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2015-12-29adjust i386 max_align_t definition to work around some broken compilersRich Felker-3/+5
at least gcc 4.7 claims c++11 support but does not accept the alignas keyword, causing breakage when stddef.h is included in c++11 mode. instead, prefer using __attribute__((__aligned__)) on any compiler with GNU extensions, and only use the alignas keyword as a fallback for other C++ compilers. C code should not be affected by this patch.
2015-12-20fix overly pessimistic realloc strategy in getdelimRich Felker-1/+1
previously, getdelim was allocating twice the space needed every time it expanded its buffer to implement exponential buffer growth (in order to avoid quadratic run time). however, this doubling was performed even when the final buffer length needed was already known, which is the common case that occurs whenever the delimiter is in the FILE's buffer. this patch makes two changes to remedy the situation: 1. over-allocation is no longer performed if the delimiter has already been found when realloc is needed. 2. growth factor is reduced from 2x to 1.5x to reduce the relative excess allocation in cases where the delimiter is not initially in the buffer, including unbuffered streams. in theory these changes could lead to quadratic time if the same buffer is reused to process a sequence of lines successively increasing in length, but once this length exceeds the stdio buffer size, the delimiter will not be found in the buffer right away and exponential growth will still kick in.
2015-12-19avoid updating caller's size when getdelim fails to reallocRich Felker-5/+6
getdelim was updating *n, the caller's stored buffer size, before calling realloc. if getdelim then failed due to realloc failure, the caller would see in *n a value larger than the actual size of the allocated block, and use of that value is unsafe. in particular, passing it again to getdelim is unsafe. now, temporary storage is used for the desired new size, and *n is not written until realloc succeeds.
2015-12-15fix crash when signal number 0 is passed to sigactionRich Felker-5/+1
this error case was overlooked in the old range checking logic. new check is moved out of __libc_sigaction to the public wrapper in order to unify the error path and reduce code size.
2015-12-15remove visibility suppression by SHARED macro in mips and x32 arch filesRich Felker-6/+0
commit 8a8fdf6398b85c99dffb237e47fa577e2ddc9e77 was intended to remove all such usage, but these arch-specific files were overlooked, leading to inconsistent declarations and definitions.
2015-12-08fix tsearch, tfind, tdelete to handle null pointer inputSzabolcs Nagy-0/+6
POSIX specifies the behaviour for null rootp input, but it was not implemented correctly.
2015-12-08tsearch code cleanupSzabolcs Nagy-24/+28
changed the insertion method to simplify the recursion logic and reduce code size a bit.
2015-12-08fix tsearch to avoid crash on oomSzabolcs Nagy-1/+1
malloc failure was not properly propagated in the insertion method which led to null pointer dereference.
2015-12-08fix tdelete to properly balance the treeSzabolcs Nagy-5/+14
the tsearch data structure is an avl tree, but it did not implement the deletion operation correctly so the tree could become unbalanced. reported by Ed Schouten.
2015-11-30properly handle point-to-point interfaces in getifaddrs()Jo-Philipp Wich-3/+16
With point-to-point interfaces, the IFA_ADDRESS netlink attribute contains the peer address while an extra attribute IFA_LOCAL carries the actual local interface address. Both the glibc and uclibc implementations of getifaddrs() handle this case by moving the ifa_addr contents to the broadcast/remote address union and overwriting ifa_addr upon receipt of an IFA_LOCAL attribute. This patch adds the same special treatment logic of IFA_LOCAL to musl's implementation of getifaddrs() in order to align its behaviour with that of uclibc and glibc. Signed-off-by: Jo-Philipp Wich <>
2015-11-28ldso: fix the dtv update logic in __tls_get_newSzabolcs Nagy-1/+1
if two or more threads accessed tls in a dso that was loaded after the threads were created, then __tls_get_new could do out-of-bound memory access (leading to segfault). accidentally byte count was used instead of element count when the new dtv pointer was computed. (dso->new_dtv is (void**).) it is rare that the same dso provides dtv for several threads, the crash was not observed in practice, but possible to trigger.
