A large number of the test-ldouble failures seen for ldbl-128ibm are
spurious "underflow" and "inexact" exceptions. These arise from such
exceptions in the underlying arithmetic; unlike other spurious
exceptions from that arithmetic, they do not in general relate to
cases where the returned result is also substantially inaccurate, are
not so readily avoidable by appropriately conditional libgcc patches,
and are widespread enough to be hard to handle through individual
XFAILing of the affected tests.
Thus, this patch documents relaxed accuracy goals for libm functions
for IBM long double and makes libm-test.inc reflect these spurious
exceptions in ldbl-128ibm arithmetic and always allow them in
ldbl-128ibm testing (while still not allowing these exceptions to be
missing where required to be present). Tested for powerpc.
* manual/math.texi (Errors in Math Functions): Document relaxed
accuracy goals for IBM long double.
* math/libm-test.inc (test_exceptions): Always allow spurious
"underflow" and "inexact" exceptions for IBM long double.
index_* and bit_* macros are used to access cpuid and feature arrays o
struct cpu_features. It is very easy to use bits and indices of cpuid
array on feature array, especially in assembly codes. For example,
sysdeps/i386/i686/multiarch/bcopy.S has
HAS_CPU_FEATURE (Fast_Rep_String)
which should be
HAS_ARCH_FEATURE (Fast_Rep_String)
We change index_* and bit_* to index_cpu_*/index_arch_* and
bit_cpu_*/bit_arch_* so that we can catch such error at build time.
[BZ #19762]
* sysdeps/unix/sysv/linux/x86_64/64/dl-librecon.h
(EXTRA_LD_ENVVARS): Add _arch_ to index_*/bit_*.
* sysdeps/x86/cpu-features.c (init_cpu_features): Likewise.
* sysdeps/x86/cpu-features.h (bit_*): Renamed to ...
(bit_arch_*): This for feature array.
(bit_*): Renamed to ...
(bit_cpu_*): This for cpu array.
(index_*): Renamed to ...
(index_arch_*): This for feature array.
(index_*): Renamed to ...
(index_cpu_*): This for cpu array.
[__ASSEMBLER__] (HAS_FEATURE): Add and use field.
[__ASSEMBLER__] (HAS_CPU_FEATURE)): Pass cpu to HAS_FEATURE.
[__ASSEMBLER__] (HAS_ARCH_FEATURE)): Pass arch to HAS_FEATURE.
[!__ASSEMBLER__] (HAS_CPU_FEATURE): Replace index_##name and
bit_##name with index_cpu_##name and bit_cpu_##name.
[!__ASSEMBLER__] (HAS_ARCH_FEATURE): Replace index_##name and
bit_##name with index_arch_##name and bit_arch_##name.
In makecontext the FDE needs to be terminated before the return
trampoline otherwise backtrace called within a context created by
makecontext yields infinite backtrace.
This bug has been present for a long time, stdlib/tst-makecontext did
not fail until recent commit e535ce25. Tested on mips-linux-gnu and
mips64el-linux-gnuabi64 and mips-linux-gnu, no regression.
This fixes stdlib/tst-makecontext on MIPS.
Changelog:
[BZ #19792]
* sysdeps/unix/sysv/linux/mips/makecontext.S (__makecontext):
Terminate FDE before return label.
The ldbl-128ibm implementation of nearbyintl uses logic that only
works in round-to-nearest mode. This contrasts with rintl, which
works in all rounding modes.
Now, arguably nearbyintl could simply be aliased to rintl, given that
spurious "inexact" is generally allowed for ldbl-128ibm, even for the
underlying arithmetic operations. But given that the only point of
nearbyintl is to avoid "inexact", this patch follows the more
conservative approach of adding conditionals to the rintl
implementation to make it suitable for use to implement nearbyintl,
then builds it for nearbyintl with USE_AS_NEARBYINTL defined. The
test test-nearbyint-except-2 shows up issues when traps on "inexact"
are enabled, which turn out to be problems with the powerpc
fenv_private.h implementation (two functions that should disable
exception traps potentially failing to do so in some cases); this
patch duly fixes that as well (I don't see any other existing cases
where this would be user-visible; there isn't much use of *_NOEX,
*hold* etc. in libm that requires exceptions to be discarded and not
trapped on).
Tested for powerpc.
[BZ #19790]
* sysdeps/ieee754/ldbl-128ibm/s_rintl.c [USE_AS_NEARBYINTL]
(rintl): Define as macro.
[USE_AS_NEARBYINTL] (__rintl): Likewise.
(__rintl) [USE_AS_NEARBYINTL]: Use SET_RESTORE_ROUND_NOEX instead
of fesetround. Ensure results are evaluated before end of scope.
* sysdeps/ieee754/ldbl-128ibm/s_nearbyintl.c: Define
USE_AS_NEARBYINTL and include s_rintl.c.
* sysdeps/powerpc/fpu/fenv_private.h (libc_feholdsetround_ppc):
Disable exception traps in new environment.
(libc_feholdsetround_ppc_ctx): Likewise.
The GNU libc testsuite fails to build on powerpc/ppc64/ppc64le with the
following error:
../sysdeps/powerpc/test-get_hwcap.c:26:22: fatal error: sys/auxv.h: No such file or director
This is because test-get_hwcap.c includes <sys/auxv.h>, but we don't
provide a wrapper in include/sys. This patch adds one.
Changelog:
* include/sys/auxv.h: New file.
Since x86 has an optimized mempcpy and GCC can inline mempcpy on x86,
define _HAVE_STRING_ARCH_mempcpy to 1 for x86.
[BZ #19759]
* sysdeps/x86/bits/string.h (_HAVE_STRING_ARCH_mempcpy): New.
The operand modifier %s on powerpc is an undocumented internal implementation
detail of GCC. Besides that, the GCC community wants to remove it. This patch
rewrites the expressions that use this modifier with logically equivalent
expressions that don't require it.
Explanation for the substitution:
The %s modifier takes an immediate operand and prints 32 less such immediate.
Thus, in the previous code, the expression resulted in:
32 - __builtin_ffs(e)
where e was guaranteed to have exactly a single bit set, by the following
expressions:
(e & (e-1) == 0) : e has at most one bit set.
(e != 0) : e is not zero, thus it has at least one bit set.
Since we guarantee that there is exactly only one bit set, the following
statement is true:
32 - __builtin_ffs(e) == __builtin_clz(e)
Thus, we can replace __builtin_ffs with __builtin_clz and remove the %s operand
modifier.
HWCAP-related code should had been updated when the 32 bits of HWCAP were
used. This patch updates the code in dl-procinfo.h to loop through all
the 32 bits in HWCAP and updates _dl_powerpc_cap_flags accordingly.
benchtests should use $(test-via-rtld-prefix) and $(+link-tests) like
other glibc tests.
[BZ #19783]
* benchtests/Makefile (run-bench): Replace $(rtld-prefix) with
$(test-via-rtld-prefix).
($(binaries-bench)): Replace $(+link) with $(+link-tests).
This patch fixes the posix/tst-execvpe5 invocation when GLIBC is
configured with --enable-hardcoded-path-in-tests which fails with:
$ cat posix/tst-execvpe5.out
Wrong number of arguments (4)
Checked on x86-64 and powerpc64le.
* posix/tst-execvpe5.c (do_test): Fix fix test invocation when
configured with --enable-hardcoded-path-in-tests.
The ldbl-128ibm implementation of remainderl has logic resulting in
incorrect tests for equality of the absolute values of the arguments
in the case of zero low parts. If the low parts are both zero but
with different signs, this can wrongly cause equal arguments to be
treated as different, resulting in turn in incorrect signs of zero
result in nondefault rounding modes arising from the subtractions done
when the arguments are not equal.
This patch fixes the logic to convert -0 low parts into +0 before the
comparison (remquo already has separate logic to deal with signs of
zero results, so doesn't need such a change). Tests are added for
remainderl and remquol similar to that for fmodl, and based on a
refactoring of it, since the bug depends on low parts which should not
be relied upon in tests not setting the representation explicitly
(although in fact the bug shows up in test-ldouble with current GCC).
Tested for powerpc.
[BZ #19677]
* sysdeps/ieee754/ldbl-128ibm/e_remainderl.c
(__ieee754_remainderl): Put zero low parts in canonical form.
* sysdeps/ieee754/ldbl-128ibm/test-fmodrem-ldbl-128ibm.c: New
file. Based on
sysdeps/ieee754/ldbl-128ibm/test-fmodl-ldbl-128ibm.c.
* sysdeps/ieee754/ldbl-128ibm/test-fmodl-ldbl-128ibm.c: Replace
with wrapper round test-fmodrem-ldbl-128ibm.c.
* sysdeps/ieee754/ldbl-128ibm/test-remainderl-ldbl-128ibm.c: New
file.
* sysdeps/ieee754/ldbl-128ibm/test-remquol-ldbl-128ibm.c:
Likewise.
* sysdeps/ieee754/ldbl-128ibm/Makefile (tests): Add
test-remainderl-ldbl-128ibm and test-remquol-ldbl-128ibm.
When using sln on some filesystems which return 64-bit inodes,
the stat call might fail during install like so:
.../elf/sln .../elf/symlink.list
/lib32/libc.so.6: invalid destination: Value too large for defined data type
/lib32/ld-linux.so.2: invalid destination: Value too large for defined data type
Makefile:104: recipe for target 'install-symbolic-link' failed
Switch to using stat64 all the time to avoid this.
URL: https://bugs.gentoo.org/576396
With older kernels, it is mostly ineffective because it causes malloc
to switch from sbrk to mmap (potentially invalidating malloc testing
compared to what real appliations do). With newer kernels which
have switched to enforcing RLIMIT_DATA for mmap as well, some test
cases will fail in an unintended fashion because the limit which was
set previously does not include room for all mmap mappings.
