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* some initial math asm for armhf (fabs[f] and sqrt[f])Rich Felker2013-08-1612-0/+32
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* fix detection of arm hardfloatRich Felker2013-08-162-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | it turns out that __SOFTFP__ does not indicate the ABI in use but rather that fpu instructions are not to be used at all. this is specified in ARM's documentation so I'm unclear on how I previously got the wrong idea. unfortunately, this resulted in the 0.9.12 release producing a dynamic linker with the wrong name. fortunately, there do not yet seem to be any public toolchain builds using the wrong name. the __ARM_PCS_VFP macro does not seem to be official from ARM, and in fact it was missing from the very earliest gcc versions (around 4.5.x) that added -mfloat-abi=hard. it would be possible on such versions to perform some ugly linker-based tests instead in hopes that the linker will reject ABI-mismatching object files, if there is demand for supporting such versions. I would probably prefer to document which versions are broken and warn users to manually add -D__ARM_PCS_VFP if using such a version. there's definitely an argument to be made that the fenv macros should be exposed even in -mfloat-abi=softfp mode. for now, I have chosen not to expose them in this case, since the math library will not necessarily have the capability to raise exceptions (it depends on the CFLAGS used to compile it), and since exceptions are officially excluded from the ARM EABI, which the plain "arm" arch aims to follow.
* support floating point environment (fenv) on armhf (hard float) subarchsRich Felker2013-08-164-0/+75
| | | | | patch by nsz. I've tested it on an armhf machine and it seems to be working correctly.
* fix build of x86_64 expl assemblyRich Felker2013-08-161-1/+1
| | | | | apparently this label change was not carried over when adapting the changes from the i386 version.
* add function types to arm crt assemblyRich Felker2013-08-153-0/+4
| | | | | | | | | without these, calls may be resolved incorrectly if the calling code has been compiled to thumb instead of arm. it's not clear to me at this point whether crt_arch.h is even working if crt1.c is built as thumb; this needs testing. but the _init and _fini issues were known to cause crashes in static-linked apps when libc was built as thumb, and this commit should fix that issue.
* math: fix pow(x,-1) to raise underflow properlySzabolcs Nagy2013-08-151-2/+14
| | | | | | if FLT_EVAL_METHOD!=0 check if (double)(1/x) is subnormal and not a power of 2 (if 1/x is power of 2 then either it is exact or the long double to double rounding already raised inexact and underflow)
* math: fix i386 atan2.s to raise underflow for subnormal resultsSzabolcs Nagy2013-08-152-2/+24
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* math: clean up atan2.cSzabolcs Nagy2013-08-154-103/+73
| | | | | | | | | * remove volatile hacks * don't care about inexact flag for now (removed all the +-tiny) * fix atanl to raise underflow properly * remove signed int arithmetics * use pi/2 instead of pi_o_2 (gcc generates the same code, which is not correct, but it does not matter: we mainly care about nearest rounding)
* math: fix x86 asin, atan, exp, log1p to raise underflowSzabolcs Nagy2013-08-156-3/+98
| | | | | | underflow is raised by an inexact subnormal float store, since subnormal operations are slow, check the underflow flag and skip the store if it's already raised
* math: fix x86 expl.s to raise underflow and clean up special case handlingSzabolcs Nagy2013-08-152-45/+31
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* math: fix asin, atan, log1p, tanh to raise underflow on subnormalSzabolcs Nagy2013-08-159-26/+39
| | | | | | | | | | | | | | | | | | for these functions f(x)=x for small inputs, because f(0)=0 and f'(0)=1, but for subnormal values they should raise the underflow flag (required by annex F), if they are approximated by a polynomial around 0 then spurious underflow should be avoided (not required by annex F) all these functions should raise inexact flag for small x if x!=0, but it's not required by the standard and it does not seem a worthy goal, so support for it is removed in some cases. raising underflow: - x*x may not raise underflow for subnormal x if FLT_EVAL_METHOD!=0 - x*x may raise spurious underflow for normal x if FLT_EVAL_METHOD==0 - in case of double subnormal x, store x as float - in case of float subnormal x, store x*x as float
* math: fix tgamma to raise underflow for large negative valuesSzabolcs Nagy2013-08-151-0/+1
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* math: fix pow(0,-inf) to raise divbyzero flagSzabolcs Nagy2013-08-152-2/+2
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* math: minor scalbn*.c simplificationSzabolcs Nagy2013-08-153-18/+10
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* fix length computation in dn_expandRich Felker2013-08-141-3/+5
| | | | | | | there are two possible points where the length is evaluated: either the first 'compression' jump, or the null terminator if no jumps have taken place yet. the previous code only measured the length of the first component.
