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2012-11-08clean up sloppy nested inclusion from pthread_impl.hRich Felker-0/+1
this mirrors the stdio_impl.h cleanup. one header which is not strictly needed, errno.h, is left in pthread_impl.h, because since pthread functions return their error codes rather than using errno, nearly every single pthread function needs the errno constants. in a few places, rather than bringing in string.h to use memset, the memset was replaced by direct assignment. this seems to generate much better code anyway, and makes many functions which were previously non-leaf functions into leaf functions (possibly eliminating a great deal of bloat on some platforms where non-leaf functions require ugly prologue and/or epilogue).
2012-10-18fix (hopefully; untested) completely broken/incomplete microblaze sigsetjmpRich Felker-3/+12
2012-10-17fix microblaze asm relocations for shared libcRich Felker-2/+2
only @PLT relocations are considered functions for purposes of -Bsymbolic-functions, so always use @PLT. it should not hurt in the static-linked case.
2012-10-11avoid the thread-ptr-init behavior of sigaction when not installing handlerRich Felker-1/+2
this is necessary because posix_spawn calls sigaction after vfork, and if the thread pointer is not already initialized, initializing it in the child corrupts the parent process's state.
2012-09-29microblaze portRich Felker-0/+20
based on initial work by rdp, with heavy modifications. some features including threads are untested because qemu app-level emulation seems to be broken and I do not have a proper system image for testing.
2012-09-06further use of _Noreturn, for non-plain-C functionsRich Felker-1/+1
note that POSIX does not specify these functions as _Noreturn, because POSIX is aligned with C99, not the new C11 standard. when POSIX is eventually updated to C11, it will almost surely give these functions the _Noreturn attribute. for now, the actual _Noreturn keyword is not used anyway when compiling with a c99 compiler, which is what POSIX requires; the GCC __attribute__ is used instead if it's available, however. in a few places, I've added infinite for loops at the end of _Noreturn functions to silence compiler warnings. presumably __buildin_unreachable could achieve the same thing, but it would only work on newer GCCs and would not be portable. the loops should have near-zero code size cost anyway. like the previous _Noreturn commit, this one is based on patches contributed by philomath.
2012-09-06use restrict everywhere it's required by c99 and/or posix 2008Rich Felker-8/+8
to deal with the fact that the public headers may be used with pre-c99 compilers, __restrict is used in place of restrict, and defined appropriately for any supported compiler. we also avoid the form [restrict] since older versions of gcc rejected it due to a bug in the original c99 standard, and instead use the form *restrict.
2012-08-09fix (hopefully) all hard-coded 8's for kernel sigset_t sizeRich Felker-7/+9
some minor changes to how hard-coded sets for thread-related purposes are handled were also needed, since the old object sizes were not necessarily sufficient. things have gotten a bit ugly in this area, and i think a cleanup is in order at some point, but for now the goal is just to get the code working on all supported archs including mips, which was badly broken by linux rejecting syscalls with the wrong sigset_t size.
2012-07-12sigsetjmp asm for mipsRich Felker-0/+27
2012-07-11initial version of mips (o32) port, based on work by Richard Pennington (rdp)Rich Felker-0/+13
basically, this version of the code was obtained by starting with rdp's work from his ellcc source tree, adapting it to musl's build system and coding style, auditing the bits headers for discrepencies with kernel definitions or glibc/LSB ABI or large file issues, fixing up incompatibility with the old binutils from aboriginal linux, and adding some new special cases to deal with the oddities of sigaction and pipe syscall interfaces on mips. at present, minimal test programs work, but some interfaces are broken or missing. threaded programs probably will not link.
2012-07-11remove unused var in new sigaction codeRich Felker-1/+1
2012-07-11changes to kernel sigaction struct handling in preparation for mips portRich Felker-14/+17
2012-07-03jmp_buf overhaul fixing several issuesRich Felker-10/+7
on arm, the location of the saved-signal-mask flag and mask were off by one between sigsetjmp and siglongjmp, causing incorrect behavior restoring the signal mask. this is because the siglongjmp code assumed an extra slot was in the non-sig jmp_buf for the flag, but arm did not have this. now, the extra slot is removed for all archs since it was useless. also, arm eabi requires jmp_buf to have 8-byte alignment. we achieve that using long long as the type rather than with non-portable gcc attribute tags.
2012-07-02fix sigsetjmp on arm (needs asm)Rich Felker-0/+13
no idea why gcc refuses to compile the C code to use a tail call, but it's best to use asm anyway so we don't have to rely on the quality of the compiler's optimizations for correct code.
