1. 20 4月, 2018 8 次提交
    • R
      using malloc implementation types/macros/idioms for memalign · 3c2cbbe7
      Rich Felker 提交于
      the generated code should be mostly unchanged, except for explicit use
      of C_INUSE in place of copying the low bits from existing chunk
      headers/footers.
      
      these changes also remove mild UB due to dubious arithmetic on
      pointers into imaginary size_t[] arrays.
      3c2cbbe7
    • R
      23389b19
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      revert detection of partially-replaced allocator · 618b18c7
      Rich Felker 提交于
      commit c9f415d7 included checks to
      make calloc fallback to memset if used with a replaced malloc that
      didn't also replace calloc, and the memalign family fail if free has
      been replaced. however, the checks gave false positives for
      replacement whenever malloc or free resolved to a PLT entry in the
      main program.
      
      for now, disable the checks so as not to leave libc in a broken state.
      this means that the properties documented in the above commit are no
      longer satisfied; failure to replace calloc and the memalign family
      along with malloc is unsafe if they are ever called.
      
      the calloc checks were correct but useless for static linking. in both
      cases (simple or full malloc), calloc and malloc are in a source file
      together, so replacement of one but not the other would give linking
      errors. the memalign-family check was useful for static linking, but
      broken for dynamic as described above, and can be replaced with a
      better link-time check.
      618b18c7
    • W
      setvbuf: minor comment typo fix · 3f3cc3e9
      Will Dietz 提交于
      3f3cc3e9
    • A
      arm: use a_ll/a_sc atomics when building for ARMv6T2 · 8c2943f0
      Andre McCurdy 提交于
      ARMv6 cores with support for Thumb2 can take advantage of the "ldrex"
      and "strex" based implementations of a_ll and a_sc.
      8c2943f0
    • A
      arm: respect both __ARM_ARCH_6KZ__ and __ARM_ARCH_6ZK__ macros · 749a06b4
      Andre McCurdy 提交于
      __ARM_ARCH_6ZK__ is a gcc specific historical typo which may not be
      defined by other compilers.
      
        https://gcc.gnu.org/ml/gcc-patches/2015-07/msg02237.html
      
      To avoid unexpected results when building for ARMv6KZ with clang, the
      correct form of the macro (ie 6KZ) needs to be tested. The incorrect
      form of the macro (ie 6ZK) still needs to be tested for compatibility
      with pre-2015 versions of gcc.
      749a06b4
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      provide optimized a_ctz_32 for arm · ea489b8b
      Andre McCurdy 提交于
      Provide an ARM specific a_ctz_32 helper function for architecture
      versions for which it can be implemented efficiently via the "rbit"
      instruction (ie all Thumb-2 capable versions of ARM v6 and above).
      ea489b8b
    • A
      remove a_ctz_l from arch specific atomic_arch.h · 0c6abb58
      Andre McCurdy 提交于
      Update atomic.h to provide a_ctz_l in all cases (atomic_arch.h should
      now only provide a_ctz_32 and/or a_ctz_64).
      
      The generic version of a_ctz_32 now takes advantage of a_clz_32 if
      available and the generic a_ctz_64 now makes use of a_ctz_32.
      0c6abb58
  2. 19 4月, 2018 8 次提交
    • M
    • R
      add support for caller-provided buffers to setvbuf · 0b80a7b0
      Rich Felker 提交于
      0b80a7b0
    • R
      clean up allocation/setup logic for open_[w]memstream · 60194592
      Rich Felker 提交于
      bring these functions up to date with the current idioms we use/prefer
      in fmemopen and fopencookie.
      60194592
    • R
      clean up allocation/setup logic for fmemopen · 0b043c7b
      Rich Felker 提交于
      rather than manually performing pointer arithmetic to carve multiple
      objects out of one allocation, use a containing struct that
      encompasses them all.
      0b043c7b
    • R
      minor cleanup in fopencookie · 4245a233
      Rich Felker 提交于
      assign entire struct rather than member-at-a-time. don't repeat buffer
      sizes; always use sizeof to ensure consistency.
      4245a233
    • R
      allow interposition/replacement of allocator (malloc) · c9f415d7
      Rich Felker 提交于
      replacement is subject to conditions on the replacement functions.
      they may only call functions which are async-signal-safe, as specified
      either by POSIX or as an implementation-defined extension. if any
      allocator functions are replaced, at least malloc, realloc, and free
      must be provided. if calloc is not provided, it will behave as
      malloc+memset. any of the memalign-family functions not provided will
      fail with ENOMEM.
      
