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2017-06-07tunables: Clean up hooks to get and set tunablesSiddhesh Poyarekar
The TUNABLE_SET_VALUE and family of macros (and my later attempt to add a TUNABLE_GET) never quite went together very well because the overall interface was not clearly defined. This patch is an attempt to do just that. This patch consolidates the API to two simple sets of macros, TUNABLE_GET* and TUNABLE_SET*. If TUNABLE_NAMESPACE is defined, TUNABLE_GET takes just the tunable name, type and a (optionally NULL) callback function to get the value of the tunable. The callback function, if non-NULL, is called if the tunable was externally set (i.e. via GLIBC_TUNABLES or any future mechanism). For example: val = TUNABLE_GET (check, int32_t, check_callback) returns the value of the glibc.malloc.check tunable (assuming TUNABLE_NAMESPACE is set to malloc) as an int32_t into VAL after calling check_callback. Likewise, TUNABLE_SET can be used to set the value of the tunable, although this is currently possible only in the dynamic linker before it relocates itself. For example: TUNABLE_SET (check, int32_t, 2) will set glibc.malloc.check to 2. Of course, this is not possible since we set (or read) glibc.malloc.check long after it is relocated. To access or set a tunable outside of TUNABLE_NAMESPACE, use the TUNABLE_GET_FULL and TUNABLE_SET_FULL macros, which have the following prototype: TUNABLE_GET_FULL (glibc, tune, hwcap_mask, uint64_t, NULL) TUNABLE_SET_FULL (glibc, tune, hwcap_mask, uint64_t, 0xffff) In future the tunable list may get split into mutable and immutable tunables where mutable tunables can be modified by the library and userspace after relocation as well and TUNABLE_SET will be more useful than it currently is. However whenever we actually do that split, we will have to ensure that the mutable tunables are protected with locks. * elf/Versions (__tunable_set_val): Rename to __tunable_get_val. * elf/dl-tunables.c: Likewise. (do_tunable_update_val): New function. (__tunable_set_val): New function. (__tunable_get_val): Call CB only if the tunable was externally initialized. (tunables_strtoul): Replace strval with initialized. * elf/dl-tunables.h (strval): Replace with a bool initialized. (TUNABLE_ENUM_NAME, TUNABLE_ENUM_NAME1): Adjust names to prevent collision. (__tunable_set_val): New function. (TUNABLE_GET, TUNABLE_GET_FULL): New macros. (TUNABLE_SET, TUNABLE_SET_FULL): Likewise. (TUNABLE_SET_VAL): Remove. (TUNABLE_SET_VAL_WITH_CALLBACK): Likewise. * README.tunables: Document the new macros. * malloc/arena.c (ptmalloc_init): Adjust.
2017-06-06x86-64: Move wcsnlen.S to multiarch/wcsnlen-sse4_1.SH.J. Lu
Since wcsnlen.S uses pminud which is the part of SSE4.1, move wcsnlen.S to multiarch/wcsnlen-sse4_1.S. * sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add wcsnlen-sse4_1 and wcsnlen-c. * sysdeps/x86_64/multiarch/ifunc-impl-list.c (__libc_ifunc_impl_list): Test __wcsnlen_sse4_1 and __wcsnlen_sse2. * sysdeps/x86_64/multiarch/ifunc-sse4_1.h: New file. * sysdeps/x86_64/multiarch/wcsnlen-c.c: Likewise. * sysdeps/x86_64/multiarch/wcsnlen-sse4_1.S: Likewise. * sysdeps/x86_64/multiarch/wcsnlen.c: Likewise. * sysdeps/x86_64/wcsnlen.S: Removed.
2017-06-06S390: Use generic spinlock code.Stefan Liebler
This patch removes the s390 specific implementation of spinlock code and is now using the generic one. ChangeLog: * sysdeps/s390/nptl/pthread_spin_init.c: Delete File. * sysdeps/s390/nptl/pthread_spin_lock.c: Likewise. * sysdeps/s390/nptl/pthread_spin_trylock.c: Likewise. * sysdeps/s390/nptl/pthread_spin_unlock.c: Likewise.