* de-duplicate dn_expand, fix return value and signature, clean upRich Felker2013-08-143-49/+24
| | | | | | | | | | | | | | | | | the duplicate code in dn_expand and its incorrect return values are both results of the history of the code: the version in __dns.c was originally written with no awareness of the legacy resolver API, and was later copy-and-paste duplicated to provide the legacy API. this commit is the first of a series that will restructure the internal dns code to share as much code as possible with the legacy resolver API functions. I have also removed the loop detection logic, since the output buffer length limit naturally prevents loops. in order to avoid long runtime when encountering a loop if the caller provided a ridiculously long buffer, the caller-provided length is clamped at the maximum dns name length.
* add arm-optimized memcpy implementation from bionic libcRich Felker2013-08-144-0/+387
| | | | | | | | | | | | | | | | | | | | the approach of this implementation was heavily investigated prior to adopting it. attempts to obtain similar performance with pure C code were capping out at about 75% of the performance of the asm, with considerably larger code size, and were fragile in that the compiler would sometimes compile part of memcpy into a call to itself. therefore, just using the asm seems to be the best option. this commit is the first to make use of the new subarch-specific asm framework. the new armel directory is the location for arm asm that should not be used for all arm subarchs, only the default one. armhf is the name of the little-endian hardfloat-ABI subarch, which can use the exact same asm. in both cases, the build system finds the asm by following a memcpy.sub file. the other two subarchs, armeb and armebhf, would need a big-endian variant of this code. it would not be hard to adapt the code to big endian, but I will hold off on doing so until there is demand for it.
* rework makefile subarch logic to allow shared filesRich Felker2013-08-141-4/+12
| | | | | | | | instead of subarchs getting their own .s files which are used directly by the makefile to replace the .c file, they now must provide a .sub file whose contents are a pathname, relative to the location of the .sub file, which will substitute for the .c file. essentially these files are acting as symbolic links, but implemented as text files.
* add missing MSG_EXCEPT in sys/msg.hRich Felker2013-08-141-0/+1
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* provide declarations for strtod_l and familyRich Felker2013-08-131-0/+4
| | | | | | | | these aliases were originally intended to be for ABI compatibility only, but their presence caused regressions in broken gnulib-based software whose configure scripts detect the existing of these functions then use them without declarations, resulting in bogus return values.
* add subarch asm support for PIC objects/shared libcRich Felker2013-08-111-0/+3
| | | | this rule was omitted in previous subarch asm commit
* add missing a_or_l to atomic.h for non-x86 archsRich Felker2013-08-114-0/+20
| | | | this is needed for recently committed sigaction code
* allow subarch-specific asm, including asm specific to the defaultRich Felker2013-08-112-0/+9
| | | | | | | | | | | | | the default subarch is the one whose full name is just the base arch name, with no suffixes. normally, either the asm in the default subarch is suitable for all subarch variants, or separate asm is mandatory for each variant. however, in the case of asm which is purely for optimization purposes, it's possible to have asm that only works (or only performs well) on the default subarch, and not any othe the other variants. thus, I have added a mechanism to give a name to the default variant, for example "armel" for the default, little-endian arm. further such default-subarch names can be added in the future as needed.
* fix _NSIG and SIGRTMAX on mipsRich Felker2013-08-102-2/+4
| | | | | | | | | | | | | | | | | | | | | a mips signal mask contains 128 bits, enough for signals 1 through 128. however, the exit status obtained from the wait-family functions only has room for values up to 127. reportedly signal 128 was causing kernelspace bugs, so it was removed from the kernel recently; even without that issue, however, it was impossible to support it correctly in userspace. at the same time, the bug was masked on musl by SIGRTMAX incorrectly yielding 64 on mips, rather than the "correct" value of 128. now that the _NSIG issue is fixed, SIGRTMAX can be fixed at the same time, exposing the full range of signals for application use. note that the (nonstandardized) libc _NSIG value is actually one greater than the max signal number, and also one greater than the kernel headers' idea of _NSIG. this is the reason for the discrepency with the recent kernel changes. since reducing _NSIG by one brought it down from 129 to 128, rather than from 128 to 127, _NSIG/8, used widely in the musl sources, is unchanged.
* fix definitions of WIFSTOPPED and WIFSIGNALED to support up to signal 127Rich Felker2013-08-102-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | mips has signal numbers up to 127 (formerly, up to 128, but the last one never worked right and caused kernel panic when used), so 127 in the "signal number" field of the wait status is insufficient for determining that the process was stopped. in addition, a nonzero value in the upper bits must be present, indicating the signal number which caused the process to be stopped. details on this issue can be seen in the email with message id CAAG0J9-d4BfEhbQovFqUAJ3QoOuXScrpsY1y95PrEPxA5DWedQ@mail.gmail.com on the linux-mips mailing list, archived at: http://www.linux-mips.org/archives/linux-mips/2013-06/msg00552.html and in the associated thread about fixing the mips kernel bug. commit 4a96b948687166da26a6c327e6c6733ad2336c5c fixed the corresponding issue in uClibc, but introduced a multiple-evaluation issue for the WIFSTOPPED macro. for the most part, none of these issues affected pure musl systems, since musl has up until now (incorrectly) defined SIGRTMAX as 64 on all archs, even mips. however, interpreting status of non-musl programs on mips may have caused problems. with this change, the full range of signal numbers can be made available on mips.
