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2018-09-01always terminate by SIGABRT when abort is calledRich Felker-4/+40
Linux makes this surprisingly difficult, but it can be done. the trick here is using the fact that we control the implementation of sigaction to prevent changing the disposition of SIGABRT to anything but SIG_DFL after abort has tried and failed to terminate the process simply by calling raise(SIGABRT).
2018-09-01optimize raise not to make a syscall for getting tidRich Felker-3/+1
assuming signals are blocked, which they are here, the tid in the thread structure is always valid and cannot change out from under us.
2018-08-30prevent perror from clobbering stderr's orientationRich Felker-0/+8
this requirement is specified by POSIX.
2018-08-30prevent psignal/psiginfo from clobbering stderr orientation, errnoRich Felker-8/+21
these functions are specified to write to stderr but not set its orientation, presumably so that they can be used in programs operating stderr in wide mode. also, they are not allowed to clobber errno on success. save and restore to meet the requirement. psiginfo is reduced to a think wrapper around psignal, since it already behaved the same. if we want to add more detailed siginfo printing at some point this will need refactoring.
2018-08-29make vfprintf set stream orientation even for zero-length outputRich Felker-1/+2
if no output is produced, no underlying fwrite will ever be called, but byte-oriented printf functions are still required to set the orientation of the stream to byte-oriented. call __towrite explicitly if the FILE is not already in write mode.
2018-08-29re-fix vfprintf temporary buffer logicRich Felker-2/+2
commit b5a8b28915aad17b6f49ccacd6d3fef3890844d1 setup the write buffer bound pointers for the temporary buffer manually to fix a buffer overflow issue, but in doing so, caused vfprintf on unbuffered files never to call __towrite, thereby failing to set the stream orientation to byte-oriented, failing to clear any prior read mode, and failing to produce an error when the stream is not writable. revert the inline setup of the bounds pointers and instead zero them, so that the underlying fwrite code will call __towrite to set them up.
2018-08-29fix missing flush of stderr at exit if it was put in buffered modeRich Felker-0/+1
commit 0b80a7b0404b6e49b0b724e3e3fe0ed5af3b08ef added the ability to set application-provided stdio FILE buffers, adding the possibility that stderr might be buffered at exit time, but __stdio_exit did not have code to flush it. this regression was not present in any release.
2018-08-29fix async thread cancellation on sh-fdpicRich Felker-0/+8
if __cp_cancel was reached via __syscall_cp, r12 will necessarily still contain a GOT pointer (for or for the static-linked main program) valid for entering __cancel. however, in the case of async cancellation, r12 may contain any scratch value; it's not necessarily even a valid GOT pointer for the code that was interrupted. unlike in commit 0ec49dab6794166d67fae4764ce7fdea42ea6103 where the corresponding issue was fixed for powerpc64, there is fundamentally no way for fdpic code to recompute its GOT pointer. so a new mechanism is introduced for cancel_handler to write a GOT register value into the interrupted context on archs where it is needed.
2018-08-29fix async thread cancellation on powerpc64Rich Felker-0/+7
entering the local entry point for __cancel from __cp_cancel is valid if __cp_cancel was reached from __syscall_cp, since both are in libc and share the same TOC pointer, but it is not valid if __cp_cancel was reached when cancel_handler rewrote the program counter for asynchronous cancellation of code outside libc. to ensure __cancel is entered with a valid TOC pointer, recompute the correct value in a PC-relative manner before jumping.
2018-08-28vfwprintf: honor field width with 'c' format typeA. Wilcox-1/+4
2018-08-28fix several values reported by sysconfRich Felker-8/+11
- REALTIME_SIGNALS is supposed to be version-valued - DELAYTIMER_MAX was wrongly using the min allowed max - unavailable compilation environments wrongly used 0 instead of -1
2018-08-28fix return value of system on failure to spawn child processRich Felker-1/+1
the value 0x7f00 (as if by _exit(127)) is specified only for the case where the child is created but then fails to exec the shell, since traditional fork+exec implementations do not admit reporting an error via errno in this case without additional machinery. it's unclear whether an implementation not subject to this failure mode needs to emulate it; one could read the standard as requiring that. if so, additional code will need to be added to map posix_spawn errors into the form system is expected to return. but for now, returning -1 to indicate an error is significantly better behavior than always reporting failures as if the shell failed to exec after fork.
