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* always provide __fpclassifyl and __signbitl definitionsRich Felker2014-10-082-1/+9
| | | | | | | | | previously the external definitions of these functions were omitted on archs where long double is the same as double, since the code paths in the math.h macros which would call them are unreachable. however, even if they are unreachable, the definitions are still mandatory. omitting them is invalid C, and in the case of a non-optimizing compiler, will result in a link error.
* ignore access mode bits of flags in mkostemps and functions that use itRich Felker2014-10-061-0/+1
| | | | | | | | | | | | | per the text accepted for inclusion in POSIX, behavior is unspecified when any of the access mode bits are set. since it's impossible to consistently report this usage error (O_RDONLY could not be detected since its value happens to be zero), the most consistent way to handle them is just to ignore them. previously, if a caller erroneously passed O_WRONLY, the resulting access mode would be O_WRONLY|O_RDWR, which has the value 3, and this resulted in a file descriptor which rejects both read and write attempts when it is subsequently used.
* fix handling of odd lengths in swab functionRich Felker2014-10-041-1/+1
| | | | | | | | this function is specified to leave the last byte with "unspecified disposition" when the length is odd, so for the most part correct programs should not be calling swab with odd lengths. however, doing so is permitted, and should not write past the end of the destination buffer.
* fix incorrect sequence generation in *rand48 prng functionsRich Felker2014-09-221-2/+2
| | | | | | | | | | | patch by Jens Gustedt. this fixes a bug reported by Nadav Har'El. the underlying issue was that a left-shift by 16 bits after promotion of unsigned short to int caused integer overflow. while some compilers define this overflow case as "shifting into the sign bit", doing so doesn't help; the sign bit then gets extended through the upper bits in subsequent arithmetic as unsigned long long. this patch imposes a promotion to unsigned prior to the shift, so that the result is well-defined and matches the specified behavior.
* fix linked list corruption in flockfile listsRich Felker2014-09-191-0/+1
| | | | | | | | | | | | | | | | commit 5345c9b884e7c4e73eb2c8bb83b8d0df20f95afb added a linked list to track the FILE streams currently locked (via flockfile) by a thread. due to a failure to fully link newly added members, removal from the list could leave behind references which could later result in writes to already-freed memory and possibly other memory corruption. implicit stdio locking was unaffected; the list is only used in conjunction with explicit flockfile locking. this bug was not present in any releases; it was introduced and fixed during the same release cycle. patch by Timo Teräs, who discovered and tracked down the bug.
* math: fix exp10 not to raise invalid exception on NaNSzabolcs Nagy2014-09-183-4/+13
| | | | | This was not caught earlier because gcc incorrectly generates quiet relational operators that never raise exceptions.
* fix overflow corner case in strtoul-family functionsRich Felker2014-09-161-0/+1
| | | | | | | | incorrect behavior occurred only in cases where the input overflows unsigned long long, not just the (possibly lower) range limit for the result type. in this case, processing of the '-' sign character was not suppressed, and the function returned a value of 1 despite setting errno to ERANGE.
* rewrite the regex pattern parser in regcompSzabolcs Nagy2014-09-131-1081/+634
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The new code is a bit simpler and the generated code is about 1KB smaller (on i386). The basic design was kept including internal interfaces, TNFA generation was not touched. The old tre parser had various issues: [^aa-z] negated overlapping ranges in a bracket expression were handled incorrectly (eg [^aa-z] was handled as [^a] instead of [^a-z]) a{,2} missing lower bound in a counted repetition should be an error, but it was accepted with broken semantics: a{,2} was treated as a{0,3}, the new parser rejects it a{999,} large min count was not rejected (a{5000,} failed with REG_ESPACE due to reaching a stack limit), the new parser enforces the RE_DUP_MAX limit \xff regcomp used to accept a pattern with illegal sequences in it (treated them as empty expression so p\xffq matched pq) the new parser rejects such patterns with REG_BADPAT or REG_ERANGE [^b-fD-H] with REG_ICASE old parser turned this into [^b-fB-F] because of the negated overlapping range issue (see above), the new parser treats it as [^b-hB-H], POSIX seems to require [^d-fD-F], but practical implementations do case-folding first and negate the character set later instead of the other way around. (Supporting the posix way efficiently would require significant changes so it was left as is, it is unclear if any application actually expects the posix behaviour, this issue is raised on the austingroup tracker: http://austingroupbugs.net/view.php?id=872 ). another case-insensitive matching issue is that unicode case folding rules can group more than two characters together while towupper and towlower can only work for a pair of upper and lower case characters, this is a limitation of POSIX so it is not fixed. invalid bracket and brace expressions may return different error codes now (REG_ERANGE instead of REG_EBRACK or REG_BADBR instead of REG_EBRACE) otherwise the new parser should be compatible with the old one. regcomp should be able to handle arbitrary pattern input if the pattern length is limited, the only exception is the use of large repetition counts (eg. (a{255}){255}) which require exp amount of memory and there is no easy workaround.