2015-11-21math: explicitly promote expressions to excess-precision typesRich Felker-4/+4
a conforming compiler for an arch with excess precision floating point (FLT_EVAL_METHOD!=0; presently i386 is the only such arch supported) computes all intermediate results in the types float_t and double_t rather than the nominal type of the expression. some incorrect compilers, however, only keep excess precision in registers, and convert down to the nominal type when spilling intermediate results to memory, yielding unpredictable results that depend on the compiler's choices of what/when to spill. in particular, this happens on old gcc versions with -ffloat-store, which we need in order to work around bugs where the compiler wrongly keeps explicitly-dropped excess precision. by explicitly converting to double_t where expressions are expected be be evaluated in double_t precision, we can avoid depending on the compiler to get types correct when spilling; the nominal and intermediate precision now match. this commit should not change the code generated by correct compilers, or by old ones on non-i386 archs where double_t is defined as double. this fixes a serious bug in argument reduction observed on i386 with gcc 4.2: for values of x outside the unit circle, sin(x) was producing results outside the interval [-1,1]. changes made in commit 0ce946cf808274c2d6e5419b139e130c8ad4bd30 were likely responsible for breaking compatibility with this and other old gcc versions. patch by Szabolcs Nagy.
2015-11-19remove undef weak refs to init/fini array symbols in libc.soRich Felker-14/+20
commit ad1cd43a86645ba2d4f7c8747240452a349d6bc1 eliminated preprocessor-level omission of references to the init/fini array symbols from object files going into the references are weak, and the intent was that the linker would resolve them to zero in, but instead it leaves undefined references that could be satisfied at runtime. normally these references would be harmless, since the code using them does not even get executed, but some older binutils versions produce a linking error: when linking a program against, ld first tries to use the hidden init/fini array symbols produced by the linker script to satisfy the references in, then produces an error because the definitions are hidden. ideally ld would have already provided definitions of these symbols when linking, but the linker script for -shared omits them. to avoid this situation, the dynamic linker now provides its own dummy definitions of the init/fini array symbols for since they are hidden, everything binds at ld time and no references remain in the dynamic symbol table. with modern binutils and --gc-sections, both the dummy empty array objects and the code referencing them get dropped at link time, anyway. the _init and _fini symbols are also switched back to using weak definitions rather than weak references since the latter behave somewhat problematically in general, and the weak definition approach was known to work well.
2015-11-18fix build regression from removal of #ifdef SHAREDRich Felker-1/+1
2015-11-15use private maps even for read-only segments of FDPIC librariesRich Felker-1/+1
the nommu kernel shares memory when it can anyway for private read-only maps, but semantically the map should be private. this can make a difference when debugging breakpoints are to be used, in which case the kernel may need to ensure that the mapping is not shared. the new behavior matches how the kernel FDPIC loader maps the main program and/or program interpreter (dynamic linker) binary.
2015-11-12remove use of SHARED macro in dynamic linker version reportingRich Felker-4/+2
also fix visibility of the glue function used.
2015-11-12unify static and dynamic linked implementations of thread-local storageRich Felker-132/+111
this both allows removal of some of the main remaining uses of the SHARED macro and clears one obstacle to static-linked dlopen support, which may be added at some point in the future. specialized single-TLS-module versions of __copy_tls and __reset_tls are removed and replaced with code adapted from their dynamic-linked versions, capable of operating on a whole chain of TLS modules, and use of the dynamic linker's DSO chain (which contains large struct dso objects) by these functions is replaced with a new chain of struct tls_module objects containing only the information needed for implementing TLS. this may also yield some performance benefit initializing TLS for a new thread when a large number of modules without TLS have been loaded, since since there is no need to walk structures for modules without TLS.
2015-11-11unify static and dynamic libc init/fini code pathsRich Felker-28/+22
use weak definitions that the dynamic linker can override instead of preprocessor conditionals on SHARED so that the same libc start and exit code can be used for both static and dynamic linking.
2015-11-11eliminate use of SHARED macro in __tls_get_addrRich Felker-6/+6
this was only a tiny optimization, and static-linked binaries should not be calling __tls_get_addr anyway since the linker is supposed to perform relaxation, resulting in use of the local-exec TLS model.