2018-08-28set stream orientations in open_[w]memstreamRich Felker-0/+3
fundamentally there is no good reason these functions need to set an orientation (morally it should be possible to write a wchar_t[] memory stream using byte functions, or a char[] memory stream using wide functions), but it's a part of the specification that they do. aside from being able to inspect the orientation with fwide, failure to set the orientation in open_wmemstream is observable if the locale changes between open_wmemstream and the first operation on the stream; this is because the encoding rule (locale) for the stream is required to be bound at the time the stream becomes wide-oriented. for open_wmemstream, call fwide to avoid duplicating the logic for binding the encoding rule. for open_memstream it suffices just to set the mode field in the FILE struct.
2018-08-28make fmemopen's w+ mode truncate the bufferRich Felker-0/+1
the w+ mode is specified to "truncate the buffer contents". like most of fmemopen, exactly what this means is underspecified. mode w and w+ of course implicitly 'truncate' the buffer if a write from the initial position is flushed, so in order for this part of the text about w+ not to be spurious, it should be interpreted as requiring something else, and the obvious reasonable interpretation is that the truncation is immediately visible if you attempt to read from the stream or the buffer before writing/flushing. this interpretation agrees with reported conformance test failures.
2018-08-28set errno when fileno is called on a FILE with no underlying fdRich Felker-4/+7
this is a POSIX requirement. also remove the gratuitous locking shenanigans and simply access f->fd under control of the lock. there is no advantage to not doing so, and it made the correctness non-obvious at best.
2018-08-28reject invalid arguments to pthread_barrierattr_setpsharedRich Felker-0/+1
this is a POSIX requirement.
2018-08-28rewrite __aeabi_read_tp in asmSzabolcs Nagy-12/+6
__aeabi_read_tp used to call c code, but that was incorrect as the arm runtime abi specifies special pcs for this function: it is only allowed to clobber r0, ip, lr and cpsr. maintainer's note: the old code explicitly saved and restored all general-purpose registers which are call-clobbered in the normal calling convention, so it's unlikely that any real-world compilers produced code that could break. however theoretically they could have chosen to use floating point registers, in which case the caller's values of those registers would be clobbered.
2018-08-28fix dubious char signedness check in limits.hRich Felker-1/+1
commit 201995f382cc698ae19289623cc06a70048ffe7b introduced a hack utilizing the signedness of character constants at the preprocessor level to avoid depending on the gcc-specific __CHAR_UNSIGNED__ predef. while this trick works on gcc and presumably other compilers being used, it's not clear that the behavior it depends on is actually conforming. C11 ¶10 defines character constants as having type int, and 6.10.1 ¶4 defines preprocessor #if arithmetic to take place in intmax_t or uintmax_t, depending on the signedness of the integer operand types, and it is specified that "this includes interpreting character constants". if character literals had type char and just promoted to int, it would be clear that when char is unsigned they should behave as uintmax_t at the preprocessor level. however, as written the text of the standard seems to require that character constants always behave as intmax_t, corresponding to int, at the preprocessor level. since there is a good deal of ambiguity about the correct behavior and a risk that compilers will disagree or that an interpretation may mandate a change in the behavior, do not rely on it for defining CHAR_MIN and CHAR_MAX correctly. instead, use the signedness of the value (as opposed to the type) of '\xff', which will be positive if and only if plain char is unsigned. this behavior is clearly specified, and the specific case '\xff' is even used in an example, under of the standard.
2018-08-28fix deadlock in async thread self-cancellationRich Felker-1/+5
with async cancellation enabled, pthread_cancel(pthread_self()) deadlocked due to pthread_kill holding killlock which is needed by pthread_exit. this could be solved by making pthread_kill block signals around the critical section, at least when the target thread is itself, but the issue only arises for cancellation, and otherwise would just be imposing unnecessary cost. instead just have pthread_cancel explicitly check for async self-cancellation and call pthread_exit(PTHREAD_CANCELED) directly rather than going through the signal machinery.
2018-08-27time: fix incorrect DST offset when using POSIX timezones without DSTA. Wilcox-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.
2018-08-23fix tls access on arm targets before armv6kSzabolcs Nagy-1/+1
commit 610c5a8524c3d6cd3ac5a5f1231422e7648a3791 changed the thread pointer setup so tp points at the end of the pthread struct on arm, but failed to update __aeabi_read_tp so it was off by 8. this broke tls access in code that is compiled with -mtp=soft, which is the default when target arch is pre armv6k or thumb1. maintainer's note: no release versions are affected.