2017-06-06Optimize generic spinlock code and use C11 like atomic macros.Stefan Liebler
This patch optimizes the generic spinlock code. The type pthread_spinlock_t is a typedef to volatile int on all archs. Passing a volatile pointer to the atomic macros which are not mapped to the C11 atomic builtins can lead to extra stores and loads to stack if such a macro creates a temporary variable by using "__typeof (*(mem)) tmp;". Thus, those macros which are used by spinlock code - atomic_exchange_acquire, atomic_load_relaxed, atomic_compare_exchange_weak - have to be adjusted. According to the comment from Szabolcs Nagy, the type of a cast expression is unqualified (see http://www.open-std.org/jtc1/sc22/wg14/www/docs/dr_423.htm): __typeof ((__typeof (*(mem)) *(mem)) tmp; Thus from spinlock perspective the variable tmp is of type int instead of type volatile int. This patch adjusts those macros in include/atomic.h. With this construct GCC >= 5 omits the extra stores and loads. The atomic macros are replaced by the C11 like atomic macros and thus the code is aligned to it. The pthread_spin_unlock implementation is now using release memory order instead of sequentially consistent memory order. The issue with passed volatile int pointers applies to the C11 like atomic macros as well as the ones used before. I've added a glibc_likely hint to the first atomic exchange in pthread_spin_lock in order to return immediately to the caller if the lock is free. Without the hint, there is an additional jump if the lock is free. I've added the atomic_spin_nop macro within the loop of plain reads. The plain reads are also realized by C11 like atomic_load_relaxed macro. The new define ATOMIC_EXCHANGE_USES_CAS determines if the first try to acquire the spinlock in pthread_spin_lock or pthread_spin_trylock is an exchange or a CAS. This is defined in atomic-machine.h for all architectures. The define SPIN_LOCK_READS_BETWEEN_CMPXCHG is now removed. There is no technical reason for throwing in a CAS every now and then, and so far we have no evidence that it can improve performance. If that would be the case, we have to adjust other spin-waiting loops elsewhere, too! Using a CAS loop without plain reads is not a good idea on many targets and wasn't used by one. Thus there is now no option to do so. Architectures are now using the generic spinlock automatically if they do not provide an own implementation. Thus the pthread_spin_lock.c files in sysdeps folder are deleted. ChangeLog: * NEWS: Mention new spinlock implementation. * include/atomic.h: (__atomic_val_bysize): Cast type to omit volatile qualifier. (atomic_exchange_acq): Likewise. (atomic_load_relaxed): Likewise. (ATOMIC_EXCHANGE_USES_CAS): Check definition. * nptl/pthread_spin_init.c (pthread_spin_init): Use atomic_store_relaxed. * nptl/pthread_spin_lock.c (pthread_spin_lock): Use C11-like atomic macros. * nptl/pthread_spin_trylock.c (pthread_spin_trylock): Likewise. * nptl/pthread_spin_unlock.c (pthread_spin_unlock): Use atomic_store_release. * sysdeps/aarch64/nptl/pthread_spin_lock.c: Delete File. * sysdeps/arm/nptl/pthread_spin_lock.c: Likewise. * sysdeps/hppa/nptl/pthread_spin_lock.c: Likewise. * sysdeps/m68k/nptl/pthread_spin_lock.c: Likewise. * sysdeps/microblaze/nptl/pthread_spin_lock.c: Likewise. * sysdeps/mips/nptl/pthread_spin_lock.c: Likewise. * sysdeps/nios2/nptl/pthread_spin_lock.c: Likewise. * sysdeps/aarch64/atomic-machine.h (ATOMIC_EXCHANGE_USES_CAS): Define. * sysdeps/alpha/atomic-machine.h: Likewise. * sysdeps/arm/atomic-machine.h: Likewise. * sysdeps/i386/atomic-machine.h: Likewise. * sysdeps/ia64/atomic-machine.h: Likewise. * sysdeps/m68k/coldfire/atomic-machine.h: Likewise. * sysdeps/m68k/m680x0/m68020/atomic-machine.h: Likewise. * sysdeps/microblaze/atomic-machine.h: Likewise. * sysdeps/mips/atomic-machine.h: Likewise. * sysdeps/powerpc/powerpc32/atomic-machine.h: Likewise. * sysdeps/powerpc/powerpc64/atomic-machine.h: Likewise. * sysdeps/s390/atomic-machine.h: Likewise. * sysdeps/sparc/sparc32/atomic-machine.h: Likewise. * sysdeps/sparc/sparc32/sparcv9/atomic-machine.h: Likewise. * sysdeps/sparc/sparc64/atomic-machine.h: Likewise. * sysdeps/tile/tilegx/atomic-machine.h: Likewise. * sysdeps/tile/tilepro/atomic-machine.h: Likewise. * sysdeps/unix/sysv/linux/hppa/atomic-machine.h: Likewise. * sysdeps/unix/sysv/linux/m68k/coldfire/atomic-machine.h: Likewise. * sysdeps/unix/sysv/linux/nios2/atomic-machine.h: Likewise. * sysdeps/unix/sysv/linux/sh/atomic-machine.h: Likewise. * sysdeps/x86_64/atomic-machine.h: Likewise.
