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2019-09-25fix data race in timer_create with SIGEV_THREAD notificationRich Felker1-2/+2
in the timer thread start function, self->timer_id was accessed without synchronization; the timer thread could fail to see the store from the calling thread, resulting in timer_delete failing to delete the correct kernel-level timer. this fix is based on a patch by changdiankang, but with the load moved to after receiving the timer_delete signal rather than just after the start barrier, so as not to retain the possibility of data race with timer_delete.
2019-08-07in clock_getres, check for null pointer before storing resultRich Felker1-1/+1
POSIX allows a null pointer, in which case the function only checks the validity of the clock id argument.
2019-08-07remove spurious null check in clock_settimeRich Felker1-1/+1
at the point of this check, the pointer has already been dereferenced. clock_settime is not defined for null pointer arguments.
2019-08-05fix regression in clock_gettime on 32-bit archs without vdsoRich Felker1-0/+1
commit 72f50245d018af0c31b38dec83c557a4e5dd1ea8 broke this by creating a code path where r is uninitialized.
2019-08-02clock_gettime: add support for 32-bit vdso with 64-bit time_tRich Felker1-0/+32
this fixes a major upcoming performance regression introduced by commit 72f50245d018af0c31b38dec83c557a4e5dd1ea8, whereby 32-bit archs would lose vdso clock_gettime after switching to 64-bit time_t, unless the kernel supports time64 and provides a time64 version of the vdso function. this would incur not just one but two syscalls: first, the failed time64 syscall, then the fallback time32 one. overflow of the 32-bit result is detected and triggers a revert to syscalls. normally, on a system that's not Y2038-ready, this would still overflow, but if the process has been migrated to a time64-capable kernel or if the kernel has been hot-patched to add time64 syscalls, it may conceivably work.
2019-08-02clock_gettime: add time64 syscall support, decouple 32-bit time_tRich Felker1-0/+19
the time64 syscall has to be used if time_t is 64-bit, since there's no way of knowing before making a syscall whether the result will fit in 32 bits, and the 32-bit syscalls do not report overflow as an error. on 64-bit archs, there is no change to the code after preprocessing. on current 32-bit archs, the result is now read from the kernel through long[2] array, then copied into the timespec, to remove the assumption that time_t is the same as long. vdso clock_gettime is still used in place of a syscall if available. 32-bit archs with 64-bit time_t must use the time64 version of the vdso function; if it's not available, performance will significantly suffer. support for both vdso functions could be added, but would break the ability to move a long-lived process from a pre-time64 kernel to one that can outlast Y2038 with checkpoint/resume, at least without added hacks to identify that the 32-bit function is no longer usable and stop using it (e.g. by seeing negative tv_sec). this possibility may be explored in future work on the function.
2019-07-29clock_getres: don't assume time_t is 32-bit on 32-bit archsRich Felker1-0/+14
the time64 syscall for this is not necessary or useful, since clock resolution is generally better than 68-year granularity. if there's a 32-bit syscall, use it and expand the result into timespec; otherwise there is only one syscall and it does the right thing to store to timespec directly. on 64-bit archs, there is no change to the code after preprocessing.
2019-07-29timer_gettime: add time64 syscall support, decouple 32-bit time_tRich Felker1-0/+16
the time64 syscall has to be used if time_t is 64-bit, since there's no way of knowing before making a syscall whether the result will fit in 32 bits, and the 32-bit syscalls do not report overflow as an error. on 64-bit archs, there is no change to the code after preprocessing. on current 32-bit archs, the result is now read from the kernel through long[4] array, then copied into the timespec, to remove the assumption that time_t is the same as long.
2019-07-29clock_settime: add time64 syscall support, decouple 32-bit time_tRich Felker1-0/+17
time64 syscall is used only if it's the only one defined for the arch, or if the requested time does not fit in 32 bits. on current 32-bit archs where time_t is a 32-bit type, this makes it statically unreachable. if the time64 syscall is needed because the requested time does not fit in 32 bits, we define this as an error ENOTSUP, for "The implementation does not support the requested feature or value". on 64-bit archs, there is no change to the code after preprocessing. on current 32-bit archs, the time is moved through an intermediate copy to remove the assumption that time_t is a 32-bit type.
2019-07-29timer_settime: add support for time64 syscall, decouple 32-bit time_tRich Felker1-0/+25
time64 syscall is used only if it's the only one defined for the arch, if either component of the itimerspec does not fit in 32 bits, or if time_t is 64-bit and the caller requested the old value, in which case there's a possibility that the old value might not fit in 32 bits. on current 32-bit archs where time_t is a 32-bit type, this makes it statically unreachable. on 64-bit archs, there is no change to the code after preprocessing. on current 32-bit archs, the time is moved through an intermediate copy to remove the assumption that time_t is a 32-bit type.