2018-08-23fix missing strerror text for EMULTIHOPRich Felker-0/+1
this is an obsolete error code from RFS, an obsolete predecessor of NFS. POSIX documents it only as "Reserved", but maintains the requirement that it be defined. as long as it is defined, it needs a string for strerror to produce; the one chosen matches glibc and documentation from other language runtimes I could find.
2018-08-23fix printf precision specifier for hex floats on non-ld80 archsRich Felker-0/+1
the code to perform rounding to the desired precision wrongly assumed the long double mantissa was an integral number of nibbles (hex digits) in length. this is true for 80-bit extended precision (64-bit mantissa) but not for double (53) or quad (113). scale the rounding value by 1<<(LDBL_MANT_DIG%4) to compensate.
2018-08-22getopt: update optarg and optind correctly on missing argumentRich Felker-6/+6
the text of the specification for getopt's handling of options that require an argument, which requires updating optarg and optind, does not exclude the error case where the end of the argument list has been reached. in that case, it is expected that optarg be assigned argv[argc] (normally null) and optind be incremented by 2, resulting in a value of argc+1.
2018-08-22fix FP_ILOGB0 and FP_ILOGBNAN definitions to be valid for use in #ifRich Felker-1/+1
commit 98c9af500125df41fdb46d7e384b00982d72493a wrongly claimed they do not need to be valid for such usage, but the last sentence of C11 7.1.4 ¶1 imposes a broad requirement that all macros specified as integer constant expressions also need to be valid for #if. simply write the value out explicitly. there is no value here in pretending that the width of int will vary.
2018-08-20remove erroneous SYMLINK_MAX definition from limits.h, pathconfRich Felker-2/+1
POSIX requires the symlink function to fail with ENAMETOOLONG if the link contents to be written exceed SYMLINK_MAX in length, but neither Linux nor our syscall wrapper code enforce this. the value 255 for SYMLINK_MAX is not meaningful and does not seem to have been motivated by anything except perhaps a wrong assumption that a definition was mandatory. it has been present (though moving through bits to top-level limits.h) since the beginning of the project history. [f]pathconf is entitled to return -1 as the limit for conf names for which there is no hard limit, with the usual POSIX note that an indefinite limit does not imply an infinite limit. in principle we might should report a limit for filesystems that impose one, but such functionality is not currently present for any of the pathconf limits, and adding it is beyond the scope of fixing the incorrect limit.
2018-08-18mips archs: fix runaway execution if start fn passed to clone returnsSegev Finer-3/+12
Call SYS_exit on return from fn in __clone. This is the expected behavior of this function. Without this the child task will crash on return from fn, since it will return to nowhere.
2018-08-16fix pthread_create return value with PTHREAD_EXPLICIT_SCHEDRich Felker-0/+1
due to moved code, commit b8742f32602add243ee2ce74d804015463726899 inadvertently used the return value of __clone, rather than the return value of SYS_sched_setscheduler in the new thread, to check whether it needed to report failure. since a successful __clone returns the tid of the new thread, which is never zero, this caused pthread_create always to return with an invalid error number in the code path for PTHREAD_EXPLICIT_SCHED. this regression was not present in any releases.
2018-08-07fix sign of strftime %z output with offsets <1 hour west of UTCRich Felker-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.
2018-08-02fix musl-gcc wrapper to be compatible with default-pie gcc toolchainsRich Felker-2/+2
the specfile for the wrapper was written assuming output is pie only if -pie appears on the command line. recent (and older patched) versions of gcc can be configured to produce pie output by default, adn when used with such a toolchain, the wrapper linked the wrong startfiles (crt*) containing pic-incompatible code. rather than trying to figure out gcc's default, simply always use the pic-compatible start files.
2018-07-27make pthread_attr_init honor defaults set by pthread_setattr_default_npRich Felker-4/+11
this fixes a major gap in the intended functionality of pthread_setattr_default_np. if application/library code creating a thread does not pass a null attribute pointer to pthread_create, but sets up an attribute object to change other properties while leaving the stack alone, the created thread will get a stack with size DEFAULT_STACK_SIZE. this makes pthread_setattr_default_np useless for working around stack overflow issues in such applications, and leaves a major risk of regression if previously-working code switches from using a null attribute pointer to an attribute object. this change aligns the behavior more closely with the glibc pthread_setattr_default_np functionality too, albeit via a different mechanism. glibc encodes "default" specially in the attribute object and reads the actual default at thread creation time. with this commit, we now copy the current default into the attribute object at pthread_attr_init time, so that applications that query the properties of the attribute object will see the right values.