2017-06-05x86: Don't use dl_x86_cpu_features in cacheinfo.cH.J. Lu
Since cpu_features is available, use it instead of dl_x86_cpu_features. * sysdeps/x86/cacheinfo.c (intel_check_word): Accept cpu_features and use it instead of dl_x86_cpu_features. (handle_intel): Replace maxidx with cpu_features. Pass cpu_features to intel_check_word. (__cache_sysconf): Pass cpu_features to handle_intel. (init_cacheinfo): Likewise. Use cpu_features instead of dl_x86_cpu_features.
2017-06-05x86-64: Optimize memcmp/wmemcmp with AVX2 and MOVBEH.J. Lu
Optimize x86-64 memcmp/wmemcmp with AVX2. It uses vector compare as much as possible. It is as fast as SSE4 memcmp for size <= 16 bytes and up to 2X faster for size > 16 bytes on Haswell and Skylake. Select AVX2 memcmp/wmemcmp on AVX2 machines where vzeroupper is preferred and AVX unaligned load is fast. NB: It uses TZCNT instead of BSF since TZCNT produces the same result as BSF for non-zero input. TZCNT is faster than BSF and is executed as BSF if machine doesn't support TZCNT. Key features: 1. For size from 2 to 7 bytes, load as big endian with movbe and bswap to avoid branches. 2. Use overlapping compare to avoid branch. 3. Use vector compare when size >= 4 bytes for memcmp or size >= 8 bytes for wmemcmp. 4. If size is 8 * VEC_SIZE or less, unroll the loop. 5. Compare 4 * VEC_SIZE at a time with the aligned first memory area. 6. Use 2 vector compares when size is 2 * VEC_SIZE or less. 7. Use 4 vector compares when size is 4 * VEC_SIZE or less. 8. Use 8 vector compares when size is 8 * VEC_SIZE or less. * sysdeps/x86/cpu-features.h (index_cpu_MOVBE): New. * sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add memcmp-avx2 and wmemcmp-avx2. * sysdeps/x86_64/multiarch/ifunc-impl-list.c (__libc_ifunc_impl_list): Test __memcmp_avx2 and __wmemcmp_avx2. * sysdeps/x86_64/multiarch/memcmp-avx2.S: New file. * sysdeps/x86_64/multiarch/wmemcmp-avx2.S: Likewise. * sysdeps/x86_64/multiarch/memcmp.S: Use __memcmp_avx2 on AVX 2 machines if AVX unaligned load is fast and vzeroupper is preferred. * sysdeps/x86_64/multiarch/wmemcmp.S: Use __wmemcmp_avx2 on AVX 2 machines if AVX unaligned load is fast and vzeroupper is preferred.