* fix C++ incompatibility in i386 definition of max_align_tRich Felker2014-09-111-0/+4
| | | | | | the C11 _Alignas keyword is not present in C++, and despite it being in the reserved namespace and thus reasonable to support even in non-C11 modes, compilers seem to fail to support it.
* add _DEFAULT_SOURCE feature profile as an alias for _BSD_SOURCERich Felker2014-09-101-0/+4
| | | | | | | | | | | | | | | | | | | | | | | as a result of commit ab8f6a6e42ff893041f7545a23e6d6a0edde07fb, this definition is now equivalent to the actual "default profile" which appears immediately below in features.h, and which defines both _BSD_SOURCE and _XOPEN_SOURCE. the intent of providing a _DEFAULT_SOURCE, which glibc also now provides, is to give applications a way to "get back" the default feature profile when it was lost either by compiler flags that inhibit it (such as -std=c99) or by library-provided predefined macros (such as -D_POSIX_C_SOURCE=200809L) which may inhibit exposure of features that were otherwise visible by default and which the application may need. without _DEFAULT_SOURCE, the application had encode knowledge of a particular libc's defaults, and such knowledge was fragile and subject to bitrot. eventually the names _GNU_SOURCE and _BSD_SOURCE should be phased out in favor of the more-descriptive and more-accurate _ALL_SOURCE and _DEFAULT_SOURCE, leaving the old names as aliases but using the new ones internally. however this is a more invasive change that would require extensive regression testing, so it is deferred.
* fix _ALL_SOURCE logic to avoid possible redefinition of _GNU_SOURCERich Felker2014-09-101-1/+1
| | | | | this could be an error if _GNU_SOURCE was already defined differently by the application.
* fix places where _BSD_SOURCE failed to yield a superset of _XOPEN_SOURCERich Felker2014-09-104-8/+2
| | | | | | | | | | | the vast majority of these failures seem to have been oversights at the time _BSD_SOURCE was added, or perhaps shortly afterward. the one which may have had some reason behind it is omission of setpgrp from the _BSD_SOURCE feature profile, since the standard setpgrp interface conflicts with a legacy (pre-POSIX) BSD interface by the same name. however, such omission is not aligned with our general policy in this area (for example, handling of similar _GNU_SOURCE cases) and should not be preserved.
* fix exp10l.c to include float.hSzabolcs Nagy2014-09-081-0/+1
| | | | | | the previous commit was a no op in exp10l because LDBL_* macros were implicitly 0 (the preprocessor does not warn about undefined symbols).
* prune math code on archs with binary64 long doubleSzabolcs Nagy2014-09-082-0/+10
| | | | | | __polevll, __p1evll and exp10l were provided on archs when long double is the same as double. The first two were completely unused and exp10l can be a wrapper around exp10.
* add new F_OFD_* macros to fcntl.h (open file description locks)Szabolcs Nagy2014-09-081-0/+4
| | | | | | | | | open file description locks are inherited across fork and only auto dropped after the last fd of the file description is closed, they can be used to synchronize between threads that open separate file descriptions for the same file. new in linux 3.15 commit 0d3f7a2dd2f5cf9642982515e020c1aee2cf7af6
* add C11 thread creation and related thread functionsRich Felker2014-09-0710-7/+84
| | | | | | | | | | | | | | | | | based on patch by Jens Gustedt. the main difficulty here is handling the difference between start function signatures and thread return types for C11 threads versus POSIX threads. pointers to void are assumed to be able to represent faithfully all values of int. the function pointer for the thread start function is cast to an incorrect type for passing through pthread_create, but is cast back to its correct type before calling so that the behavior of the call is well-defined. changes to the existing threads implementation were kept minimal to reduce the risk of regressions, and duplication of code that carries implementation-specific assumptions was avoided for ease and safety of future maintenance.
* add C11 condition variable functionsJens Gustedt2014-09-066-0/+57
| | | | | Because of the clear separation for private pthread_cond_t these interfaces are quite simple and direct.