This patch implements a new posix_spawn{p} implementation for Linux. The main
difference is it uses the clone syscall directly with CLONE_VM and CLONE_VFORK
flags and a direct allocated stack. The new stack and start function solves
most the vfork limitation (possible parent clobber due stack spilling). The
remaning issue are related to signal handling:
1. That no signal handlers must run in child context, to avoid corrupt
parent's state.
2. Child must synchronize with parent to enforce stack deallocation and
to possible return execv issues.
The first one is solved by blocking all signals in child, even NPTL-internal
ones (SIGCANCEL and SIGSETXID). The second issue is done by a stack allocation
in parent and a synchronization with using a pipe or waitpid (in case or error).
The pipe has the advantage of allowing the child signal an exec error (checked
with new tst-spawn2 test).
There is an inherent race condition in pipe2 usage for architectures that do not
support the syscall directly. In such cases the a pipe plus fctnl is used
instead and it may lead to file descriptor leak in parent (as decribed by fcntl
documentation).
The child process stack is allocate with a mmap with MAP_STACK flag using
default architecture stack size. Although it is slower than use a stack buffer
from parent, it allows some slack for the compatibility code to run scripts
with no shebang (which may use a buffer with size depending of argument list
count).
Performance should be similar to the vfork default posix implementation and
way faster than fork path (vfork on mostly linux ports are basically
clone with CLONE_VM plus CLONE_VFORK). The only difference is the syscalls
required for the stack allocation/deallocation.
It fixes BZ#10354, BZ#14750, and BZ#18433.
Tested on i386, x86_64, powerpc64le, and aarch64.
[BZ #14750]
[BZ #10354]
[BZ #18433]
* include/sched.h (__clone): Add hidden prototype.
(__clone2): Likewise.
* include/unistd.h (__dup): Likewise.
* posix/Makefile (tests): Add tst-spawn2.
* posix/tst-spawn2.c: New file.
* sysdeps/posix/dup.c (__dup): Add hidden definition.
* sysdeps/unix/sysv/linux/aarch64/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/alpha/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/arm/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/hppa/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/i386/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/ia64/clone2.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/m68k/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/microblaze/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/mips/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/nios2/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S (__clone):
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S (__clone):
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/sh/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/tile/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/x86_64/clone.S (__clone): Likewise.
* sysdeps/unix/sysv/linux/nptl-signals.h
(____nptl_is_internal_signal): New function.
* sysdeps/unix/sysv/linux/spawni.c: New file.
This patch removes all the dynamic allocation on execvpe code and
instead use direct stack allocation. This is QoI approach to make
it possible use in scenarios where memory is shared with parent
(vfork or clone with CLONE_VM).
For default process spawn (script file without a shebang), stack
allocation is bounded by NAME_MAX plus PATH_MAX plus 1. Large
file arguments returns an error (ENAMETOOLONG). This differs than
current GLIBC pratice in general, but it used to limit stack
allocation for large inputs. Also, path in PATH environment variable
larger than PATH_MAX are ignored.
The shell direct execution exeception, where execve returns ENOEXEC,
might requires a large stack allocation due large input argument list.
Tested on i686, x86_64, powerpc64le, and aarch64.
* posix/execvpe.c (__execvpe): Remove dynamic allocation.
* posix/Makefile (tests): Add tst-execvpe{1,2,3,4,5,6}.
* posix/tst-execvp1.c (do_test): Use a macro to call execvp.
* posix/tst-execvp2.c (do_test): Likewise.
* posix/tst-execvp3.c (do_test): Likewise.
* posix/tst-execvp4.c (do_test): Likewise.
* posix/tst-execvpe1.c: New file.
* posix/tst-execvpe2.c: Likewise.
* posix/tst-execvpe3.c: Likewise.
* posix/tst-execvpe4.c: Likewise.
* posix/tst-execvpe5.c: Likewise.
* posix/tst-execvpe6.c: Likewise.
GLIBC execl{e,p} implementation might use malloc if the total number of
arguments exceed initial assumption size (1024). This might lead to
issues in two situations:
1. execl/execle is stated to be async-signal-safe by POSIX [1]. However
if execl is used in a signal handler with a large argument set (that
may call malloc internally) and if the resulting call fails it might
lead malloc in the program in a bad state.
2. If the functions are used in a vfork/clone(VFORK) situation it also
might issue malloc internal bad state.
This patch fixes it by using stack allocation instead. It also fixes
BZ#19534.
Tested on x86_64.
[1] http://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html
[BZ #19534]
* posix/execl.c (execl): Remove dynamic memory allocation.
* posix/execle.c (execle): Likewise.
* posix/execlp.c (execlp): Likewise.
Since we have loaded address of PREINIT_FUNCTION into %rax, we can
avoid extra branch to PLT slot.
[BZ #19745]
* sysdeps/x86_64/crti.S (_init): Replace PREINIT_FUNCTION@PLT
with *%rax in call.
Since __libc_start_main is called very early, lazy binding isn't relevant
here. Use indirect branch via GOT to avoid extra branch to PLT slot.
[BZ #19745]
* sysdeps/x86_64/start.S (_start): __libc_start_main@PLT
with *__libc_start_main@GOTPCREL(%rip) in call.
Chek Fast_Unaligned_Load, instead of Slow_BSF, and also check for
Fast_Copy_Backward to enable __memcpy_ssse3_back. Existing selection
order is updated with following selection order:
1. __memcpy_avx_unaligned if AVX_Fast_Unaligned_Load bit is set.
2. __memcpy_sse2_unaligned if Fast_Unaligned_Load bit is set.
3. __memcpy_sse2 if SSSE3 isn't available.
4. __memcpy_ssse3_back if Fast_Copy_Backward bit it set.
5. __memcpy_ssse3
[BZ #18880]
* sysdeps/x86_64/multiarch/memcpy.S: Check Fast_Unaligned_Load,
instead of Slow_BSF, and also check for Fast_Copy_Backward to
enable __memcpy_ssse3_back.
We should turn on bit_Prefer_MAP_32BIT_EXEC in EXTRA_LD_ENVVARS without
overriding other bits.
[BZ #19758]
* sysdeps/unix/sysv/linux/x86_64/64/dl-librecon.h
(EXTRA_LD_ENVVARS): Or bit_Prefer_MAP_32BIT_EXEC.
No need to compile x86_64 _mcount.S with -pg. We can just copy the
normal static object.
* gmon/Makefile (noprof): Add $(sysdep_noprof).
* sysdeps/x86_64/Makefile (sysdep_noprof): Add _mcount.
Since __mcount_internal and __sigjmp_save are internal to x86-64 libc.so:
3532: 0000000000104530 289 FUNC LOCAL DEFAULT 13 __mcount_internal
3391: 0000000000034170 38 FUNC LOCAL DEFAULT 13 __sigjmp_save
they can be called directly without PLT.
* sysdeps/x86_64/_mcount.S (C_LABEL(_mcount)): Call
__mcount_internal directly.
(C_LABEL(__fentry__)): Likewise.
* sysdeps/x86_64/setjmp.S __sigsetjmp): Call __sigjmp_save
directly.
In 1999 the project split "localedir" into "localedir" (path to compiled
locale archives) and "msgcatdir" (path to message catalogs). This
predates the 2002 change in the GNU Coding Standard to document the use
of "localedir" for the path to the message catalogs. It appears that
newlib, gcc, and several other projects also used "msgcatdir" at one
point or another in the past, and so it is in line with historical
precedent that glibc would also use "msgcatdir." However, given that the
GNU Coding Standard uses "localedir", we will switch to that for
consistency as a GNU project. Previous uses of --localdir didn't work
anyway (see bug 14259).
I am committing this patch in the understanding that nobody would object
to fixing #14259 as part of aligning our variable usage to the GNU
Coding Standard.
Given that previous "localedir" uses were converted to "complocaledir"
by [1], we can now convert "msgcatdir" to "localedir" and complete the
transition. With an addition to config.make.in we also fix bug 14259 and
allow users to specify the locale dependent data directory with
"--localedir" at configure time. There is still no way to control at
configure time the location of the *compiled* locale directory.
Tested on x86_64 with no regressions.
Tested using "--localedir" to specify alternate locale dependent data
directory and verified with "make install DESTDIR=/tmp/glibc".
[1] 90fe682d30
Now we require Linux 3.2 or later kernel headers everywhere, the
configure test for <linux/fanotify.h> is obsolete; this patch removes
it.
Tested for x86_64.
* sysdeps/unix/sysv/linux/configure.ac (linux/fanotify.h): Do not
test for header.
* sysdeps/unix/sysv/linux/configure: Regenerated.
* config.h.in (HAVE_LINUX_FANOTIFY_H): Remove #undef.
* sysdeps/unix/sysv/linux/tst-fanotify.c [!HAVE_LINUX_FANOTIFY_H]:
Remove conditional code.
[HAVE_LINUX_FANOTIFY_H]: Make code unconditional.
In <https://sourceware.org/ml/libc-alpha/2016-01/msg00885.html> I
proposed a minimum Linux kernel version of 3.2 for glibc 2.24, since
Linux 2.6.32 has reached EOL.
In the discussion in February, some concerns were expressed about
compatibility with OpenVZ containers. It's not clear that these are
real issues, given OpenVZ backporting kernel features and faking the
kernel version for guest software, as discussed in
<https://sourceware.org/ml/libc-alpha/2016-02/msg00278.html>. It's
also not clear that supporting running GNU/Linux distributions from
late 2016 (at the earliest) on a kernel series from 2009 is a sensible
expectation. However, as an interim step, this patch increases the
requirement everywhere except x86 / x86_64 (since the controversy was
only about those architectures); the special caveats and settings can
easily be removed later when we're ready to increase the requirements
on x86 / x86_64 (and if someone would like to raise the issue on LWN
as suggested in the previous discussion, that would be welcome). 3.2
kernel headers are required everywhere by this patch.