2015-11-11eliminate use of SHARED macro to suppress visibility attributesRich Felker-32/+5
this is the first and simplest stage of removal of the SHARED macro, which will eventually allow libc.a and to be produced from the same object files. the original motivation for these #ifdefs which are now being removed was to allow building a static-only libc using a compiler that does not support visibility. however, SHARED was the wrong condition to test for this anyway; various assembly-language sources refer to hidden symbols and declare them with the .hidden directive, making it wrong to define the referenced symbols as non-hidden. if there is a need in the future to build libc using compilers that lack visibility, support could be moved to the build system or perhaps the __PIC__ macro could be checked instead of SHARED.
2015-11-11use correct nofpu versions of setjmp/longjmp used on sh-nofpu-fdpicRich Felker-0/+4
when adding the fdpic subarchs, the need for these sub files was overlooked. thus setjmp and longjmp performed illegal instructions.
2015-11-11fix dynamic loader library mapping for nommu systemsRich Felker-4/+21
on linux/nommu, non-writable private mappings of files may actually use memory shared with other processes or the fs cache. the old nommu loader code (used when mmap with MAP_FIXED fails) simply wrote over top of the original file mapping, possibly clobbering this shared memory. no such breakage was observed in practice, but it should have been possible. the new code starts by mapping anonymous writable memory on archs that might support nommu, then maps load segments over top of it, falling back to read if MAP_FIXED fails. we use an anonymous map rather than a writable file map to avoid reading more data from disk than needed. since pages cannot be loaded lazily on fault, in case of large data/bss, mapping the full file may read a lot of data that will subsequently be thrown away when processing additional LOAD segments. as a result, we cannot skip the first LOAD segment when operating in this mode. these changes affect only non-FDPIC nommu support.
2015-11-10fix return value of nl_langinfo for invalid item argumentsRich Felker-5/+5
it was wrongly returning a null pointer instead of an empty string.
2015-11-10explicitly assemble all arm asm sources as UALRich Felker-0/+20
these files are all accepted as legacy arm syntax when producing arm code, but legacy syntax cannot be used for producing thumb2 with access to the full ISA. even after switching to UAL, some asm source files contain instructions which are not valid in thumb mode, so these will need to be addressed separately.
2015-11-09remove non-working pre-armv4t support from arm asmRich Felker-31/+2
the idea of the three-instruction sequence being removed was to be able to return to thumb code when used on armv4t+ from a thumb caller, but also to be able to run on armv4 without the bx instruction available (in which case the low bit of lr would always be 0). however, without compiler support for generating such a sequence from C code, which does not exist and which there is unlikely to be interest in implementing, there is little point in having it in the asm, and it would likely be easier to add pre-armv4t support via enhanced linker handling of R_ARM_V4BX than at the compiler level. removing this code simplifies adding support for building libc in thumb2-only form (for cortex-m).
2015-11-09use vfp mnemonics rather than hard-coded opcodes in arm setjmp/longjmpRich Felker-2/+10
the code to save/restore vfp registers needs to build even when the configured target does not have fpu; this is because code using vfp fpu (but with the standard soft-float EABI) may call a libc built for a soft-float only, and the EABI considers these registers call-saved when they exist. thus, extra directives are used to force the assembler to allow vfp instructions and to avoid marking the resulting object files as requiring vfp. moving away from using hard-coded opcode words is necessary in order to eventually support producing thumb2-only output for cortex-m. conditional execution of these instructions based on hwcap flags was already implemented. when building for arm (non-thumb) output, the only currently-supported configuration, this commit does not change the code emitted.
2015-11-07work around toolchains with broken visibility in libgcc/libpccRich Felker-0/+5
2015-11-05use vfp mnemonics instead of p10 coprocessor ones in armhf fenv asmSzabolcs Nagy-10/+10
mrc/mcr p10 coprocessor mnemonics are deprecated by some toolchains.
2015-11-05convert arm memcpy asm to UAL, remove .word hacksRich Felker-22/+24
contrary to commit 9367fe926196f407705bb07cd29c6e40eb1774dd, all relevant gas versions actually do support .syntax unified.