      in order to implement the above properties, calloc and __memalign
      check that they are using their own malloc or free, respectively.
      choice to check malloc or free is based on considerations of
      supporting __simple_malloc. in order to make this work, calloc is
      split into separate versions for __simple_malloc and full malloc;
      commit ba819787 already did most of
      the split anyway, and completing it saves an extra call frame.
      
      previously, use of -Bsymbolic-functions made dynamic interposition
      impossible. now, we are using an explicit dynamic-list, so add
      allocator functions to the list. most are not referenced anyway, but
      all are added for completeness.
      c9f415d7
    • R
      c1014a81
    • R
      fix stdio lock dependency on read-after-free not faulting · c21f7507
      Rich Felker 提交于
      instead of using a waiters count, add a bit to the lock field
      indicating that the lock may have waiters. threads which obtain the
      lock after contending for it will perform a potentially-spurious wake
      when they release the lock.
      c21f7507
  3. 18 4月, 2018 7 次提交
    • R
      remove unused __brk function/source file · 50202754
      Rich Felker 提交于
      commit e3bc22f1 removed all references
      to __brk.
      50202754
    • R
      enable reclaim_gaps for fdpic · d610c148
      Rich Felker 提交于
      the existing laddr function for fdpic cannot translate ELF virtual
      addresses outside of the LOAD segments to runtime addresses because
      the fdpic loadmap only covers the logically-mapped part. however the
      whole point of reclaim_gaps is to recover the slack space up to the
      page boundaries, so it needs to work with such addresses.
      
      add a new laddr_pg function that accepts any address in the page range
      for the LOAD segment by expanding the loadmap records out to page
      boundaries. only use the new version for reclaim_gaps, so as not to
      impact performance of other address lookups.
      
      also, only use laddr_pg for the start address of a gap; the end
      address lies one byte beyond the end, potentially in a different page
      where it would get mapped differently. instead of mapping end, apply
      the length (end-start) to the mapped value of start.
      d610c148
    • R
      comment __malloc_donate overflow logic · 14032c30
      Rich Felker 提交于
      14032c30
    • A
      ldso, malloc: implement reclaim_gaps via __malloc_donate · ce7ae11a
      Alexander Monakov 提交于
      Split 'free' into unmap_chunk and bin_chunk, use the latter to introduce
      __malloc_donate and use it in reclaim_gaps instead of calling 'free'.
      ce7ae11a
    • A
      malloc: fix an over-allocation bug · d889cc34
      Alexander Monakov 提交于
      Fix an instance where realloc code would overallocate by OVERHEAD bytes
      amount. Manually arrange for reuse of memcpy-free-return exit sequence.
      d889cc34
    • R
      use explicit dynamic-list rather than symbolic-functions for linking · b9410061
      Rich Felker 提交于
      we have always bound symbols at libc.so link time rather than runtime
      to minimize startup-time relocations and overhead of calls through the
      PLT, and possibly also to preclude interposition that would not work
      correctly anyway if allowed. historically, binding at link-time was
      also necessary for the dynamic linker to work, but the dynamic linker
      bootstrap overhaul in commit f3ddd173
      made it unnecessary.
      
      our use of -Bsymbolic-functions, rather than -Bsymbolic, was chosen
      because the latter is incompatible with public global data; it makes
      it incompatible with copy relocations in the main program. however,
      not all global data needs to be public. by using --dynamic-list
      instead with an explicit list, we can reduce the number of symbolic
      relocations left for runtime.
      