2017-06-05x86-64: Optimize wmemset with SSE2/AVX2/AVX512H.J. Lu
The difference between memset and wmemset is byte vs int. Add stubs to SSE2/AVX2/AVX512 memset for wmemset with updated constant and size: SSE2 wmemset: shl $0x2,%rdx movd %esi,%xmm0 mov %rdi,%rax pshufd $0x0,%xmm0,%xmm0 jmp entry_from_wmemset SSE2 memset: movd %esi,%xmm0 mov %rdi,%rax punpcklbw %xmm0,%xmm0 punpcklwd %xmm0,%xmm0 pshufd $0x0,%xmm0,%xmm0 entry_from_wmemset: Since the ERMS versions of wmemset requires "rep stosl" instead of "rep stosb", only the vector store stubs of SSE2/AVX2/AVX512 wmemset are added. The SSE2 wmemset is about 3X faster and the AVX2 wmemset is about 6X faster on Haswell. * include/wchar.h (__wmemset_chk): New. * sysdeps/x86_64/memset.S (VDUP_TO_VEC0_AND_SET_RETURN): Renamed to MEMSET_VDUP_TO_VEC0_AND_SET_RETURN. (WMEMSET_VDUP_TO_VEC0_AND_SET_RETURN): New. (WMEMSET_CHK_SYMBOL): Likewise. (WMEMSET_SYMBOL): Likewise. (__wmemset): Add hidden definition. (wmemset): Add weak hidden definition. * sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add wmemset_chk-nonshared. * sysdeps/x86_64/multiarch/ifunc-impl-list.c (__libc_ifunc_impl_list): Add __wmemset_sse2_unaligned, __wmemset_avx2_unaligned, __wmemset_avx512_unaligned, __wmemset_chk_sse2_unaligned, __wmemset_chk_avx2_unaligned and __wmemset_chk_avx512_unaligned. * sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S (VDUP_TO_VEC0_AND_SET_RETURN): Renamed to ... (MEMSET_VDUP_TO_VEC0_AND_SET_RETURN): This. (WMEMSET_VDUP_TO_VEC0_AND_SET_RETURN): New. (WMEMSET_SYMBOL): Likewise. * sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S (VDUP_TO_VEC0_AND_SET_RETURN): Renamed to ... (MEMSET_VDUP_TO_VEC0_AND_SET_RETURN): This. (WMEMSET_VDUP_TO_VEC0_AND_SET_RETURN): New. (WMEMSET_SYMBOL): Likewise. * sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S: Updated. (WMEMSET_CHK_SYMBOL): New. (WMEMSET_CHK_SYMBOL (__wmemset_chk, unaligned)): Likewise. (WMEMSET_SYMBOL (__wmemset, unaligned)): Likewise. * sysdeps/x86_64/multiarch/memset.S (WMEMSET_SYMBOL): New. (libc_hidden_builtin_def): Also define __GI_wmemset and __GI___wmemset. (weak_alias): New. * sysdeps/x86_64/multiarch/wmemset.c: New file. * sysdeps/x86_64/multiarch/wmemset.h: Likewise. * sysdeps/x86_64/multiarch/wmemset_chk-nonshared.S: Likewise. * sysdeps/x86_64/multiarch/wmemset_chk.c: Likewise. * sysdeps/x86_64/wmemset.c: Likewise. * sysdeps/x86_64/wmemset_chk.c: Likewise.
2017-06-05x86: Add macros to implement ifunce selection in CH.J. Lu
These macros are used to implement ifunc selection in C. To implement an ifunc function, foo, which returns the address of __foo_sse2 or __foo_avx2: __foo_avx2: #define foo __redirect_foo #define __foo __redirect___foo #include <foo.h> #undef foo #undef __foo #define SYMBOL_NAME foo #include <init-arch.h> extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2) attribute_hidden; extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2) attribute_hidden; static inline void * foo_selector (void) { if (use AVX2) return OPTIMIZE (avx2); return OPTIMIZE (sse2); } libc_ifunc_redirected (__redirect_foo, foo, foo_selector ()); * sysdeps/x86/init-arch.h (PASTER1): New. (EVALUATOR1): Likewise. (PASTER2): Likewise. (EVALUATOR2): Likewise. (REDIRECT_NAME): Likewise. (OPTIMIZE): Likewise. (IFUNC_SELECTOR): Likewise.
2017-06-05x86-64: Update strlen.S to support wcslen/wcsnlenH.J. Lu
The difference between strlen and wcslen is byte vs int. We can replace pminub and pcmpeqb with pminud and pcmpeqd to turn strlen into wcslen. * sysdeps/x86_64/strlen.S (PMINU): New. (PCMPEQ): Likewise. (SHIFT_RETURN): Likewise. (FIND_ZERO): Replace pcmpeqb with PCMPEQ. (strlen): Add SHIFT_RETURN before ret. Replace pcmpeqb and pminub with PCMPEQ and PMINU. * sysdeps/x86_64/wcsnlen.S: New file.
