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2012-10-11i386 vsyscall support (vdso-provided sysenter/syscall instruction based)Rich Felker-16/+59
this doubles the performance of the fastest syscalls on the atom I tested it on; improvement is reportedly much more dramatic on worst-case cpus. cannot be used for cancellable syscalls.
2012-10-05support for TLS in dynamic-loaded (dlopen) modulesRich Felker-3/+4
unlike other implementations, this one reserves memory for new TLS in all pre-existing threads at dlopen-time, and dlopen will fail with no resources consumed and no new libraries loaded if memory is not available. memory is not immediately distributed to running threads; that would be too complex and too costly. instead, assurances are made that threads needing the new TLS can obtain it in an async-signal-safe way from a buffer belonging to the dynamic linker/new module (via atomic fetch-and-add based allocator). I've re-appropriated the lock that was previously used for __synccall (synchronizing set*id() syscalls between threads) as a general pthread_create lock. it's a "backwards" rwlock where the "read" operation is safe atomic modification of the live thread count, which multiple threads can perform at the same time, and the "write" operation is making sure the count does not increase during an operation that depends on it remaining bounded (__synccall or dlopen). in static-linked programs that don't use __synccall, this lock is a no-op and has no cost.
2012-10-04beginnings of full TLS support in shared librariesRich Felker-1/+1
this code will not work yet because the necessary relocations are not supported, and cannot be supported without some internal changes to how relocation processing works (coming soon).
2012-10-04TLS (GNU/C11 thread-local storage) support for static-linked programsRich Felker-0/+1
the design for TLS in dynamic-linked programs is mostly complete too, but I have not yet implemented it. cost is nonzero but still low for programs which do not use TLS and/or do not use threads (a few hundred bytes of new code, plus dependency on memcpy). i believe it can be made smaller at some point by merging __init_tls and __init_security into __libc_start_main and avoiding duplicate auxv-parsing code. at the same time, I've also slightly changed the logic pthread_create uses to allocate guard pages to ensure that guard pages are not counted towards commit charge.
2012-09-29microblaze portRich Felker-0/+13
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.
2012-09-09add 7-arg syscall support for mipsRich Felker-4/+8
no syscalls actually use that many arguments; the issue is that some syscalls with 64-bit arguments have them ordered badly so that breaking them into aligned 32-bit half-arguments wastes slots with padding, and a 7th slot is needed for the last argument.
2012-09-09fix broken mips syscall asmRich Felker-2/+2
this code was using $10 to save the syscall number, but $10 is not necessarily preserved by the kernel across syscalls. only mattered for syscalls that got interrupted by a signal and restarted. as far as i can tell, $25 is preserved by the kernel across syscalls.
2012-09-08syscall organization overhaulRich Felker-5/+138
now public syscall.h only exposes __NR_* and SYS_* constants and the variadic syscall function. no macros or inline functions, no __syscall_ret or other internal details, no 16-/32-bit legacy syscall renaming, etc. this logic has all been moved to src/internal/syscall.h with the arch-specific parts in arch/$(ARCH)/syscall_arch.h, and the amount of arch-specific stuff has been reduced to a minimum. changes still need to be reviewed/double-checked. minimal testing on i386 and mips has already been performed.
2012-08-17fix float parsing logic for long decimal expansionsRich Felker-1/+1
this affects at least the case of very long inputs, but may also affect shorter inputs that become long due to growth while upscaling. basically, the logic for the circular buffer indices of the initial base-10^9 digit and the slot one past the final digit, and for simplicity of the loop logic, assumes an invariant that they're not equal. the upscale loop, which can increase the length of the base-10^9 representation, attempted to preserve this invariant, but was actually only ensuring that the end index did not loop around past the start index, not that the two never become equal. the main (only?) effect of this bug was that subsequent logic treats the excessively long number as having no digits, leading to junk results.
2012-08-11add bsd fgetln functionRich Felker-1/+1
optimized to avoid allocation and return lines directly out of the stream buffer whenever possible.
2012-08-09fix (hopefully) all hard-coded 8's for kernel sigset_t sizeRich Felker-2/+5
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.
2012-07-27save AT_HWCAP from auxv for subsequent use in machine-specific codeRich Felker-0/+3
it's expected that this will be needed/useful only in asm, so I've given it its own symbol that can be addressed in pc-relative ways from asm rather than adding a field in the __libc structure which would require hard-coding the offset wherever it's used.