2012-05-05update license of njk contributed code (x86_64 asm)Rich Felker-1/+1
these changes are based on the following communication via email: "I hereby grant that all of the code I have contributed to musl on or before April 23, 2012 may be licensed under the terms of the following MIT license: Copyright (c) 2011-2012 Nicholas J. Kain Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE."
2012-02-27work around "signal loses thread pointer" issue with "approach 2"Rich Felker-0/+5
this was discussed on the mailing list and no consensus on the preferred solution was reached, so in anticipation of a release, i'm just committing a minimally-invasive solution that avoids the problem by ensuring that multi-threaded-capable programs will always have initialized the thread pointer before any signal handler can run. in the long term we may switch to initializing the thread pointer at program start time whenever the program has the potential to access any per-thread data.
2011-09-18initial commit of the arm portRich Felker-0/+11
this port assumes eabi calling conventions, eabi linux syscall convention, and presence of the kernel helpers at 0xffff0f?0 needed for threads support. otherwise it makes very few assumptions, and the code should work even on armv4 without thumb support, as well as on systems with thumb interworking. the bits headers declare this a little endian system, but as far as i can tell the code should work equally well on big endian. some small details are probably broken; so far, testing has been limited to qemu/aboriginal linux.
2011-09-16fix generic sigsetjmp (unused anyway) pointer signedness errorRich Felker-1/+1
2011-09-12implement gnu sigisemptysetRich Felker-0/+9
2011-09-02fix missing prototypes/wrong signature for psiginfo, psignalRich Felker-1/+1
2011-08-05fix off-by-one bug in siglongjmp that caused unpredictable behaviorRich Felker-1/+1
if saved, signal mask would not be restored unless some low signals were masked. if not saved, signal mask could be wrongly restored to uninitialized values. in any, wrong mask would be restored. i believe this function was written for a very old version of the jmp_buf structure which did not contain a final 0 field for compatibility with siglongjmp, and never updated...
2011-07-30fix race condition in sigqueueRich Felker-2/+8
this race is fundamentally due to linux's bogus requirement that userspace, rather than kernelspace, fill in the siginfo structure. an intervening signal handler that calls fork could cause both the parent and child process to send signals claiming to be from the parent, which could in turn have harmful effects depending on what the recipient does with the signal. we simply block all signals for the interval between getuid and sigqueue syscalls (much like what raise() does already) to prevent the race and make the getuid/sigqueue pair atomic. this will be a non-issue if linux is fixed to validate the siginfo structure or fill it in from kernelspace.
2011-07-30clean up pthread_sigmask/sigprocmask dependency orderRich Felker-8/+4
it's nicer for the function that doesn't use errno to be independent, and have the other one call it. saves some time and avoids clobbering errno.
2011-06-14restore use of .type in asm, but use modern @function (vs %function)Rich Felker-0/+6
this seems to be necessary to make the linker accept the functions in a shared library (perhaps to generate PLT entries?) strictly speaking libc-internal asm should not need it. i might clean that up later.
2011-06-13remove all .size and .type directives for functions from the asmRich Felker-10/+0
these are useless and have caused problems for users trying to build with non-gnu tools like tcc's assembler.
2011-06-08implement psignal and psiginfoRich Felker-0/+20
2011-05-07overhaul implementation-internal signal protectionsRich Felker-29/+18
the new approach relies on the fact that the only ways to create sigset_t objects without invoking UB are to use the sig*set() functions, or from the masks returned by sigprocmask, sigaction, etc. or in the ucontext_t argument to a signal handler. thus, as long as sigfillset and sigaddset avoid adding the "protected" signals, there is no way the application will ever obtain a sigset_t including these bits, and thus no need to add the overhead of checking/clearing them when sigprocmask or sigaction is called. note that the old code actually *failed* to remove the bits from sa_mask when sigaction was called. the new implementations are also significantly smaller, simpler, and faster due to ignoring the useless "GNU HURD signals" 65-1024, which are not used and, if there's any sanity in the world, never will be used.
2011-04-17overhaul pthread cancellationRich Felker-12/+3
this patch improves the correctness, simplicity, and size of cancellation-related code. modulo any small errors, it should now be completely conformant, safe, and resource-leak free. the notion of entering and exiting cancellation-point context has been completely eliminated and replaced with alternative syscall assembly code for cancellable syscalls. the assembly is responsible for setting up execution context information (stack pointer and address of the syscall instruction) which the cancellation signal handler can use to determine whether the interrupted code was in a cancellable state. these changes eliminate race conditions in the previous generation of cancellation handling code (whereby a cancellation request received just prior to the syscall would not be processed, leaving the syscall to block, potentially indefinitely), and remedy an issue where non-cancellable syscalls made from signal handlers became cancellable if the signal handler interrupted a cancellation point. x86_64 asm is untested and may need a second try to get it right.