2018-07-23bsearch: simplify and optimizeFangrui Song-6/+6
maintainer's note: the key observation here is that the compared element is the first slot of the second ceil(half) of the array, and thus can be removed for further comparison when it does not match, so that we descend into the second ceil(half)-1 rather than ceil(half) elements. this change ensures that nel strictly decreases with each iteration, so that the case of != but nel==1 does not need to be special-cased anymore.
2018-07-20move inclusion of linux headers for kd.h, soundcard.h, vt.h to bitsmidipix-3/+6
maintainer's note: while musl does not use the linux kernel headers, it does provide these three sys/* headers which do nothing but include the corresponding linux/* headers, since the sys/* versions are the ones documented for application use (and they arguably provide interfaces that are not linux-specific but common to other unices). these headers should probably not be provided by libc (rather by a separate package), but as long as they are, use the bits header framework as an aid to out-of-tree ports of musl for non-linux systems that want to implement them in some other way.
2018-07-20remove inclusion guard hacks for sys/kd.hmidipix-7/+0
maintainer's note: at some point, probably long before linux separated the uapi headers, it was the case, or at least I believed it was the case, that linux/types.h was unsafe to include from userspace. thus, the inclusion guard macro _LINUX_TYPES_H was defined in sys/kd.h to prevent linux/kd.h from including linux/types.h (which it spuriously includes but does not use). as far as I can tell, whatever problem this was meant to solve does not seem to have been present for a long time, and the hack was not done correctly anyway, so removing it is the right thing to do.
2018-07-18remove spurious declaration of __getdents from readdir.cRich Felker-2/+0
2018-07-18fix regression in alignment of dirent structs produced by readdirRich Felker-1/+7
commit 32482f61da7650ff10741bd5aedd66bbc3ea165b reduced the number of int members before the dirent buf from 4 to 3, thereby misaligning it mod sizeof(off_t), producing invalid accesses on any arch where alignof(off_t)==sizeof(off_t). rather than re-adding wasted padding, reorder the struct to meet the requirement and add a comment and static assertion to prevent this from getting broken again.
2018-07-17add support for arch-specific ptrace command macrosSzabolcs Nagy-0/+123
sys/ptrace.h is target specific, use bits/ptrace.h to add target specific macro definitions. these macros are kept in the generic sys/ptrace.h even though some targets don't support them: PTRACE_GETREGS PTRACE_SETREGS PTRACE_GETFPREGS PTRACE_SETFPREGS PTRACE_GETFPXREGS PTRACE_SETFPXREGS so no macro definition got removed in this patch on any target. only s390x has a numerically conflicting macro definition (PTRACE_SINGLEBLOCK). the PT_ aliases follow glibc headers, otherwise the definitions come from linux uapi headers except ones that are skipped in glibc and there is no real kernel support (s390x PTRACE_*_AREA) or need special type definitions (mips PTRACE_*_WATCH_*) or only relevant for linux 2.4 compatibility (PTRACE_OLDSETOPTIONS).
2018-07-17sys/ptrace.h: add missing PTRACE_EVENT_STOPSzabolcs Nagy-0/+1
new in linux v3.1 commit 3544d72a0e10d0aa1c1bd59ed77a53a59cdc12f7 changed in linux v3.4 commit 5cdf389aee90109e2e3d88085dea4dd5508a3be7 A tracer recieves this event in the waitpid status of a PTRACED_SEIZED process.
2018-07-17uchar.h: define char16_t and char32_t for old c++Szabolcs Nagy-1/+3
including uchar.h in c++ code is only well defined in c++11 onwards where char16_t and char32_t type definitions must be hidden since they are keywords. however some c++ code compiled for older c++ standard include uchar.h too and they need the typedefs, this fix makes such code work.
2018-07-16block dlopen of libraries with initial-exec refs to dynamic TLSRich Felker-0/+8
previously, this operation succeeded, and the relocation results worked for access from new threads created after dlopen, but produced invalid accesses (and possibly clobbered other memory) from threads that already existed. the way the check is written, it still permits dlopen of libraries containing initial-exec references to static TLS (TLS in the main program or in a dynamic library loaded at startup).
2018-07-16fix inefficient choice of tlsdesc function due to off-by-oneRich Felker-1/+1
tls_id is one-based, whereas [static_]tls_cnt is a count, so comparison for checking that a given tls_id is dynamic rather than static needs to use strict inequality.