(x32 already requires 3.4 or later, so is unaffected by this patch.)
As usual for such a change, this patch only changes the configure
scripts and associated documentation. The intent is to follow up with
removal of dead __LINUX_KERNEL_VERSION conditionals. Each __ASSUME_*
or other macro that becomes dead can then be removed independently.
Tested for x86_64 and x86.
* sysdeps/unix/sysv/linux/configure.ac (LIBC_LINUX_VERSION):
Define to 3.2.0.
(arch_minimum_kernel): Likewise.
* sysdeps/unix/sysv/linux/configure: Regenerated.
* sysdeps/unix/sysv/linux/i386/configure.ac (arch_minimum_kernel):
Define to 2.6.32.
* sysdeps/unix/sysv/linux/i386/configure: Regenerated.
* sysdeps/unix/sysv/linux/x86_64/64/configure.ac
(arch_minimum_kernel): Define to 2.6.32.
* sysdeps/unix/sysv/linux/x86_64/64/configure: Regenerated.
* README: Document Linux 3.2 requirement.
* manual/install.texi (Linux): Document Linux 3.2 headers
requirement.
* INSTALL: Regenerated.
HAVE_BUILTIN_EXPECT macro was removed by commit glibc-2.14-280-g3ce1f29,
but then its use was unintentionally reintroduced during merge with GNU
gettext 0.19.3 by commit glibc-2.20-324-g6d24885, effectively disabling
all optimization based on __builtin_expect. As intl files are also part
of GNU gettext, HAVE_BUILTIN_EXPECT macro cannot be removed, so define
it unconditionally in config.h.in instead.
[BZ #19512]
* config.h.in (HAVE_BUILTIN_EXPECT): New macro.
The build of posix/tst-dir.c fails due to undefined DIAG_* macros.
The usage of the macros were introduced in recent commit
7584a3f96d
"Deprecate readdir_r, readdir64_r [BZ #19056]".
This patch adds the missing header libc-internal.h.
Due to GCC bug:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066
__tls_get_addr may be called with 8-byte stack alignment. Although
this bug has been fixed in GCC 4.9.4, 5.3 and 6, we can't assume
that stack will be always aligned at 16 bytes. Since SSE optimized
memory/string functions with aligned SSE register load and store are
used in the dynamic linker, we must set DL_RUNTIME_UNALIGNED_VEC_SIZE
to 8 so that _dl_runtime_resolve_sse will align the stack before
calling _dl_fixup:
Dump of assembler code for function _dl_runtime_resolve_sse:
0x00007ffff7deea90 <+0>: push %rbx
0x00007ffff7deea91 <+1>: mov %rsp,%rbx
0x00007ffff7deea94 <+4>: and $0xfffffffffffffff0,%rsp
^^^^^^^^^^^ Align stack to 16 bytes
0x00007ffff7deea98 <+8>: sub $0x100,%rsp
0x00007ffff7deea9f <+15>: mov %rax,0xc0(%rsp)
0x00007ffff7deeaa7 <+23>: mov %rcx,0xc8(%rsp)
0x00007ffff7deeaaf <+31>: mov %rdx,0xd0(%rsp)
0x00007ffff7deeab7 <+39>: mov %rsi,0xd8(%rsp)
0x00007ffff7deeabf <+47>: mov %rdi,0xe0(%rsp)
0x00007ffff7deeac7 <+55>: mov %r8,0xe8(%rsp)
0x00007ffff7deeacf <+63>: mov %r9,0xf0(%rsp)
0x00007ffff7deead7 <+71>: movaps %xmm0,(%rsp)
0x00007ffff7deeadb <+75>: movaps %xmm1,0x10(%rsp)
0x00007ffff7deeae0 <+80>: movaps %xmm2,0x20(%rsp)
0x00007ffff7deeae5 <+85>: movaps %xmm3,0x30(%rsp)
0x00007ffff7deeaea <+90>: movaps %xmm4,0x40(%rsp)
0x00007ffff7deeaef <+95>: movaps %xmm5,0x50(%rsp)
0x00007ffff7deeaf4 <+100>: movaps %xmm6,0x60(%rsp)
0x00007ffff7deeaf9 <+105>: movaps %xmm7,0x70(%rsp)
[BZ #19679]
* sysdeps/x86_64/dl-trampoline.S (DL_RUNIME_UNALIGNED_VEC_SIZE):
Renamed to ...
(DL_RUNTIME_UNALIGNED_VEC_SIZE): This. Set to 8.
(DL_RUNIME_RESOLVE_REALIGN_STACK): Renamed to ...
(DL_RUNTIME_RESOLVE_REALIGN_STACK): This. Updated.
(DL_RUNIME_RESOLVE_REALIGN_STACK): Renamed to ...
(DL_RUNTIME_RESOLVE_REALIGN_STACK): This.
* sysdeps/x86_64/dl-trampoline.h
(DL_RUNIME_RESOLVE_REALIGN_STACK): Renamed to ...
(DL_RUNTIME_RESOLVE_REALIGN_STACK): This.
The following new 386 and X86_64 were added to binutils. They are
non-dynamic relocations, so don't need direct handling in glibc.
But other programs, like elfutils, use the glibc elf.h definitions
for the names and numbers when inspecting ET_REL files.
R_386_GOT32X was proposed in
https://groups.google.com/forum/#!topic/ia32-abi/GbJJskkid4I
X86_64_GOTPCRELX and R_X86_64_REX_GOTPCRELX were proposed in
https://groups.google.com/forum/#!topic/x86-64-abi/n9AWHogmVY0
There also used to be R_X86_64_PC32_BND and R_X86_64_PLT32_BND
but those already got deprecated in
https://groups.google.com/d/msg/x86-64-abi/-hdQyMixt8Y/XFDOvioG85cJ
* elf/elf.h (R_386_GOT32X): New.
(R_386_NUM): Update.
(R_X86_64_GOTPCRELX: New.
(R_X86_64_REX_GOTPCRELX): New.
(R_X86_64_NUM): Update.
The vast majority of timeouts I've seen w/glibc tests are due to:
- slow system (e.g. <1 GHz cpu)
- loaded system (e.g. lots of parallelism)
Even then, I've seen timeouts on system I don't generally consider
slow, or even loaded, and considering TIMEOUT is set to <=10 in ~60
tests (and <=20 in ~75 tests), it seems I'm not alone. I've just
gotten in the habit of doing `export TIMEOUTFACTOR=10` on all my
setups.
In the edge case where there is a bug in the test and the timeout is
hit, I think we all agree that's either a problem with the test or a
real bug in the library somewhere. In either case, the incident rate
should be low, so catering to that seems like the wrong trade-off.
Other developers too usually set large timeout factors. Increase the
default to 20 seconds to match reality.
The ldbl-128ibm implementation of nextafterl / nexttowardl returns -0
in FE_DOWNWARD mode when taking the next value below the least
positive subnormal, when it should return +0. This patch fixes it to
check explicitly for this case.
Tested for powerpc.
[BZ #19678]
* sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c (__nextafterl):
Ensure +0.0 is returned when taking the next value below the least
positive value.
The ldbl-128ibm implementation of powl has some problems in the case
of overflow or underflow, which are mainly visible in non-default
rounding modes.
* When overflow or underflow is detected early, the correct sign of an
overflowing or underflowing result is not allowed for. This is
mostly hidden in the default rounding mode by the errno-setting
wrappers recomputing the result (except in non-default
error-handling modes such as -lieee), but visible in other rounding
modes where a result that is not zero or infinity causes the
wrappers not to do the recomputation.
* The final scaling is done before the sign is incorporated in the
result, but should be done afterwards for correct overflowing and
underflowing results in directed rounding modes.
This patch fixes those problems. Tested for powerpc.
[BZ #19674]
* sysdeps/ieee754/ldbl-128ibm/e_powl.c (__ieee754_powl): Include
sign in overflowing and underflowing results when overflow or
underflow is detected early. Include sign in result before rather
than after scaling.
The ldbl-128ibm implementations of remainderl and remquol have logic
resulting in incorrect tests for equality of the absolute values of
the arguments. Equality is tested based on the integer
representations of the high and low parts, with the sign bit masked
off the high part - but when this changes the sign of the high part,
the sign of the low part needs to be changed as well, and failure to
do this means arguments are wrongly treated as equal when they are
not.
This patch fixes the logic to adjust signs of low parts as needed.
Tested for powerpc.
[BZ #19603]
* sysdeps/ieee754/ldbl-128ibm/e_remainderl.c
(__ieee754_remainderl): Adjust sign of integer version of low part
when taking absolute value of high part.
* sysdeps/ieee754/ldbl-128ibm/s_remquol.c (__remquol): Likewise.
* math/libm-test.inc (remainder_test_data): Add another test.
(remquo_test_data): Likewise.
The ldbl-128ibm implementation of fmodl has logic to detect when the
first argument has absolute value less than or equal to the second.
This logic is only correct for nonzero low parts; if the high parts
are equal and the low parts are zero, then the signs of the low parts
(which have no semantic effect on the value of the long double number)
can result in equal values being wrongly treated as unequal, and an
incorrect result being returned from fmodl. This patch fixes this by
checking for the case of zero low parts.
Although this does show up in tests from libm-test.inc (both tests of
fmodl, and, indirectly, of remainderl / dreml), the dependence on
non-semantic zero low parts means that test shouldn't be expected to
reproduce it reliably; thus, this patch adds a standalone test that
sets up affected values using unions.