2011-04-14use a separate signal from SIGCANCEL for SIGEV_THREAD timersRich Felker-2/+3
otherwise we cannot support an application's desire to use asynchronous cancellation within the callback function. this change also slightly debloats pthread_create.c.
2011-04-08fix broken sigsetjmp on x86_64Rich Felker-7/+9
2011-04-06consistency: change all remaining syscalls to use SYS_ rather than __NR_ prefixRich Felker-3/+3
2011-03-25fix all implicit conversion between signed/unsigned pointersRich Felker-1/+1
sadly the C language does not specify any such implicit conversion, so this is not a matter of just fixing warnings (as gcc treats it) but actual errors. i would like to revisit a number of these changes and possibly revise the types used to reduce the number of casts required.
2011-03-24overhaul cancellation to fix resource leaks and dangerous behavior with signalsRich Felker-0/+2
this commit addresses two issues: 1. a race condition, whereby a cancellation request occurring after a syscall returned from kernelspace but before the subsequent CANCELPT_END would cause cancellable resource-allocating syscalls (like open) to leak resources. 2. signal handlers invoked while the thread was blocked at a cancellation point behaved as if asynchronous cancellation mode wer in effect, resulting in potentially dangerous state corruption if a cancellation request occurs. the glibc/nptl implementation of threads shares both of these issues. with this commit, both are fixed. however, cancellation points encountered in a signal handler will not be acted upon if the signal was received while the thread was already at a cancellation point. they will of course be acted upon after the signal handler returns, so in real-world usage where signal handlers quickly return, it should not be a problem. it's possible to solve this problem too by having sigaction() wrap all signal handlers with a function that uses a pthread_cleanup handler to catch cancellation, patch up the saved context, and return into the cancellable function that will catch and act upon the cancellation. however that would be a lot of complexity for minimal if any benefit...
2011-03-20global cleanup to use the new syscall interfaceRich Felker-23/+10
2011-03-19syscall overhaul part two - unify public and internal syscall interfaceRich Felker-3/+3
with this patch, the syscallN() functions are no longer needed; a variadic syscall() macro allows syscalls with anywhere from 0 to 6 arguments to be made with a single macro name. also, manually casting each non-integer argument with (long) is no longer necessary; the casts are hidden in the macros. some source files which depended on being able to define the old macro SYSCALL_RETURNS_ERRNO have been modified to directly use __syscall() instead of syscall(). references to SYSCALL_SIGSET_SIZE and SYSCALL_LL have also been changed. x86_64 has not been tested, and may need a follow-up commit to fix any minor bugs/oversights.
2011-03-10fix errors in sigqueue (potential information leak, wrong behavior)Rich Felker-5/+7
1. any padding in the siginfo struct was not necessarily zero-filled, so it might have contained private data off the caller's stack. 2. the uid and pid must be filled in from userspace. the previous rsyscall fix broke rsyscalls because the values were always incorrect.
2011-03-10remove useless return value checks for functions that cannot failRich Felker-3/+2
2011-03-10make sigsuspend a cancellation pointRich Felker-1/+6
2011-03-10make sigtimedwait a cancellation pointRich Felker-0/+3
2011-03-10don't fail with EINTR in sigtimedwaitRich Felker-6/+6
POSIX allows either behavior, but sigwait is not allowed to fail with EINTR, so the retry loop would have to be in one or the other anyway.
2011-03-10fix sigsuspend syscallRich Felker-1/+1
2011-03-10make sigaltstack work (missing macros in signal.h, error conditions)Rich Felker-1/+11
2011-03-09fix error handling for pthread_sigmaskRich Felker-1/+5
it must return errno, not -1, and should reject invalud values for how.
2011-03-09fix race condition in raise - just mask signalsRich Felker-9/+9
a signal handler could fork after the pid/tid were read, causing the wrong process to be signalled. i'm not sure if this is supposed to have UB or not, but raise is async-signal-safe, so it probably is allowed. the current solution is slightly expensive so this implementation is likely to be changed in the future.
2011-03-09fix raise semantics with threads.Rich Felker-1/+12
2011-02-20fix null pointer dereference introduced in last sigprocmask commitRich Felker-1/+1
2011-02-19prevent sigprocmask/pthread_sigmask from blocking implementation signalsRich Felker-3/+5
this code was wrongly disabled because the old version was trying to be too clever and didn't work. replaced it with a simple version for now.
2011-02-15Port musl to x86-64. One giant commit!Nicholas J. Kain-0/+22
2011-02-14header cleanup, conformance fixes - signalsRich Felker-6/+3
2011-02-13fix previous commit that broke sigreturn. looks like the asm is needed.Rich Felker-5/+17