero, and this flag is commonly used by udev to setup the /dev/rtc symlink to /dev/rtcN, which can cause pain for older applications. While the udev rules could use some work to be less fragile, breaking userland should strongly be avoided. Additionally the compile time optimizations are fairly minor, and the code being optimized is likely to be reworked in the future, so lets revert this change. Reported-by: Kay Sievers <kay@vrfy.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: stable <stable@vger.kernel.org> #3.9 Cc: Feng Tang <feng.tang@intel.com> Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> Link: http://lkml.kernel.org/r/1366828376-18124-1-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-03-22timekeeping: Add CLOCK_TAI clockidJohn Stultz1-0/+1
This add a CLOCK_TAI clockid and the needed accessors. CC: Thomas Gleixner <tglx@linutronix.de> CC: Eric Dumazet <eric.dumazet@gmail.com> CC: Richard Cochran <richardcochran@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-03-22timekeeping: Move TAI managment into timekeeping core from ntpJohn Stultz1-0/+2
Currently NTP manages the TAI offset. Since there's plans for a CLOCK_TAI clockid, push the TAI management into the timekeeping core. CC: Thomas Gleixner <tglx@linutronix.de> CC: Eric Dumazet <eric.dumazet@gmail.com> CC: Richard Cochran <richardcochran@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-02-21Merge tag 'cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-socLinus Torvalds1-3/+1
Pull ARM SoC cleanups from Arnd Bergmann: "A large number of cleanups, all over the platforms. This is dominated largely by the Samsung platforms (s3c, s5p, exynos) and a few of the others moving code out of arch/arm into more appropriate subsystems. The clocksource and irqchip drivers are now abstracted to the point where platforms that are already cleaned up do not need to even specify the driver they use, it can all get configured from the device tree as we do for normal device drivers. The clocksource changes basically touch every single platform in the process. We further clean up the use of platform specific header files here, with the goal of turning more of the platforms over to being "multiplatform" enabled, which implies that they cannot expose their headers to architecture independent code any more. It is expected that no functional changes are part of the cleanup. The overall reduction in total code lines is mostly the result of removing broken and obsolete code." * tag 'cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (133 commits) ARM: mvebu: correct gated clock documentation ARM: kirkwood: add missing include for nsa310 ARM: exynos: move exynos4210-combiner to drivers/irqchip mfd: db8500-prcmu: update resource passing drivers/db8500-cpufreq: delete dangling include ARM: at91: remove NEOCORE 926 board sunxi: Cleanup the reset code and add meaningful registers defines ARM: S3C24XX: header mach/regs-mem.h local ARM: S3C24XX: header mach/regs-power.h local ARM: S3C24XX: header mach/regs-s3c2412-mem.h local ARM: S3C24XX: Remove plat-s3c24xx directory in arch/arm/ ARM: S3C24XX: transform s3c2443 subirqs into new structure ARM: S3C24XX: modify s3c2443 irq init to initialize all irqs ARM: S3C24XX: move s3c2443 irq code to irq.c ARM: S3C24XX: transform s3c2416 irqs into new structure ARM: S3C24XX: modify s3c2416 irq init to initialize all irqs ARM: S3C24XX: move s3c2416 irq init to common irq code ARM: S3C24XX: Modify s3c_irq_wake to use the hwirq property ARM: S3C24XX: Move irq syscore-ops to irq-pm clocksource: always define CLOCKSOURCE_OF_DECLARE ...