2017-06-05x86_64: Remove redundant REX bytes from memrchr.SH.J. Lu
By x86-64 specification, 32-bit destination registers are zero-extended to 64 bits. There is no need to use 64-bit registers when only the lower 32 bits are non-zero. Also 2 instructions in: mov %rdi, %rcx and $15, %rcx jz L(length_less16_offset0) mov %rdi, %rcx <<< redundant and $15, %rcx <<< redundant are redundant. * sysdeps/x86_64/memrchr.S (__memrchr): Use 32-bit registers for the lower 32 bits. Remove redundant instructions.
2017-06-05x86-64: Update LO_HI_LONG for p{readv,writev}{64}v2H.J. Lu
The kernel interface for p{readv,writev}{64}v is (unsigned long fd, {const }struct iovec *iov, unsigned long vlen, unsigned long pos_l, unsigned long pos_h) Except for targets which define __ARCH_WANT_COMPAT_SYS_PREADV64 and __ARCH_WANT_COMPAT_SYS_PWRITEV64, (unsigned long fd, {const }struct iovec *iov, unsigned long vlen, off64_t pos) is used for p{readv,writev}{64}v. X32 is the only such target. The LO_HI_LONG macro is used to pass offset to the pos_l and pos_h pair. Since pos_h is ignored when size of offset == sizeof of pos_l, x86-64 has #define LO_HI_LONG(val) (val) But the kernel interface for p{readv,writev}{64}v2 is (unsigned long fd, {const }struct iovec *iov, unsigned long vlen, unsigned long pos_l, unsigned long pos_h, int flags) Except for targets which define __ARCH_WANT_COMPAT_SYS_PREADV64V2 and __ARCH_WANT_COMPAT_SYS_PWRITEV64V2, (unsigned long fd, {const }struct iovec *iov, unsigned long vlen, off64_t pos, int flags) is used for p{readv,writev}{64}v2. X32 is the only such target. Update x86-64 LO_HI_LONG to pass 0 as the high part of the offset argument for p{readv,writev}{64}v2 and define a different LO_HI_LONG for x32 to only pass one argument for offset. Tested on x32 and x86-64. * sysdeps/unix/sysv/linux/x86_64/sysdep.h (LO_HI_LONG): Pass 0 as the high part of offset. * sysdeps/unix/sysv/linux/x86_64/x32/sysdep.h (LO_HI_LONG): New.
2017-06-05Define SIG_HOLD for XPG4 (bug 21538).Joseph Myers
Various bits/signum.h headers define SIG_HOLD if __USE_UNIX98. That should be __USE_XOPEN, as this macro is in XPG4. This patch fixes the conditionals accordingly. Because of other header bugs, this does not allow any XFAILs to be removed (however, the XPG4/signal.h/conform XFAIL only depends on a few such straightforward header bugs, not on the more complicated to fix ucontext_t issues, as ucontext_t isn't included in signal.h in XPG4). Tested for x86_64. [BZ #21538] * bits/signum.h (SIG_HOLD): Define if [__USE_XOPEN], not [__USE_UNIX98]. * sysdeps/unix/bsd/bits/signum.h (SIG_HOLD): Likewise. * sysdeps/unix/sysv/linux/alpha/bits/signum.h (SIG_HOLD): Likewise. * sysdeps/unix/sysv/linux/bits/signum.h (SIG_HOLD): Likewise. * sysdeps/unix/sysv/linux/hppa/bits/signum.h (SIG_HOLD): Likewise. * sysdeps/unix/sysv/linux/mips/bits/signum.h (SIG_HOLD): Likewise. * sysdeps/unix/sysv/linux/sparc/bits/signum.h (SIG_HOLD): Likewise.
