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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 6.4.4.4 ¶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 6.4.4.4 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 127.0.0.1 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.
2018-06-27avoid using undefined pointer arithmetic in dladdrRich Felker-8/+9
2018-06-26fix missing timeout argument to futex syscall in __futexwaitPatrick Oppenlander-2/+2
2018-06-26add explicit_bzero implementationDavid Carlier-0/+9
maintainer's note: past sentiment was that, despite being imperfect and unable to force clearing of all possible copies of sensitive data (e.g. in registers, register spills, signal contexts left on the stack, etc.) this function would be added if major implementations agreed on it, which has happened -- several BSDs and glibc all include it.
2018-06-26inet_ntop: do not compress single zeros in IPv6Arthur Jones-1/+1
maintainer's note: this change is for conformance with RFC 5952, 4.2.2, which explicitly forbids use of :: to shorten a single 16-bit 0 field when producing the canonical text representation for an IPv6 address. fixes a test failure reported by Philip Homburg, who also submitted a patch, but this fix is simpler and should produce smaller code.
2018-06-26strftime: fix underlying format string in %z formatDaniel Sabogal-1/+1
the expression (tm->__tm_gmtoff)/3600 has type long. use %+.2ld instead.
2018-06-26resolver: omit final dot (root/suppress-search) in canonical nameRich Felker-0/+4
if a final dot was included in the queried host name to anchor it to the dns root/suppress search domains, and the result was not a CNAME, the returned canonical name included the final dot. this was not consistent with other implementations, confused some applications, and does not seem desirable. POSIX specifies returning a pointer to, or to a copy of, the input nodename, when the canonical name is not available, but does not attempt to specify what constitutes "not available". in the case of search, we already have an implementation-defined "availability" of a canonical name as the fully-qualified name resulting from search, so defining it similarly in the no-search case seems reasonable in addition to being consistent with other implementations. as a bonus, fix the case where more than one trailing dot is included, since otherwise the changes made here would wrongly cause lookups with two trailing dots to succeed. previously this case resulted in malformed dns queries and produced EAI_AGAIN after a timeout. now it fails immediately with EAI_NONAME.
2018-06-26fix regression in powerpc[64] SO_PEERSEC definitionRich Felker-0/+2
commit 587f5a53bc3a68d80b239ba515d583df690a96df moved the definition of SO_PEERSEC to bits/socket.h for archs where the SO_* macros differ from their standard values, but failed to add copies of the generic definition for powerpc and powerpc64.
2018-06-26fix value of SO_PEERSEC on mips archsRich Felker-1/+4
adapted from patch by Matthias Schiffer.
2018-06-26add m68k reg.h and user.hRich Felker-0/+78
2018-06-26fix dynamic linker mapping/clearing bss in first/only LOAD segmentRich Felker-6/+5
writable load segments can have size-in-memory larger than their size in the ELF file, representing bss or equivalent. the initial partial page has to be zero-filled, and additional anonymous pages have to be mapped such that accesses don't failt with SIGBUS. map_library skips redundant MAP_FIXED mapping of the initial (lowest-address) segment when processing LOAD segments since it was already mapped when reserving the virtual address range, but in doing so, inadvertently also skipped the code to fill/map bss. typical executable and library files have two or more LOAD segments, and the first one is text/rodata (non-writable) and thus has no bss, but it is syntactically valid for an ELF program/library to put its writable segment first, or to have only one segment (everything writable). the binutils bfd-based linker has been observed to create such programs in the presence of unusual sections or linker scripts. fix by moving only the mmap_fixed operation under the conditional rather than skipping the remainder of the loop body. add a check to avoid bss processing in the case where the segment is not writable; this should not happen, but if it does, the change would be a crashing regression without this check.
2018-06-20add memfd_create syscall wrapperSzabolcs Nagy-0/+13
memfd_create was added in linux v3.17 and glibc has api for it.
2018-06-20add mlock2 linux syscall wrapperSzabolcs Nagy-3/+18
mlock2 syscall was added in linux v4.4 and glibc has api for it. It falls back to mlock in case of flags==0, so that case works even on older kernels. MLOCK_ONFAULT is moved under _GNU_SOURCE following glibc.
2018-06-20fix m68k float.h long double exponent rangeRich Felker-2/+2
unlike the x86 variant, the m68k ld80 format allows (biased) exponent zero with mantissa msb set, thereby extending the normal range.