2019-07-28clock_nanosleep: add time64 syscall support, decouple 32-bit time_tRich Felker1-0/+25
time64 syscall is used only if it's the only one defined for the arch, or if the requested time does not fit in 32 bits. on current 32-bit archs where time_t is a 32-bit type, this makes it statically unreachable. on 64-bit archs, there is no change to the code after preprocessing. on current 32-bit archs, the time is moved through an intermediate copy to remove the assumption that time_t is a 32-bit type.
2019-07-27refactor thrd_sleep and nanosleep in terms of clock_nanosleepRich Felker2-4/+8
for namespace-safety with thrd_sleep, this requires an alias, which is also added. this eliminates all but one direct call point for nanosleep syscalls, and arranges that 64-bit time_t conversion logic will only need to exist in one file rather than three. as a bonus, clock_nanosleep with CLOCK_REALTIME and empty flags is now implemented as SYS_nanosleep, thereby working on older kernels that may lack POSIX clocks functionality.
2019-02-15always block signals for starting new threads, refactor start argsRich Felker1-1/+0
whether signals need to be blocked at thread start, and whether unblocking is necessary in the entry point function, has historically depended on intricacies of the cancellation design and on whether there are scheduling operations to perform on the new thread before its successful creation can be committed. future changes to track an AS-safe list of live threads will require signals to be blocked whenever changes are made to the list, so ... prior to commits b8742f32602add243ee2ce74d804015463726899 and 40bae2d32fd6f3ffea437fa745ad38a1fe77b27e, a signal mask for the entry function to restore was part of the pthread structure. it was removed to trim down the size of the structure, which both saved a small amount of stack space and improved code generation on archs where small immediate displacements are less costly than arbitrary ones, by limiting the range of offsets between the base of the thread structure, its members, and the thread pointer. these commits moved the saved mask to a special structure used only when special scheduling was needed, in which case the pthread_create caller and new thread had to synchronize with each other and could use this memory to pass a mask. this commit partially reverts the above two commits, but instead of putting the mask back in the pthread structure, it moves all "start argument" members out of the pthread structure, trimming it down further, and puts them in a separate structure passed on the new thread's stack. the code path for explicit scheduling of the new thread is also changed to synchronize with the calling thread in such a way to avoid spurious futex wakes.
2019-02-15for SIGEV_THREAD timer threads, replace signal handler with sigwaitinfoRich Felker2-21/+16
this eliminates some ugly hacks that were repurposing the start function and start argument fields in the pthread structure for timer use, and the need to longjmp out of a signal handler.
2019-01-21fix call to __pthread_tsd_run_dtors with too many argumentsRich Felker1-1/+1
commit a6054e3c94aa0491d7366e4b05ae0d73f661bfe2 removed the argument, making it a constraint violation to pass one. caught by cparser/firm; other compilers seem to ignore it.
2018-10-22don't omit setting errno in internal __map_file functionRich Felker1-2/+2
a caller needs the reason for open (or fstat, albeit unlikely) failure if it's going to make decisions about continuing a path search or similar.
2018-09-15always reset DST rules during tzsetBenjamin Peterson1-1/+2
do_tzset() did't always reset the DST transition rules r0 and r1. That means the rules from older TZ settings could leak into newer ones.
2018-09-12split internal lock API out of libc.h, creating lock.hRich Felker1-0/+1
this further reduces the number of source files which need to include libc.h and thereby be potentially exposed to libc global state and internals. this will also facilitate further improvements like adding an inline fast-path, if we want to do so later.
2018-09-12reduce spurious inclusion of libc.hRich Felker8-8/+1
libc.h was intended to be a header for access to global libc state and related interfaces, but ended up included all over the place because it was the way to get the weak_alias macro. most of the inclusions removed here are places where weak_alias was needed. a few were recently introduced for hidden. some go all the way back to when libc.h defined CANCELPT_BEGIN and _END, and all (wrongly implemented) cancellation points had to include it. remaining spurious users are mostly callers of the LOCK/UNLOCK macros and files that use the LFS64 macro to define the awful *64 aliases. in a few places, new inclusion of libc.h is added because several internal headers no longer implicitly include libc.h. declarations for __lockfile and __unlockfile are moved from libc.h to stdio_impl.h so that the latter does not need libc.h. putting them in libc.h made no sense at all, since the macros in stdio_impl.h are needed to use them correctly anyway.