      this change will also allow us to permit interposition of specific
      functions (e.g. the allocator) if/when we want to, by adding them to
      the dynamic list.
      b9410061
    • R
      fix return value of nice function · 4bf0717e
      Rich Felker 提交于
      the Linux SYS_nice syscall is unusable because it does not return the
      newly set priority. always use SYS_setpriority. also avoid overflows
      in addition of inc by handling large inc values directly without
      examining the old nice value.
      4bf0717e
  4. 12 4月, 2018 2 次提交
    • A
      optimize malloc0 · 424eab22
      Alexander Monakov 提交于
      Implementation of __malloc0 in malloc.c takes care to preserve zero
      pages by overwriting only non-zero data. However, malloc must have
      already modified auxiliary heap data just before and beyond the
      allocated region, so we know that edge pages need not be preserved.
      
      For allocations smaller than one page, pass them immediately to memset.
      Otherwise, use memset to handle partial pages at the head and tail of
      the allocation, and scan complete pages in the interior. Optimize the
      scanning loop by processing 16 bytes per iteration and handling rest of
      page via memset as soon as a non-zero byte is found.
      424eab22
    • R
      fix incorrect results for catan with some inputs · 10e4bd37
      Rich Felker 提交于
      the catan implementation from OpenBSD includes a FIXME-annotated
      "overflow" branch that produces a meaningless and incorrect
      large-magnitude result. it was reachable via three paths,
      corresponding to gotos removed by this commit, in order:
      
      1. pure imaginary argument with imaginary component greater than 1 in
         magnitude. this case does not seem at all exceptional and is
         handled (at least with the quality currently expected from our
         complex math functions) by the existing non-exceptional code path.
      
      2. arguments on the unit circle, including the pure-real argument 1.0.
         these are not exceptional except for ±i, which should produce
         results with infinite imaginary component and which lead to
         computation of atan2(±0,0) in the existing non-exceptional code
         path. such calls to atan2() however are well-defined by POSIX.
      
      3. the specific argument +i. this route should be unreachable due to
         the above (2), but subtle rounding effects might have made it
         possible in rare cases. continuing on the non-exceptional code path
         in this case would lead to computing the (real) log of an infinite
         argument, then producing a NAN when multiplying it by I.
      
      for now, remove the exceptional code paths entirely. replace the
      multiplication by I with construction of a complex number using the
      CMPLX macro so that the NAN issue (3) prevented cannot arise.
      
      with these changes, catan should give reasonably correct results for
      real arguments, and should no longer give completely-wrong results for
      pure-imaginary arguments outside the interval (-i,+i).
      10e4bd37
  5. 10 4月, 2018 1 次提交
    • R
      fix wrong result in casin and many related complex functions · ae2a01da
      Rich Felker 提交于
      the factor of -i noted in the comment at the top of casin.c was
      omitted from the actual code, yielding a result rotated 90 degrees and
      propagating into errors in other functions defined in terms of casin.
      
      implement multiplication by -i as a rotation of the real and imaginary
      parts of the result, rather than by actual multiplication, since the
      latter cannot be optimized without knowledge that the operand is
      finite. here, the rotation is the actual intent, anyway.
      ae2a01da
  6. 08 4月, 2018 1 次提交
    • S
      implement wcsftime padding specifier extensions · ea81529f
      Samuel Holland 提交于
      Commit 8a6bd730 added support for
      padding specifier extensions to strftime, but did not modify wcsftime.
      In the process, it added a parameter to __strftime_fmt_1 in strftime.c,
      but failed to update the prototype in wcsftime.c. This was found by
      compiling musl with LTO:
      
          src/time/wcsftime.c:7:13: warning: type of '__strftime_fmt_1' does \
              not match original declaration [-Wlto-type-mismatch]
      
