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2011-04-18recheck cancellation disabled flag after syscall returns EINTRRich Felker-1/+1
we already checked before making the syscall, but it's possible that a signal handler interrupted the blocking syscall and disabled cancellation, and that this is the cause of EINTR. in this case, the old behavior was testably wrong.
2011-04-18remove bogus extra logic for close cancellabilityRich Felker-3/+1
like all other syscalls, close should return to the caller if and only if it successfully performed its action. it is necessary that the application be able to determine whether the close succeeded.
2011-04-17fix typo in x86_64 cancellable syscall asmRich Felker-1/+1
2011-04-17minimal realpath implementation using /procRich Felker-0/+43
clean and simple, but fails when the caller does not have permissions to open the file for reading or when /proc is not available. i may replace this with a full implementation later, possibly leaving this version as an optimization to use when it works.
2011-04-17pthread_exit is not supposed to affect cancellabilityRich Felker-2/+0
if the exit was caused by cancellation, __cancel has already set these flags anyway.
2011-04-17fix pthread_exit from cancellation handlerRich Felker-5/+5
cancellation frames were not correctly popped, so this usage would not only loop, but also reuse discarded and invalid parts of the stack.
2011-04-17clean up handling of thread/nothread mode, lockingRich Felker-27/+16
2011-04-17debloat: use __syscall instead of syscall where possibleRich Felker-8/+8
don't waste time (and significant code size due to function call overhead!) setting errno when the result of a syscall does not matter or when it can't fail.
2011-04-17fix bugs in cancellable syscall asmRich Felker-11/+12
x86_64 was just plain wrong in the cancel-flag-already-set path, and crashing. the more subtle error was not clearing the saved stack pointer before returning to c code. this could result in the signal handler misidentifying c code as the pre-syscall part of the asm, and acting on cancellation at the wrong time, and thus resource leak race conditions. also, now __cancel (in the c code) is responsible for clearing the saved sp in the already-cancelled branch. this means we have to use call rather than jmp to ensure the stack pointer in the c will never match what the asm saved.
2011-04-17optimize cancellation enable/disable codeRich Felker-4/+11
the goal is to be able to use pthread_setcancelstate internally in the implementation, whenever a function might want to use functions which are cancellation points but avoid becoming a cancellation point itself. i could have just used a separate internal function for temporarily inhibiting cancellation, but the solution in this commit is better because (1) it's one less implementation-specific detail in functions that need to use it, and (2) application code can also get the same benefit. previously, pthread_setcancelstate dependend on pthread_self, which would pull in unwanted thread setup overhead for non-threaded programs. now, it temporarily stores the state in the global libc struct if threads have not been initialized, and later moves it if needed. this way we can instead use __pthread_self, which has no dependencies and assumes that the thread register is already valid.
2011-04-17don't use pthread_once when there is no danger in raceRich Felker-2/+5
2011-04-17fix some minor issues in cancellation handling patchRich Felker-11/+19
signals were wrongly left masked, and cancellability state was not switched to disabled, during the execution of cleanup handlers.
2011-04-17overhaul pthread cancellationRich Felker-227/+247
this patch improves the correctness, simplicity, and size of cancellation-related code. modulo any small errors, it should now be completely conformant, safe, and resource-leak free. the notion of entering and exiting cancellation-point context has been completely eliminated and replaced with alternative syscall assembly code for cancellable syscalls. the assembly is responsible for setting up execution context information (stack pointer and address of the syscall instruction) which the cancellation signal handler can use to determine whether the interrupted code was in a cancellable state. these changes eliminate race conditions in the previous generation of cancellation handling code (whereby a cancellation request received just prior to the syscall would not be processed, leaving the syscall to block, potentially indefinitely), and remedy an issue where non-cancellable syscalls made from signal handlers became cancellable if the signal handler interrupted a cancellation point. x86_64 asm is untested and may need a second try to get it right.
2011-04-15remove stupid debug code in wordexpRich Felker-1/+0
2011-04-15implement wordexp. first try, may be buggy. intended to be safe.Rich Felker-0/+128
2011-04-15avoid setting errno when checking for ttyRich Felker-2/+2
setting errno here is completely valid, but some programs, notably busybox printf, assume that errno will not be set during output and treat this as an error condition. in any case, skipping it slightly reduces code size and saves time.