Tested for powerpc.
[BZ #19602]
* sysdeps/ieee754/ldbl-128ibm/e_fmodl.c (__ieee754_fmodl): Handle
equal high parts and both low parts zero specially.
* sysdeps/ieee754/ldbl-128ibm/test-fmodl-ldbl-128ibm.c: New test.
* sysdeps/ieee754/ldbl-128ibm/Makefile [$(subdir) = math] (tests):
Add test-fmodl-ldbl-128ibm.
The ldbl-128ibm implementation of fmodl has completely bogus logic for
subnormal results (in this context, that means results for which the
result is in the subnormal range for double, not results with absolute
value below LDBL_MIN), based on code used for ldbl-128 that is correct
in that case but incorrect in the ldbl-128ibm use. This patch fixes
it to convert the mantissa into the correct form expected by
ldbl_insert_mantissa, removing the other cases of the code that were
incorrect and in one case unreachable for ldbl-128ibm. A correct
exponent value is then passed to ldbl_insert_mantissa to reflect the
shifted result.
Tested for powerpc.
[BZ #19595]
* sysdeps/ieee754/ldbl-128ibm/e_fmodl.c (__ieee754_fmodl): Use
common logic for all cases of shifting subnormal results. Do not
insert sign bit in shifted mantissa. Always pass -1023 as biased
exponent to ldbl_insert_mantissa in subnormal case.
The ldbl-128ibm implementation of roundl is only correct in
round-to-nearest mode (in other modes, there are incorrect results and
overflow exceptions in some cases). This patch reimplements it along
the lines used for floorl, ceill and truncl, using __round on the high
part, and on the low part if the high part is an integer, and then
adjusting in the cases where this is incorrect.
Tested for powerpc.
[BZ #19594]
* sysdeps/ieee754/ldbl-128ibm/s_roundl.c (__roundl): Use __round
on high and low parts then adjust result and use
ldbl_canonicalize_int if needed.
The ldbl-128ibm implementation of truncl is only correct in
round-to-nearest mode (in other modes, there are incorrect results and
overflow exceptions in some cases). It is also unnecessarily
complicated, rounding both high and low parts to the nearest integer
and then adjusting for the semantics of trunc, when it seems more
natural to take the truncation of the high part (__trunc optimized
inline versions can be used), and the floor or ceiling of the low part
(depending on the sign of the high part) if the high part is an
integer, as was done for floorl and ceill. This patch makes it use
that simpler approach.
Tested for powerpc.
[BZ #19593]
* sysdeps/ieee754/ldbl-128ibm/s_truncl.c (__truncl): Use __trunc
on high part and __floor or __ceil on low part then use
ldbl_canonicalize_int if needed.
The ldbl-128ibm implementation of ceill is only correct in
round-to-nearest mode (in other modes, there are incorrect results and
overflow exceptions in some cases). It is also unnecessarily
complicated, rounding both high and low parts to the nearest integer
and then adjusting for the semantics of ceil, when it seems more
natural to take the ceiling of the high part (__ceil optimized inline
versions can be used), and that of the low part if the high part is an
integer, as was done for floorl. This patch makes it use that simpler
approach.
Tested for powerpc.
[BZ #19592]
* sysdeps/ieee754/ldbl-128ibm/s_ceill.c (__ceill): Use __ceil on
high and low parts then use ldbl_canonicalize_int if needed.
The ldbl-128ibm implementation of floorl is only correct in
round-to-nearest mode (in other modes, there are incorrect results and
overflow exceptions in some cases going beyond the incorrect signs of
zero results noted in bug 17899). It is also unnecessarily
complicated, rounding both high and low parts to the nearest integer
and then adjusting for the semantics of floor, when it seems more
natural to take the floor of the high part (__floor optimized inline
versions can be used), and that of the low part if the high part is an
integer. This patch makes it use that simpler approach, with a
canonicalization that works in all rounding modes (given that the only
way the result can be noncanonical is if taking the floor of a
negative noninteger low part increased its exponent).
Tested for powerpc, where over a thousand failures are removed from
test-ldouble.out (floorl problems affect many powl tests).
[BZ #17899]
* sysdeps/ieee754/ldbl-128ibm/math_ldbl.h (ldbl_canonicalize_int):
New function.
* sysdeps/ieee754/ldbl-128ibm/s_floorl.c (__floorl): Use __floor
on high and low parts then use ldbl_canonicalize_int if needed.
As discussed in
https://sourceware.org/ml/libc-alpha/2015-10/msg00403.html
the setting of _STRING_ARCH_unaligned currently controls the external
GLIBC ABI as well as selecting the use of unaligned accesses withing
GLIBC.
Since _STRING_ARCH_unaligned was recently changed for AArch64, this
would potentially break the ABI in GLIBC 2.23, so split the uses and add
_STRING_INLINE_unaligned to select the string ABI. This setting must be
fixed for each target, while _STRING_ARCH_unaligned may be changed from
release to release. _STRING_ARCH_unaligned is used unconditionally in
glibc. But <bits/string.h>, which defines _STRING_ARCH_unaligned, isn't
included with -Os. Since _STRING_ARCH_unaligned is internal to glibc and
may change between glibc releases, it should be made private to glibc.
_STRING_ARCH_unaligned should defined in the new string_private.h heade
file which is included unconditionally from internal <string.h> for glibc
build.
[BZ #19462]
* bits/string.h (_STRING_ARCH_unaligned): Renamed to ...
(_STRING_INLINE_unaligned): This.
* include/string.h: Include <string_private.h>.
* string/bits/string2.h: Replace _STRING_ARCH_unaligned with
_STRING_INLINE_unaligned.
* sysdeps/aarch64/bits/string.h (_STRING_ARCH_unaligned): Removed.
(_STRING_INLINE_unaligned): New.
* sysdeps/aarch64/string_private.h: New file.
* sysdeps/generic/string_private.h: Likewise.
* sysdeps/m68k/m680x0/m68020/string_private.h: Likewise.
* sysdeps/s390/string_private.h: Likewise.
* sysdeps/x86/string_private.h: Likewise.
* sysdeps/m68k/m680x0/m68020/bits/string.h
(_STRING_ARCH_unaligned): Renamed to ...
(_STRING_INLINE_unaligned): This.
* sysdeps/s390/bits/string.h (_STRING_ARCH_unaligned): Renamed
to ...
(_STRING_INLINE_unaligned): This.
* sysdeps/sparc/bits/string.h (_STRING_ARCH_unaligned): Renamed
to ...
(_STRING_INLINE_unaligned): This.
* sysdeps/x86/bits/string.h (_STRING_ARCH_unaligned): Renamed
to ...
(_STRING_INLINE_unaligned): This.
Since libmvec_nonshared.a may be linked into shared objects, ALIAS_IMPL
should use PIC relocation.
[BZ #19590]
* sysdeps/x86_64/fpu/svml_finite_alias.S (ALIAS_IMPL): Use PIC
relocation.
* A stack-based buffer overflow was found in libresolv when invoked from
libnss_dns, allowing specially crafted DNS responses to seize control
of execution flow in the DNS client. The buffer overflow occurs in
the functions send_dg (send datagram) and send_vc (send TCP) for the
NSS module libnss_dns.so.2 when calling getaddrinfo with AF_UNSPEC
family. The use of AF_UNSPEC triggers the low-level resolver code to
send out two parallel queries for A and AAAA. A mismanagement of the
buffers used for those queries could result in the response of a query
writing beyond the alloca allocated buffer created by
_nss_dns_gethostbyname4_r. Buffer management is simplified to remove
the overflow. Thanks to the Google Security Team and Red Hat for
reporting the security impact of this issue, and Robert Holiday of
Ciena for reporting the related bug 18665. (CVE-2015-7547)
See also:
https://sourceware.org/ml/libc-alpha/2016-02/msg00416.htmlhttps://sourceware.org/ml/libc-alpha/2016-02/msg00418.html
In ICO C++11 mode ensure that isinff, isinfl, isnanf, and isnanl
are defined. These functions were accidentally removed from the
header as part of commit d9b965fa56,
but being GNU extensions, they should have been left in place.
The handling of negative offsets in MIPS mmap is inconsistent with
other architectures, as shown by failure of the test
posix/tst-mmap-offset for o32 and n32. The MIPS mmap syscall uses a
signed argument and does a signed arithmetic shift on it, whereas the
glibc semantics expected by that test are for the offset to be
considered as a large positive offset. This patch makes MIPS
consistent with other architectures as far as possible by using the
mmap2 syscall on o32 (#including the generic implementation), and
making mmap not an alias for mmap64 for n32, with a custom
implementation for n32 that zero-extends the offset argument to 64-bit
before calling the mmap syscall.
Tested for MIPS64 (o32, n32, n64).
[BZ #19550]
* sysdeps/unix/sysv/linux/mips/mips32/mmap.c: New file.
* sysdeps/unix/sysv/linux/mips/mips64/mmap64.c: Move to ....
* sysdeps/unix/sysv/linux/mips/mips64/n64/mmap64.c: ... here.
* sysdeps/unix/sysv/linux/mips/mips64/n32/mmap.c: New file.
* sysdeps/unix/sysv/linux/mips/mips64/n32/syscalls.list (mmap64):
New syscall entry.
* sysdeps/unix/sysv/linux/mips/mips64/n64/syscalls.list (mmap):
New syscall entry.
* sysdeps/unix/sysv/linux/mips/mips64/syscalls.list (mmap): Remove
syscall entry.
The following new 386 and X86_64 were added to binutils. They are
non-dynamic relocations, so don't need direct handling in glibc.
But other programs, like elfutils, use the glibc elf.h definitions
for the names and numbers when inspecting ET_REL files.
