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* overhaul i386 syscall mechanism not to depend on external asm sourceRich Felker2019-04-101-9/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | this is the first part of a series of patches intended to make __syscall fully self-contained in the object file produced using syscall.h, which will make it possible for crt1 code to perform syscalls. the (confusingly named) i386 __vsyscall mechanism, which this commit removes, was introduced before the presence of a valid thread pointer was mandatory; back then the thread pointer was setup lazily only if threads were used. the intent was to be able to perform syscalls using the kernel's fast entry point in the VDSO, which can use the sysenter (Intel) or syscall (AMD) instruction instead of int $128, but without inlining an access to the __syscall global at the point of each syscall, which would incur a significant size cost from PIC setup everywhere. the mechanism also shuffled registers/calling convention around to avoid spills of call-saved registers, and to avoid allocating ebx or ebp via asm constraints, since there are plenty of broken-but-supported compiler versions which are incapable of allocating ebx with -fPIC or ebp with -fno-omit-frame-pointer. the new mechanism preserves the properties of avoiding spills and avoiding allocation of ebx/ebp in constraints, but does it inline, using some fairly simple register shuffling, and uses a field of the thread structure rather than global data for the vdso-provided syscall code address. for now, the external __syscall function is refactored not to use the old __vsyscall so it can be kept, but the intent is to remove it too.
* add io_pgetevents and rseq syscall numbers from linux v4.18Szabolcs Nagy2018-12-091-0/+2
| | | | | | | | io_pgetevents is new in linux commit 7a074e96dee62586c935c80cecd931431bfdd0be rseq is new in linux commit d7822b1e24f2df5df98c76f0e94a5416349ff759
* make thread-pointer-loading asm non-volatileRich Felker2018-10-161-1/+1
| | | | | | | | | | this will allow the compiler to cache and reuse the result, meaning we no longer have to take care not to load it more than once for the sake of archs where the load may be expensive. depends on commit 1c84c99913bf1cd47b866ed31e665848a0da84a2 for correctness, since otherwise the compiler could hoist loads during stage 3 of dynamic linking before the initial thread-pointer setup.
* add support for arch-specific ptrace command macrosSzabolcs Nagy2018-07-171-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | 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).
* remove a_ctz_l from arch specific atomic_arch.hAndre McCurdy2018-04-191-3/+3
| | | | | | | | Update atomic.h to provide a_ctz_l in all cases (atomic_arch.h should now only provide a_ctz_32 and/or a_ctz_64). The generic version of a_ctz_32 now takes advantage of a_clz_32 if available and the generic a_ctz_64 now makes use of a_ctz_32.
* use PAGESIZE rather than PAGE_SIZE in user.h bitsRich Felker2018-03-101-2/+2
| | | | align with commit c9c2cd3e6955cb1d57b8be01d4b072bf44058762.
* reverse definition dependency between PAGESIZE and PAGE_SIZERich Felker2018-03-101-1/+1
| | | | | | PAGESIZE is actually the version defined in POSIX base, with PAGE_SIZE being in the XSI option. use PAGESIZE as the underlying definition to facilitate making exposure of PAGE_SIZE conditional.
* i386: add arch_prctl syscall number from linux v4.12Szabolcs Nagy2017-11-051-0/+1
| | | | | syscall for i386 compat mode on x86_64 for non-x86_64 prctls. new in linux commit 79170fda313ed5be2394f87aa2a00d597f8ed4a1
* add statx syscall numbers from linux v4.11Szabolcs Nagy2017-11-051-0/+1
| | | | | statx was added in linux commit a528d35e8bfcc521d7cb70aaf03e1bd296c8493f (there is no libc wrapper yet and microblaze and sh misses the number).