2013-02-08time, Fix setting of hardware clock in NTP codePrarit Bhargava1-0/+1
At init time, if the system time is "warped" forward in warp_clock() it will differ from the hardware clock by sys_tz.tz_minuteswest. This time difference is not taken into account when ntp updates the hardware clock, and this causes the system time to jump forward by this offset every reboot. The kernel must take this offset into account when writing the system time to the hardware clock in the ntp code. This patch adds persistent_clock_is_local which indicates that an offset has been applied in warp_clock() and accounts for the "warp" before writing the hardware clock. x86 does not have this problem as rtc writes are software limited to a +/-15 minute window relative to the current rtc time. Other arches, such as powerpc, however do a full synchronization of the system time to the rtc and will see this problem. [v2]: generated against tip/timers/core Signed-off-by: Prarit Bhargava <prarit@redhat.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-01-29timekeeping: Switch HAS_PERSISTENT_CLOCK to ALWAYS_USE_PERSISTENT_CLOCKJohn Stultz1-1/+1
Jason pointed out the HAS_PERSISTENT_CLOCK name isn't quite accurate for the config, as some systems may have the persistent_clock in some cases, but not always. So change the config name to the more clear ALWAYS_USE_PERSISTENT_CLOCK. Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-01-15timekeeping: Add CONFIG_HAS_PERSISTENT_CLOCK optionFeng Tang1-0/+5
Make the persistent clock check a kernel config option, so that some platform can explicitely select it, also make CONFIG_RTC_HCTOSYS and RTC_SYSTOHC depend on its non-existence, which could prevent the persistent clock and RTC code from doing similar thing twice during system's init/suspend/resume phases. If the CONFIG_HAS_PERSISTENT_CLOCK=n, then no change happens for kernel which still does the persistent clock check in timekeeping_init(). Cc: Thomas Gleixner <tglx@linutronix.de> Suggested-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Feng Tang <feng.tang@intel.com> [jstultz: Added dependency for RTC_SYSTOHC as well] Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-01-15timekeeping: Add persistent_clock_exist flagFeng Tang1-0/+6
In current kernel, there are several places which need to check whether there is a persistent clock for the platform. Current check is done by calling the read_persistent_clock() and validating its return value. So one optimization is to do the check only once in timekeeping_init(), and use a flag persistent_clock_exist to record it. v2: Add a has_persistent_clock() helper function, as suggested by John. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-01-15time: create __getnstimeofday for WARNless callsKees Cook1-0/+1
The pstore RAM backend can get called during resume, and must be defensive against a suspended time source. Expose getnstimeofday logic that returns an error instead of a WARN. This can be detected and the timestamp can be zeroed out. Reported-by: Doug Anderson <dianders@chromium.org> Cc: John Stultz <johnstul@us.ibm.com> Cc: Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
2012-12-24time: convert arch_gettimeoffset to a pointerStephen Warren1-3/+1
Currently, whenever CONFIG_ARCH_USES_GETTIMEOFFSET is enabled, each arch core provides a single implementation of arch_gettimeoffset(). In many cases, different sub-architectures, different machines, or different timer providers exist, and so the arch ends up implementing arch_gettimeoffset() as a call-through-pointer anyway. Examples are ARM, Cris, M68K, and it's arguable that the remaining architectures, M32R and Blackfin, should be doing this anyway. Modify arch_gettimeoffset so that it itself is a function pointer, which the arch initializes. This will allow later changes to move the initialization of this function into individual machine support or timer drivers. This is particularly useful for code in drivers/clocksource which should rely on an arch-independant mechanism to register their implementation of arch_gettimeoffset(). This patch also converts the Cris architecture to set arch_gettimeoffset directly to the final implementation in time_init(), because Cris already had separate time_init() functions per sub-architecture. M68K and ARM are converted to set arch_gettimeoffset to the final implementation in later patches, because they already have function pointers in place for this purpose. Cc: Russell King <linux@arm.linux.org.uk> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Mikael Starvik <starvik@axis.com> Cc: Hirokazu Takata <takata@linux-m32r.org> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: Stephen Warren <swarren@nvidia.com>
2012-10-13UAPI: (Scripted) Disintegrate include/linuxDavid Howells1-71/+1
Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Dave Jones <davej@redhat.com>
2012-09-01time: Move ktime_t overflow checking into timespec_valid_strictJohn Stultz1-0/+7
Andreas Bombe reported that the added ktime_t overflow checking added to timespec_valid in commit 4e8b14526ca7 ("time: Improve sanity checking of timekeeping inputs") was causing problems with X.org because it caused timeouts larger then KTIME_T to be invalid. Previously, these large timeouts would be clamped to KTIME_MAX and would never expire, which is valid. This patch splits the ktime_t overflow checking into a new timespec_valid_strict function, and converts the timekeeping codes internal checking to use this more strict function. Reported-and-tested-by: Andreas Bombe <aeb@debian.org> Cc: Zhouping Liu <zliu@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-15time: Improve sanity checking of timekeeping inputsJohn Stultz1-2/+20
Unexpected behavior could occur if the time is set to a value large enough to overflow a 64bit ktime_t (which is something larger then the year 2262). Also unexpected behavior could occur if large negative offsets are injected via adjtimex. So this patch improves the sanity check timekeeping inputs by improving the timespec_valid() check, and then makes better use of timespec_valid() to make sure we don't set the time to an invalid negative value or one that overflows ktime_t. Note: This does not protect from setting the time close to overflowing ktime_t and then letting natural accumulation cause the overflow. Reported-by: CAI Qian <caiqian@redhat.com> Reported-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Zhouping Liu <zliu@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1344454580-17031-1-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-07-26posix_types.h: Cleanup stale __NFDBITS and related definitionsJosh Boyer1-8/+0
Recently, glibc made a change to suppress sign-conversion warnings in FD_SET (glibc commit ceb9e56b3d1). This uncovered an issue with the kernel's definition of __NFDBITS if applications #include <linux/types.h> after including <sys/select.h>. A build failure would be seen when passing the -Werror=sign-compare and -D_FORTIFY_SOURCE=2 flags to gcc. It was suggested that the kernel should either match the glibc definition of __NFDBITS or remove that entirely. The current in-kernel uses of __NFDBITS can be replaced with BITS_PER_LONG, and there are no uses of the related __FDELT and __FDMASK defines. Given that, we'll continue the cleanup that was started with commit 8b3d1cda4f5f ("posix_types: Remove fd_set macros") and drop the remaining unused macros. Additionally, linux/time.h has similar macros defined that expand to nothing so we'll remove those at the same time. Reported-by: Jeff Law <law@redhat.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> CC: <stable@vger.kernel.org> Signed-off-by: Josh Boyer <jwboyer@redhat.com> [ .. and fix up whitespace as per akpm ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-21time: remove obsolete declarationRichard Cochran1-1/+0
The function, timekeeping_leap_insert, was removed in commit 6b43ae8a619d17c4935c3320d2ef9e92bdeed05d Signed-off-by: Richard Cochran <richardcochran@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2012-03-29Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-0/+1
Pull x32 support for x86-64 from Ingo Molnar: "This tree introduces the X32 binary format and execution mode for x86: 32-bit data space binaries using 64-bit instructions and 64-bit kernel syscalls. This allows applications whose working set fits into a 32 bits address space to make use of 64-bit instructions while using a 32-bit address space with shorter pointers, more compressed data structures, etc." Fix up trivial context conflicts in arch/x86/{Kconfig,vdso/vma.c} * 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits) x32: Fix alignment fail in struct compat_siginfo x32: Fix stupid ia32/x32 inversion in the siginfo format x32: Add ptrace for x32 x32: Switch to a 64-bit clock_t x32: Provide separate is_ia32_task() and is_x32_task() predicates x86, mtrr: Use explicit sizing and padding for the 64-bit ioctls x86/x32: Fix the binutils auto-detect x32: Warn and disable rather than error if binutils too old x32: Only clear TIF_X32 flag once x32: Make sure TS_COMPAT is cleared for x32 tasks fs: Remove missed ->fds_bits from cessation use of fd_set structs internally fs: Fix close_on_exec pointer in alloc_fdtable x32: Drop non-__vdso weak symbols from the x32 VDSO x32: Fix coding style violations in the x32 VDSO code x32: Add x32 VDSO support x32: Allow x32 to be configured x32: If configured, add x32 system calls to system call tables x32: Handle process creation x32: Signal-related system calls x86: Add #ifdef CONFIG_COMPAT to <asm/sys_ia32.h> ...