R_386_GOT32X was proposed in
https://groups.google.com/forum/#!topic/ia32-abi/GbJJskkid4I
X86_64_GOTPCRELX and R_X86_64_REX_GOTPCRELX were proposed in
https://groups.google.com/forum/#!topic/x86-64-abi/n9AWHogmVY0
There also used to be R_X86_64_PC32_BND and R_X86_64_PLT32_BND
but those already got deprecated in
https://groups.google.com/d/msg/x86-64-abi/-hdQyMixt8Y/XFDOvioG85cJ
* elf/elf.h (R_386_GOT32X): New.
(R_386_NUM): Update.
(R_X86_64_GOTPCRELX: New.
(R_X86_64_REX_GOTPCRELX): New.
(R_X86_64_NUM): Update.
The MIPS memcpy optimizations at
<https://sourceware.org/ml/libc-alpha/2015-10/msg00597.html>
introduced a bug causing many string function tests to fail with
segfaults for n32 and n64:
FAIL: string/stratcliff
FAIL: string/test-bcopy
FAIL: string/test-memccpy
FAIL: string/test-memcmp
FAIL: string/test-memcpy
FAIL: string/test-memmove
FAIL: string/test-mempcpy
FAIL: string/test-stpncpy
FAIL: string/test-strncmp
FAIL: string/test-strncpy
(Some failures in other directories could also be caused by this bug.)
The problem is that after the check for whether a word of input is
left that can be copied as a word before moving to byte copies, a load
can occur in the branch delay slot, resulting in a segfault if we are
at the end of a page and the following page is unmapped. I don't see
how this would have passed the tests as reported in the original patch
posting (different kernel configurations affecting the code setting up
unmapped pages, maybe?), since the tests in question don't appear to
have changed recently.
This patch moves a later instruction into the delay slot, as suggested
at <https://sourceware.org/ml/libc-alpha/2016-01/msg00584.html>.
Tested for n32 and n64.
2016-01-28 Steve Ellcey <sellcey@imgtec.com>
Joseph Myers <joseph@codesourcery.com>
* sysdeps/mips/memcpy.S (MEMCPY_NAME) [USE_DOUBLE]: Avoid word
load in branch delay slot when less than a word of input left.
Error checking mutexes are not supposed to be subject to lock elision.
That would defeat the error checking nature of the mutex because lock
elision doesn't record ownership.
Building string/tst-endian.c with gcc 6 produces an build warning/error on s390 (big endian machine):
gcc tst-endian.c -c -std=gnu11 -fgnu89-inline -O2 or -O3 ...
tst-endian.c: In function ‘do_test’:
tst-endian.c:16:30: error: self-comparison always evaluates to false [-Werror=tautological-compare]
if (htobe16 (be16toh (i)) != i)
^~
...
See definitions of htobexx, bexxtoh in string/endian.h:
...
This patch silences these warnings with DIAG_* macros if build with gcc 6
and newer.
The same warnings occur on little endian machines with the
"htoleXX (leXXtoh (i)) != i" if-statements.
ChangeLog:
* string/tst-endian.c: Include <libc-internal.h>.
(do_test): Ignore tautological-compare warnings around
"htobeXX (beXXtoh (i)) != i" and
"htoleXX (leXXtoh (i)) != i" if-statements.
Complement the addition of the required kernel support, present upstream
as from commit 2b5e869ecfcb3112f7e1267cb0328f3ff6d49b18 ("MIPS: ELF:
Interpret the NAN2008 file header flag") and released with Linux 4.5-rc1
on Jan 24th, 2016.
* sysdeps/unix/sysv/linux/mips/configure.ac: Set
`arch_minimum_kernel' to 4.5.0 if 2008 NaN encoding is used.
* sysdeps/unix/sysv/linux/mips/configure: Regenerate.
pthread_barrier_wait can return either PTHREAD_BARRIER_SERIAL_THREAD
or 0. Posix makes no guarantees about which thread return the unique
value.
Additionally, pthread_join was not called despite seemingly checking
for the error.
The changes to restrict implementation-namespace symbol aliases such
as __finitel to compat symbols used code for __finitel in libm
analogous to that for __finitel in libc. However, the versions for
the two symbols are actually different, GLIBC_2.0 in libc and
GLIBC_2.1 in libm. This patch fixes the handling of the libm compat
symbol.
Tested for mips (o32), where it fixes an ABI test failure.
* sysdeps/ieee754/dbl-64/s_finite.c
[NO_LONG_DOUBLE && LDBL_CLASSIFY_COMPAT] (__finitel): Define
compat symbol at version GLIBC_2_1 and use GLIBC_2_1 in
SHLIB_COMPAT condition for libm, not GLIBC_2_0.
* sysdeps/ieee754/dbl-64/wordsize-64/s_finite.c
[NO_LONG_DOUBLE && LDBL_CLASSIFY_COMPAT] (__finitel): Likewise.
Testing for powerpc-nofpu showed that localplt.data was out of date.
Two new soft-fp functions showed up in the list: __gtsf2 and
__unordsf2; this patch adds these as optional. __signbit and
__signbitl no longer appear as local PLT entries; given the move to
__builtin_signbit* for all GCC versions supported for building glibc
(and given the use of the type-generic signbit macro within glibc),
those can safely be removed from the list, which this patch does.
Tested for powerpc-nofpu.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/localplt.data
(__gtsf2): Add as optional for libc.so.
(__unordsf2): Likewise.
(__signbit): Remove for libc.so.
(__signbitl): Likewise.
This fixes the following build error on S390 31bit while building the test
iconvdata/bug-iconv11.c with gcc 5.3:
bug-iconv11.c: In function ‘test_ibm93x’:
bug-iconv11.c:59:11: error: format ‘%td’ expects argument of type ‘ptrdiff_t’, but argument 2 has type ‘size_t {aka long unsigned int}’ [-Werror=format=]
printf (" ==> %td: %s\n"
^
cc1: all warnings being treated as errors
This patch uses %zu format specifier for argument size_t ret instead of %td.
ChangeLog:
* iconvdata/bug-iconv11.c (test_ibm93x):
Use %zu printf format specifier for size_t argument.
On running tests after from-scratch ulps regeneration, I found that
some libm tests failed with ulps in excess of those recorded in the
from-scratch regeneration, which should never happen unless those ulps
exceed the limit on ulps that can go in libm-test-ulps files.
Failure: Test: atan2_upward (inf, -inf)
Result:
is: 2.35619498e+00 0x1.2d97ccp+1
should be: 2.35619450e+00 0x1.2d97c8p+1
difference: 4.76837159e-07 0x1.000000p-21
ulp : 2.0000
max.ulp : 1.0000
Maximal error of `atan2_upward'
is : 2 ulp
accepted: 1 ulp
Failure: Test: carg_upward (-inf + inf i)
Result:
is: 2.35619498e+00 0x1.2d97ccp+1
should be: 2.35619450e+00 0x1.2d97c8p+1
difference: 4.76837159e-07 0x1.000000p-21
ulp : 2.0000
max.ulp : 1.0000
Maximal error of `carg_upward'
is : 2 ulp
accepted: 1 ulp
The problem comes from the addition of tests for the finite-math-only
versions of libm functions. Those tests share ulps with the default
function variants. make regen-ulps runs the default tests before the
finite-math-only tests, concatenating the resulting ulps before
feeding them to gen-libm-test.pl to generate a new libm-test-ulps
file. But gen-libm-test.pl always takes the last ulps value given for
any (function, type) pair. So, if the largest ulps for a function
come from non-finite inputs, a from-scratch regeneration loses those
ulps.
This patch fixes gen-libm-test.pl, in the case where there are
multiple ulps values for a (function, type) pair - which can only
happen as part of a regeneration - to take the largest ulps value
rather than the last one.
Tested for ARM / MIPS / powerpc-nofpu.
* math/gen-libm-test.pl (parse_ulps): Do not reduce
already-recorded ulps.
* sysdeps/arm/libm-test-ulps: Regenerated.
* sysdeps/mips/mips32/libm-test-ulps: Likewise.
* sysdeps/mips/mips64/libm-test-ulps: Likewise.
* sysdeps/powerpc/nofpu/libm-test-ulps: Likewise.
I've regenerated ulps from scratch for s390/s390x.
All math testcases are passing afterwards.
ChangeLog:
* sysdeps/s390/fpu/libm-test-ulps: Regenerated.
I get some math test-failures on s390 for float/double/ldouble for
various lrint/lround functions like:
lrint (0x1p64): Exception "Inexact" set
lrint (-0x1p64): Exception "Inexact" set
lround (0x1p64): Exception "Inexact" set
lround (-0x1p64): Exception "Inexact" set
...
GCC emits "convert to fixed" instructions for casting floating point
values to integer values. These instructions raise invalid and inexact
exceptions if the floating point value exceeds the integer type ranges.
This patch enables the various FIX_DBL_LONG_CONVERT_OVERFLOW macros in
order to avoid a cast from floating point to integer type and raise the
invalid exception with feraiseexcept.
The ldbl-128 rint/round functions are now using the same logic.
ChangeLog:
[BZ #19486]
* sysdeps/s390/fix-fp-int-convert-overflow.h: New File.
* sysdeps/generic/fix-fp-int-convert-overflow.h
(FIX_LDBL_LONG_CONVERT_OVERFLOW,
FIX_LDBL_LLONG_CONVERT_OVERFLOW): New define.
* sysdeps/arm/fix-fp-int-convert-overflow.h: Likewise.
* sysdeps/mips/mips32/fpu/fix-fp-int-convert-overflow.h:
Likewise.
* sysdeps/ieee754/ldbl-128/s_lrintl.c (__lrintl):
Avoid conversions to long int where inexact exceptions
could be raised.