2018-07-14implement getaddrinfo's AI_ADDRCONFIG flagRich Felker-0/+39
this flag is notoriously under-/mis-specified, and in the past it was implemented as a nop, essentially considering the absence of a loopback interface with and ::1 addresses an unsupported configuration. however, common real-world container environments omit IPv6 support (even for the network-namespaced loopback interface), and some kernels omit IPv6 support entirely. future systems on the other hand might omit IPv4 entirely. treat these as supported configurations and suppress results of the unconfigured/unsupported address families when AI_ADDRCONFIG is requested. use routability of the loopback address to make the determination; unlike other implementations, we do not exclude loopback from the "an address is configured" condition, since there is no basis in the specification for such exclusion. obtaining a result with AI_ADDRCONFIG does not imply routability of the result, and applications must still be able to cope with unroutable results even if they pass AI_ADDRCONFIG.
2018-07-13fix writes outside buffer by ungetc after setvbufRich Felker-1/+1
commit 0b80a7b0404b6e49b0b724e3e3fe0ed5af3b08ef, which added non-stub setvbuf, applied the UNGET pushback adjustment to the size of the buffer passed in, but inadvertently omitted offsetting the start by the same amount, thereby allowing unget to clobber up to 8 bytes before the start of the buffer. this bug was introduced in the present release cycle; no releases are affected.
2018-07-12add ST_RELATIME to statvfs.hRich Felker-0/+1
2018-07-11resolver: don't depend on v4mapped ipv6 to probe routability of v4 addrsRich Felker-15/+32
to produce sorted results roughly corresponding to RFC 3484/6724, __lookup_name computes routability and choice of source address via dummy UDP connect operations (which do not produce any packets). since at the logical level, the properties fed into the sort key are computed on ipv6 addresses, the code was written to use the v4mapped ipv6 form of ipv4 addresses and share a common code path for them all. however, on kernels where ipv6 support has been completely omitted, this causes ipv4 to appear equally unroutable as ipv6, thereby putting unreachable ipv6 addresses before ipv4 addresses in the results. instead, use only ipv4 sockets to compute routability for ipv4 addresses. some gratuitous conversion back and forth is left so that the logic is not affected by these changes. it may be possible to simplify the ipv4 case considerably, thereby reducing code size and complexity.
2018-07-02optimize explicit_bzero for sizeAlexander Monakov-1/+1
Avoid saving/restoring the incoming argument by reusing memset return value.
2018-06-28avoid spurious dso matches by dladdr outside bounds of load segmentsRich Felker-1/+10
since slack space at the beginning and/or end of writable load maps is donated to malloc, the application could obtain valid pointers in these ranges which dladdr would erroneously identify as part of the shared object whose mapping they came from. instead of checking the queried address against the mapping base and length, check it against the load segments from the program headers, and only match the dso if it lies within the bounds of one of them. as a shortcut, if the address does match the range of the mapping but not any of the load segments, we know it cannot match any other dso and can immediately return failure.
2018-06-28make dladdr consistently produce the first symbol in presence of aliasesRich Felker-1/+1
the early-exit condition for the symbol match loop on exact matches caused dladdr to produce the first match for an exact match, but the last match for an inexact match. in the interest of consistency, require a strictly-closer match to replace an already-found one.
2018-06-28fix symtab-order-dependent spurious matches in dladdrRich Felker-5/+8
commit 8b8fb7f03721c42445f982582f462144ab60a1a0 added logic to prevent matching a symbol with no recorded size (closest-match) when there is an intervening symbol whose size was recorded, but it only worked when the intervening symbol was encountered later in the search. instead of rejecting symbols where addr falls outside their recorded size during the closest-match search, accept them to find the true closest-match, then reject such a result only once the search has finished.
2018-06-27correctly handle non-matching symbols in dladdrRich Felker-4/+13
based on patch by Axel Siebenborn, with fixes discussed on the mailing list after submission and and rebased around the UB fix in commit e829695fcc880f8578c2b964ea2d090f0016c9d7. avoid spurious symbol matches by dladdr beyond symbol size. for symbols with a size recorded, only match if the queried address lies within the address range determined by the symbol address and size. for symbols with no size recorded, the old closest-match behavior is kept, as long as there is no intervening symbol with a recorded size. the case where no symbol is matched, but the address does lie within the memory range of a shared object, is specified as success. fix the return value and produce a valid (with null dli_sname and dli_saddr) Dl_info structure.