* add C11 mutex functionsJens Gustedt2014-09-066-0/+69
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* add C11 thread functions operating on tss_t and once_flagJens Gustedt2014-09-065-0/+42
| | | | | | These all have POSIX equivalents, but aside from tss_get, they all have minor changes to the signature or return value and thus need to exist as separate functions.
* add threads.h and needed per-arch types for mtx_t and cnd_tRich Felker2014-09-0610-0/+103
| | | | | | | | | | | | | | | | based on patch by Jens Gustedt. mtx_t and cnd_t are defined in such a way that they are formally "compatible types" with pthread_mutex_t and pthread_cond_t, respectively, when accessed from a different translation unit. this makes it possible to implement the C11 functions using the pthread functions (which will dereference them with the pthread types) without having to use the same types, which would necessitate either namespace violations (exposing pthread type names in threads.h) or incompatible changes to the C++ name mangling ABI for the pthread types. for the rest of the types, things are much simpler; using identical types is possible without any namespace considerations.
* use weak symbols for the POSIX functions that will be used by C threadsJens Gustedt2014-09-0615-29/+76
| | | | | | | | | | The intent of this is to avoid name space pollution of the C threads implementation. This has two sides to it. First we have to provide symbols that wouldn't pollute the name space for the C threads implementation. Second we have to clean up some internal uses of POSIX functions such that they don't implicitly drag in such symbols.
* add C11 timespec_get function, with associated time.h changes for C11Rich Felker2014-09-062-1/+15
| | | | | | based on patch by Jens Gustedt for inclusion with C11 threads implementation, but committed separately since it's independent of threads.
* fix non-static dummy function that slipped in with locale implementationRich Felker2014-09-061-1/+1
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* fix macros for LFS *64_t types in sys/stat.h, sys/types.h, glob.hSzabolcs Nagy2014-09-053-2/+3
| | | | | | there is no blksize64_t (blksize_t is always long) but there are fsblkcnt64_t and fsfilcnt64_t types in sys/stat.h and sys/types.h. and glob.h missed glob64_t.
* add missing legacy LFS *64 symbol aliasesSzabolcs Nagy2014-09-058-0/+23
| | | | | | versionsort64, aio*64 and lio*64 symbols were missing, they are only needed for glibc ABI compatibility, on the source level dirent.h and aio.h already redirect them.
* fix memory leak in regexec when input contains illegal sequenceSzabolcs Nagy2014-09-051-5/+6
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* fix off-by-one in bounds check in fpathconfRich Felker2014-09-051-1/+1
| | | | | | this error resulted in an out-of-bounds read, as opposed to a reported error, when calling the function with an argument one greater than the max valid index.
* fix potential read past end of buffer in getnameinfo service name lookupRich Felker2014-09-051-1/+1
| | | | | | | | | if the loop stopped due to reaching the end of the string, the subsequent increment could possibly move the position one past the end of the buffer. no further writes happen, the reads cannot fault anyway unless the stack completely lacks any zero bytes, and reading junk should not yield an incorrect result from the function either. nonetheless the code was wrong and needs to be fixed.
* remove incorrect and useless check in network service name lookup codeRich Felker2014-09-051-1/+0
| | | | | | the condition was probably intended to be !*p rather than !p, but neither is needed here. the subsequent code naturally handles the case where it's already at end of string.
* fix case mapping for U+00DF (ß)Rich Felker2014-09-052-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | U+00DF ('ß') has had an uppercase form (U+1E9E) available since Unicode 5.1, but Unicode lacks the case mappings for it due to stability policy. when I added support for the new character in commit 1a63a9fc30e7a1f1239e3cedcb5041e5ec1c5351, I omitted the mapping in the lowercase-to-uppercase direction. this choice was not based on any actual information, only assumptions. this commit adds bidirectional case mappings between U+00DF and U+1E9E, and removes the special-case hack that allowed U+00DF to be identified as lowecase despite lacking a mapping. aside from strong evidence that this is the "right" behavior for real-world usage of these characters, several factors informed this decision: - the other "potentially correct" mapping, to "SS", is not representable in the C case-mapping system anyway. - leaving one letter in lowercase form when transforming a string to uppercase is obviously wrong. - having a character which is nominally lowercase but which is fixed under case mapping violates reasonable invariants.
* make non-waiting paths of sem_[timed]wait and pthread_join cancelableRich Felker2014-09-052-0/+3
| | | | | | | per POSIX these functions are both cancellation points, so they must act on any cancellation request which is pending prior to the call. previously, only the code path where actual waiting took place could act on cancellation.
