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2011-09-25fix logic for when wakeup is not desired on cond bcastRich Felker-3/+4
somehow i forgot that normal-type mutexes don't store the owner tid.
2011-09-25new futex-requeue-based pthread_cond_broadcast implementationRich Felker-7/+69
this avoids the "stampede effect" where pthread_cond_broadcast would result in all waiters waking up simultaneously, only to immediately contend for the mutex and go back to sleep.
2011-09-23fix ABA race in cond vars, improve them overallRich Felker-11/+12
previously, a waiter could miss the 1->0 transition of block if another thread set block to 1 again after the signal function set block to 0. we now use the caller's thread id as a unique token to store in block, which no other thread will ever write there. this ensures that if block still contains the tid, no signal has occurred. spurious wakeups will of course occur whenever there is a spurious return from the futex wait and another thread has begun waiting on the cond var. this should be a rare occurrence except perhaps in the presence of interrupting signal handlers. signal/bcast operations have been improved by noting that they need not avoid inspecting the cond var's memory after changing the futex value. because the standard allows spurious wakeups, there is no way for an application to distinguish between a spurious wakeup just before another thread called signal/bcast, and the deliberate wakeup resulting from the signal/bcast call. thus the woken thread must assume that the signalling thread may still be waiting to act on the cond var, and therefore it cannot destroy/unmap the cond var.
2011-09-22fix deadlock in condition wait whenever there are multiple waitersRich Felker-5/+18
it's amazing none of the conformance tests i've run even bothered to check whether something so basic works...
2011-09-21protect against/handle cancellation reading shadow passwordsRich Felker-1/+11
2011-09-21make dns lookups (and thus getaddrinfo) cancellableRich Felker-4/+11
2011-09-21use poll rather than select in dns lookups (also clock_gettime)Rich Felker-12/+10
if the file descriptor resource limit has been increased past FD_SETSIZE, this is actually a security issue; we could write past the end of the fd_set object. using poll makes it a non-issue, and simplifies the code at the same time. also, use clock_gettime instead of gettimeofday, for reduced bloat and better entropy.
2011-09-21avoid setting FILE lock count when not using flockfileRich Felker-1/+1
for now this is just a tiny optimization, but later if we support cancellation from __stdio_read and __stdio_write, it will be necessary for the recusrive lock count to be zero in order for these functions to know they are responsible for unlocking the FILE on cancellation.
2011-09-21update syscalls with off_t arguments to handle argument alignment, if neededRich Felker-8/+8
the arm syscall abi requires 64-bit arguments to be aligned on an even register boundary. these new macros facilitate meeting the abi requirement without imposing significant ugliness on the code.
2011-09-20fix statvfs.c to match new fsid_t definitionRich Felker-1/+1
2011-09-19fix the definition of struct statvfs to match lsb abiRich Felker-19/+46
at the same time, make struct statfs match the traditional definition and make it more useful, especially the fsid_t stuff.
2011-09-19fix incorrect long double parameters on arm (and other future ports)Rich Felker-0/+12
this was the cause of crashes in printf when attempting to print floating point values.
2011-09-18initial commit of the arm portRich Felker-0/+136
this port assumes eabi calling conventions, eabi linux syscall convention, and presence of the kernel helpers at 0xffff0f?0 needed for threads support. otherwise it makes very few assumptions, and the code should work even on armv4 without thumb support, as well as on systems with thumb interworking. the bits headers declare this a little endian system, but as far as i can tell the code should work equally well on big endian. some small details are probably broken; so far, testing has been limited to qemu/aboriginal linux.
2011-09-18disable dynamic linking/loading code in static libc builds, for nowRich Felker-0/+2
it does not work, but some configure scripts will falsely detect support then generate programs that crash when they call dlopen.
2011-09-18overhaul clone syscall wrappingRich Felker-62/+108
several things are changed. first, i have removed the old __uniclone function signature and replaced it with the "standard" linux __clone/clone signature. this was necessary to expose clone to applications anyway, and it makes it easier to port __clone to new archs, since it's now testable independently of pthread_create. secondly, i have removed all references to the ugly ldt descriptor structure (i386 only) from the c code and pthread structure. in places where it is needed, it is now created on the stack just when it's needed, in assembly code. thus, the i386 __clone function takes the desired thread pointer as its argument, rather than an ldt descriptor pointer, just like on all other sane archs. this should not affect applications since there is really no way an application can use clone with threads/tls in a way that doesn't horribly conflict with and clobber the underlying implementation's use. applications are expected to use clone only for creating actual processes, possibly with new namespace features and whatnot.
2011-09-17dummy implementation of set_thread_areaRich Felker-0/+6
eventually we may have a working "generic" implementation for archs that don't need anything special. in any case, the goal of having stubs like this is to allow early testing of new ports before all the details needed for threads have been filled in. more functions like this will follow.