2017-06-05Fix struct sigaltstack namespace (bug 21517).Joseph Myers
glibc defines the stack_t type with the tag struct sigaltstack. This is not permitted by POSIX; sigaltstack is only reserved with file scope in the namespace of ordinary identifiers, not the tag namespace, and in the case where stack_t is obtained from ucontext.h rather than signal.h, it's not reserved with file scope at all. This patch removes the tag accordingly and updates uses in glibc of struct sigaltstack. This is similar to the removal of the "struct siginfo" tag a few years ago: C++ name mangling changes are an unavoidable consequence. A NEWS item is added to note the changed mangling. There is inevitably some risk of breaking builds of anything that relies on the struct sigaltstack name (though the first few hits I looked at from codesearch.debian.net generally seemed to involve code that could use the stack_t name conditionally, so depending on how they determine the conditionals they may work with glibc not defining the struct tag anyway). Tested for x86_64 and x86, and with build-many-glibcs.py. [BZ #21517] * bits/types/stack_t.h (stack_t): Remove struct tag. * sysdeps/unix/sysv/linux/bits/types/stack_t.h (stack_t): Likewise. * sysdeps/unix/sysv/linux/mips/bits/types/stack_t.h (stack_t): Likewise. * debug/segfault.c (install_handler): Use stack_t instead of struct sigaltstack. * hurd/hurd/signal.h (struct hurd_sigstate): Likewise. * hurd/trampoline.c (_hurd_setup_sighandler): Likewise. * include/signal.h (__sigaltstack): Likwise. * signal/sigaltstack.c (__sigaltstack): Likewise. * signal/signal.h (sigaltstack): Likewise. * sysdeps/mach/hurd/i386/signal-defines.sym (SIGALTSTACK__SS_SP__OFFSET): Likewise. (SIGALTSTACK__SS_SIZE__OFFSET): Likewise. (SIGALTSTACK__SS_FLAGS__OFFSET): Likewise. * sysdeps/mach/hurd/sigaltstack.c (__sigaltstack): Likewise. * sysdeps/mach/hurd/sigstack.c (sigstack): Likewise. * sysdeps/unix/sysv/linux/alpha/sys/procfs.h (struct elf_prstatus): Likewise. * sysdeps/unix/sysv/linux/hppa/____longjmp_chk.c (CHECK_SP): Likewise. * sysdeps/unix/sysv/linux/ia64/sys/procfs.h (struct elf_prstatus): Likewise. * sysdeps/unix/sysv/linux/m68k/____longjmp_chk.c (CHECK_SP): Likewise. * sysdeps/unix/sysv/linux/powerpc/sys/procfs.h (struct elf_prstatus): Likewise. * sysdeps/unix/sysv/linux/sh/sys/procfs.h (struct elf_prstatus): Likewise. * sysdeps/unix/sysv/linux/sys/procfs.h (struct elf_prstatus): Likewise.
2017-06-04Regenerate sysdeps/gnu/errlist.c.Zack Weinberg
This file needs to be regenerated whenever errno.texi changes.
2017-06-04benchtests: Add more tests for memrchrH.J. Lu
bench-memchr.c is shared with bench-memrchr.c. This patch adds some tests for positions close to the beginning for memrchr, which are equivalent to positions close to the end for memchr. * benchtests/bench-memchr.c (do_test): Print out both length and position. (test_main): Also test the position close to the beginning for memrchr.