2011-04-14document some changes in the upcoming releaseRich Felker-1/+18
2011-04-14fix O_SYNC definition, cleanup fcntl.hRich Felker-22/+18
2011-04-14fix FAPPEND typo on x86_64 (previously only fixed on i386)Rich Felker-1/+1
2011-04-14fcntl.h: move macros that do not vary between archs out of bitsRich Felker-48/+24
2011-04-14fix broken fcntl locks on x86_64Rich Felker-3/+3
2011-04-14make tmpfile slightly more efficient (use unlink syscall instead of remove)Rich Felker-1/+1
2011-04-14fix typo in legacy FAPPEND definitionRich Felker-1/+1
2011-04-14add useless type fd_mask. it's in the reserved namespace.Rich Felker-0/+2
2011-04-14change sem_trywait algorithm so it never has to call __wakeRich Felker-3/+2
2011-04-14cheap trick to further optimize locking normal mutexesRich Felker-2/+2
2011-04-14use a separate signal from SIGCANCEL for SIGEV_THREAD timersRich Felker-11/+29
otherwise we cannot support an application's desire to use asynchronous cancellation within the callback function. this change also slightly debloats pthread_create.c.
2011-04-13simplify cancellation point handlingRich Felker-16/+5
we take advantage of the fact that unless self->cancelpt is 1, cancellation cannot happen. so just increment it by 2 to temporarily block cancellation. this drops pthread_create.o well under 1k.
2011-04-13simplify syslog, add vsyslog interface (nonstandard)Rich Felker-31/+36
with datagram sockets, depending on fprintf not to flush the output early was very fragile; the new version simply uses a small fixed-size buffer. it could be updated to dynamic-allocate large buffers if needed, but i can't envision any admin being happy about finding 64kb-long lines in their syslog...
2011-04-13remove useless SIGPIPE protection from syslogRich Felker-9/+0
per the standard, SIGPIPE is not generated for SOCK_DGRAM.
2011-04-13fix syslog (corrected SIGPIPE blocking, and using dgram instead of stream)Rich Felker-10/+8
it actually appears the hacks to block SIGPIPE are probably not necessary, and potentially harmful. if i can confirm this, i'll remove them.
2011-04-13numerous fixes to sysv ipcRich Felker-66/+96
some of these definitions were just plain wrong, others based on outdated ancient "non-64" versions of the kernel interface. as much as possible has now been moved out of bits/* these changes break abi (the old abi for these functions was wrong), but since they were not working anyway it can hardly matter.
2011-04-13add syslog.h cruft for syslogd to use...Rich Felker-0/+45
2011-04-13add profile for getmntent_rRich Felker-0/+1
2011-04-13add syscall wrapper for flockRich Felker-0/+7
it should be noted that flock does not mix well with standard fcntl locking, but nonetheless some applications will attempt to use flock instead of fcntl if both exist. options to configure or small patches may be needed. debian maintainers have plenty of experience with this unfortunate situation...
2011-04-13fix bug whereby getopt_long allowed mismatch in last char of option nameRich Felker-1/+1
2011-04-13fix typos on RLIM_NLIMITS, remove _GNU_SOURCE test for itRich Felker-3/+1
RLIM_* is in the reserved namespace for this header
2011-04-13fix and cleanup suseconds_t/timeval stuff (broken on 64-bit)Rich Felker-10/+2
trash in the upper 32 bits was making the kernel sleep forever in select on 64-bit systems.
2011-04-13implement getgrouplist (for initgroups), formerly dummied-outv0.7.8Rich Felker-4/+16
2011-04-13fix prototypes/signature for setgroups, etc.Rich Felker-2/+8
2011-04-13fix incorrect GNU sighandler_t typedefRich Felker-1/+1
2011-04-13implement memrchr (nonstandard) and optimize strrchr in terms of itRich Felker-4/+16
2011-04-13add ptsname_r (nonstandard) and split ptsname (standard) to separate fileRich Felker-11/+17
this eliminates the ugly static buffer in programs that use ptsname_r.
2011-04-12speed up threaded forkRich Felker-2/+1
after fork, we have a new process and the pid is equal to the tid of the new main thread. there is no need to make two separate syscalls to obtain the same number.
2011-04-12more changes for upcoming 0.7.8Rich Felker-1/+12
2011-04-12optimize ntohl etc. in terms of bswap functionsRich Felker-20/+12
we can do this without violating the namespace now that they are macros/inline functions rather than extern functions. the motivation is that gcc was generating giant, slow, horrible code for the old functions, and now generates a single byte-swapping instruction.
2011-04-12move bswap functions to static inline in byteswap.hRich Felker-16/+25
2011-04-12fix broken bswap_32Rich Felker-1/+1
2011-04-12utmpx.h is no longer under standards, so expose ut_exit structureRich Felker-3/+3
2011-04-12add some traditional aliases to stat.hRich Felker-0/+6