1. 14 8月, 2013 4 次提交
    • R
      add arm-optimized memcpy implementation from bionic libc · cccc1844
      Rich Felker 提交于
      the approach of this implementation was heavily investigated prior to
      adopting it. attempts to obtain similar performance with pure C code
      were capping out at about 75% of the performance of the asm, with
      considerably larger code size, and were fragile in that the compiler
      would sometimes compile part of memcpy into a call to itself.
      therefore, just using the asm seems to be the best option.
      
      this commit is the first to make use of the new subarch-specific asm
      framework. the new armel directory is the location for arm asm that
      should not be used for all arm subarchs, only the default one. armhf
      is the name of the little-endian hardfloat-ABI subarch, which can use
      the exact same asm. in both cases, the build system finds the asm by
      following a memcpy.sub file.
      
      the other two subarchs, armeb and armebhf, would need a big-endian
      variant of this code. it would not be hard to adapt the code to big
      endian, but I will hold off on doing so until there is demand for it.
      cccc1844
    • R
      rework makefile subarch logic to allow shared files · fb72a97d
      Rich Felker 提交于
      instead of subarchs getting their own .s files which are used directly
      by the makefile to replace the .c file, they now must provide a .sub
      file whose contents are a pathname, relative to the location of the
      .sub file, which will substitute for the .c file. essentially these
      files are acting as symbolic links, but implemented as text files.
      fb72a97d
    • R
      add missing MSG_EXCEPT in sys/msg.h · 4ce6bd83
      Rich Felker 提交于
      4ce6bd83
    • R
      provide declarations for strtod_l and family · 35eb1a1a
      Rich Felker 提交于
      these aliases were originally intended to be for ABI compatibility
      only, but their presence caused regressions in broken gnulib-based
      software whose configure scripts detect the existing of these
      functions then use them without declarations, resulting in bogus
      return values.
      35eb1a1a
  2. 11 8月, 2013 7 次提交
    • R
      add subarch asm support for PIC objects/shared libc · 804e9940
      Rich Felker 提交于
      this rule was omitted in previous subarch asm commit
      804e9940
    • R
      add missing a_or_l to atomic.h for non-x86 archs · 7568ee4c
      Rich Felker 提交于
      this is needed for recently committed sigaction code
      7568ee4c
    • R
      allow subarch-specific asm, including asm specific to the default · 90d77722
      Rich Felker 提交于
      the default subarch is the one whose full name is just the base arch
      name, with no suffixes. normally, either the asm in the default
      subarch is suitable for all subarch variants, or separate asm is
      mandatory for each variant. however, in the case of asm which is
      purely for optimization purposes, it's possible to have asm that only
      works (or only performs well) on the default subarch, and not any othe
      the other variants. thus, I have added a mechanism to give a name to
      the default variant, for example "armel" for the default,
      little-endian arm. further such default-subarch names can be added in
      the future as needed.
      90d77722
    • R
      fix _NSIG and SIGRTMAX on mips · 7c440977
      Rich Felker 提交于
      a mips signal mask contains 128 bits, enough for signals 1 through
      128. however, the exit status obtained from the wait-family functions
      only has room for values up to 127. reportedly signal 128 was causing
      kernelspace bugs, so it was removed from the kernel recently; even
      without that issue, however, it was impossible to support it correctly
      in userspace.
      
      at the same time, the bug was masked on musl by SIGRTMAX incorrectly
      yielding 64 on mips, rather than the "correct" value of 128. now that
      the _NSIG issue is fixed, SIGRTMAX can be fixed at the same time,
      exposing the full range of signals for application use.
      
      note that the (nonstandardized) libc _NSIG value is actually one
      greater than the max signal number, and also one greater than the
      kernel headers' idea of _NSIG. this is the reason for the discrepency
      with the recent kernel changes. since reducing _NSIG by one brought it
      down from 129 to 128, rather than from 128 to 127, _NSIG/8, used
      widely in the musl sources, is unchanged.
      7c440977
    • R
      fix definitions of WIFSTOPPED and WIFSIGNALED to support up to signal 127 · 41c63282
      Rich Felker 提交于
      mips has signal numbers up to 127 (formerly, up to 128, but the last
      one never worked right and caused kernel panic when used), so 127 in
      the "signal number" field of the wait status is insufficient for
      determining that the process was stopped. in addition, a nonzero value
      in the upper bits must be present, indicating the signal number which
      caused the process to be stopped.
      