2018-09-12move declaration and apply hidden visibility to __utc stringRich Felker3-4/+1
2018-09-12remove or make static various unused __-prefixed symbolsRich Felker1-1/+1
2018-09-12apply hidden visibility to internal time[zone] implementation functionsRich Felker1-8/+8
2018-09-12overhaul internally-public declarations using wrapper headersRich Felker11-23/+1
commits leading up to this one have moved the vast majority of libc-internal interface declarations to appropriate internal headers, allowing them to be type-checked and setting the stage to limit their visibility. the ones that have not yet been moved are mostly namespace-protected aliases for standard/public interfaces, which exist to facilitate implementing plain C functions in terms of POSIX functionality, or C or POSIX functionality in terms of extensions that are not standardized. some don't quite fit this description, but are "internally public" interfacs between subsystems of libc. rather than create a number of newly-named headers to declare these functions, and having to add explicit include directives for them to every source file where they're needed, I have introduced a method of wrapping the corresponding public headers. parallel to the public headers in $(srcdir)/include, we now have wrappers in $(srcdir)/src/include that come earlier in the include path order. they include the public header they're wrapping, then add declarations for namespace-protected versions of the same interfaces and any "internally public" interfaces for the subsystem they correspond to. along these lines, the wrapper for features.h is now responsible for the definition of the hidden, weak, and weak_alias macros. this means source files will no longer need to include any special headers to access these features. over time, it is my expectation that the scope of what is "internally public" will expand, reducing the number of source files which need to include *_impl.h and related headers down to those which are actually implementing the corresponding subsystems, not just using them.
2018-09-12move declarations of tls setup/access functions to pthread_impl.hRich Felker1-2/+0
it's already included in all places where these are needed, and aside from __tls_get_addr, they're all implementation internals.
2018-09-12move __strftime_fmt_1 declaration to time_impl.hRich Felker2-2/+2
this is a helper function from strftime that's also used by wcsftime.
2018-09-12move __tm_to_tzname declaration to time_impl.h with related functionsRich Felker2-1/+1
this function was added later for strftime use and the existence of time_impl.h as the appropriate place for it seems to have been overlooked.
2018-09-12fix type-mismatched declarations of __nl_langinfo_l in source filesRich Felker2-2/+2
obviously the type "should be" const, but it inherited non-const from the standard nl_langinfo_l.
2018-09-12use idiomatic weak alias approach for defining asctime_rRich Felker3-33/+28
get rid of a gratuitous translation unit and call frame between asctime_r and the actual implementation of the function. this is the way gmtime_r and localtime_r are already done.
2018-09-12move and deduplicate declarations of __vdsosym to make it checkableRich Felker1-2/+0
2018-08-27time: fix incorrect DST offset when using POSIX timezones without DSTA. Wilcox1-1/+1
This manifests itself in mktime if tm_isdst = 1 and the current TZ= is a POSIX timezone specification. mktime would see that tm_isdst was set to 0 by __secs_to_zone, and subtract 'oppoff' (dst_off) - gmtoff from the resultant time. This meant that mktime returned a time that was exactly double the GMT offset of the desired timezone when tm_isdst was = 1.
2018-08-07fix sign of strftime %z output with offsets <1 hour west of UTCRich Felker1-3/+2
the sign character produced came from the sign of tm_gmtoff/3600 as an integer division, which is zero for negative offsets smaller in magnitude than 3600. instead of printing the hours and minutes as separate fields, print them as a single value of the form hours*100+minutes, which naturally has the correct sign.
2018-06-26strftime: fix underlying format string in %z formatDaniel Sabogal1-1/+1
the expression (tm->__tm_gmtoff)/3600 has type long. use %+.2ld instead.
2018-04-07implement wcsftime padding specifier extensionsSamuel Holland1-3/+5
Commit 8a6bd7307da3fc4d08dd6a9277b611ccb4971354 added support for padding specifier extensions to strftime, but did not modify wcsftime. In the process, it added a parameter to __strftime_fmt_1 in strftime.c, but failed to update the prototype in wcsftime.c. This was found by compiling musl with LTO: src/time/wcsftime.c:7:13: warning: type of '__strftime_fmt_1' does \ not match original declaration [-Wlto-type-mismatch] Fix the prototype of __strftime_fmt_1 in wcsftime.c, and generate the 'pad' argument the same way as it is done in strftime.