* remove an extra layer of buffer copying in getnameinfo reverse dnsRich Felker2014-09-051-3/+2
| | | | | | | | | | | the outer getnameinfo function already has a properly-sized temporary buffer for storing the reverse dns (ptr) result. there is no reason for the callback to use a secondary buffer and copy it on success, and doing so potentially expanded the impact of the dn_expand bug that was fixed in commit 49d2c8c6bcf8c926e52c7f510033b6adc31355f5. this change reduces the code size by a small amount, and also reduces the run-time stack space requirements by about 256 bytes.
* fix multiple stdio functions' behavior on zero-length operationsRich Felker2014-09-044-9/+7
| | | | | | | | | | | previously, fgets, fputs, fread, and fwrite completely omitted locking and access to the FILE object when their arguments yielded a zero length read or write operation independent of the FILE state. this optimization was invalid; it wrongly skipped marking the stream as byte-oriented (a C conformance bug) and exposed observably missing synchronization (a POSIX conformance bug) where one of these functions could wrongly complete despite another thread provably holding the lock.
* suppress null termination when fgets reads EOF with no dataRich Felker2014-09-041-1/+1
| | | | | | | | | the C standard requires that "the contents of the array remain unchanged" in this case. this patch also changes the behavior on read errors, but in that case "the array contents are indeterminate", so the application cannot inspect them anyway.
* fix dn_expand empty name handling and offsets to 0Szabolcs Nagy2014-09-041-6/+9
| | | | | | | | | | Empty name was rejected in dn_expand since commit 56b57f37a46dab432247bf29d96fcb11fbd02a6d which is a regression as reported by Natanael Copa. Furthermore if an offset pointer in a compressed name pointed to a terminating 0 byte (instead of a label) the returned name was not null terminated.
* add static_assert and hide noreturn, alignas, alignof from C++Szabolcs Nagy2014-08-273-0/+11
| | | | | add static_assert and protect the other new C11 keyword macros with #ifndef __cplusplus so they don't conflict with C++ keywords.
* add C11 floating-point characteristic macros to float.hSzabolcs Nagy2014-08-271-0/+7
| | | | C11 introduced *_DECIMAL_DIG and *_HAS_SUBNORM macros.
* add malloc_usable_size function and non-stub malloc.hRich Felker2014-08-252-0/+42
| | | | | | | | | | | | | | | | | | | | | | this function is needed for some important practical applications of ABI compatibility, and may be useful for supporting some non-portable software at the source level too. I was hesitant to add a function which imposes any constraints on malloc internals; however, it turns out that any malloc implementation which has realloc must already have an efficient way to determine the size of existing allocations, so no additional constraint is imposed. for now, some internal malloc definitions are duplicated in the new source file. if/when malloc is refactored to put them in a shared internal header file, these could be removed. since malloc_usable_size is conventionally declared in malloc.h, the empty stub version of this file was no longer suitable. it's updated to provide the standard allocator functions, nonstandard ones (even if stdlib.h would not expose them based on the feature test macros in effect), and any malloc-extension functions provided (currently, only malloc_usable_size).
* refrain from spinning on locks when there is already a waiterRich Felker2014-08-255-5/+5
| | | | | | | | | | if there is already a waiter for a lock, spinning on the lock is essentially an attempt to steal it from whichever waiter would obtain it via any priority rules in place, and is therefore undesirable. in the current implementation, there is always an inherent race window at unlock during which a newly-arriving thread may steal the lock from the existing waiters, but we should aim to keep this window minimal rather than enlarging it.
* spin before waiting on futex in mutex and rwlock lock operationsRich Felker2014-08-253-0/+20
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* spin in sem_[timed]wait before performing futex waitRich Felker2014-08-251-0/+5
| | | | | | | | | empirically, this increases the maximum rate of wait/post operations between two threads by 20-150 times on machines I tested, including x86 and arm. conceptually, it makes sense to do some spinning because semaphores are intended to be usable as a notification mechanism between threads, not just as locks, and low-latency notification is a valuable property to have.
* fix build error on arm due to new a_spin codeRich Felker2014-08-251-1/+1
| | | | this was broken by commit ea818ea8340c13742a4f41e6077f732291aea4bc.