2017-06-04Add forgotten changelog entry for 82f43dd2d1Zack Weinberg
2017-06-04Include shlib-compat.h in many sunrpc/nis source files.Zack Weinberg
Every file that uses libc_hidden_nolink_sunrpc or libnsl_hidden_nolink_def needs to include shlib-compat.h. Currently, most of them are getting it via stdio.h, because libio.h refers to SHLIB_COMPAT when _LIBC is defined, so it includes shlib-compat.h. My experimental patch to not install libio.h breaks that chain; stdio.h no longer pulls in libio.h even for internal users. Accordingly, this patch adds #include <shlib-compat.h> to many files in sunrpc/ and nis/. There are also a small number of really obvious fixups to includes that caught my eye while proofreading the patch - not including headers twice in a row, not worrying about portability to Ultrix anymore, sort of thing. * nis/nis_add.c, nis/nis_addmember.c, nis/nis_call.c * nis/nis_checkpoint.c, nis/nis_clone_dir.c, nis/nis_clone_obj.c * nis/nis_clone_res.c, nis/nis_creategroup.c, nis/nis_defaults.c * nis/nis_destroygroup.c, nis/nis_domain_of.c * nis/nis_domain_of_r.c, nis/nis_error.c, nis/nis_file.c * nis/nis_free.c, nis/nis_getservlist.c, nis/nis_ismember.c * nis/nis_local_names.c, nis/nis_lookup.c, nis/nis_mkdir.c * nis/nis_modify.c, nis/nis_ping.c, nis/nis_print.c * nis/nis_print_group_entry.c, nis/nis_remove.c * nis/nis_removemember.c, nis/nis_rmdir.c, nis/nis_server.c * nis/nis_subr.c, nis/nis_table.c, nis/nis_util.c * nis/nis_verifygroup.c, nis/nis_xdr.c, nis/yp_xdr.c * nis/ypclnt.c, nis/ypupdate_xdr.c, sunrpc/auth_des.c * sunrpc/auth_none.c, sunrpc/auth_unix.c, sunrpc/authdes_prot.c * sunrpc/authuxprot.c, sunrpc/clnt_gen.c, sunrpc/clnt_perr.c * sunrpc/clnt_raw.c, sunrpc/clnt_simp.c, sunrpc/clnt_tcp.c * sunrpc/clnt_udp.c, sunrpc/clnt_unix.c, sunrpc/des_crypt.c * sunrpc/des_soft.c, sunrpc/get_myaddr.c, sunrpc/key_call.c * sunrpc/key_prot.c, sunrpc/netname.c, sunrpc/pm_getmaps.c * sunrpc/pm_getport.c, sunrpc/pmap_clnt.c, sunrpc/pmap_prot.c * sunrpc/pmap_prot2.c, sunrpc/pmap_rmt.c, sunrpc/publickey.c * sunrpc/rpc_cmsg.c, sunrpc/rpc_dtable.c, sunrpc/rpc_prot.c * sunrpc/rpc_thread.c, sunrpc/rtime.c, sunrpc/svc.c * sunrpc/svc_auth.c, sunrpc/svc_raw.c, sunrpc/svc_run.c * sunrpc/svc_tcp.c, sunrpc/svc_udp.c, sunrpc/svc_unix.c * sunrpc/svcauth_des.c, sunrpc/xdr.c, sunrpc/xdr_array.c * sunrpc/xdr_float.c, sunrpc/xdr_intXX_t.c, sunrpc/xdr_mem.c * sunrpc/xdr_rec.c, sunrpc/xdr_ref.c, sunrpc/xdr_sizeof.c * sunrpc/xdr_stdio.c: Include shlib-compat.h. * sunrpc/des_crypt.c, sunrpc/des_soft.c: No need to include abi-versions.h as well as shlib-compat.h. * sunrpc/get_myaddr.c: Remove obsolete comment. * sunrpc/pmap_rmt.c: Remove obsolete comment and #undef. * sunrpc/rpc_thread.c: Include libc-lock.h only once. * resolv/res_libc.c: Include shlib-compat.h only once.
2017-06-03getaddrinfo: Eliminate another strdup callFlorian Weimer
2017-06-02x86: Update __x86_shared_non_temporal_thresholdH.J. Lu
__x86_shared_non_temporal_threshold was set to 6 times of per-core shared cache size, based on the large memcpy micro benchmark in glibc on a 8-core processor. For a processor with more than 8 cores, the threshold is too low. Set __x86_shared_non_temporal_threshold to the 3/4 of the total shared cache size so that it is unchanged on 8-core processors. On processors with less than 8 cores, the threshold is lower. * sysdeps/x86/cacheinfo.c (__x86_shared_non_temporal_threshold): Set to the 3/4 of the total shared cache size.
2017-06-02manual: Provide consistent errno documentation.Rical Jasan
The @errno macro is extended to render the canonical error string in every documented errno error. Redundant entries and "???" are removed. Sixty-six errors now at least contain the error string as the description, where no description (or "???") existed before. * manual/errno.texi: Remove redundant error strings. * manual/macros.texi (@errno): Render the error string in every description.