2018-02-06adjust strftime + modifier to match apparent intent of POSIXRich Felker1-6/+12
it's unclear from the specification whether the word "consumes" in "consumes more than four bytes to represent a year" refers just to significant places or includes leading zeros due to field width padding. however the examples in the rationale indicate that the latter was the intent. in particular, the year 270 is shown being formatted by %+5Y as +0270 rather than 00270. previously '+' prefixing was implemented just by comparing the year against 10000. instead, count the number of significant digits and padding bytes to be added, and use the total to determine whether to apply the '+' prefix. based on testing by Dennis Wölfing.
2018-02-05fix strftime field widths with %F format and zero yearRich Felker1-1/+2
the code to strip initial sign and leading zeros inadvertently stripped all the zeros and the subsequent '-' separating the month. instead, only strip sign characters from the very first position, and only strip zeros when they are followed by another digit. based on testing by Dennis Wölfing.
2018-01-09revise the definition of multiple basic locks in the codeJens Gustedt1-1/+1
In all cases this is just a change from two volatile int to one.
2017-12-14use the name UTC instead of GMT for UTC timezoneNatanael Copa3-12/+12
notes by maintainer: both C and POSIX use the term UTC to specify related functionality, despite POSIX defining it as something more like UT1 or historical (pre-UTC) GMT without leap seconds. neither specifies the associated string for %Z. old choice of "GMT" violated principle of least surprise for users and some applications/tests. use "UTC" instead.
2017-12-11implement strftime padding specifier extensionsTimo Teräs1-8/+14
notes added by maintainer: the '-' specifier allows default padding to be suppressed, and '_' allows padding with spaces instead of the default (zeros). these extensions seem to be included in several other implementations including FreeBSD and derivatives, and Solaris. while portable software should not depend on them, time format strings are often exposed to the user for configurable time display. reportedly some python programs also use and depend on them.
2017-11-09fix mismatched type of __pthread_tsd_run_dtors weak definitionRich Felker1-2/+2
commit a6054e3c94aa0491d7366e4b05ae0d73f661bfe2 changed this function not to take an argument, but the weak definition used by timer_create was not updated to match. reported by Pascal Cuoq.
2017-06-20handle errors from localtime_r in ctime_rRich Felker1-3/+2
POSIX requires ctime_r return a null pointer on failure, which can occur if the input time_t value is not representable in broken down form. based on patch by Alexander Monakov.
2017-06-15handle localtime errors in ctimeRich Felker1-1/+3
ctime passes the result from localtime directly to asctime. But in case of error, localtime returns 0. This causes an error (NULL pointer dereference) in asctime. based on patch by Omer Anson.
2017-06-14getdate: correctly specify error numberA. Wilcox1-1/+2
POSIX defines getdate error #5 as: "An I/O error is encountered while reading the template file." POSIX defines getdate error #7 as: "There is no line in the template that matches the input." This change correctly disambiguates between the two error conditions.
2017-03-21fix strptime output for %C without %yJulien Ramseier1-2/+3
in this case, a potentially-uninitialized or unrelated existing value in tm_year was being used. instead use 0 if %y was not present.
2017-03-21fix processing of strptime %p formatJulien Ramseier1-0/+2
string pointer was not advanced after matching.
2017-03-21fix off-by-one in strptime %jJulien Ramseier1-0/+1
tm_yday range is 0-365 while %j is 1-366
2017-03-15fix POSIX-format TZ dst transition times for southern hemisphereRich Felker1-8/+4
the time of day at which daylight time switches over is specified in local time in the dst state prior to the transition. the code for handling this wrongly assumed it needed to switch whether dst or standard offset is applied to the transition time when the dst end date is before the dst start date (souther hemisphere summer), but in fact the end transition time should always be adjusted for dst, and the start transition time should always be adjusted for standard time.
2017-01-02fix strftime %y for negative yearsRich Felker1-2/+2
commit 583ea83541dcc6481c7a1bd1a9b485526bad84a1 fixed the case where tm_year is negative but the resulting year (offset by 1900) was still positive, which is always the case for time_t values that fit in 32 bits, but not for arbitrary inputs. based on an earlier patch by Julien Ramseier which was overlooked at the time the previous fix was applied.
2016-11-07fix integer overflow of tm_year in __secs_to_tmDaniel Sabogal1-4/+5
the overflow check for years+100 did not account for the extra year computed from the remaining months. instead, perform this check after obtaining the final number of years.
2016-11-07fix parsing of quoted time zone namesHannu Nyman1-1/+1
Fix parsing of the < > quoted time zone names. Compare the correct character instead of repeatedly comparing the first character.
2016-10-20fix gratuitous undefined behavior in strptimeRich Felker1-2/+7
accessing an object of type const char *restrict as if it had type char * is not defined.