* add pthread_setaffinity_np and pthread_getaffinity_np functionsRich Felker2013-08-104-18/+29
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* add cpu affinity interfacesRich Felker2013-08-104-0/+90
| | | | | | | this first commit just includes the CPU_* and sched_* interfaces, not the pthread_* interfaces, which may be added later. simple sanity-check testing has been done for the basic interfaces, but most of the macros have not yet been tested.
* change sigset_t functions to restrict to _NSIGRich Felker2013-08-094-5/+5
| | | | | | | the idea here is to avoid advertising signals that don't exist and to make these functions safe to call (e.g. from within other parts of the implementation) on fake sigset_t objects which do not have the HURD padding.
* optimize posix_spawn to avoid spurious sigaction syscallsRich Felker2013-08-093-12/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | the trick here is that sigaction can track for us which signals have ever had a signal handler set for them, and only those signals need to be considered for reset. this tracking mask may have false positives, since it is impossible to remove bits from it without race conditions. false negatives are not possible since the mask is updated with atomic operations prior to making the sigaction syscall. implementation-internal signals are set to SIG_IGN rather than SIG_DFL so that a signal raised in the parent (e.g. calling pthread_cancel on the thread executing pthread_spawn) does not have any chance make it to the child, where it would cause spurious termination by signal. this change reduces the minimum/typical number of syscalls in the child from around 70 to 4 (including execve). this should greatly improve the performance of posix_spawn and other interfaces which use it (popen and system). to facilitate these changes, sigismember is also changed to return 0 rather than -1 for invalid signals, and to return the actual status of implementation-internal signals. POSIX allows but does not require an error on invalid signal numbers, and in fact returning an error tends to confuse applications which wrongly assume the return value of sigismember is boolean.
* fix missing errno from exec failure in posix_spawnRich Felker2013-08-091-0/+1
| | | | | failures prior to the exec attempt were reported correctly, but on exec failure, the return value contained junk.
* block all signals, even implementation-internal ones, in faccessat childRich Felker2013-08-091-1/+1
| | | | | | the child process's stack may be insufficient size to support a signal frame, and there is no reason these signal handlers should run in the child anyway.
* block signals during forkRich Felker2013-08-081-0/+3
| | | | | | | | | | | there are several reasons for this. some of them are related to race conditions that arise since fork is required to be async-signal-safe: if fork or pthread_create is called from a signal handler after the fork syscall has returned but before the subsequent userspace code has finished, inconsistent state could result. also, there seem to be kernel and/or strace bugs related to arrival of signals during fork, at least on some versions, and simply blocking signals eliminates the possibility of such bugs.
* work around libraries with versioned symbols in dynamic linkerRich Felker2013-08-081-11/+14
| | | | | | | | | | | | | | | | this commit does not add versioning support; it merely fixes incorrect lookups of symbols in libraries that contain versioned symbols. previously, the version information was completely ignored, and empirically this seems to have resulted in the oldest version being chosen, but I am uncertain if that behavior was even reliable. the new behavior being introduced is to completely ignore symbols which are marked "hidden" (this seems to be the confusing nomenclature for non-current-version) when versioning is present. this should solve all problems related to libraries with symbol versioning as long as all binaries involved are up-to-date (compatible with the latest-version symbols), and it's the needed behavior for dlsym under all circumstances.
* sys/personality.h: add missing C++ compatrofl0r2013-08-081-0/+7
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* sys/personality.h: add missing macrosrofl0r2013-08-081-0/+33
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* add Big5 charset support to iconvRich Felker2013-08-072-0/+1066
| | | | | | at this point, it is just the common base charset equivalent to Windows CP 950, with no further extensions. HKSCS and possibly other supersets will be added later. other aliases may need to be added too.
* make fcvt decimal point location for zero make more senseRich Felker2013-08-071-1/+1
| | | | | | | | | | the (obsolete) standard allows either 0 or 1 for the decimal point location in this case, but since the number of zero digits returned in the output string (in this implementation) is one more than the number of digits the caller requested, it makes sense for the decimal point to be logically "after" the first digit. in a sense, this change goes with the previous commit which fixed the value of the decimal point location for non-zero inputs.