2012-03-23time: remove no_sync_cmos_clockCesar Eduardo Barros1-1/+0
Commit 9863c90f682fba34cdc26c3437e8c00da6c83fa4 (x86, vmware: Remove deprecated VMI kernel support) removed the only place which set no_sync_cmos_clock. Since that commit, this variable is never set. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Signed-off-by: John Stultz <john.stultz@linaro.org>
2012-02-19Delete the __FD_*() funcs for operating on fd_set from linux/time.hDavid Howells1-23/+0
Delete the __FD_*() functions for operating on fd_set structs from linux/time.h as they're no longer used within the kernel with the preceding patch and are not exported to userspace. Whilst linux/time.h *does* export the FD_*() equivalents as wrappers around __FD_*(), userspace provides its own definition of __FD_*(). Note that the definition of FD_ZERO() in linux/time.h may not be used with the fd_sets associated with struct fdtable as the fd_set may have been allocated in a truncated fashion. Signed-off-by: David Howells <dhowells@redhat.com> Link: http://lkml.kernel.org/r/20120216175006.23314.18984.stgit@warthog.procyon.org.uk Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Al Viro <viro@zeniv.linux.org.uk>
2012-02-14posix_types: Remove fd_set macrosH. Peter Anvin1-0/+24
<asm/posix_types.h> includes a set of macros that operate on file descriptors. Way long ago those were exported to user space, but nowadays they are #ifdef __KERNEL__. However, they are nothing but standard (nonatomic) bit operations, and we already have optimized versions of bit operations in the kernel. We can't include <linux/bitops.h> in <asm/posix_types.h> but we can move the definitions to <linux/time.h> and define them there in terms of standard kernel bitops. [ v2: folds the following fixes in: a) Stray space in __FD_SET(), reported by Andrew Morton b) #include <linux/string.h> needed for memset(), reported by Tony Luck ] Signed-off-by: H. Peter Anvin <hpa@zytor.com> Link: http://lkml.kernel.org/r/1328677745-20121-22-git-send-email-hpa@zytor.com Cc: Arnd Bergmann <arnd@arndb.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org>
2011-04-26timers: Posix interface for alarm-timersJohn Stultz1-0/+2
This patch exposes alarm-timers to userland via the posix clock and timers interface, using two new clockids: CLOCK_REALTIME_ALARM and CLOCK_BOOTTIME_ALARM. Both clockids behave identically to CLOCK_REALTIME and CLOCK_BOOTTIME, respectively, but timers set against the _ALARM suffixed clockids will wake the system if it is suspended. Some background can be found here: https://lwn.net/Articles/429925/ The concept for Alarm-timers was inspired by the Android Alarm driver (by Arve Hjønnevåg) found in the Android kernel tree. See: http://android.git.kernel.org/?p=kernel/common.git;a=blob;f=drivers/rtc/alarm.c;h=1250edfbdf3302f5e4ea6194847c6ef4bb7beb1c;hb=android-2.6.36 While the in-kernel interface is pretty similar between alarm-timers and Android alarm driver, the user-space interface for the Android alarm driver is via ioctls to a new char device. As mentioned above, I've instead chosen to export this functionality via the posix interface, as it seemed a little simpler and avoids creating duplicate interfaces to things like CLOCK_REALTIME and CLOCK_MONOTONIC under alternate names (ie:ANDROID_ALARM_RTC and ANDROID_ALARM_SYSTEMTIME). The semantics of the Android alarm driver are different from what this posix interface provides. For instance, threads other then the thread waiting on the Android alarm driver are able to modify the alarm being waited on. Also this interface does not allow the same wakelock semantics that the Android driver provides (ie: kernel takes a wakelock on RTC alarm-interupt, and holds it through process wakeup, and while the process runs, until the process either closes the char device or calls back in to wait on a new alarm). One potential way to implement similar semantics may be via the timerfd infrastructure, but this needs more research. There may also need to be some sort of sysfs system level policy hooks that allow alarm timers to be disabled to keep them from firing at inappropriate times (ie: laptop in a well insulated bag, mid-flight). CC: Arve Hjønnevåg <arve@android.com> CC: Thomas Gleixner <tglx@linutronix.de> CC: Alessandro Zummo <a.zummo@towertech.it> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
2011-04-26time: Add timekeeping_inject_sleeptimeJohn Stultz1-0/+1
Some platforms cannot implement read_persistent_clock, as their RTC devices are only accessible when interrupts are enabled. This keeps them from being used by the timekeeping code on resume to measure the time in suspend. The RTC layer tries to work around this, by calling do_settimeofday on resume after irqs are reenabled to set the time properly. However, this only corrects CLOCK_REALTIME, and does not properly adjust the sleep time value. This causes btime in /proc/stat to be incorrect as well as making the new CLOCK_BOTTTIME inaccurate. This patch resolves the issue by introducing a new timekeeping hook to allow the RTC layer to inject the sleep time on resume. The code also checks to make sure that read_persistent_clock is nonfunctional before setting the sleep time, so that should the RTC's HCTOSYS option be configured in on a system that does support read_persistent_clock we will not increase the total_sleep_time twice. CC: Arve Hjønnevåg <arve@android.com> CC: Thomas Gleixner <tglx@linutronix.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: John Stultz <john.stultz@linaro.org>