* sysdeps/ieee754/ldbl-128/s_lroundl.c (__lroundl):
Likewise.
* sysdeps/ieee754/ldbl-128/s_llrintl.c (__llrintl):
Avoid conversions to long long int where inexact exceptions
could be raised.
* sysdeps/ieee754/ldbl-128/s_llroundl.c (__llroundl):
Likewise.
The previous barrier implementation did not fulfill the POSIX requirements
for when a barrier can be destroyed. Specifically, it was possible that
threads that haven't noticed yet that their round is complete still access
the barrier's memory, and that those accesses can happen after the barrier
has been legally destroyed.
The new algorithm does not have this issue, and it avoids using a lock
internally.
The check is done on line 117 by a thread spawned
from do_child(), forked from do_test(). This test
generates a signal in the forked process.
Either thread may handle the signal, and on ppc,
it happens to be done on do_child, on the thread
which is not doing the check on line 117.
This exposes a race condition whereby the test
incorrectly fails as the signal is caught during
or after the check.
This is mitigated by ensuring the signal is blocked
in the child thread while thread is running.
IBM907, and IBM909.
Patch for bug #17197 changes the encoder to avoid generating redundant
shift sequences. However, those sequences may already be present in
data encododed by prior versions of the encoder. This change modifies
the decoder to also avoid rejecting redundant shift sequences.
[BZ #19432]
* iconvdata/Makefile: Add bug-iconv11.
* iconvdata/bug-iconv11.c: New test.
* iconvdata/ibm930.c: Do not reject redundant shift sequences.
* iconvdata/ibm933.c: Same.
* iconvdata/ibm935.c: Same.
* iconvdata/ibm937.c: Same.
* iconvdata/ibm939.c: Same.
GLIBC benchtest testcases shows SSE2_Unaligned based implementations
are performing faster compare to SSE2 based implementations for
routines: strcmp, strcat, strncat, stpcpy, stpncpy, strcpy, strncpy
and strstr. Flag index_Fast_Unaligned_Load is set for Excavator family
0x15h CPU's. This makes SSE2_Unaligned based implementations as
default for these routines.
[BZ #19467]
* sysdeps/x86/cpu-features.c (init_cpu_features): Set
index_Fast_Unaligned_Load flag for Excavator family CPUs.
Preparation for gcc -fsplit-stack support (gcc bug #68191). The new
field is basically identical to the one on x86. Its TCB offset needs
to be constant, as it'll be hardcoded in gcc.
ChangeLog:
* sysdeps/s390/nptl/tls.h (struct tcbhead_t): Add __private_ss field.
This patch adds some new header definitions from Linux 4.4:
* MCL_ONFAULT is added to bits/mman.h / bits/mman-linux.h (this was
already done for hppa).
* PTRACE_SECCOMP_GET_FILTER is added to sys/ptrace.h. Along with it,
the older PTRACE_GETSIGMASK and PTRACE_SETSIGMASK, added in Linux
3.11 but missed at the time, are also added.
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).
* bits/mman-linux.h [!MCL_CURRENT] (MCL_ONFAULT): New macro.
* sysdeps/unix/sysv/linux/alpha/bits/mman.h (MCL_ONFAULT):
Likewise.
* sysdeps/unix/sysv/linux/powerpc/bits/mman.h (MCL_ONFAULT):
Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/mman.h (MCL_ONFAULT):
Likewise.
* sysdeps/unix/sysv/linux/sys/ptrace.h (PTRACE_GETSIGMASK): New
enum constant and macro.
(PTRACE_SETSIGMASK): Likewise.
(PTRACE_SECCOMP_GET_FILTER): Likewise.
* sysdeps/unix/sysv/linux/aarch64/sys/ptrace.h
(PTRACE_GETSIGMASK): Likewise.
(PTRACE_SETSIGMASK): Likewise.
(PTRACE_SECCOMP_GET_FILTER): Likewise.
* sysdeps/unix/sysv/linux/ia64/sys/ptrace.h (PTRACE_GETSIGMASK):
Likewise.
(PTRACE_SETSIGMASK): Likewise.
(PTRACE_SECCOMP_GET_FILTER): Likewise.
* sysdeps/unix/sysv/linux/powerpc/sys/ptrace.h
(PTRACE_GETSIGMASK): Likewise.
(PTRACE_SETSIGMASK): Likewise.
(PTRACE_SECCOMP_GET_FILTER): Likewise.
* sysdeps/unix/sysv/linux/s390/sys/ptrace.h (PTRACE_GETSIGMASK):
Likewise.
(PTRACE_SETSIGMASK): Likewise.
(PTRACE_SECCOMP_GET_FILTER): Likewise.
* sysdeps/unix/sysv/linux/sparc/sys/ptrace.h (PTRACE_GETSIGMASK):
Likewise.
(PTRACE_SETSIGMASK): Likewise.
(PTRACE_SECCOMP_GET_FILTER): Likewise.
* sysdeps/unix/sysv/linux/tile/sys/ptrace.h (PTRACE_GETSIGMASK):
Likewise.
(PTRACE_SETSIGMASK): Likewise.
(PTRACE_SECCOMP_GET_FILTER): Likewise.
GLIBC declares isinf and isnan as expected by Unix98 and for C99 programs
these functions are hidden by the generics inf and isnan macros.
However C++11 defines isinf and isnan with the same semantics as C99
but requires that they are functions not macros (C++11 26.8 [c.math]
paragraph 10).
This then results in a conflict for perfectly valid C++11 programs:
--
using std::isinf;
using std::isnan;
double d1 = isinf(1.0);
double d2 = isnan(1.0);
d.cc:3:12: error: ‘constexpr bool std::isinf(double)’ conflicts with a previous declaration
using std::isinf;
[...]
/usr/include/bits/mathcalls.h:201:1: note: previous declaration ‘int isinf(double)’
__MATHDECL_1 (int,isinf,, (_Mdouble_ __value)) __attribute__ ((__const__));
[...]
--
This patch fixes the prototypes by leaving the obsolete functions
defined for C++98 code (since they do not conflict with any standard
function in C++98), however preventing them on C++11.
No issues found in libstdc++ tests and check on x86_64 and i686 with
glibc testsuite.
Patch from Jonathan Wakely <jwakely.gcc@gmail.com>.
[BZ #19439]
* math/bits/mathcalls.h
[!__cplusplus || __cplusplus < 201103L] (isinf): Do not declare
prototype.
[!__cplusplus || __cplusplus < 201103L] (isnan): Likewise.
If the TZDEFRULES file was used to set the DST rules when $TZ didn't
provide any we need to make sure that the next time it is used we
recompute everything as __tzfile_default changes some setting from what is
provided by TZDEFRULES.
Work around a GCC behavior with hardware transactional memory built-ins.
GCC doesn't treat the PowerPC transactional built-ins as compiler
barriers, moving instructions past the transaction boundaries and
altering their atomicity.
The attached patch fixes dladdr on hppa.
Instead of using the generic version of _dl_lookup_address, we use an
implementation more or less modeled after __canonicalize_funcptr_for_compare()
in gcc. The function pointer is analyzed and if it points to the
trampoline used to call _dl_runtime_resolve just before the global
offset table, then we call _dl_fixup to resolve the function pointer.
Then, we return the instruction pointer from the first word of the
descriptor.
The change fixes the testcase provided in [BZ #19415] and the Debian
nss package now builds successfully.
We define __ASSUME_ST_INO_64_BIT by default for Linux targets, and then
undef it for alpha/sh targets. But the code that uses it looks at its
value (as 0/1) rather than whether it's defined (like all other assume
knobs). Change the code to see if it's defined to fix build Wundef build
errors for alpha/sh.
This patch updates the timezone code from tzcode 2015g. The Makefile
and README changes are based on those in Paul's patch
<https://sourceware.org/ml/libc-alpha/2015-05/msg00553.html>.
Tested for x86_64 and x86.
2016-01-06 Paul Eggert <eggert@cs.ucla.edu>
Joseph Myers <joseph@codesourcery.com>
* timezone/private.h: Update from tzcode 2015g.
* timezone/tzfile.h: Likewise.
* timezone/tzselect.ksh: Likewise.
* timezone/zdump.c: Likewise.
* timezone/zic.c: Likewise.
* timezone/ialloc.c: Remove file.
* timezone/scheck.c: Likewise.
* timezone/Makefile (extra-objs): Remove variable.
($(objpfx)zic): Do not depend on scheck.o and ialloc.o.
(tz-cflags): Add -DHAVE_GETTEXT -DUSE_LTZ=0
-Wno-maybe-uninitialized.
(CFLAGS-zdump.c): Remove -fwrapv -DNOID -DHAVE_GETTEXT.
(CFLAGS-zic.c): Remove -DNOID -DHAVE_GETTEXT.
(CFLAGS-ialloc.c): Remove variable.
(CFLAGS-scheck.c): Likewise.
* timezone/README: Update list of files from tzcode.
Since internal unistd functions are only used internally in ld.so and
libc.so, they can be made hidden. __close, __getcwd, __getpid,
__libc_read and __libc_write can't be hidden in ld.so on Hurd since they
will be preempted by the ones in libc.so after bootstrap.
[BZ #19122]
* include/unistd.h [IS_IN (rtld)]: Include <dl-unistd.h>.
* sysdeps/generic/dl-unistd.h: New file.
* sysdeps/mach/hurd/dl-unistd.h: Likewise.
Since ld.so internal mmap functions are only used internally in ld.so,
they can be made hidden. Don't hide __mmap on Hurd, since __mmap in
ld.so will be preempted by the one in libc.so after bootstrap.
[BZ #19122]
* include/sys/mman.h [IS_IN (rtld)]: Include <dl-mman.h>.