* fix ecvt/fcvt decimal point position outputRich Felker2013-08-071-1/+1
| | | | | | | | | | | these functions are obsolete and have no modern standard. the text in SUSv2 is highly ambiguous, specifying that "negative means to the left of the returned digits", which suggested to me that 0 would mean to the right of the first digit. however, this does not agree with historic practice, and the Linux man pages are more clear, specifying that a negative value means "that the decimal point is to the left of the start of the string" (in which case, 0 would mean the start of the string, in accordance with historic practice).
* iconv support for legacy Korean encodingsRich Felker2013-08-052-0/+678
| | | | | | | | | | | | | | | | | | | | | like for other character sets, stateful iso-2022 form is not supported yet but everything else should work. all charset aliases are treated the same, as Windows codepage 949, because reportedly the EUC-KR charset name is in widespread (mis?)usage in email and on the web for data which actually uses the extended characters outside the standard 93x94 grid. this could easily be changed if desired. the principle of this converter for handling the giant bulk of rare Hangul syllables outside of the standard KS X 1001 93x94 grid is the same as the GB18030 converter's treatment of non-explicitly-coded Unicode codepoints: sequences in the extension range are mapped to an integer index N, and the converter explicitly computes the Nth Hangul syllable not explicitly encoded in the character map. empirically, this requires at most 7 passes over the grid. this approach reduces the table size required for Korean legacy encodings from roughly 44k to 17k and should have minimal performance impact on real-world text conversions since the "slow" characters are rare. where it does have impact, the cost is merely a large constant time factor.
* have new timer threads unblock their own SIGTIMERRich Felker2013-08-031-2/+2
| | | | | | | unblocking it in the pthread_once init function is not sufficient, since multiple threads, some of them with the signal blocked, could already exist before this is called; timers started from such threads would be non-functional.
* add system for resetting TLS to initial valuesRich Felker2013-08-034-14/+56
| | | | | | | | | | | | | | | this is needed for reused threads in the SIGEV_THREAD timer notification system, and could be reused elsewhere in the future if needed, though it should be refactored for such use. for static linking, __init_tls.c is simply modified to export the TLS info in a structure with external linkage, rather than using statics. this perhaps makes the code more clear, since the statics were poorly named for statics. the new __reset_tls.c is only linked if it is used. for dynamic linking, the code is in dynlink.c. sharing code with __copy_tls is not practical since __reset_tls must also re-zero thread-local bss.
* fix multiple bugs in SIGEV_THREAD timersRich Felker2013-08-036-22/+36
| | | | | | | | | | | | | | | | | | 1. the thread result field was reused for storing a kernel timer id, but would be overwritten if the application code exited or cancelled the thread. 2. low pointer values were used as the indicator that the timer id is a kernel timer id rather than a thread id. this is not portable, as mmap may return low pointers on some conditions. instead, use the fact that pointers must be aligned and kernel timer ids must be non-negative to map pointers into the negative integer space. 3. signals were not blocked until after the timer thread started, so a race condition could allow a signal handler to run in the timer thread when it's not supposed to exist. this is mainly problematic if the calling thread was the only thread where the signal was unblocked and the signal handler assumes it runs in that thread.
* add some new linux AT_* flagsRich Felker2013-08-031-0/+2
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* fix faccessat to support AT_EACCESS flagRich Felker2013-08-031-1/+46
| | | | | | | | | | | | | | this is another case of the kernel syscall failing to support flags where it needs to, leading to horrible workarounds in userspace. this time the workaround requires changing uid/gid, and that's not safe to do in the current process. in the worst case, kernel resource limits might prevent recovering the original values, and then there would be no way to safely return. so, use the safe but horribly inefficient alternative: forking. clone is used instead of fork to suppress signals from the child. fortunately this worst-case code is only needed when effective and real ids mismatch, which mainly happens in suid programs.
* collapse euidaccess to a call to faccessatRich Felker2013-08-031-9/+1
| | | | | | it turns out Linux is buggy for faccessat, just like fchmodat: the kernel does not actually take a flags argument. so we're going to have to emulate it there.
* add prototypes for euidaccess/eaccessRich Felker2013-08-031-0/+2
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* add legacy euidaccess function and eaccess alias for itRich Felker2013-08-031-0/+18
| | | | this is mainly for ABI compat purposes.
* make tdestroy allow null function pointer if no destructor is neededRich Felker2013-08-021-1/+1
| | | | this change is to align with a change in the glibc interface.
* fix aliasing violations in tsearch functionsRich Felker2013-08-021-2/+10
| | | | | | | patch by nsz. the actual object the caller has storing the tree root has type void *, so accessing it as struct node * is not valid. instead, simply access the value, move it to a temporary of the appropriate type and work from there, then move the result back.
* protect against long double type mismatches (mainly powerpc for now)Rich Felker2013-08-022-0/+28
| | | | | | check in configure to be polite (failing early if we're going to fail) and in vfprintf.c since that is the point at which a mismatching type would be extremely dangerous.