AgeCommit message (Collapse)AuthorLines
2012-11-04mips cache flush/ctl syscall support and headerRich Felker-0/+40
2012-11-01remove one unnecessary static var from dynamic linkerRich Felker-2/+2
2012-11-01fix more unused variable warningsRich Felker-6/+5
some of these were coming from stdio functions locking files without unlocking them. I believe it's useful for this to throw a warning, so I added a new macro that's self-documenting that the file will never be unlocked to avoid the warning in the few places where it's wrong.
2012-11-01fix unused variable warningsRich Felker-2/+1
2012-11-01avoid breakage if somebody wrongly defines empty feature test macrosRich Felker-3/+3
2012-10-31add dl_iterate_phdr interfaceRich Felker-7/+114
patches by Alex Caudill (npx). the dynamic-linked version is almost identical to the final submitted patch; I just added a couple missing lines for saving the phdr address when the dynamic linker is invoked directly to run a program, and removed a couple to avoid introducing another unnecessary type. the static-linked version is based on npx's draft. it could use some improvements which are contingent on the startup code saving some additional information for later use.
2012-10-28system is a cancellation pointRich Felker-0/+3
ideally, system would also be cancellable while running the external command, but I cannot find any way to make that work without either leaking zombie processes or introducing behavior that is far outside what the standard specifies. glibc handles cancellation by killing the child process with SIGKILL, but this could be unsafe in that it could leave the data being manipulated by the command in an inconsistent state.
2012-10-28release notes for 0.9.7v0.9.7Rich Felker-0/+31
2012-10-28fix shmdt syscall calling convention on old archsRich Felker-1/+1
2012-10-27separate getc/putc from fgetc/fputcRich Felker-6/+25
for conformance, two functions should not have the same address. a conforming program could use the addresses of getc and fgetc in ways that assume they are distinct. normally i would just use a wrapper, but these functions are so small and performance-critical that an extra layer of function call could make the one that's a wrapper nearly twice as slow, so I'm just duplicating the code instead.
2012-10-26update documentationRich Felker-33/+67
2012-10-26further pcc fixes in configureRich Felker-3/+4
-lpcc only works if -nostdlib is not passed, so it's useless. instead, use -print-file-name to look up the full pathname for libpcc.a, and check whether that succeeds before trying to link with the result. also, silence pcc's junk printed on stdout during tests.
2012-10-26add support for detecting pcc's compiler runtimeRich Felker-0/+1
in old versions of pcc, the directory containing libpcc.a was not in the library path, and other options like -print-file-name may have been needed to locate it. however, -print-file-name itself seems to have been added around the same time that the directory was added to the search path, and moreover, I see no evidence that older versions of pcc are capable of building a working musl shared library. thus, it seems reasonable to just test whether -lpcc is accepted.
2012-10-25use explicit visibility to optimize a few hot-path function callsRich Felker-11/+13
on x86 and some other archs, functions which make function calls which might go through a PLT incur a significant overhead cost loading the GOT register prior to making the call. this load is utterly useless in musl, since all calls are bound at library-creation time using -Bsymbolic-functions, but the compiler has no way of knowing this, and attempts to set the default visibility to protected have failed due to bugs in GCC and binutils. this commit simply manually assigns hidden/protected visibility, as appropriate, to a few internal-use-only functions which have many callers, or which have callers that are hot paths like getc/putc. it shaves about 5k off the i386 with -Os. many of the improvements are in syscall wrappers, where the benefit is just size and performance improvement is unmeasurable noise amid the syscall overhead. however, stdio may be measurably faster. if in the future there are toolchains that can do the same thing globally without introducing linking bugs, it might be worth considering removing these workarounds.
2012-10-25configure: test not just compiling but linking with -march/-mtuneRich Felker-2/+2
pcc wrongly passes any option beginning with -m to the linker, and will break at link time if these options were added to CFLAGS. testing linking lets us catch this at configure time and skip them.