* sysdeps/generic/dl-mman.h: New file.
* sysdeps/mach/hurd/dl-mman.h: Likewise.
This patch updates texinfo.tex, config.guess, config.sub and
move-if-change from their respective upstream sources.
* manual/texinfo.tex: Update to version 2016-01-04.21 with
trailing whitespace removed.
* scripts/config.guess: Update to version 2016-01-01.
* scripts/config.sub: Update to version 2016-01-01.
* scripts/move-if-change: Update from gnulib.
When looking at the code generated for pow() on ppc64 I noticed quite
a few sign extensions. Making the array indices unsigned reduces the
number of sign extensions from 24 to 7.
Tested for powerpc64le and x86_64.
The attached patch adds some upstream defines like MAP_HUGETLB and MAP_STACK
in mman.h for the hppa architecture.
The existing MADV_xxK_PAGES defines were dropped upstream, because they were
originally added many years ago based on a proposed patch for the Linux kernel
which was never applied. So, this patch drops those unneeded defines.
The rework in commit d709042a6e broke
buiding on ia64 due to compat_symbol expanding into ... in some cases.
The common files were wrapped in a BUILD_LGAMMA check, but the ia64
ones were not. Add that logic to the ia64 files too.
The personality system call, starting with linux kernel commit
v2.6.29-6609-g11d06b2a1e5658f448a308aa3beb97bacd64a940, always
successfully changes the personality if requested. The syscall
wrapper, however, still can return an error in the following cases:
- the value returned by the system call looks like an error
due to architecture limitations of 32-bit kernels;
- a personality greater than 0xffffffff is passed to the system call,
and the 64-bit kernel does not have commit
v2.6.35-rc1-372-g485d527686850d68a0e9006dd9904f19f122485e
that would truncate this value to unsigned int;
- on sparc64, the value returned by the system call looks like an error
due to sparc64 kernel sign extension bug.
The solution is three-fold:
- move generic syscalls.list personality entry to generic 64-bit
syscalls.list file;
- for each 32-bit architecture that use negated errno semantics,
add a NOERRNO personality entry to their syscalls.list file;
- for sparc64 and 32-bit architectures that use dedicated registers
to flag syscall errors, add a wrapper around personality syscall;
if the system call return value is flagged as an error, this wrapper
returns the negated "would be errno" value, otherwise it returns
the system call return value; on sparc64, it also truncates the
personality argument to unsigned int before passing it to the kernel.
[BZ #19408]
* sysdeps/unix/sysv/linux/personality.c: New file.
* sysdeps/unix/sysv/linux/sparc/sparc64/personality.c: Likewise.
* sysdeps/unix/sysv/linux/tst-personality.c: Likewise.
* sysdeps/unix/sysv/linux/Makefile [$(subdir) == misc]
(sysdep_routines): Add personality.
(tests): Add tst-personality.
* sysdeps/unix/sysv/linux/syscalls.list (personality): Move ...
* sysdeps/unix/sysv/linux/wordsize-64/syscalls.list: ... here.
* sysdeps/unix/sysv/linux/arm/syscalls.list (personality): New entry.
* sysdeps/unix/sysv/linux/hppa/syscalls.list (personality): Likewise.
* sysdeps/unix/sysv/linux/i386/syscalls.list (personality): Likewise.
* sysdeps/unix/sysv/linux/m68k/syscalls.list (personality): Likewise.
* sysdeps/unix/sysv/linux/microblaze/syscalls.list (personality):
Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n32/syscalls.list (personality):
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/syscalls.list (personality):
Likewise.
* sysdeps/unix/sysv/linux/sh/syscalls.list (personality): Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/syscalls.list (personality):
Likewise.
Since GLIBC requires a minimum 2.6.32 kernel, the sysctl (CTL_BUS,
CTL_BUS_ISA, ISA_*) is always available. We can therefore remove the
fallback code reading /etc/arm_systype or parsing /proc/cpuinfo.
Remove fscanf from localplt.data as it is no longer called from within
GLIBC.
* sysdeps/unix/sysv/linux/arm/ioperm.c: Do not include <string.h>.
(PATH_ARM_SYSTYPE): Remove.
(PATH_CPUINFO): Likewise.
(IO_BASE_FOOTBRIDGE): Likewise.
(IO_SHIFT_FOOTBRIDGE): Likewise.
(struct platform): Likewise.
(init_iosys): Remove compatibility code for 2.4 kernels.
* sysdeps/unix/sysv/linux/arm/localplt.data: Remove fscanf.
This test case exercises unusual code paths in allocation functions,
related to allocation failures. Specifically, the test can reveal
the following bugs:
(a) calloc returns non-zero memory on fallback to sysmalloc.
(b) calloc can self-deadlock because it fails to release
the arena lock on certain allocation failures.
(c) pvalloc can dereference a NULL arena pointer.
(a) and (b) appear specific to a faulty downstream backport.
(c) was fixed as part of commit 10ad46bc65.
The test for (a) was inspired by a reproducer supplied by Jeff Layton.
Resetting defdname (default domain name) before use in __res_vinit
ensures that the default domain name is correctly set to a default
value when it is not set by the LOCALDOMAIN environment variable or
the "domain" or "search" parameters in resolv.conf
Tested using the steps from:
https://sourceware.org/bugzilla/show_bug.cgi?id=19369
The attached patch fixes BZ #19270 and the Debian gmt package now builds
successfully. Aside from the comment, the define of __NO_LONG_DOUBLE_MATH
is similar to that in the generic version of glibc.
Build tested on hppa-unknown-linux-gnu with no observed regressions.
POSIX and C++11 require that a thread can destroy a mutex if no other
thread owns the mutex, is blocked on the mutex, or will try to acquire
it in the future. After destroying the mutex, it can reuse or unmap the
underlying memory. Thus, we must not access a mutex' memory after
releasing it. Currently, we can load the private flag after releasing
the mutex, which is fixed by this patch.
See https://sourceware.org/bugzilla/show_bug.cgi?id=13690 for more
background.
We need to call futex_wake on the lock after releasing it, however. This
is by design, and can lead to spurious wake-ups on unrelated futex words
(e.g., when the mutex memory is reused for another mutex). This behavior
is documented in the glibc-internal futex API and in recent drafts of the
Linux kernel's futex documentation (see the draft_futex branch of
git://git.kernel.org/pub/scm/docs/man-pages/man-pages.git).
Commit 67385a01d2 added a new feature for
powerpc, where we store HWCAP/Platform bits in the TCB. In the dynamic
linking case, we use the versioned symbol
'__parse_hwcap_and_convert_at_platform' to verify if this feature is
available. However, the same symbol was not exported to libc.a, making
it not possible for GCC to check for it prior to link time.
This fixes build when _IO_funlockfile is a macro, fixes build where
_IO_acquire_lock_clear_flags2 is used, and fixes unlocking on unexpected
stack unwind.
* sysdeps/generic/stdio-lock.h [__EXCEPTIONS] (_IO_acquire_lock,
_IO_release_lock ): Use cleanup attribute on new
_IO_acquire_lock_file variable instead of assuming that
_IO_release_lock will be called.
[!__EXCEPTIONS] (_IO_acquire_lock): Define to non-existing
_IO_acquire_lock_needs_exceptions_enabled.
(_IO_acquire_lock_clear_flags2): New macro.
* malloc/arena.c (list_lock): Document lock ordering requirements.
(free_list_lock): New lock.
(ptmalloc_lock_all): Comment on free_list_lock.
(ptmalloc_unlock_all2): Reinitialize free_list_lock.
(detach_arena): Update comment. free_list_lock is now needed.
(_int_new_arena): Use free_list_lock around detach_arena call.
Acquire arena lock after list_lock. Add comment, including FIXME
about incorrect synchronization.
(get_free_list): Switch to free_list_lock.
(reused_arena): Acquire free_list_lock around detach_arena call
and attached threads counter update. Add two FIXMEs about
incorrect synchronization.
(arena_thread_freeres): Switch to free_list_lock.
* malloc/malloc.c (struct malloc_state): Update comments to
mention free_list_lock.
Like the previous change, exploit the fact that computation for sin
and cos is identical except that it is apart by a quadrant. Also
remove csloww, csloww1 and csloww2 since they can easily be expressed
in terms of sloww, sloww1 and sloww2.
The sin and cos computation for this range of input is identical
except for a difference in quadrants by 1. Exploit that fact and the
common argument reduction to reduce computations for sincos.
Range reduction needs to be done only once for sin and cos, so copy
over all of the relevant functions (__sin, __cos, reduce_and_compute)
and consolidate common code.
The i386 ULPs are actually the i686/multiarch ones. The i686/multiarch
float ULPs are more precise as the SSE2 version (when available) uses
double for the cosf and sinf functions.
On the other hand the higher precision of the x86 FPU improves the
precision for a few other math functions.
* sysdeps/i386/fpu/libm-test-ulps: Move to ....
* sysdeps/i386/i686/multiarch/fpu/libm-test-ulps: ...here.
* sysdeps/i386/fpu/libm-test-ulps: Regenerate.
It shows improvement up to 28% over AVX2 memset (performance results
attached at <https://sourceware.org/ml/libc-alpha/2015-12/msg00052.html>).
* sysdeps/x86_64/multiarch/memset-avx512-no-vzeroupper.S: New file.
* sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Added new file.
* sysdeps/x86_64/multiarch/ifunc-impl-list.c: Added new tests.
* sysdeps/x86_64/multiarch/memset.S: Added new IFUNC branch.
* sysdeps/x86_64/multiarch/memset_chk.S: Likewise.
* sysdeps/x86/cpu-features.h (bit_Prefer_No_VZEROUPPER,
index_Prefer_No_VZEROUPPER): New.