      details on this issue can be seen in the email with message id
      CAAG0J9-d4BfEhbQovFqUAJ3QoOuXScrpsY1y95PrEPxA5DWedQ@mail.gmail.com on
      the linux-mips mailing list, archived at:
      http://www.linux-mips.org/archives/linux-mips/2013-06/msg00552.html
      and in the associated thread about fixing the mips kernel bug.
      
      commit 4a96b948687166da26a6c327e6c6733ad2336c5c fixed the
      corresponding issue in uClibc, but introduced a multiple-evaluation
      issue for the WIFSTOPPED macro.
      
      for the most part, none of these issues affected pure musl systems,
      since musl has up until now (incorrectly) defined SIGRTMAX as 64 on
      all archs, even mips. however, interpreting status of non-musl
      programs on mips may have caused problems. with this change, the full
      range of signal numbers can be made available on mips.
      41c63282
    • R
      7406fdf5
    • R
      add cpu affinity interfaces · eeb0328f
      Rich Felker 提交于
      this first commit just includes the CPU_* and sched_* interfaces, not
      the pthread_* interfaces, which may be added later. simple
      sanity-check testing has been done for the basic interfaces, but most
      of the macros have not yet been tested.
      eeb0328f
  3. 10 8月, 2013 4 次提交
    • R
      change sigset_t functions to restrict to _NSIG · 76fbf6ad
      Rich Felker 提交于
      the idea here is to avoid advertising signals that don't exist and to
      make these functions safe to call (e.g. from within other parts of the
      implementation) on fake sigset_t objects which do not have the HURD
      padding.
      76fbf6ad
    • R
      optimize posix_spawn to avoid spurious sigaction syscalls · 3c5c5e6f
      Rich Felker 提交于
      the trick here is that sigaction can track for us which signals have
      ever had a signal handler set for them, and only those signals need to
      be considered for reset. this tracking mask may have false positives,
      since it is impossible to remove bits from it without race conditions.
      false negatives are not possible since the mask is updated with atomic
      operations prior to making the sigaction syscall.
      
      implementation-internal signals are set to SIG_IGN rather than SIG_DFL
      so that a signal raised in the parent (e.g. calling pthread_cancel on
      the thread executing pthread_spawn) does not have any chance make it
      to the child, where it would cause spurious termination by signal.
      
      this change reduces the minimum/typical number of syscalls in the
      child from around 70 to 4 (including execve). this should greatly
      improve the performance of posix_spawn and other interfaces which use
      it (popen and system).
      
      to facilitate these changes, sigismember is also changed to return 0
      rather than -1 for invalid signals, and to return the actual status of
      implementation-internal signals. POSIX allows but does not require an
      error on invalid signal numbers, and in fact returning an error tends
      to confuse applications which wrongly assume the return value of
      sigismember is boolean.
      3c5c5e6f
    • R
      fix missing errno from exec failure in posix_spawn · 65d7aa4d
      Rich Felker 提交于
      failures prior to the exec attempt were reported correctly, but on
      exec failure, the return value contained junk.
      65d7aa4d
    • R
      block all signals, even implementation-internal ones, in faccessat child · 9848e648
      Rich Felker 提交于
      the child process's stack may be insufficient size to support a signal
      frame, and there is no reason these signal handlers should run in the
      child anyway.
      9848e648
  4. 09 8月, 2013 4 次提交
    • R
      block signals during fork · d4d6d6f3
      Rich Felker 提交于
      there are several reasons for this. some of them are related to race
      conditions that arise since fork is required to be async-signal-safe:
      if fork or pthread_create is called from a signal handler after the
      fork syscall has returned but before the subsequent userspace code has
      finished, inconsistent state could result. also, there seem to be
      kernel and/or strace bugs related to arrival of signals during fork,
      at least on some versions, and simply blocking signals eliminates the
      possibility of such bugs.
      d4d6d6f3
    • R
      work around libraries with versioned symbols in dynamic linker · 72482f90
      Rich Felker 提交于
      this commit does not add versioning support; it merely fixes incorrect
      lookups of symbols in libraries that contain versioned symbols.
      previously, the version information was completely ignored, and
      empirically this seems to have resulted in the oldest version being
      chosen, but I am uncertain if that behavior was even reliable.
      
