AgeCommit message (Collapse)AuthorLines
2012-05-04update INSTALL file to reflect configure script usageRich Felker-13/+23
2012-05-04initial commit of configure scriptRich Felker-0/+275
this script is not based on autoconf; however it attempts to follow the same interface contracts for ease of integration with build systems. it is also not necessary to use musl. manually written config.mak files are still supported, as is building without any config.mak at all as long as you are happy with the default options and you supply at least ARCH on the command line to make.
2012-05-04make pthread stacks non-executableRich Felker-1/+1
this change is necessary or pthread_create will always fail on security-hardened kernels. i considered first trying to make the stack executable and simply retrying without execute permissions when the first try fails, but (1) this would incur a serious performance penalty on hardened systems, and (2) having the stack be executable is just a bad idea from a security standpoint. if there is real-world "GNU C" code that uses nested functions with threads, and it can't be fixed, we'll have to consider other ways of solving the problem, but for now this seems like the best fix.
2012-05-04improve the build rules for installing /lib/ld-musl-$ARCH.soRich Felker-2/+4
these new rules should avoid spurious error messages when the directory (usually /lib) and the dynamic linker symlink already exist, and minimize the spam when they can't be created.
2012-05-04Merge remote-tracking branch 'nsz/master'Rich Felker-20/+16
2012-05-04fix error reporting for dlsym with global symbolsRich Felker-1/+2
2012-05-05math: change the formula used for acos.snsz-20/+16
old: 2*atan2(sqrt(1-x),sqrt(1+x)) new: atan2(fabs(sqrt((1-x)*(1+x))),x) improvements: * all edge cases are fixed (sign of zero in downward rounding) * a bit faster (here a single call is about 131ns vs 162ns) * a bit more precise (at most 1ulp error on 1M uniform random samples in [0,1), the old formula gave some 2ulp errors as well)
2012-05-04fix uninitialized var in vfwprintf printing 0-prec stringRich Felker-1/+1
this could lead to spurious failures of wide printf functions
2012-05-04add *64 junk for sys/*.h headersRich Felker-0/+50
2012-05-04add support for ugly *64 functions with _LARGEFILE64_SOURCERich Felker-0/+68
musl does not support legacy 32-bit-off_t whatsoever. off_t is always 64 bit, and correct programs that use off_t and the standard functions will just work out of the box. (on glibc, they would require -D_FILE_OFFSET_BITS=64 to work.) however, some programs instead define _LARGEFILE64_SOURCE and use alternate versions of all the standard types and functions with "64" appended to their names. we do not want code to actually get linked against these functions (it's ugly and inconsistent), so macros are used instead of prototypes with weak aliases in the library itself. eventually the weak aliases may be added at the library level for the sake of using code that was originally built against glibc, but the macros will still be the desired solution in the headers.
2012-05-03avoid setting nondefault scheduler tooRich Felker-1/+1
2012-05-03implement stub versions of sched_*Rich Felker-0/+49
these actually work, but for now they prohibit actually setting priority levels and report min/max priority as 0.
2012-05-03uglify headers for the sake of junk that compiles with gcc -std=c89/-ansiRich Felker-6/+24
2012-05-03add additional compatibility union member for ipv6 addressesRich Felker-0/+2
in6_* is in the reserved namespace, so this is valid
2012-05-03overhaul SSP support to use a real canaryRich Felker-12/+25
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).
2012-05-03make all .o files depend on *_impl.h and libc.hRich Felker-2/+3
hopefully the annoyance of this will be minimal. these files all define internal interfaces which can change at any time; if different modules are using different versions of the interfaces, the library will badly break. ideally we would scan and add the dependency only for C files that actually reference the affected interfaces, but for now, err on the side of caution and force a rebuild of everything if any of them have changed. this commit is in preparation for the upcoming ssp overhaul commit, which will change internals of the pthread struct.
2012-05-02remove some junk from x86_64 start filesRich Felker-4/+0
looks like nik copied these "extra arguments" from the i386 code. they're not actually arguments there, just 1-byte instructions to make sure the stack is aligned to 16 bytes after all the other arguments are pushed. since each push is 8 bytes on x86_64, they happened to have no effect here, but their presence is confusing and a minor waste of space.
2012-05-02PIE support for x86_64 (untested)Rich Felker-0/+18
2012-05-02consistency cleanup: removed redundant size suffixed from i386 asmRich Felker-22/+22
2012-05-02PIE support for i386Rich Felker-1/+25
2012-05-02remove attempts to be pie-compatible from i386 crt1.sRich Felker-6/+3
it does not work; after further consideration, a separate Scrt1.s for pie really is essential. it would be nice if the unified approach worked, but the linker fails to generate the correct PLT entries and instead puts textrels in the main program, which don't work because the kernel maps the text read-only. new Scrt1.s will be committed soon in place of this.
2012-05-02fix longstanding exit logic bugs in mbsnrtowcs and wcsnrtombsRich Felker-4/+9
these are POSIX 2008 (previously GNU extension) functions that are rarely used. apparently they had never been tested before, since the end-of-string logic was completely missing. mbsnrtowcs is used by modern versions of bash for its glob implementation, and and this bug was causing tab completion to hang in an infinite loop.
2012-05-01remove minimal linux kernel headersRich Felker-621/+0
these were at best of limited usefulness (for bootstrapping new systems, mainly) and at worst caused real kernel headers to get overwritten when upgrading libc. in case they're needed by anyone, the exact same files are now available in a new git repository: git://
2012-05-01reorganize Makefile to support "least surprise" config/make semanticsRich Felker-11/+23
the major change here is that CFLAGS is now a variable that can be changed entirely under user control, without causing essential flags to be lost. previously, "CFLAGS += ..." was valid in config.mak, but using "CFLAGS = ..." in config.mak would have badly broken the build process unless the user took care to copy the necessary flags out of the main Makefile. I have also added a distclean target that removes config.mak.