2012-07-12fix several locks that weren't updated right for new futex-based __lockRich Felker-3/+3
these could have caused memory corruption due to invalid accesses to the next field. all should be fixed now; I found the errors with fgrep -r '__lock(&', which is bogus since the argument should be an array.
2012-07-12fix breakage of x86_64 sigaction from recent changes for mipsRich Felker-1/+1
2012-07-11initial version of mips (o32) port, based on work by Richard Pennington (rdp)Rich Felker-0/+22
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.
2012-07-11use unsigned bitmask for consistency in ksigactionRich Felker-1/+1
the type doesn't actually matter, just the size, but it's nice to be consistent...
2012-07-11fix breakage from last commit: forgot to include ksigaction.hRich Felker-0/+6
this file can be overridden by a same-named file in an arch dir.
2012-06-19remove flush hook cruft that was never used from stdioRich Felker-1/+1
there is no need/use for a flush hook. the write function serves this purpose already. i originally created the hook for implementing mem streams based on a mistaken reading of posix, and later realized it wasn't useful but never removed it until now.
2012-06-09add pthread_attr_setstack interface (and get)Rich Felker-1/+2
i originally omitted these (optional, per POSIX) interfaces because i considered them backwards implementation details. however, someone later brought to my attention a fairly legitimate use case: allocating thread stacks in memory that's setup for sharing and/or fast transfer between CPU and GPU so that the thread can move data to a GPU directly from automatic-storage buffers without having to go through additional buffer copies. perhaps there are other situations in which these interfaces are useful too.
2012-06-08fix scanning of "-0x" pseudo-hex float (must give negative zero)Rich Felker-1/+1
2012-06-02increase default thread stack size to 80kRich Felker-1/+1
I've been looking for data that would suggest a good default, and since little has shown up, i'm doing this based on the limited data I have. the value 80k is chosen to accommodate 64k of application data (which happens to be the size of the buffer in git that made it crash without a patch to call pthread_attr_setstacksize) plus the max stack usage of most libc functions (with a few exceptions like crypt, which will be fixed soon to avoid excessive stack usage, and [n]ftw, which inherently uses a fair bit in recursive directory searching). if further evidence emerges suggesting that the default should be larger, I'll consider changing it again, but I'd like to avoid it getting too large to avoid the issues of large commit charge and rapid address space exhaustion on 32-bit machines.
2012-05-31enable LARGEFILE64 aliasesRich Felker-2/+1
these will NOT be used when compiling with -D_LARGEFILE64_SOURCE on musl; instead, they exist in the hopes of eventually being able to run some glibc-linked apps with musl sitting in place of glibc. also remove the (apparently incorrect) fcntl alias.
2012-05-25remove cruft from pthread structure (old cancellation stuff)Rich Felker-2/+0
2012-05-22remove everything related to forkallRich Felker-1/+0
i made a best attempt, but the intended semantics of this function are fundamentally contradictory. there is no consistent way to handle ownership of locks when forking a multi-threaded process. the code could have worked by accident for programs that only used normal mutexes and nothing else (since they don't actually store or care about their owner), but that's about it. broken-by-design interfaces that aren't even in glibc (only solaris) don't belong in musl.
2012-05-21fix out-of-bounds array access in pthread barriers on 64-bitRich Felker-1/+1
it's ok to overlap with integer slot 3 on 32-bit because only slots 0-2 are used on process-local barriers.
2012-05-06add FORCE_EVAL macro to evaluate float expr for their side effectnsz-0/+13
updated nextafter* to use FORCE_EVAL, it can be used in many other places in the math code to improve readability.
2012-05-03overhaul SSP support to use a real canaryRich Felker-0/+4
pthread structure has been adjusted to match the glibc/GCC abi for where the canary is stored on i386 and x86_64. it will need variants for other archs to provide the added security of the canary's entropy, but even without that it still works as well as the old "minimal" ssp support. eventually such changes will be made anyway, since they are also needed for GCC/C11 thread-local storage support (not yet implemented). care is taken not to attempt initializing the thread pointer unless the program actually uses SSP (by reference to __stack_chk_fail).
2012-04-30fix off-by-one error that caused uninitialized memory read in floatscanRich Felker-1/+1
this caused misreading of certain floating point values that are exact multiples of large powers of ten, unpredictable depending on prior stack contents.