2015-11-04remove external linkage from __simple_malloc definitionRich Felker-1/+1
this function is used only as a weak definition for malloc, for static linking in programs which do not call realloc or free. since it had external linkage and was thereby exported in's dynamic symbol table, --gc-sections was unable to drop it. this was merely an oversight; there's no reason for it to be external, so make it static.
2015-11-04have configure check/add --gc-sections linker optionRich Felker-0/+4
this allowing the linker to drop certain weak definitions that are only used as dummies for static linking. they could be eliminated for shared library builds using the preprocessor instead, but we are trying to transition to using the same object files for shared and static libc, so a link-time solution is preferable.
2015-11-04have configure check/add linker options to reduce size lost to paddingRich Felker-0/+6
based on patch by Denys Vlasenko. sorting sections and common data symbols by alignment acts as an approximation for optimal packing, which the linker does not actually support.
2015-11-04have configure check/add -ffunction-sections and -fdata-sectionsRich Felker-0/+11
based on patch by Denys Vlasenko. the original intent for using these options was to enable linking optimizations. these are immediately available for static linking applications to libc.a, and will also be used for linking in a subsequent commit. in addition to the original motives, this change works around a whole class of toolchain bugs where the compiler generates relative address expressions using a weak symbol and the assembler "optimizes out" the relocation which should result by using the weak definition. (see gas pr 18561 and gcc pr 66609, 68178, etc. for examples.) by having different functions and data objects in their own sections, all relative address expressions are cross-section and thus cannot be resolved to constants until link time. this allows us to retain support for affected compiler/assembler versions without invasive and fragile source-level workarounds.
2015-11-02fix mismatched parens in CMPLX def for annex-g-conforming compilersRich Felker-1/+1
this conditional path was never tested because there are no compilers that conform to annex g (none with _Imaginary_I).
2015-11-02generalize sh entry point asm not to assume call dests fit in 12 bitsRich Felker-5/+12
this assumption is borderline-unsafe to begin with, and fails badly with -ffunction-sections since the linker can move the callee arbitrarily far away when it lies in a different section.
2015-11-02keep user-provided CFLAGS/LDFLAGS separate from those added by configureRich Felker-6/+12
this way, overriding these variables on the make command line (or just re-passing the originally-passed values when invoking make) won't suppress use of the flags added by configure.
2015-11-02fix mremap memory synchronization and use of variadic argumentRich Felker-4/+11
since mremap with the MREMAP_FIXED flag is an operation that unmaps existing mappings, it needs to use the vm lock mechanism to ensure that any in-progress synchronization operations using vm identities from before the call have finished. also, the variadic argument was erroneously being read even if the MREMAP_FIXED flag was not passed. in practice this didn't break anything, but it's UB and in theory LTO could turn it into a hard error.
2015-11-02prevent allocs than PTRDIFF_MAX via mremapDaniel Micay-1/+8
It's quite feasible for this to happen via MREMAP_MAYMOVE.
2015-11-02use explicit __cp_cancel label in cancellable syscall asm for all archsRich Felker-28/+32
previously, only archs that needed to do stack cleanup defined a __cp_cancel label for acting on cancellation in their syscall asm, and a default definition was provided by a weak alias to __cancel, the C function. this resulted in wrong codegen for arm on gcc versions affected by pr 68178 and possibly similar issues (like pr 66609) on other archs, and also created an inconsistency where the __cp_begin and __cp_end labels were treated as const data but __cp_cancel was treated as a function. this in turn caused incorrect code generation on archs where function pointers point to function descriptors rather than code (for now, only sh/fdpic).
2015-11-02properly access mcontext_t program counter in cancellation handlerRich Felker-15/+14
using the actual mcontext_t definition rather than an overlaid pointer array both improves correctness/readability and eliminates some ugly hacks for archs with 64-bit registers bit 32-bit program counter. also fix UB due to comparison of pointers not in a common array object.
