1. 25 7月, 2013 17 次提交
  2. 24 7月, 2013 5 次提交
    • R
      support STB_GNU_UNIQUE symbol bindings in dynamic linker · e152ee97
      Rich Felker 提交于
      these are needed for some C++ library binaries including most builds
      of libstdc++. I'm not entirely clear on the rationale. this patch does
      not implement any special semantics for them, but as far as I can
      tell, no special treatment is needed in correctly-linked programs;
      this binding seems to exist only for catching incorrectly-linked
      programs.
      e152ee97
    • R
      move the dynamic linker's jmp_buf from static to automatic storage · 17276be3
      Rich Felker 提交于
      this more than compensates for the size increase of jmp_buf, and
      greatly reduces bss/data size on archs with huge jmp_buf.
      17276be3
    • R
      change jmp_buf to share an underlying type and struct tag with sigjmp_buf · 9693501c
      Rich Felker 提交于
      this is necessary to meet the C++ ABI target. alternatives were
      considered to avoid the size increase for non-sig jmp_buf objects, but
      they seemed to have worse properties. moreover, the relative size
      increase is only extreme on x86[_64]; one way of interpreting this is
      that, if the size increase from this patch makes jmp_buf use too much
      memory, then the program was already using too much memory when built
      for non-x86 archs.
      9693501c
    • R
      remove redundant check in memalign · 4a30ba5c
      Rich Felker 提交于
      the case where mem was already aligned is handled earlier in the
      function now.
      4a30ba5c
    • R
      fix heap corruption bug in memalign · 70a92bc9
      Rich Felker 提交于
      this bug was caught by the new footer-corruption check in realloc and
      free.
      
      if the block returned by malloc was already aligned to the desired
      alignment, memalign's logic to split off the misaligned head was
      incorrect; rather than writing to a point inside the allocated block,
      it was overwriting the footer of the previous block on the heap with
      the value 1 (length 0 plus an in-use flag).
      
      fortunately, the impact of this bug was fairly low. (this is probably
      why it was not caught sooner.) due to the way the heap works, malloc
      will never return a block whose previous block is free. (doing so would
      be harmful because it would increase fragmentation with no benefit.)
      the footer is actually not needed for in-use blocks, except that its
      in-use bit needs to remain set so that it does not get merged with
      free blocks, so there was no harm in it being set to 1 instead of the
      correct value.
      
      however, there is one case where this bug could have had an impact: in
      multi-threaded programs, if another thread freed the previous block
      after memalign's call to malloc returned, but before memalign
      overwrote the previous block's footer, the resulting block in the free
      list could be left in a corrupt state. I have not analyzed the impact
      of this bad state and whether it could lead to more serious
      malfunction.
      70a92bc9
  3. 23 7月, 2013 10 次提交
    • R
      enhance build process to allow selective -O3 optimization · a80847d8
      Rich Felker 提交于
      the motivation for this patch is that the vast majority of libc is
      code that does not benefit at all from optimizations, but that certain
      components like string/memory operations can be major performance
      bottlenecks.
      
      at the same time, the old -falign-*=1 options are removed, since they
      were only beneficial for avoiding bloat when global -O3 was used, and
      in that case, they may have prevented some of the performance gains.
      
      to be the most useful, this patch will need further tuning. in
      particular, research is needed to determine which components should be
      built with -O3 by default, and it may be desirable to remove the
      hard-coded -O3 and instead allow more customization of the
      optimization level used for selected modules.
      a80847d8
    • R
      undefine internal-use type macros at the end of alltypes.h · 9578f053
      Rich Felker 提交于
      this patch is something of a compromise for a compatibility
      regression discovered after the header refactoring: libtiff uses
      _Int64 for its own use. this is absolutely wrong, invalid C, and
      should not be supported, but it's also frustrating for users when code
      that used to work suddenly breaks.
      
