1. 04 5月, 2012 7 次提交
    • R
      add support for ugly *64 functions with _LARGEFILE64_SOURCE · 2dd8d5e1
      Rich Felker 提交于
      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.
      2dd8d5e1
    • R
      avoid setting nondefault scheduler too · b4560a6d
      Rich Felker 提交于
      b4560a6d
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      implement stub versions of sched_* · 61be1cfe
      Rich Felker 提交于
      these actually work, but for now they prohibit actually setting
      priority levels and report min/max priority as 0.
      61be1cfe
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      add additional compatibility union member for ipv6 addresses · ca2d3c6e
      Rich Felker 提交于
      in6_* is in the reserved namespace, so this is valid
      ca2d3c6e
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      overhaul SSP support to use a real canary · 58aa5f45
      Rich Felker 提交于
      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).
      58aa5f45
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      make all .o files depend on *_impl.h and libc.h · e765239f
      Rich Felker 提交于
      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.
      e765239f
  2. 03 5月, 2012 6 次提交
  3. 02 5月, 2012 3 次提交
    • R
      remove minimal linux kernel headers · 6f0cf306
      Rich Felker 提交于
      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://git.etalabs.net/mini-lkh
      6f0cf306
    • R
      reorganize Makefile to support "least surprise" config/make semantics · d76eafcb
      Rich Felker 提交于
      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.
      d76eafcb
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      remove objcopy --weaken from the makefile · d86d2829
      Rich Felker 提交于
      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.
      d86d2829
  4. 01 5月, 2012 2 次提交
  5. 30 4月, 2012 7 次提交
  6. 29 4月, 2012 2 次提交
    • R
      8b711219
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      new fnmatch implementation · 45b38550
      Rich Felker 提交于
      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.
      45b38550
  7. 27 4月, 2012 2 次提交
  8. 26 4月, 2012 1 次提交
  9. 25 4月, 2012 6 次提交
    • R
      gdb shared library debugging support · 3ec8d29c
      Rich Felker 提交于
      provide the minimal level of dynamic linker-to-debugger glue needed to
      let gdb find loaded libraries and load their symbols.
      3ec8d29c
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      first attempt at enabling stack protector support · 60872cf9
      Rich Felker 提交于
      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.
      60872cf9
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      use signed char rather than plain char for int8_t · 848d30a1
      Rich Felker 提交于
      otherwise this BADLY breaks if -funsigned-char is passed to gcc
      848d30a1
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      add another example option to dist/config.mak · e4d35ea9
      Rich Felker 提交于
      e4d35ea9
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      ditch the priority inheritance locks; use malloc's version of lock · 4750cf42
      Rich Felker 提交于
      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).
      4750cf42
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      internal locks: new owner of contended lock must set waiters flag · e7655ed3
      Rich Felker 提交于
      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.
      e7655ed3
  10. 24 4月, 2012 4 次提交
    • R
      new internal locking primitive; drop spinlocks · f34d0ea5
      Rich Felker 提交于
      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).
      f34d0ea5
    • R
      new wcwidth implementation (fast table-based) · 1b0ce9af
      Rich Felker 提交于
      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.
      1b0ce9af
    • R
      sync case mappings with unicode 6.1 · 1a63a9fc
      Rich Felker 提交于
      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...
      1a63a9fc
    • R
      optimize iswprint · 38b5d7d0
      Rich Felker 提交于
      38b5d7d0