2012-05-01remove objcopy --weaken from the makefileRich Felker-2/+0
as far as I can tell, it's not useful and never way. I wrote it way back under the assumption that non-weak symbols in the POSIX or extension namespace could conflict with legitimate uses of the same symbol name in the main program or other libraries, but that does not seem to be the case.
2012-05-01support alternate glibc name pow10 for exp10Rich Felker-0/+12
2012-04-30add C stub for sqrtl (already implemented in asm on i386 and x86_64)Rich Felker-0/+9
2012-04-30first try at writing an efficient and "correct" exp10Rich Felker-0/+59
this is a nonstandard function so it's not clear what conditions it should satisfy. my intent is that it be fast and exact for positive integral exponents when the result fits in the destination type, and fast and correctly rounded for small negative integral exponents. otherwise we aim for at most 1ulp error; it seems to differ from pow by at most 1ulp and it's often 2-5 times faster than pow.
2012-04-30make stack protector work with gcc configured for non-tls canaryRich Felker-0/+2
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.
2012-04-29fix typo in the x86_64 rounding asmRich Felker-4/+4
2012-04-29new math asm (abs/rounding) for x86_64Rich Felker-0/+36
2012-04-29fix float_t and double_t defs on x86 when -mfpmath=sse -msse2 is usedRich Felker-0/+5
2012-04-29add linux-specific unshare syscall wrapperRich Felker-0/+9
2012-04-29fix longstanding missing static in mq_notify (namespace pollution)Rich Felker-1/+1
2012-04-28new fnmatch implementationRich Felker-131/+273
unlike the old one, this one's algorithm does not suffer from potential stack overflow issues or pathologically bad performance on certain patterns. instead of backtracking, it uses a matching algorithm which I have not seen before (unsure whether I invented or re-invented it) that runs in O(1) space and O(nm) time. it may be possible to improve the time to O(n), but not without significantly greater complexity.
2012-04-27support FLT_EVAL_METHOD changing on x86 with gcc -msse2 -mfpmath=sseRich Felker-0/+4
if the compiler provides a value, use it; otherwise fallback to the platform default (2).
2012-04-26update fnmatch to POSIX 2008 semanticsRich Felker-4/+11
an invalid bracket expression must be treated as if the opening bracket were just a literal character. this is to fix a bug whereby POSIX left the behavior of the "[" shell command undefined due to it being an invalid bracket expression.
2012-04-25release notes for 0.8.10v0.8.10Rich Felker-0/+28
2012-04-25gdb shared library debugging supportRich Felker-5/+32
provide the minimal level of dynamic linker-to-debugger glue needed to let gdb find loaded libraries and load their symbols.
2012-04-24first attempt at enabling stack protector supportRich Felker-0/+28
the code is written to pre-init the thread pointer in static linked programs that pull in __stack_chk_fail or dynamic-linked programs that lookup the symbol. no explicit canary is set; the canary will be whatever happens to be in the thread structure at the offset gcc hard-coded. this can be improved later.
2012-04-24use signed char rather than plain char for int8_tRich Felker-12/+12
otherwise this BADLY breaks if -funsigned-char is passed to gcc
2012-04-24add another example option to dist/config.makRich Felker-0/+3
2012-04-24ditch the priority inheritance locks; use malloc's version of lockRich Felker-77/+54
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).
2012-04-24internal locks: new owner of contended lock must set waiters flagRich Felker-1/+1
this bug probably would have gone unnoticed since it's only used in the fallback code for systems where priority-inheritance locking fails. unfortunately this approach results in one spurious wake syscall on the final unlock, when there are no waiters remaining. the alternative (possibly better) would be to use broadcast wakes instead of reflagging the waiter unconditionally, and let each waiter reflag itself; this saves one syscall at the expense of invoking the "thundering herd" effect (worse performance degredation) when there are many waiters. ideally we would be able to update all of our locks to use an array of two ints rather than a single int, and use a separate counter system like proper mutexes use; then we could avoid all spurious wake calls without resorting to broadcasts. however, it's not clear to me that priority inheritance futexes support this usage. the kernel sets the waiters flag for them (just like we're doing now) and i can't tell if it's safe to bypass the kernel when unlocking just because we know (from private data, the waiter count) that there are no waiters. this is something that could be explored in the future.
2012-04-24new internal locking primitive; drop spinlocksRich Felker-7/+29
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).
2012-04-24new wcwidth implementation (fast table-based)Rich Felker-179/+125
i tried to go with improving the old binary-search-based algorithm, but between growth in the number of ranges, bad performance, and lack of confidence in the binary search code's stability under changes in the table, i decided it was worth the extra 1.8k to have something clean and maintainable. also note that, like the alpha and punct tables, there's definitely room to optimize the nonspacing/wide tables by overlapping subtables. this is not a high priority, but i've begun looking into how to do it, and i suspect the table sizes can be roughly halved. if that turns out to be true, the new, fast, table-based implementation will be roughly the same size as if i had just extended the old binary search one.
2012-04-23sync case mappings with unicode 6.1Rich Felker-8/+30
also special-case ß (U+00DF) as lowercase even though it does not have a mapping to uppercase. unicode added an uppercase version of this character but does not map it, presumably because the uppercase version is not actually used except for some obscure purpose...
2012-04-23optimize iswprintRich Felker-3/+12
2012-04-23fix spurious punct class for some surrogate codepoints (invalid)Rich Felker-59/+56
this happened due to their entries in UnicodeData.txt