      rather than leave the breakage in place or change musl internals to
      accommodate broken software, I've found a change that makes the
      problem go away and improves musl. by undefining these macros at the
      end of alltypes.h, the temptation to use them in other headers is
      removed. (for example, I almost used _Int64 in sys/types.h to define
      u_int64_t rather than adding it back to alltypes.h.) by confining use
      of these macros to alltypes.h, we keep it easy to go back and change
      the implementation of alltypes later, if needed.
      9578f053
    • R
      remove SIG_ATOMIC_MIN/MAX from stdint bits headers · 3f08154a
      Rich Felker 提交于
      i386 was done with the big commit but I missed the others
      3f08154a
    • R
      move register_t and u_int64_t (back) to alltypes · 009f1868
      Rich Felker 提交于
      during the header refactoring, I had moved u_int64_t out of alltypes
      under the assumption that we could just use long long everywhere.
      however, it seems some broken applications make inconsistent mixed use
      of u_int64_t and uint64_t, resulting in build errors when the
      underlying type differs.
      009f1868
    • R
      fix regression in size of nlink_t (broken stat struct) on x86_64 · 1c6cace0
      Rich Felker 提交于
      rather than moving nlink_t back to the arch-specific file, I've added
      a macro _Reg defined to the canonical type for register-size values on
      the arch. this is not the same as _Addr for (not-yet-supported)
      32-on-64 pseudo-archs like x32 and mips n32, so a new macro was
      needed.
      1c6cace0
    • R
      make regoff_t and regex_t match C++ ABI · 8327ae0c
      Rich Felker 提交于
      for regoff_t, it's impossible to match on 64-bit archs because glibc
      defined the type in a non-conforming way. however this change makes
      the type match on 32-bit archs.
      8327ae0c
    • R
      disable legacy init/fini processing on ARM · 1da53dad
      Rich Felker 提交于
      since the old, poorly-thought-out musl approach to init/fini arrays on
      ARM (when it was the only arch that needed them) was to put the code
      in crti/crtn and have the legacy _init/_fini code run the arrays,
      adding proper init/fini array support caused the arrays to get
      processed twice on ARM. I'm not sure skipping legacy init/fini
      processing is the best solution to the problem, but it works, and it
      shouldn't break anything since the legacy init/fini system was never
      used for ARM EABI.
      1da53dad
    • R
      make pthread_key_t unsigned to match ABI · 4e3c6b43
      Rich Felker 提交于
      4e3c6b43
    • R
      make pthread attribute types structs, even when they just have one field · 0109d950
      Rich Felker 提交于
      this change is to get the right tags for C++ ABI matching. it should
      have no other effects.
      0109d950
    • R
      change wint_t to unsigned · c4dd0c98
      Rich Felker 提交于
      aside from the obvious C++ ABI purpose for this change, it also brings
      musl into alignment with the compiler's idea of the definition of
      wint_t (use in -Wformat), and makes the situation less awkward on ARM,
      where wchar_t is unsigned.
      
      internal code using wint_t and WEOF was checked against this change,
      and while a few cases of storing WEOF into wchar_t were found, they
      all seem to operate properly with the natural conversion from unsigned
      to signed.
      c4dd0c98
  4. 22 7月, 2013 1 次提交
    • R
      refactor headers, especially alltypes.h, and improve C++ ABI compat · 9448b051
      Rich Felker 提交于
      the arch-specific bits/alltypes.h.sh has been replaced with a generic
      alltypes.h.in and minimal arch-specific bits/alltypes.h.in.
      
      this commit is intended to have no functional changes except:
      - exposing additional symbols that POSIX allows but does not require
      - changing the C++ name mangling for some types
      - fixing the signedness of blksize_t on powerpc (POSIX requires signed)
      - fixing the limit macros for sig_atomic_t on x86_64
      - making dev_t an unsigned type (ABI matching goal, and more logical)
      
      in addition, some types that were wrongly defined with long on 32-bit
      archs were changed to int, and vice versa; this change is
      non-functional except for the possibility of making pointer types
      mismatch, and only affects programs that were using them incorrectly,
      and only at build-time, not runtime.
      
      the following changes were made in the interest of moving
      non-arch-specific types out of the alltypes system and into the
      headers they're associated with, and also will tend to improve
      application compatibility:
      - netdb.h now includes netinet/in.h (for socklen_t and uint32_t)
      - netinet/in.h now includes sys/socket.h and inttypes.h
      - sys/resource.h now includes sys/time.h (for struct timeval)
      - sys/wait.h now includes signal.h (for siginfo_t)
      - langinfo.h now includes nl_types.h (for nl_item)
      
      for the types in stdint.h:
      - types which are of no interest to other headers were moved out of
        the alltypes system.
      - fast types for 8- and 64-bit are hard-coded (at least for now); only
        the 16- and 32-bit ones have reason to vary by arch.
      
