1. 16 5月, 2015 1 次提交
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      in i386 __set_thread_area, don't assume %gs register is initially zero · 707d7c30
      Rich Felker 提交于
      commit f630df09 added logic to handle
      the case where __set_thread_area is called more than once by reusing
      the GDT slot already in the %gs register, and only setting up a new
      GDT slot when %gs is zero. this created a hidden assumption that %gs
      is zero when a new process image starts, which is true in practice on
      Linux, but does not seem to be documented ABI, and fails to hold under
      qemu app-level emulation.
      
      while it would in theory be possible to zero %gs in the entry point
      code, this code is shared between static and dynamic binaries, and
      dynamic binaries must not clobber the value of %gs already setup by
      the dynamic linker.
      
      the alternative solution implemented in this commit simply uses global
      data to store the GDT index that's selected. __set_thread_area should
      only be called in the initial thread anyway (subsequent threads get
      their thread pointer setup by __clone), but even if it were called by
      another thread, it would simply read and write back the same GDT index
      that was already assigned to the initial thread, and thus (in the x86
      memory model) there is no data race.
      707d7c30
  2. 15 5月, 2015 2 次提交
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      make arm reloc.h CRTJMP macro compatible with thumb · c0f10cf0
      Rich Felker 提交于
      compilers targeting armv7 may be configured to produce thumb2 code
      instead of arm code by default, and in the future we may wish to
      support targets where only the thumb instruction set is available.
      
      the instructions this patch omits in thumb mode are needed only for
      non-thumb versions of armv4 or earlier, which are not supported by any
      current compilers/toolchains and thus rather pointless to have. at
      some point these compatibility return sequences may be removed from
      all asm source files, and in that case it would make sense to remove
      them here too and remove the ifdef.
      c0f10cf0
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      make arm crt_arch.h compatible with thumb code generation · 83340c7a
      Rich Felker 提交于
      compilers targeting armv7 may be configured to produce thumb2 code
      instead of arm code by default, and in the future we may wish to
      support targets where only the thumb instruction set is available.
      
      the changes made here avoid operating directly on the sp register,
      which is not possible in thumb code, and address an issue with the way
      the address of _DYNAMIC is computed.
      
      previously, the relative address of _DYNAMIC was stored with an
      additional offset of -8 versus the pc-relative add instruction, since
      on arm the pc register evaluates to ".+8". in thumb code, it instead
      evaluates to ".+4". both are two (normal-size) instructions beyond "."
      in the current execution mode, so the numbered label 2 used in the
      relative address expression is simply moved two instructions ahead to
      be compatible with both instruction sets.
      83340c7a
  3. 13 5月, 2015 1 次提交
  4. 08 5月, 2015 1 次提交
  5. 07 5月, 2015 2 次提交
    • R
      fix futimes legacy function with null tv pointer · ece0c48a
      Rich Felker 提交于
      a null pointer is valid here and indicates that the current time
      should be used. based on patch by Felix Janda, simplified.
      ece0c48a
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      fix stack protector crashes on x32 & powerpc due to misplaced TLS canary · 484194db
      Rich Felker 提交于
      i386, x86_64, x32, and powerpc all use TLS for stack protector canary
      values in the default stack protector ABI, but the location only
      matched the ABI on i386 and x86_64. on x32, the expected location for
      the canary contained the tid, thus producing spurious mismatches
      (resulting in process termination) upon fork. on powerpc, the expected
      location contained the stdio_locks list head, so returning from a
      function after calling flockfile produced spurious mismatches. in both
      cases, the random canary was not present, and a predictable value was
      used instead, making the stack protector hardening much less effective
      than it should be.
      
      in the current fix, the thread structure has been expanded to have
      canary fields at all three possible locations, and archs that use a
      non-default location must define a macro in pthread_arch.h to choose
      which location is used. for most archs (which lack TLS canary ABI) the
      choice does not matter.
      484194db
  6. 03 5月, 2015 2 次提交
  7. 02 5月, 2015 7 次提交
  8. 01 5月, 2015 2 次提交
  9. 28 4月, 2015 2 次提交
    • R
      fix sh jmp_buf size to match ABI · 85d12e02
      Rich Felker 提交于
      while the sh port is still experimental and subject to ABI
      instability, this is not actually an application/libc boundary ABI
      change. it only affects third-party APIs where jmp_buf is used in a
      shared structure at the ABI boundary, because nothing anywhere near
      the end of the jmp_buf object (which includes the oversized sigset_t)
      is accessed by libc.
      