2012-04-24ditch the priority inheritance locks; use malloc's version of lockRich Felker-3/+3
i did some testing trying to switch malloc to use the new internal lock with priority inheritance, and my malloc contention test got 20-100 times slower. if priority inheritance futexes are this slow, it's simply too high a price to pay for avoiding priority inversion. maybe we can consider them somewhere down the road once the kernel folks get their act together on this (and perferably don't link it to glibc's inefficient lock API)... as such, i've switch __lock to use malloc's implementation of lightweight locks, and updated all the users of the code to use an array with a waiter count for their locks. this should give optimal performance in the vast majority of cases, and it's simple. malloc is still using its own internal copy of the lock code because it seems to yield measurably better performance with -O3 when it's inlined (20% or more difference in the contention stress test).
2012-04-24new internal locking primitive; drop spinlocksRich Felker-1/+2
we use priority inheritance futexes if possible so that the library cannot hit internal priority inversion deadlocks in the presence of realtime priority scheduling (full support to be added later).
2012-04-22remove redundant (unmaintained) check in floatscanRich Felker-3/+3
also be extra careful to avoid wrapping the circular buffer early
2012-04-21make floatscan correctly set errno for overflow/underflowRich Felker-4/+16
care is taken that the setting of errno correctly reflects underflow condition. scanning exact denormal values does not result in ERANGE, nor does scanning values (such as the usual string definition of FLT_MIN) which are actually less than the smallest normal number but which round to a normal result. only the decimal case is handled so far; hex float require a separate fix to come later.
2012-04-21skip leading zeros even after decimal point in floatscanRich Felker-4/+9
in principle this should just be an optimization, but it happens to also fix a nasty bug where values like 0.00000000001 were getting caught by the early zero detection path and wrongly scanned as zero.
2012-04-21fix overread (consuming an extra byte) scanning NANRich Felker-1/+1
bug detected by glib test suite
2012-04-19fix really bad breakage in strtol, etc.: failure to accept leading spacesRich Felker-4/+5
2012-04-18fix typo in exponent reading code or floatsRich Felker-1/+1
this was basically harmless, but could have resulted in misreading inputs with more than a few gigabytes worth of digits..
2012-04-17fix failure to read infinity in scanfRich Felker-3/+4
this code worked in strtod, but not in scanf. more evidence that i should design a better interface for discarding multiple tail characters than just calling unget repeatedly...
2012-04-17fix failure of int parser to unget an initial mismatching characterRich Felker-0/+1
2012-04-16use the new integer parser (FILE/shgetc based) for strtol, wcstol, etc.Rich Felker-127/+0
2012-04-16new scanf implementation and corresponding integer parser/converterRich Felker-0/+107
advantages over the old code: - correct results for floating point (old code was bogus) - wide/regular scanf separated so scanf does not pull in wide code - well-defined behavior on integers that overflow dest type - support for %[a-b] ranges with %[ (impl-defined by widely used) - no intermediate conversion of fmt string to wide string - cleaner, easier to share code with strto* functions - better standards conformance for corner cases the old code remains in the source tree, as the wide versions of the scanf-family functions are still using it. it will be removed when no longer needed.
2012-04-16fix buggy limiter handling in shgetcRich Felker-4/+3
this is needed for upcoming new scanf
2012-04-16fix broken shgetc limiter logic (wasn't working)Rich Felker-2/+5
2012-04-16floatscan: fix incorrect count of leading nonzero digitsRich Felker-1/+1
this off-by-one error was causing values with just one digit past the decimal point to be treated by the integer case. in many cases it would yield the correct result, but if expressions are evaluated in excess precision, double rounding may occur.
2012-04-13use fast version of the int reading code for the high-order digits tooRich Felker-3/+13
this increases code size slightly, but it's considerably faster, especially for power-of-2 bases.
2012-04-13use macros instead of inline functions in shgetc.hRich Felker-20/+4
at -Os optimization level, gcc refuses to inline these functions even though the inlined code would roughly the same size as the function call, and much faster. the easy solution is to make them into macros.
2012-04-13fix spurious overflows in strtoull with small basesRich Felker-7/+3
whenever the base was small enough that more than one digit could still fit after UINTMAX_MAX/36-1 was reached, only the first would be allowed; subsequent digits would trigger spurious overflow, making it impossible to read the largest values in low bases.
2012-04-12remove magic numbers from floatscanRich Felker-5/+5
2012-04-12optimize more integer cases in floatscan; comment the whole procedureRich Felker-8/+27
2012-04-11revert invalid optimization in floatscanRich Felker-2/+2
2012-04-11fix stupid typo in floatscan that caused excess rounding of some valuesRich Felker-1/+1