* make syscall.h consistent with linuxSzabolcs Nagy2017-09-061-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | most of the found naming differences don't matter to musl, because internally it unifies the syscall names that vary across targets, but for external code the names should match the kernel uapi. aarch64: __NR_fstatat is called __NR_newfstatat in linux. __NR_or1k_atomic got mistakenly copied from or1k. arm: __NR_arm_sync_file_range is an alias for __NR_sync_file_range2 __NR_fadvise64_64 is called __NR_arm_fadvise64_64 in linux, the old non-arm name is kept too, it should not cause issues. (powerpc has similar nonstandard fadvise and it uses the normal name.) i386: __NR_madvise1 was removed from linux in commit 303395ac3bf3e2cb488435537d416bc840438fcb 2011-11-11 microblaze: __NR_fadvise, __NR_fstatat, __NR_pread, __NR_pwrite had different name in linux. mips: __NR_fadvise, __NR_fstatat, __NR_pread, __NR_pwrite, __NR_select had different name in linux. mipsn32: __NR_fstatat is called __NR_newfstatat in linux. or1k: __NR__llseek is called __NR_llseek in linux. the old name is kept too because that's the name musl uses internally. powerpc: __NR_{get,set}res{gid,uid}32 was never present in powerpc linux. __NR_timerfd was briefly defined in linux but then got renamed.
* add a_clz_64 helper functionSzabolcs Nagy2017-08-291-0/+7
| | | | | | | | | counts leading zero bits of a 64bit int, undefined on zero input. (has nothing to do with atomics, added to atomic.h so target specific helper functions are together.) there is a logarithmic generic implementation and another in terms of a 32bit a_clz_32 on targets where that's available.
* reduce impact of REG_* namespace pollution in x86[_64] signal.hRich Felker2017-01-041-19/+38
| | | | | | | | | | | | | | | | | | when _GNU_SOURCE is defined, which is always the case when compiling c++ with gcc, these macros for the the indices in gregset_t are exposed and likely to clash with applications. by using enum constants rather than macros defined with integer literals, we can make the clash slightly less likely to break software. the macros are still defined in case anything checks for them with #ifdef, but they're defined to expand to themselves so that non-file-scope (e.g. namespaced) identifiers by the same names still work. for the sake of avoiding mistakes, the changes were generated with sed via the command: sed -i -e 's/#define *\(REG_[A-Z_0-9]\{1,\}\) *\([0-9]\{1,\}\)'\ '/enum { \1 = \2 };\n#define \1 \1/' \ arch/i386/bits/signal.h arch/x86_64/bits/signal.h arch/x32/bits/signal.h
* add pkey_{mprotect,alloc,free} syscalls from linux v4.9Szabolcs Nagy2016-12-291-0/+3
| | | | | see linux commit e8c24d3a23a469f1f40d4de24d872ca7023ced0a and linux Documentation/x86/protection-keys.txt
* remove legacy i386 fallback stdarg implementation and frameworkRich Felker2016-12-151-9/+0
| | | | | | | | | this has been slated for removal for a long time. there is fundamentally no way to implement stdarg without compiler assistance; any attempt to do so has serious undefined behavior; its working depends not just (as a common misconception goes) on ABI, but also on assumptions about compiler code generation internal to a translation unit, which is not subject to external ABI constraints.
* make brace placement in public header typedef'd structs consistentRich Felker2016-07-031-4/+2
| | | | | | commit befa5866ee30d09c0c96e88af2eabff5911342ea performed this change for struct definitions that did not also involve typedef, but omitted the latter.
* make brace placement in public header struct definitions consistentRich Felker2016-07-032-6/+3
| | | | | | | | | | | | | | placing the opening brace on the same line as the struct keyword/tag is the style I prefer and seems to be the prevailing practice in more recent additions. these changes were generated by the command: find include/ arch/*/bits -name '*.h' \ -exec sed -i '/^struct [^;{]*$/{N;s/\n/ /;}' {} + and subsequently checked by hand to ensure that the regex did not pick up any false positives.