      both glibc and uclibc have 15-slot jmp_buf for sh. presumably the
      smaller version was used in musl because the slots for fpu status
      register and thread pointer register (gbr) were incorrect and must not
      be restored by longjmp, but the size should have been preserved, as
      it's generally treated as a libc-agnostic ABI property for the arch,
      and having extra slots free in case we ever need them for something is
      useful anyway.
      85d12e02
    • R
      fix name of sh crt asm directory · 82acacce
      Rich Felker 提交于
      82acacce
  10. 25 4月, 2015 2 次提交
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      fix build regression in aarch64 sigsetjmp · 94f4c823
      Rich Felker 提交于
      at least some assembler versions do not accept the register name lr.
      use the name x30 instead.
      94f4c823
    • R
      fix ldso name for sh-nofpu subarch · 1fb0878e
      Rich Felker 提交于
      previously it was using the same name as the default ABI with hard
      float (floating point args and return value in registers).
      
      the test __SH_FPU_ANY__ || __SH4__ matches what's used in the
      configure script already, and seems correct under casual review
      against gcc's config/sh.h, but may need tweaks. the logic for
      predefined macros for sh, and what they all mean, is very complex.
      eventually this should be documented in comments here.
      
      configure already rejects "half-hard" configurations on sh where
      double=float since these do not conform to Annex F and are not
      suitable for musl, so these do not need to be considered here.
      1fb0878e
  11. 24 4月, 2015 6 次提交
  12. 23 4月, 2015 2 次提交
  13. 22 4月, 2015 10 次提交
    • R
      minor optimization to pthread_spin_trylock · afbcac68
      Rich Felker 提交于
      use CAS instead of swap since it's lighter for most archs, and keep
      EBUSY in the lock value so that the old value obtained by CAS can be
      used directly as the return value for pthread_spin_trylock.
      afbcac68
    • R
      7b1fb0c5
    • R
      in visibility preinclude, remove overrides for stdin/stdout/stderr · b8dda24f
      Rich Felker 提交于
      the motivation for this change is that the extra declaration (with or
      without visibility) using "struct _IO_FILE" instead of "FILE" seems to
      trigger a bug in gcc 3.x where it considers the types mismatched.
      however, this change also results in slightly better code and it is
      valid because (1) these three objects are constant, and (2) applying
      the & operator to any of them is invalid C, since they are not even
      specified to be objects. thus it does not matter if the application
      and libc see different addresses for them, as long as the (initial,
      unchanging) value is seen the same by both.
      b8dda24f
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      fix inconsistent visibility for __hwcap and __sysinfo symbols · f203b351
      Rich Felker 提交于
      these are used as hidden by asm files (and such use is the whole
      reason they exist), but their actual definitions were not hidden.
      f203b351
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      remove additional libc struct accessor cruft · 3e827b7e
      Rich Felker 提交于
      commit f9cccfc1 left behind the part
      in libc.c; remove it too.
      3e827b7e
    • R
      remove useless visibility application from static-linking-only code · c267fb84
      Rich Felker 提交于
      part of the goal here is to eliminate use of the ATTR_LIBC_VISIBILITY
      macro outside of libc.h, since it was never intended to be 'public'.
      c267fb84
    • R
      9d836f44
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      remove cruft for libc struct accessor function and broken visibility · f9cccfc1
      Rich Felker 提交于
      these were hacks to work around toolchains that could not properly
      optimize PIC accesses based on visibility and would generate GOT
      lookups even for hidden data, which broke the old dynamic linker.
      since commit f3ddd173 it no longer
      matters; the dynamic linker does not assume accessibility of this data
      until stage 3.
      f9cccfc1
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      make configure check for visibility preinclude compatible with pcc · 428462a4
      Rich Felker 提交于
      pcc does not search for -include relative to the working directory
      unless -I. is used. rather than adding -I., which could be problematic
      if there's extra junk in the top-level directory, switch back to the
      old method (reverting commit 60ed988f)
      of using -include vis.h and relying on -I./src/internal being present
      on the command line (which the Makefile guarantees). to fix the
      breakage that was present in trycppif checks with the old method,
      $CFLAGS_AUTO is removed from the command line passed to trycppif; this
      is valid since $CFLAGS_AUTO should not contain options that alter
      compiler semantics or ABI, only optimizations, warnings, etc.
      428462a4
    • R
      fix duplocale clobbering of new locale struct with memcpy of old · 873e0ec7
      Rich Felker 提交于
      when the non-stub duplocale code was added as part of the locale
      framework in commit 0bc03091, the old
      code to memcpy the old locale object to the new one was left behind.
      the conditional for the memcpy no longer makes sense, because the
      conditions are now always-true when it's reached, and the memcpy is
      wrong because it clobbers the new->messages_name pointer setup just
      above.
      
      since the messages_name and ctype_utf8 members have already been
      copied, all that remains is the cat[] array. these pointers are
      volatile, so using memcpy to copy them is formally wrong; use a for
      loop instead.
      873e0ec7