      Fix the prototype of __strftime_fmt_1 in wcsftime.c, and generate the
      'pad' argument the same way as it is done in strftime.
      ea81529f
  7. 05 4月, 2018 1 次提交
    • R
      prevent bypass of guarantee that suids start with fd 0/1/2 open · 119bc55b
      Rich Felker 提交于
      it was reported by Erik Bosman that poll fails without setting revents
      when the nfds argument exceeds the current value for RLIMIT_NOFILE,
      causing the subsequent open calls to be bypassed. if the rlimit is
      either 1 or 2, this leaves fd 0 and 1 potentially closed but openable
      when the application code is reached.
      
      based on a brief reading of the poll syscall documentation and code,
      it may be possible for poll to fail under other attacker-controlled
      conditions as well. if it turns out these are reasonable conditions
      that may happen in the real world, we may have to go back and
      implement fallbacks to probe each fd individually if poll fails, but
      for now, keep things simple and treat all poll failures as fatal.
      119bc55b
  8. 03 4月, 2018 1 次提交
    • S
      fix fmaf wrong result · 282b1cd2
      Szabolcs Nagy 提交于
      if double precision r=x*y+z is not a half way case between two single
      precision floats or it is an exact result then fmaf returns (float)r.
      
      however the exactness check was wrong when |x*y| < |z| and could cause
      incorrectly rounded result in nearest rounding mode when r is a half
      way case.
      
      fmaf(-0x1.26524ep-54, -0x1.cb7868p+11, 0x1.d10f5ep-29)
      was incorrectly rounded up to 0x1.d117ap-29 instead of 0x1.d1179ep-29.
      (exact result is 0x1.d1179efffffffecp-29, r is 0x1.d1179fp-29)
      282b1cd2
  9. 29 3月, 2018 1 次提交
    • R
      fix default feature profile in tar.h · 729fef0a
      Rich Felker 提交于
      commit d93c0740 added use of feature
      test macros without including features.h, causing a definition that
      should be exposed in the default profile, TSVTX, to appear only when
      _XOPEN_SOURCE or higher is explicitly defined.
      729fef0a
  10. 25 3月, 2018 2 次提交
    • R
      adjust makefile target-specific CFLAGS rules to be more robust & complete · c7bb9c41
      Rich Felker 提交于
      previously, MEMOPS_SRCS failed to include arch-specific replacement
      files for memcpy, etc., omitting CFLAGS_MEMOPS and thereby potentially
      causing build failure if an arch provided C (rather than asm)
      replacements for these files.
      
      instead of trying to explicitly include all the files that might have
      arch replacements, which is prone to human error, extract final names
      to be used out of $(LIBC_OBJS), where the rules for arch replacements
      have already been applied. do the same for NOSSP_OBJS, using CRT_OBJS
      and LDSO_OBJS rather than repeating ourselves with $(wildcard...) and
      explicit pathnames again.
      c7bb9c41
    • R
      fix out-of-tree build of crt files with stack protector enabled · a7c53e0c
      Rich Felker 提交于
      the makefile logic for these files was wrong in the out-of-tree case,
      but it likely only affected the "all" level of stack protector.
      a7c53e0c
  11. 13 3月, 2018 1 次提交
    • R
      explicitly use signed keyword to define intNN_t and derivative types · 919ad8d5
      Rich Felker 提交于
      standing alone, both the signed and int keywords identify the same
      type, a (signed) int. however the C language has an exception where,
      when the lone keyword int is used to declare a bitfield, it's
      implementation-defined whether the bitfield is signed or unsigned. C11
      footnote 125 extends this implementation-definedness to typedefs, and
      DR#315 extends it to other integer types (for which support with
      bitfields is implementation-defined).
      
      while reasonable ABIs (all the ones we support) define bitfields as
      signed by default, GCC and compatible compilers offer an option
      -funsigned-bitfields to change the default. while any signed types
      defined without explicit use of the signed keyword are affected, the
      stdint.h types, especially intNN_t, have a natural use in bitfields.
      ensure that bitfields defined with these types always have the correct
      signedness regardless of compiler & flags used.
      
      see also GCC PR 83294.
      919ad8d5
  12. 11 3月, 2018 7 次提交