* add preadv2 and pwritev2 syscall numbers for linux v4.6Szabolcs Nagy2016-06-091-0/+2
| | | | | | | | the syscalls take an additional flag argument, they were added in commit f17d8b35452cab31a70d224964cd583fb2845449 and a RWF_HIPRI priority hint flag was added to linux/fs.h in 97be7ebe53915af504fb491fb99f064c7cf3cb09. the syscall is not allocated for microblaze and sh yet.
* deduplicate __NR_* and SYS_* syscall number definitionsBobby Bingham2016-05-121-381/+0
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* fix regression disabling use of pause instruction for x86 a_spinRich Felker2016-03-291-1/+1
| | | | | | | | | | | commits e24984efd5c6ac5ea8e6cb6cd914fa8435d458bc and 16b55298dc4b6a54d287d7494e04542667ef8861 inadvertently disabled the a_spin implementations for i386, x86_64, and x32 by defining a macro named a_pause instead of a_spin. this should not have caused any functional regression, but it inhibited cpu relaxation while spinning for locks. bug reported by George Kulakowski.
* add copy_file_range syscall numbers from linux v4.5Szabolcs Nagy2016-03-191-0/+2
| | | | | | | it was introduced for offloading copying between regular files in linux commit 29732938a6289a15e907da234d6692a2ead71855 (microblaze and sh does not yet have the syscall number.)
* deduplicate bits/mman.hSzabolcs Nagy2016-03-181-59/+0
| | | | | | | | | | | currently five targets use the same mman.h constants and the rest share most constants too, so move them to sys/mman.h before the bits/mman.h include where the differences can be corrected by redefinition of the macros. this fixes two minor bugs: POSIX_MADV_DONTNEED was wrong on most targets (it should be the same as MADV_DONTNEED), and sh defined the x86-only MAP_32BIT mmap flag.
* deduplicate the bulk of the arch bits headersRich Felker2016-01-2712-630/+0
| | | | | | | | | | | | all bits headers that were identical for a number of 'clean' archs are moved to the new arch/generic tree. in addition, a few headers that differed only cosmetically from the new generic version are removed. additional deduplication may be possible in mman.h and in several headers (limits.h, posix.h, stdint.h) that mostly depend on whether the arch is 32- or 64-bit, but they are left alone for now because greater gains are likely possible with more invasive changes to header logic, which is beyond the scope of this commit.
* add MCL_ONFAULT and MLOCK_ONFAULT mlockall and mlock2 flagsSzabolcs Nagy2016-01-261-0/+1
| | | | | | | | they lock faulted pages into memory (useful when a small part of a large mapped file needs efficient access), new in linux v4.4, commit b0f205c2a3082dd9081f9a94e50658c5fa906ff1 MLOCK_* is not in the POSIX reserved namespace for sys/mman.h
* add mlock2 syscall number from linux v4.4Szabolcs Nagy2016-01-261-0/+2
| | | | | | | this is mlock with a flags argument, new in linux commit a8ca5d0ecbdde5cc3d7accacbd69968b0c98764e as usual microblaze and sh don't have allocated syscall number yet.
* add new membarrier, userfaultfd and switch_endian syscallsSzabolcs Nagy2016-01-261-0/+4
| | | | | | | | | | | | | | | new in linux v4.3 added for aarch64, arm, i386, mips, or1k, powerpc, x32 and x86_64. membarrier is a system wide memory barrier, moves most of the synchronization cost to one side, new in kernel commit 5b25b13ab08f616efd566347d809b4ece54570d1 userfaultfd is useful for qemu and is new in kernel commit 8d2afd96c20316d112e04d935d9e09150e988397 switch_endian is powerpc only for switching endianness, new in commit 529d235a0e190ded1d21ccc80a73e625ebcad09b
* add new i386 socket syscall numbersSzabolcs Nagy2016-01-261-0/+30
| | | | | | | | new in linux v4.3 commit 9dea5dc921b5f4045a18c63eb92e84dc274d17eb direct calls instead of socketcall allow better seccomp filtering. musl continues to use socketcalls internally on i386. (older kernels would need a fallback mechanism if the direct calls were used.)