2012-10-24correct locking in stdio functions that tried to be lock-freeRich Felker-16/+36
these functions must behave as if they obtain the lock via flockfile to satisfy POSIX requirements. since another thread can provably hold the lock when they are called, they must wait to obtain the lock before they can return, even if the correct return value could be obtained without locking. in the case of fclose and freopen, failure to do so could cause correct (albeit obscure) programs to crash or otherwise misbehave; in the case of feof, ferror, and fwide, failure to obtain the lock could sometimes return incorrect results. in any case, having these functions proceed and return while another thread held the lock was wrong.
2012-10-24greatly improve freopen behaviorRich Felker-17/+41
1. don't open /dev/null just as a basis to copy flags; use shared __fmodeflags function to get the right file flags for the mode. 2. handle the case (probably invalid, but whatever) case where the original stream's file descriptor was closed; previously, the logic re-closed it. 3. accept the "e" mode flag for close-on-exec; update dup3 to fallback to using dup2 so we can simply call __dup3 instead of putting fallback logic in freopen itself.
2012-10-24remove useless failure-check from freopen (can't happen)Rich Felker-2/+2
2012-10-22simplify logic in stpcpy; avoid copying first aligned byte twiceRich Felker-4/+4
gcc seems to be generating identical or near-identical code for both versions, but the newer code is more expressive of what it's doing.
2012-10-21fix issues with wait constants in stdlib.hRich Felker-6/+5
the W* namespace is not reserved, so the nonstandard ones must be moved under extension features. also WNOHANG and WUNTRACED were missing.
2012-10-21as an extension, have putenv("VAR") behave as unsetenv("VAR")Rich Felker-5/+5
the behavior of putenv is left undefined if the argument does not contain an equal sign, but traditional implementations behave this way and gnulib replaces putenv if it doesn't do this.
2012-10-21accept "nan(n-char-sequence)" in strtod/scanf functionsRich Felker-1/+19
this will prevent gnulib from wrapping our strtod to handle this useless feature.
2012-10-21fix copy/paste error in popen changes that broke signalsRich Felker-1/+1
signal mask was not being restored after fork, but instead blocked again.
2012-10-21complex: make _Complex_I work with gcc -std=c99 -pedantic-errorsnsz-0/+4
2012-10-19support looking up thread-local objects with dlsymRich Felker-0/+6
2012-10-19fix breakage in dlsym for looking up RTLD_DEFAULT, etc.Rich Felker-2/+5
this was broken during the early dynamic-linked TLS commits, which rearranged some of the code for handling new relocation types.
2012-10-19fix struct stat size/padding on microblazeRich Felker-1/+2
2012-10-19fix usage of locks with vforkRich Felker-3/+4
__release_ptc() is only valid in the parent; if it's performed in the child, the lock will be unlocked early then double-unlocked later, corrupting the lock state.
2012-10-19fix crashes in static-linked multithreaded programs without TLSRich Felker-0/+2
2012-10-19fix order of syscall args for microblaze clone syscallRich Felker-3/+2
with this commit, based on testing with patches to qemu which are not yet upstream,
2012-10-18use $CC rather than "$CC" in configure scriptRich Felker-4/+4
this is necessary to allow $CC with arguments in it
2012-10-18inline syscalls for microblazeRich Felker-0/+97
2012-10-18ensure microblaze __set_thread_area returns successRich Felker-1/+2
since it did not set the return-value register, the caller could wrongly interpret this as failure.
2012-10-18better support for reverse-endian variants of arm/mips/microblazeRich Felker-0/+12
these macros are supported by more compilers
2012-10-18avoid raising spurious division-by-zero exception in printfRich Felker-1/+1
2012-10-18floating point environment/exceptions support for mipsRich Felker-3/+73
2012-10-18fix parent-memory-clobber in posix_spawn (environ)Rich Felker-9/+17
2012-10-18overhaul system() and popen() to use vfork; fix various related bugsRich Felker-56/+110
since we target systems without overcommit, special care should be taken that system() and popen(), like posix_spawn(), do not fail in processes whose commit charges are too high to allow ordinary forking. this in turn requires special precautions to ensure that the parent process's signal handlers do not end up running in the shared-memory child, where they could corrupt the state of the parent process. popen has also been updated to use pipe2, so it does not have a fd-leak race in multi-threaded programs. since pipe2 is missing on older kernels, (non-atomic) emulation has been added. some silly bugs in the old code should be gone too.