2011-09-16fix assumptions that char is signedRich Felker-2/+2
2011-09-16fix more instances of old a_xchg (use new a_swap name)Rich Felker-3/+3
2011-09-16use a_swap rather than old name a_xchgRich Felker-1/+1
2011-09-16fix generic sigsetjmp (unused anyway) pointer signedness errorRich Felker-1/+1
2011-09-16fix idiotic const-correctness error in lio_listioRich Felker-1/+1
i blame this one on posix for using hideous const-qualified double pointers which are unusable without hideous casts.
2011-09-16fix ptrace (maybe)Rich Felker-1/+8
2011-09-15implement ptrace syscall wrapper (untested)Rich Felker-0/+18
2011-09-14remove incorrectly-made-visible internal dst offset variableRich Felker-1/+0
2011-09-14fix inconsistent signature for aio_errorRich Felker-1/+1
2011-09-13fix return types for aio_read and aio_write againRich Felker-2/+2
previous fix was backwards and propagated the wrong type rather than the right one...
2011-09-13fix various errors in function signatures/prototypes found by nszRich Felker-8/+11
2011-09-13add missing posix_spawnattr_init/destroy functionsRich Felker-0/+13
2011-09-13remove some stray trailing space charactersRich Felker-4/+4
2011-09-12implement gnu sigisemptysetRich Felker-0/+9
2011-09-11add dummied strverscmp (obnoxious GNU function)Rich Felker-0/+7
programs that use this tend to horribly botch international text support, so it's questionable whether we want to support it even in the long term... for now, it's just a dummy that calls strcmp.
2011-09-11fix serious bug in pthread_joinRich Felker-2/+2
on spurious wakeups/returns from __timedwait, pthread_join would "succeed" and unmap the thread's stack while it was still running. at best this would lead to SIGSEGV when the thread resumed execution, but in the worst case, the thread would later resume executing on top of another new thread's stack mapped at the same address. spent about 4 hours tracking this bug down, chasing rare difficult-to-reproduce stack corruption in a stress test program. still no idea *what* caused the spurious wakeups; i suspect it's a kernel bug.
2011-09-09fix pthread_join wait call: thread termination tid futex is not privateRich Felker-1/+1
this seeme to be the bug that prevented enabling of private futex support. i'm going to hold off on switching to private futexes until after the next release, and until i get a chance to audit all wait/wake calls to make sure they're using the correct private argument, but with this change it should be safe to enable private futex support.
2011-09-09implement POSIX asynchronous ioRich Felker-0/+338
some features are not yet supported, and only minimal testing has been performed. should be considered experimental at this point.
2011-09-05fix incorrect overflow errors on strtoul, etc.Rich Felker-8/+20
2011-09-05strptime: fix use of uninitialized dest field in converting integerRich Felker-1/+1
2011-09-04more fmemopen null termination fixesRich Felker-2/+3
null termination is only added when current size grows. in update modes, null termination is not added if it does not fit (i.e. it is not allowed to clobber data). these rules make very little sense, but that's how it goes..
2011-09-04fix some fmemopen behaviorsRich Felker-4/+7
read should not be allowed past "current size". append mode should write at "current size", not buffer size. null termination should not be written except when "current size" grows.
2011-09-04handle pending cancellation when enabling async cancellationRich Felker-0/+1
this is not strictly required by the standard, but without it, there is a race condition where cancellation arriving just before async cancellation is enabled might not be acted upon. it is impossible for a conforming application to work around this race condition since calling pthread_testcancel after setting async cancellation mode is not allowed (pthread_testcancel is not specified to be async-cancel-safe). thus the implementation should be responsible for eliminating the race, from a quality-of-implementation standpoint.
2011-09-04fmemopen: fix eof handling, hopefully right this timeRich Felker-3/+4
2011-09-04fmemopen fixesRich Felker-1/+3
disallow seek past end of buffer (per posix) fix position accounting to include data buffered for read don't set eof flag when no data was requested
2011-09-04memstreams: fix incorrect handling of file pos > current sizeRich Felker-4/+4
the addition is safe and cannot overflow because both operands are positive when considered as signed quantities.
2011-09-04optimize seek function for memory streamsRich Felker-24/+6
2011-09-04fix twos complement overflow bug in mem streams boundary checkRich Felker-2/+2
the expression -off is not safe in case off is the most-negative value. instead apply - to base which is known to be non-negative and bounded within sanity.
2011-09-03implement fmemopenRich Felker-18/+66
testing so far has been minimal. may need further work.
2011-09-03fix some length calculations in memory streamsRich Felker-3/+3
2011-09-03implement open_wmemstreamRich Felker-0/+95
not heavily tested, but it seems to be correct, including the odd behavior that seeking is in terms of wide character count. this precludes any simple buffering, so we just make the stream unbuffered.
2011-09-03fix RTLD_NEXT on x86_64Rich Felker-1/+1
the return address was being truncated to 32 bits, preventing the dlsym code from determining which module contains the calling code.
2011-09-03implement open_memstreamRich Felker-0/+94
this is the first attempt, and may have bugs. only minimal testing has been performed.
2011-09-02fix missing prototypes/wrong signature for psiginfo, psignalRich Felker-1/+1