* sanitize number of spins in userspace before futex waitRich Felker2014-08-252-2/+2
| | | | | | | | | | | | | | | the previous spin limit of 10000 was utterly unreasonable. empirically, it could consume up to 200000 cycles, whereas a failed futex wait (EAGAIN) typically takes 1000 cycles or less, and even a true wait/wake round seems much less expensive. the new counts (100 for general wait, 200 in barrier) were simply chosen to be in the range of what's reasonable without having adverse effects on casual micro-benchmark tests I have been running. they may still be too high, from a standpoint of not wasting cpu cycles, but at least they're a lot better than before. rigorous testing across different archs and cpu models should be performed at some point to determine whether further adjustments should be made.
* add working a_spin() atomic for non-x86 targetsRich Felker2014-08-256-0/+6
| | | | | | | | | | | | | conceptually, a_spin needs to be at least a compiler barrier, so the compiler will not optimize out loops (and the load on each iteration) while spinning. it should also be a memory barrier, or the spinning thread might keep spinning without noticing stores from other threads, thus delaying for longer than it should. ideally, an optimal a_spin implementation that avoids unnecessary cache/memory contention should be chosen for each arch, but for now, the easiest thing is to perform a useless a_cas on the calling thread's stack.
* fix false ownership of stdio FILEs due to tid reuseRich Felker2014-08-236-2/+40
| | | | | | | | | | | | | this is analogous commit fffc5cda10e0c5c910b40f7be0d4fa4e15bb3f48 which fixed the corresponding issue for mutexes. the robust list can't be used here because the locks do not share a common layout with mutexes. at some point it may make sense to simply incorporate a mutex object into the FILE structure and use it, but that would be a much more invasive change, and it doesn't mesh well with the current design that uses a simpler code path for internal locking and pulls in the recursive-mutex-like code when the flockfile API is used explicitly.
* fix fallback checks for kernels without private futex supportRich Felker2014-08-225-5/+5
| | | | for unknown syscall commands, the kernel produces ENOSYS, not EINVAL.
* fix use of uninitialized memory with application-provided thread stacksRich Felker2014-08-221-0/+2
| | | | | | | | | | the subsequent code in pthread_create and the code which copies TLS initialization images to the new thread's TLS space assume that the memory provided to them is zero-initialized, which is true when it's obtained by pthread_create using mmap. however, when the caller provides a stack using pthread_attr_setstack, pthread_create cannot make any assumptions about the contents. simply zero-filling the relevant memory in this case is the simplest and safest fix.
* add max_align_t definition for C11 and C++11Rich Felker2014-08-2010-0/+21
| | | | | | | | | | | | | | | | | unfortunately this needs to be able to vary by arch, because of a huge mess GCC made: the GCC definition, which became the ABI, depends on quirks in GCC's definition of __alignof__, which does not match the formal alignment of the type. GCC's __alignof__ unexpectedly exposes the an implementation detail, its "preferred alignment" for the type, rather than the formal/ABI alignment of the type, which it only actually uses in structures. on most archs the two values are the same, but on some (at least i386) the preferred alignment is greater than the ABI alignment. I considered using _Alignas(8) unconditionally, but on at least one arch (or1k), the alignment of max_align_t with GCC's definition is only 4 (even the "preferred alignment" for these types is only 4).
* further simplify and optimize new cond varRich Felker2014-08-181-29/+21
| | | | | | | | | | | | | | the main idea of the changes made is to have waiters wait directly on the "barrier" lock that was used to prevent them from making forward progress too early rather than first waiting on the atomic state value and then attempting to lock the barrier. in addition, adjustments to the mutex waiter count are optimized. previously, each waking waiter decremented the count (unless it was the first) then immediately incremented it again for the next waiter (unless it was the last). this was a roundabout was of achieving the equivalent of incrementing it once for the first waiter and decrementing it once for the last.
* simplify and improve new cond var implementationRich Felker2014-08-181-40/+22
| | | | | | | | | | | | | | | | | | | | previously, wake order could be unpredictable: if a waiter happened to leave its futex wait on the state early, e.g. due to EAGAIN while restarting after a signal handler, it could acquire the mutex out of turn. handling this required ugly O(n) list walking in the unwait function and accounting to remove waiters that already woke from the list. with the new changes, the "barrier" locks in each waiter node are only unlocked in turn. in addition to simplifying the code, this seems to improve performance slightly, probably by reducing the number of accesses threads make to each other's stacks. as an additional benefit, unrecoverable mutex re-locking errors (mainly ENOTRECOVERABLE for robust mutexes) no longer need to be handled with deadlock; they can be reported to the caller, since the unlocking sequence makes it unnecessary to rely on the mutex to synchronize access to the waiter list.
generated by cgit-pink 1.4.1 (git 2.36.1) at 2024-11-10 20:51:45 +0000