* change the internal socketcall selection logicSzabolcs Nagy2016-01-261-0/+2
| | | | | | | | 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.
* clean up i386 atomics for new atomics frameworkRich Felker2016-01-221-66/+58
| | | | | | | | | | | | this commit mostly makes consistent things like spacing, function ordering in atomic_arch.h, argument names, use of volatile, etc. the fake 64-bit and/or atomics are also removed because the shared atomic.h does a better job of implementing them; it avoids making two atomic memory accesses when only one 32-bit half needs to be touched. no major overhaul is needed or possible because x86 actually has native versions of all the usual atomic operations, rather than using ll/sc or needing cas loops.
* refactor internal atomic.hRich Felker2016-01-211-17/+16
| | | | | | | | | | | | | | | 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.
* adjust i386 max_align_t definition to work around some broken compilersRich Felker2015-12-291-3/+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.
* properly access mcontext_t program counter in cancellation handlerRich Felker2015-11-021-1/+1
| | | | | | | | | 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.
* introduce new symbol-lookup-free rcrt1/dlstart stage chainingRich Felker2015-09-171-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | previously, the call into stage 2 was made by looking up the symbol name "__dls2" (which was chosen short to be easy to look up) from the dynamic symbol table. this was no problem for the dynamic linker, since it always exports all its symbols. in the case of the static pie entry point, however, the dynamic symbol table does not contain the necessary symbol unless -rdynamic/-E was used when linking. this linking requirement is a major obstacle both to practical use of static-pie as a nommu binary format (since it greatly enlarges the file) and to upstream toolchain support for static-pie (adding -E to default linking specs is not reasonable). this patch replaces the runtime symbolic lookup with a link-time lookup via an inline asm fragment, which reloc.h is responsible for providing. in this initial commit, the asm is provided only for i386, and the old lookup code is left in place as a fallback for archs that have not yet transitioned. modifying crt_arch.h to pass the stage-2 function pointer as an argument was considered as an alternative, but such an approach would not be compatible with fdpic, where it's impossible to compute function pointers without already having performed relocations. it was also deemed desirable to keep crt_arch.h as simple/minimal as possible. in principle, archs with pc-relative or got-relative addressing of static variables could instead load the stage-2 function pointer from a static volatile object. that does not work for fdpic, and is not safe against reordering on mips-like archs that use got slots even for static functions, but it's a valid on i386 and many others, and could provide a reasonable default implementation in the future.
* fix missing earlyclobber flag in i386 a_ctz_64 asmRich Felker2015-09-091-1/+1
| | | | | | | | | this error was only found by reading the code, but it seems to have been causing gcc to produce wrong code in malloc: the same register was used for the output and the high word of the input. in principle this could have caused an infinite loop searching for an available bin, but in practice most x86 models seem to implement the "undefined" result of the bsf instruction as "unchanged".
* fix missing synchronization in atomic store on i386 and x86_64Rich Felker2015-07-281-1/+1
| | | | | | | | | | | | | | | | | despite being strongly ordered, the x86 memory model does not preclude reordering of loads across earlier stores. while a plain store suffices as a release barrier, we actually need a full barrier, since users of a_store subsequently load a waiter count to determine whether to issue a futex wait, and using a stale count will result in soft (fail-to-wake) deadlocks. these deadlocks were observed in malloc and possible with stdio locks and other libc-internal locking. on i386, an atomic operation on the caller's stack is used as the barrier rather than performing the store itself using xchg; this avoids the need to read the cache line on which the store is being performed. mfence is used on x86_64 where it's always available, and could be used on i386 with the appropriate cpu model checks if it's shown to perform better.
* fix inconsistency in a_and and a_or argument types on x86[_64]Rich Felker2015-05-201-4/+4
| | | | | | conceptually, and on other archs, these functions take a pointer to int, but in the i386, x86_64, and x32 versions of atomic.h, they took a pointer to void instead.