      the new behavior being introduced is to completely ignore symbols
      which are marked "hidden" (this seems to be the confusing nomenclature
      for non-current-version) when versioning is present. this should solve
      all problems related to libraries with symbol versioning as long as
      all binaries involved are up-to-date (compatible with the
      latest-version symbols), and it's the needed behavior for dlsym under
      all circumstances.
      72482f90
    • R
      sys/personality.h: add missing C++ compat · e28c2eca
      rofl0r 提交于
      e28c2eca
    • R
      sys/personality.h: add missing macros · 6a0aa82f
      rofl0r 提交于
      6a0aa82f
  5. 08 8月, 2013 1 次提交
    • R
      add Big5 charset support to iconv · 19b4a0a2
      Rich Felker 提交于
      at this point, it is just the common base charset equivalent to
      Windows CP 950, with no further extensions. HKSCS and possibly other
      supersets will be added later. other aliases may need to be added too.
      19b4a0a2
  6. 07 8月, 2013 2 次提交
    • R
      make fcvt decimal point location for zero make more sense · 983acebc
      Rich Felker 提交于
      the (obsolete) standard allows either 0 or 1 for the decimal point
      location in this case, but since the number of zero digits returned in
      the output string (in this implementation) is one more than the number
      of digits the caller requested, it makes sense for the decimal point
      to be logically "after" the first digit. in a sense, this change goes
      with the previous commit which fixed the value of the decimal point
      location for non-zero inputs.
      983acebc
    • R
      fix ecvt/fcvt decimal point position output · a0cc022c
      Rich Felker 提交于
      these functions are obsolete and have no modern standard. the text in
      SUSv2 is highly ambiguous, specifying that "negative means to the left
      of the returned digits", which suggested to me that 0 would mean to
      the right of the first digit. however, this does not agree with
      historic practice, and the Linux man pages are more clear, specifying
      that a negative value means "that the decimal point is to the left of
      the start of the string" (in which case, 0 would mean the start of the
      string, in accordance with historic practice).
      a0cc022c
  7. 06 8月, 2013 1 次提交
    • R
      iconv support for legacy Korean encodings · 734062b2
      Rich Felker 提交于
      like for other character sets, stateful iso-2022 form is not supported
      yet but everything else should work. all charset aliases are treated
      the same, as Windows codepage 949, because reportedly the EUC-KR
      charset name is in widespread (mis?)usage in email and on the web for
      data which actually uses the extended characters outside the standard
      93x94 grid. this could easily be changed if desired.
      
      the principle of this converter for handling the giant bulk of rare
      Hangul syllables outside of the standard KS X 1001 93x94 grid is the
      same as the GB18030 converter's treatment of non-explicitly-coded
      Unicode codepoints: sequences in the extension range are mapped to an
      integer index N, and the converter explicitly computes the Nth Hangul
      syllable not explicitly encoded in the character map. empirically,
      this requires at most 7 passes over the grid. this approach reduces
      the table size required for Korean legacy encodings from roughly 44k
      to 17k and should have minimal performance impact on real-world text
      conversions since the "slow" characters are rare. where it does have
      impact, the cost is merely a large constant time factor.
      734062b2
  8. 04 8月, 2013 3 次提交
    • R
      have new timer threads unblock their own SIGTIMER · a7f18a55
      Rich Felker 提交于
      unblocking it in the pthread_once init function is not sufficient,
      since multiple threads, some of them with the signal blocked, could
      already exist before this is called; timers started from such threads
      would be non-functional.
      a7f18a55
    • R
      add system for resetting TLS to initial values · 7c6c2906
      Rich Felker 提交于
      this is needed for reused threads in the SIGEV_THREAD timer
      notification system, and could be reused elsewhere in the future if
      needed, though it should be refactored for such use.
      
      for static linking, __init_tls.c is simply modified to export the TLS
      info in a structure with external linkage, rather than using statics.
      this perhaps makes the code more clear, since the statics were poorly
      named for statics. the new __reset_tls.c is only linked if it is used.
      
      for dynamic linking, the code is in dynlink.c. sharing code with
      __copy_tls is not practical since __reset_tls must also re-zero
      thread-local bss.
      7c6c2906
    • R
      fix multiple bugs in SIGEV_THREAD timers · 7356c255
      Rich Felker 提交于
      1. the thread result field was reused for storing a kernel timer id,
      but would be overwritten if the application code exited or cancelled
      the thread.
      
      2. low pointer values were used as the indicator that the timer id is
      a kernel timer id rather than a thread id. this is not portable, as
      mmap may return low pointers on some conditions. instead, use the fact
      that pointers must be aligned and kernel timer ids must be
      non-negative to map pointers into the negative integer space.
      
      3. signals were not blocked until after the timer thread started, so a
      race condition could allow a signal handler to run in the timer thread
      when it's not supposed to exist. this is mainly problematic if the
      calling thread was the only thread where the signal was unblocked and
      the signal handler assumes it runs in that thread.
      7356c255
  9. 03 8月, 2013 14 次提交