      and the following types have been changed for C++ ABI purposes;
      - mbstate_t now has a struct tag, __mbstate_t
      - FILE's struct tag has been changed to _IO_FILE
      - DIR's struct tag has been changed to __dirstream
      - locale_t's struct tag has been changed to __locale_struct
      - pthread_t is defined as unsigned long in C++ mode only
      - fpos_t now has a struct tag, _G_fpos64_t
      - fsid_t's struct tag has been changed to __fsid_t
      - idtype_t has been made an enum type (also required by POSIX)
      - nl_catd has been changed from long to void *
      - siginfo_t's struct tag has been removed
      - sigset_t's has been given a struct tag, __sigset_t
      - stack_t has been given a struct tag, sigaltstack
      - suseconds_t has been changed to long on 32-bit archs
      - [u]intptr_t have been changed from long to int rank on 32-bit archs
      - dev_t has been made unsigned
      
      summary of tests that have been performed against these changes:
      - nsz's libc-test (diff -u before and after)
      - C++ ABI check symbol dump (diff -u before, after, glibc)
      - grepped for __NEED, made sure types needed are still in alltypes
      - built gcc 3.4.6
      9448b051
  5. 21 7月, 2013 6 次提交
    • R
      remove init/fini array asm from arm crti/crtn files · 976c0fdc
      Rich Felker 提交于
      this code has been replaced by portable C code that works on all
      archs. the old asm needs to be removed or ctors/dtors will run twice.
      976c0fdc
    • R
      remove __libc_csu_* cruft · 3edfd070
      Rich Felker 提交于
      these functions were mistakenly assumed to be needed to match glibc
      ABI, but glibc has them as part of the non-shared part of libc that's
      always statically linked into the main program. moreover, the only
      place they are referenced from is glibc's crt1.o.
      3edfd070
    • R
      add support for init/fini array in main program, and greatly simplify · 7586360b
      Rich Felker 提交于
      modern (4.7.x and later) gcc uses init/fini arrays, rather than the
      legacy _init/_fini function pasting and crtbegin/crtend ctors/dtors
      system, on most or all archs. some archs had already switched a long
      time ago. without following this change, global ctors/dtors will cease
      to work under musl when building with new gcc versions.
      
      the most surprising part of this patch is that it actually reduces the
      size of the init code, for both static and shared libc. this is
      achieved by (1) unifying the handling main program and shared
      libraries in the dynamic linker, and (2) eliminating the
      glibc-inspired rube goldberg machine for passing around init and fini
      function pointers. to clarify, some background:
      
      the function signature for __libc_start_main was based on glibc, as
      part of the original goal of being able to run some glibc-linked
      binaries. it worked by having the crt1 code, which is linked into
      every application, static or dynamic, obtain and pass pointers to the
      init and fini functions, which __libc_start_main is then responsible
      for using and recording for later use, as necessary. however, in
      neither the static-linked nor dynamic-linked case do we actually need
      crt1.o's help. with dynamic linking, all the pointers are available in
      the _DYNAMIC block. with static linking, it's safe to simply access
      the _init/_fini and __init_array_start, etc. symbols directly.
      
      obviously changing the __libc_start_main function signature in an
      incompatible way would break both old musl-linked programs and
      glibc-linked programs, so let's not do that. instead, the function can
      just ignore the information it doesn't need. new archs need not even
      provide the useless args in their versions of crt1.o. existing archs
      should continue to provide it as long as there is an interest in
      having newly-linked applications be able to run on old versions of
      musl; at some point in the future, this support can be removed.
      7586360b
    • R
      fix order of fini_array execution for shared libs · 1b413572
      Rich Felker 提交于
      1b413572
    • R
      e69ae844
    • R
      fix shm_open wrongly being cancellable · ce8a9957
      Rich Felker 提交于
      ce8a9957
  6. 20 7月, 2013 1 次提交
    • R
      fix uninitialized/stale use of alloc (%m modifier) flag in scanf · 1d92cddb
      Rich Felker 提交于
      for conversion specifiers, alloc is always set when the specifier is
      parsed. however, if scanf stops due to mismatching literal text,
      either an uninitialized (if no conversions have been performed yet) or
      stale (from the previous conversion) of the flag will be used,
      possibly causing an invalid pointer to be passed to free when the
      function returns.
      1d92cddb