2012-10-18fix (hopefully; untested) completely broken/incomplete microblaze sigsetjmpRich Felker-3/+12
2012-10-17fix microblaze asm relocations for shared libcRich Felker-6/+6
only @PLT relocations are considered functions for purposes of -Bsymbolic-functions, so always use @PLT. it should not hurt in the static-linked case.
2012-10-17assert() is supposed to have type voidRich Felker-1/+1
2012-10-15add memmem function (gnu extension)Rich Felker-0/+149
based on strstr. passes gnulib tests and a few quick checks of my own.
2012-10-15microblaze TLS relocation support, completely untestedRich Felker-1/+14
2012-10-15add support for TLS variant I, presently needed for arm and mipsRich Felker-17/+79
despite documentation that makes it sound a lot different, the only ABI-constraint difference between TLS variants II and I seems to be that variant II stores the initial TLS segment immediately below the thread pointer (i.e. the thread pointer points to the end of it) and variant I stores the initial TLS segment above the thread pointer, requiring the thread descriptor to be stored below. the actual value stored in the thread pointer register also tends to have per-arch random offsets applied to it for silly micro-optimization purposes. with these changes applied, TLS should be basically working on all supported archs except microblaze. I'm still working on getting the necessary information and a working toolchain that can build TLS binaries for microblaze, but in theory, static-linked programs with TLS and dynamic-linked programs where only the main executable uses TLS should already work on microblaze. alignment constraints have not yet been heavily tested, so it's possible that this code does not always align TLS segments correctly on archs that need TLS variant I.
2012-10-15block uid/gid changes during posix_spawnRich Felker-0/+10
usage of vfork creates a situation where a process of lower privilege may momentarily have write access to the memory of a process of higher privilege. consider the case of a multi-threaded suid program which is calling posix_spawn in one thread while another thread drops the elevated privileges then runs untrusted (relative to the elevated privilege) code as the original invoking user. this untrusted code can then potentially modify the data the child process will use before calling exec, for example changing the pathname or arguments that will be passed to exec. note that if vfork is implemented as fork, the lock will not be held until the child execs, but since memory is not shared it does not matter.
2012-10-14fix overlap of thread stacks with thread tls segmentsRich Felker-2/+1
2012-10-14fix main program TLS alignment for dynamic-linked programsRich Felker-6/+5
this change brings the behavior in line with the static-linked code, which seems to be correct.
2012-10-13workaround broken hidden-visibility handling in pccRich Felker-1/+1
with this change, pcc-built musl seems to work correctly. the problem is that pcc generates GOT lookups for external-linkage symbols even if they are hidden, rather than using GOT-relative addressing. the entire reason we're using hidden visibility on the __libc object is to make it accessible prior to relocations -- not to mention inexpensive to access. unfortunately, the workaround makes it even more expensive on pcc. when the pcc issue is fixed, an appropriate version test should be added so new pcc can use the much more efficient variant.
2012-10-13ensure pointer decay in inline-asm arg for i386 syscall6Rich Felker-1/+1
this is actually a rather subtle issue: do arrays decay to pointers when used as inline asm args? gcc says yes, but currently pcc says no. hopefully this discrepency in pcc will be fixed, but since the behavior is not clearly defined anywhere I can find, I'm using an explicit operation to cause the decay to occur.
2012-10-13fix namespace clash (libc) in dynlink.cRich Felker-14/+13
this makes it so the #undef libc and __libc name are no longer needed, which were problematic because the "accessor function" mode for accessing the libc struct could not be used, breaking build on any compiler without (working) visibility.