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2016-01-27improve clock_gettime and adapt it to support slightly-broken vdsoRich Felker-22/+39
these changes are motivated by a functionally similar patch by Hauke Mehrtens to address the needs of the new mips vdso clock_gettime, which wrongly fails with ENOSYS rather than falling back to making a syscall for clock ids it cannot handle from userspace. in the process of preparing to handle that case, it was noticed that the old clock_gettime use of the vdso was actually wrong with respect to error handling -- the tail call to the vdso function failed to set errno and instead returned an error code. since tail calls to vdso are no longer possible and since the plain syscall code is now needed as a fallback path anyway, it does not make sense to use a function pointer to call the plain syscall code path. instead, it's inlined at the end of the main clock_gettime function. the new code also avoids the need to test for initialization of the vdso function pointer by statically initializing it to a self-init function, and eliminates redundant loads from the volatile pointer object. finally, the use of a_cas_p on an object of type other than void *, which is not permitted aliasing, is replaced by using an object with the correct type and casting the value.
2016-01-26change the internal socketcall selection logicSzabolcs Nagy-1/+1
only use SYS_socketcall if SYSCALL_USE_SOCKETCALL is defined internally, otherwise use direct syscalls. this commit does not change the current behaviour, it is preparation for adding direct syscall numbers for i386.
2016-01-25move dynamic linker to its own top-level directory, ldsoRich Felker-2087/+0
this eliminates the last need for the SHARED macro to control how files in the src tree are compiled. the same code is used for both libc.a and, with additional code for the dynamic linker (from the new ldso tree) being added to but not libc.a. separate .o and .lo object files still exist for the src tree, but the only difference is that the .lo files are built as PIC. in the future, if/when we add dlopen support for static-linked programs, much of the code in dynlink.c may be moved back into the src tree, but properly factored into separate source files. in that case, the code in the ldso tree will be reduced to just the dynamic linker entry point, self-relocation, and loading of libraries needed by the main application.
2016-01-25adapt static dl_iterate_phdr not to depend on !defined(SHARED)Rich Felker-4/+3
like elsewhere, use a weak alias that the dynamic linker will override with a more complete version capable of handling shared libraries.
2016-01-25move static-linked stub dlsym out of dynlink.cRich Felker-11/+15
the function name is still __-prefixed because it requires an asm wrapper to pass the caller's address in order for RTLD_NEXT to work. since this was the last function in dynlink.c still used for static linking, now the whole file is conditional on SHARED being defined.
2016-01-25move static-linked stub dlopen out of dynlink.cRich Felker-5/+13
2016-01-25move dlinfo out of dynlink.cRich Felker-16/+12
2016-01-25move dlclose out of dynlink.c to its own source fileRich Felker-5/+9
2016-01-25move static-linked stub invalid dso handle checking out of dynlink.cRich Felker-9/+20
2016-01-25move static/stub version of dladdr out of dynlink.cRich Felker-9/+6
2016-01-25factor dlerror and error-setting code out of dynlink.cRich Felker-32/+55
the ultimate goal of this change is to get all code used in libc.a out of dynlink.c, so that the dynamic linker code can be moved to its own tree and object files in the src tree can all be shared between libc.a and
2016-01-22add arch/abi info to dynamic linker's id/version outputRich Felker-1/+1
2016-01-22move sh port's __shcall internal function from arch/sh/src to src treeRich Felker-0/+5
2016-01-22move sh __unmapself code from arch/sh/src to main src treeRich Felker-0/+24
2016-01-22move x32 sysinfo impl and syscall fixup code out of arch/x32/srcRich Felker-1/+88
all such arch-specific translation units are being moved to appropriate arch dirs under the main src tree.
2016-01-22move arm-specific translation units out of arch/arm/src, to src/*/armRich Felker-1/+244
this is possible with the new build system that allows src/*/$(ARCH)/* files which do not shadow a file in the parent directory, and yields a more logical organization. eventually it will be possible to remove arch/*/src from the build system.
2016-01-21overhaul sh atomics for new atomics framework, add j-core cas.l backendRich Felker-0/+105
sh needs runtime-selected atomic backends since there are a number of supported models that use non-forwards-compatible (non-smp-compatible) atomic mechanisms. previously, the code paths for this were highly inefficient since they involved C function calls with multiple branches in the callee and heavy spills in the caller. the new code performs calls the runtime-selected asm fragment from inline asm with extremely minimal clobbers, rather than using a function call. for the sh4a case where the atomic mechanism is known and there is no forward-compatibility issue, the movli.l and movco.l instructions are provided as a_ll and a_sc, allowing the new shared atomic.h to generate efficient inline versions of all the basic atomic operations without needing a cas loop.
2016-01-21refactor internal atomic.hRich Felker-0/+275
rather than having each arch provide its own atomic.h, there is a new shared atomic.h in src/internal which pulls arch-specific definitions from arc/$(ARCH)/atomic_arch.h. the latter can be extremely minimal, defining only a_cas or new ll/sc type primitives which the shared atomic.h will use to construct everything else. this commit avoids making heavy changes to the individual archs' atomic implementations. definitions which are identical or near-identical to what the new shared atomic.h would produce have been removed, but otherwise the changes made are just hooking up the arch-specific files to the new infrastructure. major changes to take advantage of the new system will come in subsequent commits.
2016-01-20exclude vis.h when compiling assembly filesKhem Raj-1/+1
otherwise C declarations are included into preprocessed (.S) asm source files, producing errors from the assembler.
2016-01-20switch arm, sh, and mips fenv asm from .sub system to .S filesRich Felker-6/+21
2016-01-20switch sh and mips setjmp asm from .sub system to .S filesRich Felker-109/+12
2016-01-20replace armhf math asm source files with inline asmRich Felker-40/+60
this makes it possible to inline them with LTO, and is the simplest approach to eliminating the use of .sub files. this also makes VFP sqrt available for use with the standard EABI (plain arm rather than armhf subarch) when libc is built with -mfloat-abi=softfp. the same could have been done for fabs, but when the argument and return value are in integer registers, moving to VFP registers and back is almost certainly more costly than a simple integer operation.
2016-01-20adapt build of arm memcpy asm not to use .sub filesRich Felker-2/+7
this depends on commit 9f5eb77992b42d484d69e879d24ef86466f20f21, which made it possible to use a .c file for arch-specific replacements, and on commit 2f853dd6b9a95d5b13ee8f9df762125e0588df5d, the out-of-tree build support, which made it so that src/*/$(ARCH)/* 'replacement' files get used even if they don't match the base name of a .c file in the parent directory.
2016-01-17fix if_nametoindex return value when socket open failsRon Yorston-1/+1
The return value of if_nametoindex is unsigned; it should return 0 on error.
2016-01-06add missing protocols to protoent lookup functionsTimo Teräs-1/+16
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.
2015-12-08fix 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.
2015-11-15use 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/+19
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/+15
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-16/+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.
2015-11-05use 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.