* sysdeps/x86/cpu-features.c (init_cpu_features): Set the
Prefer_No_VZEROUPPER for Knights Landing.
This patch fixes the SYSCALL_CANCEL macro for usage with zero argument
number (for instance SYSCALL_CANCEL (pause)) using a similar approach
used for SOCKETCALL_CANCEL.
GLIBC build still does not hit this issue still since SYSCALL_CANCEL
is not currently being used for zero arguments calls.
Tested on i386, x86_64, powerpc64le, aarch64.
* sysdeps/unix/sysdep.h (SYSCALL_CANCEL): Fix macro for zero argument
syscalls.
(__SYSCALL0): New macro.
(__SYSCALL1): Likewise.
(__SYSCALL2): Likewise.
(__SYSCALL3): Likewise.
(__SYSCALL4): Likewise.
(__SYSCALL5): Likewise.
(__SYSCALL6): Likewise.
(__SYSCALL7): Likewise.
(__SYSCALL_CONCAT_X): Likewise.
(__SYSCALL_CONCAT): Likewise.
(__SYSCALL_DIST): Likewise.
(__SYSCALL_CALL): Likewise.
Since times returns 64-bit clock_t on x32, we need to provide x32 times
by redefining INTERNAL_SYSCALL_NCS and INTERNAL_SYSCALL_ERROR_P with
64-bit return type for syscall. All system calls returning 64-bit
integer, which are lseek, time and times, must be handled specially for
x32. lseek is handled by x32 lseek.S and time doesn't check syscall
return. times is the only missed one. Before this patch, there are
0000000 <__times>:
0: b8 64 00 00 40 mov $0x40000064,%eax
5: 0f 05 syscall
7: 48 63 d0 movslq %eax,%rdx
^^^^^^^^^^ Incorrect signed extension
a: 48 83 fa f2 cmp $0xfffffffffffffff2,%rdx
e: 75 07 jne 17 <__times+0x17>
10: 3d 00 f0 ff ff cmp $0xfffff000,%eax
^^^^^^^^^^^^^^^^^^^^^ 32-bit compare
15: 77 11 ja 28 <__times+0x28>
17: 48 83 fa ff cmp $0xffffffffffffffff,%rdx
1b: b8 00 00 00 00 mov $0x0,%eax
20: 48 0f 45 c2 cmovne %rdx,%rax
24: c3 retq
After this patch, there are
00000000 <__times>:
0: b8 64 00 00 40 mov $0x40000064,%eax
5: 0f 05 syscall
7: 48 83 f8 f2 cmp $0xfffffffffffffff2,%rax
b: 75 08 jne 15 <__times+0x15>
d: 48 3d 00 f0 ff ff cmp $0xfffffffffffff000,%rax
13: 77 13 ja 28 <__times+0x28>
15: 48 83 f8 ff cmp $0xffffffffffffffff,%rax
19: ba 00 00 00 00 mov $0x0,%edx
1e: 48 0f 44 c2 cmove %rdx,%rax
22: c3 retq
The incorrect signed extension and 32-bit compare are gone.
[BZ #19363]
* sysdeps/unix/sysv/linux/x86_64/x32/times.c: New file.
The optimized POWER7 logb implementation does not use the absolute
value of the word extracted from the input to apply the leading 0-bits
builtin (to ignore the float sign). This patch fixes it by
clearing the signal bit in the resulting word.
It fixes the subnormal tests failures when running on POWER7 ou
newer chip.
Tested on powerpc64le (POWER8).
[BZ# 19375]
* sysdeps/powerpc/power7/fpu/s_logb.c (__logb): Fix return for
negative subnormals.
X86-64 system calls use a different calling convention, which clobbers
CC, %r11 an %rcx registers. Define REGISTERS_CLOBBERED_BY_SYSCALL for
x86-64 inline asm statements.
* sysdeps/unix/sysv/linux/x86_64/sysdep.h
(REGISTERS_CLOBBERED_BY_SYSCALL): New.
(INTERNAL_SYSCALL_NCS): Use it.
(INTERNAL_SYSCALL_NCS_TYPES): Likewise.
reused_arena can increase the attached thread count of arenas on the
free list. This means that the assertion that the reference count is
zero is incorrect. In this case, the reference count initialization
is incorrect as well and could cause arenas to be put on the free
list too early (while they still have attached threads).
* malloc/arena.c (get_free_list): Remove assert and adjust
reference count handling. Add comment about reused_arena
interaction.
(reused_arena): Add comments abount get_free_list interaction.
* malloc/tst-malloc-thread-exit.c: New file.
* malloc/Makefile (tests): Add tst-malloc-thread-exit.
(tst-malloc-thread-exit): Link against libpthread.
Knights Landing processor is based on Silvermont. This patch enables
Silvermont optimizations for Knights Landing.
* sysdeps/x86/cpu-features.c (init_cpu_features): Enable
Silvermont optimizations for Knights Landing.
Various Linux kernel syscalls have become obsolete over time.
Specifically, the following are obsolete in all kernel versions
supported by glibc, are not present for architectures more recently
added to the kernel, and as such, the wrapper functions for them
should be compat symbols, not in static libc and not available for new
links with shared libc.
* bdflush: in Linux 2.6, does nothing if present.
* create_module get_kernel_syms query_module: Linux 2.4 module
interface, syscalls not present in Linux 2.6.
* uselib: part of the mechanism for loading a.out shared libraries,
irrelevant with ELF.
This patch adds support for syscalls.list to list syscall aliases of
the form NAME@VERSION:OBSOLETED, with SHLIB_COMPAT conditionals being
generated for such aliases. Those five syscalls are then made into
compat symbols (obsoleted in glibc 2.23, so future ports won't have
these symbols at all), with the header <sys/kdaemon.h> declaring
bdflush being removed. When we move to 3.2 as minimum kernel version,
the same can be done for nfsservctl (removed in Linux 3.1) as well.
Tested for x86_64 and x86 (testsuite, as well as checking that the
symbols in question indeed become compat symbols, that they are indeed
omitted from static libc, and that the generated SHLIB_COMPAT
conditionals look right).
[BZ #18472]
* sysdeps/unix/Makefile ($(objpfx)stub-syscalls.c): Handle entries
for the form NAME@VERSION:OBSOLETED and generate SHLIB_COMPAT
conditionals for them.
* sysdeps/unix/make-syscalls.sh (emit_weak_aliases): Likewise.
* sysdeps/unix/sysv/linux/sys/kdaemon.h: Remove file.
* sysdeps/unix/sysv/linux/Makefile (sysdep_headers): Remove
sys/kdaemon.h.
* sysdeps/unix/sysv/linux/syscalls.list (bdflush): Make into
compat-only syscall, obsoleted in glibc 2.23.
(create_module): Likewise.
(get_kernel_syms): Likewise.
(query_module): Likewise.
(uselib): Likewise.
* manual/sysinfo.texi (System Parameters): Do not mention bdflush.
According to POSIX the grantpt() function does the following:
The grantpt() function shall change the mode and ownership of the
slave pseudo-terminal device associated with its master
pseudo-terminal counterpart. The fildes argument is a file descriptor
that refers to a master pseudo-terminal device. The user ID of the
slave shall be set to the real UID of the calling process and the
group ID shall be set to an unspecified group ID. The permission
mode of the slave pseudo-terminal shall be set to readable and
writable by the owner, and writable by the group.
Historically the GNU libc has been responsible to setup the permission
mode to 0620 and the group to 'tty' usually number 5, using the pt_chown
helper, badly known for its security issues. With the creation of the
devpts filesytem in the Linux kernel, this responsibility has been moved
to the Linux kernel. The system is responsible to mount the devpts
filesystem in /dev/pts with the options gid=5 and mode=0620. In that
case the GNU libc has nothing to do and pt_chown is not need anymore. So
far so good.
The problem is that by default the devpts filesystem is shared between
all mounts, and that contrary to other filesystem, the mount options are
honored at the second mount, including for the default mount options.
Given it corresponds to mode=0600 without gid parameter (that is the
filesystem GID of the creating process), it's common to see systems
where the devpts filesystem is mounted using these options. It is enough
to run a "mount -t devpts devpts /mychroot/dev/pts" to come into this
situation, and it's unfortunately wrongly used in a lot of scripts
dealing with chroots, or for creating virtual machines images.
When this happens the GNU libc tries to fix the group and permission
mode of the pty nodes, and given it fails to do so for non-root users,
grantpt() almost always fail. It means users are not able to open new
terminals.
This patch changes grantpt() to not enforce this anymore, while still
enforcing minimum security measures to the permission mode. Therefore
the responsibility to follow POSIX is now shared at the system level,
i.e. kernel + system scripts + GNU libc. It stops trying to change the
group, and makes the pty node readable and writable by the owner, and
writable by the group only when originally writable and when the group
is the tty one.
As a result, on a system wrongly mounted with gid=0 and mode=0600, the
pty nodes won't be accessible by the tty group, but the grantpt()
function will succeed and users will have a working system. The system
is not fully POSIX compliant (which might be an admin choice to default
to "mesg n" mode), but the GNU libc is not to blame here, as without the
pt_chown helper it can't do anything.
With this patch there should not be any reason left to build the GNU
libc with the --enable-pt_chown configure option on a GNU/Linux system.
* manual/examples/strncat.c: Remove.
This example was misleading, as the code would have undefined
behavior if "hello" was longer than SIZE. Anyway, the manual
shouldn't encourage strncpy+strncat for this sort of thing.
* manual/string.texi (Copying Strings and Arrays): Split into
three sections Copying Strings and Arrays, Concatenating Strings,
and Truncating Strings, as this section was way too long. All
cross-referenced changed. Add advice about string-truncation
functions. Remove misleading strncat example.