2015-10-28fix missing bss handling in FDPIC ELF loaderRich Felker-0/+13
when a library being loaded has bss (i.e. data segment with p_memsz>p_filesz), this region needs to be zeroed with a combination of memset and/or mmap. the regular ELF loader always did this but the FDPIC code path omitted it, leading to objects in bss having uninitialized/junk contents.
2015-10-26getnameinfo: make size check not fail for bigger sizesHauke Mehrtens-2/+2
getnameinfo() compares the size of the given struct sockaddr with sizeof(struct sockaddr_in) and sizeof(struct sockaddr_in6) depending on the net family. When you add a sockaddr of size sizeof(struct sockaddr_storage) this function will fail because the size of the sockaddr is too big. Change the check that it only fails if the size is too small, but make it work when it is too big for example when someone calls this function with a struct sockaddr_storage and its size. This fixes a problem with IoTivity 1.0.0 and musl. glibc and bionic are only failing if it is smaller, net/freebsd implemented the != check. Signed-off-by: Hauke Mehrtens <>
2015-10-26safely handle failure to open hosts, services, resolv.conf filesRich Felker-4/+29
previously, transient failures like fd exhaustion or other resource-related errors were treated the same as non-existence of these files, leading to fallbacks or false-negative results. in particular: - failure to open hosts resulted in fallback to dns, possibly yielding EAI_NONAME for a hostname that should be defined locally, or an unwanted result from dns that the hosts file was intended to replace. - failure to open services resulted in EAI_SERVICE. - failure to open resolv.conf resulted in querying localhost rather than the configured nameservers. now, only permanent errors trigger the fallback behaviors above; all other errors are reportable to the caller as EAI_SYSTEM.
2015-10-24fix single-byte overflow of malloc'd buffer in getdelimRich Felker-1/+1
the buffer enlargement logic here accounted for the terminating null byte, but not for the possibility of hitting the delimiter in the buffer-refill code path that uses getc_unlocked, in which case two additional bytes (the delimiter and the null termination) are written without another chance to enlarge the buffer. this patch and the corresponding bug report are by Felix Janda.
2015-10-23prevent user CFLAGS overrides from exposing executable stackRich Felker-7/+7
the option to suppress executable stack tagging was placed in CFLAGS, which is treated as optional and overridable by the build system. if a user replaces CFLAGS after configure has run, it could get lost, resulting in a that's flagged as needing executable stack, which would cause the kernel to map the initial stack as executable. move -Wa,--noexecstack to CFLAGS_C99FSE, the make variable used for mandatory compiler options.
2015-10-22fix breakage when user overrides CFLAGS on the make command lineRich Felker-4/+4
these per-target CFLAGS adjustments are mandatory additions to the command line for building the affected targets, not part of the user-provided CFLAGS for tuning. my intent was always that the variable append operations would take place after user settings, but when a variable is set on the command line, it overrides all definitions in the makefile, including target-specific ones. based on patch by Szabolcs Nagy.
2015-10-19release 1.1.12v1.1.12Rich Felker-1/+36
2015-10-19declare fpu usage to the assembler in arm hard-float asm filesSzabolcs Nagy-0/+6
Some armhf gcc toolchains (built with --with-float=hard but without --with-fpu=vfp*) do not pass -mfpu=vfp to the assembler and then binutils rejects the UAL mnemonics for VFP unless there is an .fpu vfp directive in the asm source.
2015-10-15add missing memory barrier to pthread_joinBobby Bingham-0/+1
POSIX requires pthread_join to synchronize memory on success. The futex wait inside __timedwait_cp cannot handle this because it's not called in all cases. Also, in the case of a spurious wake, tid can become zero between the wake and when the joining thread checks it.
2015-10-15fix dladdr treatment of function descriptors for fdpicRich Felker-9/+22
when determining which module an address belongs to, all function descriptor ranges must be checked first, in case the allocated memory falls inside another module's memory range. dladdr itself must also check addresses against function descriptors before doing a best-match search against the symbol table. even when doing the latter (e.g. for code addresses obtained from mcontext_t), also check whether the best-match was a function, and if so, replace the result with a function descriptor address. which is the nominal "base address" of the function and which the caller needs if it intends to subsequently call the matching function.