* use hidden visibility for i386 asm-internal __vsyscall symbolRich Felker2015-04-141-7/+7
| | | | | otherwise the call instruction in the inline syscall asm results in textrels without ld-time binding.
* dynamic linker bootstrap overhaulRich Felker2015-04-132-44/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | this overhaul further reduces the amount of arch-specific code needed by the dynamic linker and removes a number of assumptions, including: - that symbolic function references inside libc are bound at link time via the linker option -Bsymbolic-functions. - that libc functions used by the dynamic linker do not require access to data symbols. - that static/internal function calls and data accesses can be made without performing any relocations, or that arch-specific startup code handled any such relocations needed. removing these assumptions paves the way for allowing libc.so itself to be built with stack protector (among other things), and is achieved by a three-stage bootstrap process: 1. relative relocations are processed with a flat function. 2. symbolic relocations are processed with no external calls/data. 3. main program and dependency libs are processed with a fully-functional libc/ldso. reduction in arch-specific code is achived through the following: - crt_arch.h, used for generating crt1.o, now provides the entry point for the dynamic linker too. - asm is no longer responsible for skipping the beginning of argv[] when ldso is invoked as a command. - the functionality previously provided by __reloc_self for heavily GOT-dependent RISC archs is now the arch-agnostic stage-1. - arch-specific relocation type codes are mapped directly as macros rather than via an inline translation function/switch statement.
* move O_PATH definition back to arch bitsRich Felker2015-04-011-0/+1
| | | | | | | while it's the same for all presently supported archs, it differs at least on sparc, and conceptually it's no less arch-specific than the other O_* macros. O_SEARCH and O_EXEC are still defined in terms of O_PATH in the main fcntl.h.
* fix MINSIGSTKSZ values for archs with large signal contextsRich Felker2015-03-181-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | the previous values (2k min and 8k default) were too small for some archs. aarch64 reserves 4k in the signal context for future extensions and requires about 4.5k total, and powerpc reportedly uses over 2k. the new minimums are chosen to fit the saved context and also allow a minimal signal handler to run. since the default (SIGSTKSZ) has always been 6k larger than the minimum, it is also increased to maintain the 6k usable by the signal handler. this happens to be able to store one pathname buffer and should be sufficient for calling any function in libc that doesn't involve conversion between floating point and decimal representations. x86 (both 32-bit and 64-bit variants) may also need a larger minimum (around 2.5k) in the future to support avx-512, but the values on these archs are left alone for now pending further analysis. the value for PTHREAD_STACK_MIN is not increased to match MINSIGSTKSZ at this time. this is so as not to preclude applications from using extremely small thread stacks when they know they will not be handling signals. unfortunately cancellation and multi-threaded set*id() use signals as an implementation detail and therefore require a stack large enough for a signal context, so applications which use extremely small thread stacks may still need to avoid using these features.
* fix FLT_ROUNDS to reflect the current rounding modeSzabolcs Nagy2015-03-071-1/+0
| | | | | Implemented as a wrapper around fegetround introducing a new function to the ABI: __flt_rounds. (fegetround cannot be used directly from float.h)
* fix POLLWRNORM and POLLWRBAND on mipsTrutz Behn2015-03-041-0/+0
| | | | | | these macros have the same distinct definition on blackfin, frv, m68k, mips, sparc and xtensa kernels. POLLMSG and POLLRDHUP additionally differ on sparc.
* make all objects used with atomic operations volatileRich Felker2015-03-031-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | the memory model we use internally for atomics permits plain loads of values which may be subject to concurrent modification without requiring that a special load function be used. since a compiler is free to make transformations that alter the number of loads or the way in which loads are performed, the compiler is theoretically free to break this usage. the most obvious concern is with atomic cas constructs: something of the form tmp=*p;a_cas(p,tmp,f(tmp)); could be transformed to a_cas(p,*p,f(*p)); where the latter is intended to show multiple loads of *p whose resulting values might fail to be equal; this would break the atomicity of the whole operation. but even more fundamental breakage is possible. with the changes being made now, objects that may be modified by atomics are modeled as volatile, and the atomic operations performed on them by other threads are modeled as asynchronous stores by hardware which happens to be acting on the request of another thread. such modeling of course does not itself address memory synchronization between cores/cpus, but that aspect was already handled. this all seems less than ideal, but it's the best we can do without mandating a C11 compiler and using the C11 model for atomics. in the case of pthread_once_t, the ABI type of the underlying object is not volatile-qualified. so we are assuming that accessing the object through a volatile-qualified lvalue via casts yields volatile access semantics. the language of the C standard is somewhat unclear on this matter, but this is an assumption the linux kernel also makes, and seems to be the correct interpretation of the standard.
* add syscall numbers for the new execveat syscallSzabolcs Nagy2015-02-091-0/+2
| | | | | | | | | this syscall allows fexecve to be implemented without /proc, it is new in linux v3.19, added in commit 51f39a1f0cea1cacf8c787f652f26dfee9611874 (sh and microblaze do not have allocated syscall numbers yet) added a x32 fix as well: the io_setup and io_submit syscalls are no longer common with x86_64, so use the x32 specific numbers.
* move MREMAP_MAYMOVE and MREMAP_FIXED out of bitsTrutz Behn2015-01-301-3/+0
| | | | | | the definitions are generic for all kernel archs. exposure of these macros now only occurs on the same feature test as for the function accepting them, which is believed to be more correct.
* add new syscall numbers for bpf and kexec_file_loadSzabolcs Nagy2014-12-231-0/+2
| | | | | | | | | | | these syscalls are new in linux v3.18, bpf is present on all supported archs except sh, kexec_file_load is only allocted for x86_64 and x32 yet. bpf was added in linux commit 99c55f7d47c0dc6fc64729f37bf435abf43f4c60 kexec_file_load syscall number was allocated in commit f0895685c7fd8c938c91a9d8a6f7c11f22df58d2
* move wint_t definition to the shared part of alltypes.h.inRich Felker2014-12-211-1/+0
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* add explicit barrier operation to internal atomic.h APIRich Felker2014-10-101-0/+5
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* add new syscall numbers for seccomp, getrandom, memfd_createSzabolcs Nagy2014-10-081-0/+6
| | | | | | | | | | | | | | | | | | these syscalls are new in linux v3.17 and present on all supported archs except sh. seccomp was added in commit 48dc92b9fc3926844257316e75ba11eb5c742b2c it has operation, flags and pointer arguments (if flags==0 then it is the same as prctl(PR_SET_SECCOMP,...)), the uapi header for flag definitions is linux/seccomp.h getrandom was added in commit c6e9d6f38894798696f23c8084ca7edbf16ee895 it provides an entropy source when open("/dev/urandom",..) would fail, the uapi header for flags is linux/random.h memfd_create was added in commit 9183df25fe7b194563db3fec6dc3202a5855839c it allows anon mmap to have an fd, that can be shared, sealed and needs no mount point, the uapi header for flags is linux/memfd.h
* fix C++ incompatibility in i386 definition of max_align_tRich Felker2014-09-111-0/+4
| | | | | | the C11 _Alignas keyword is not present in C++, and despite it being in the reserved namespace and thus reasonable to support even in non-C11 modes, compilers seem to fail to support it.
* add threads.h and needed per-arch types for mtx_t and cnd_tRich Felker2014-09-061-0/+2
| | | | | | | | | | | | | | | | based on patch by Jens Gustedt. mtx_t and cnd_t are defined in such a way that they are formally "compatible types" with pthread_mutex_t and pthread_cond_t, respectively, when accessed from a different translation unit. this makes it possible to implement the C11 functions using the pthread functions (which will dereference them with the pthread types) without having to use the same types, which would necessitate either namespace violations (exposing pthread type names in threads.h) or incompatible changes to the C++ name mangling ABI for the pthread types. for the rest of the types, things are much simpler; using identical types is possible without any namespace considerations.
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