2017-06-02Fix sigevent namespace (bug 21543).Joseph Myers
signal.h defines the sigevent structure and constants if defined __USE_POSIX199309 || defined __USE_XOPEN_EXTENDED. The __USE_XOPEN_EXTENDED condition is incorrect; this structure does not appear in XSI standards before Unix98 (which implies __USE_POSIX199309). This patch fixes the conditionals accordingly (the existing conditional is correct for siginfo_t, just not for sigevent). Tested for x86_64. This does not allow any conform/ XFAILs to be removed because of other signal.h namespace bugs. [BZ #21543] * signal/signal.h: Only include <bits/types/sigevent_t.h> and <bits/sigevent-consts.h> if [__USE_POSIX199309], not if [__USE_XOPEN_EXTENDED].
2017-06-02getaddrinfo: Fix localplt failure involving strdupFlorian Weimer
2017-06-02posix: Add missing build flags for p{write,read}v2Adhemerval Zanella
This patch adds the missing compiler flags for correct pthread cancellation on some architectures for the p{read,write}v2 implementation (52bd9381692fd23). Checked on x86_64-linux-gnu and powerpc64le-linux-gnu. * misc/Makefile (CFLAGS-preadv2.c): New rule. (CFLAGS-preadv64v2.c): Likewise. (CFLAGS-pwritev2.c): Likewise. (CFLAGS-pwritev64v2.c): Likewise.
2017-06-02resolv: Tests for various versions of res_initFlorian Weimer
2017-06-02getaddrinfo: Always allocate canonical name on the heapFlorian Weimer
A further simplification could eliminate the canon variable in gaih_inet and replace it with canonbuf. However, canonbuf is used as a flag in the nscd code, which makes this somewhat non-straightforward.
2017-06-02Add internal facility for dynamic array handlingFlorian Weimer
This is intended as a type-safe alternative to obstacks and hand-written realloc constructs. The implementation avoids writing function pointers to the heap.
2017-06-01Include sys/param.h in stdlib/gmp-impl.h instead of redefining MAX/MINGabriel F. T. Gomes
In stdlib/gmp-impl.h, the macros MAX and MIN are defined exactly the same as in sys/param.h. This patch removes the redefinition and makes gmp-impl.h include sys/param.h instead. Tested for powerpc64le and s390x. * stdlib/gmp-impl.h: Include sys/param.h instead of redefining the macros MAX and MIN.
2017-06-01conformtest: Correct signal.h expectations for XPG4 / XPG42.Joseph Myers
Various of the signal.h conform/ failures for XPG4 and XPG42 are actually the result of incorrect test expectations rather than header bugs. This patch fixes the expectations to accord with those standards (this does not however allow any XFAILs to be removed, as some header bugs remain). Note for anyone comparing with the standards: corrigendum U013/16 removes the mention of a sigmask function in signal.h (C435 lists such a function in the definition of signal.h, but without any actual specification for the function itself), so sigmask is not included in the expectations. Tested for x86_64. * conform/data/signal.h-data (sa_sigaction): Do not expect for [XPG4]. (SA_SIGINFO): Likewise. (SA_ONSTACK): Likewise. (SA_RESETHAND): Likewise. (SA_RESTART): Likewise. (SA_NOCLDWAIT): Likewise. (SA_NODEFER): Likewise. (SS_ONSTACK): Likewise. (SS_DISABLE): Likewise. (MINSIGSTKSZ): Likewise. (SIGSTKSZ): Likewise. (ucontext_t): Likewise. (stack_t): Likewise. (struct sigstack): Likewise. (SI_USER): Do not expect for [XPG4 || XPG42]. (SI_QUEUE): Likewise. (SI_TIMER): Likewise. (SI_ASYNCIO): Likewise. (SI_MESGQ): Likewise. (bsd_signal): Do not expect for [XPG4]. (killpg): Likewise. (sigaltstack): Likewise. (sighold): Likewise. (sigignore): Likewise. (siginterrupt): Likewise. (sigpause): Likewise. (sigrelse): Likewise. (sigset): Likewise. (sigwait): Do not expect for [XPG4 || XPG42].
2017-06-01Add shim header for bits/syscall.h.Zack Weinberg
On Linux-based configurations, bits/syscall.h is a generated file. To avoid build-ordering problems, the Linux sys/syscall.h only includes bits/syscall.h if _LIBC is not defined. After the _ISOMAC-testsuite changes, this means any test case that includes sys/syscall.h tries to pull in bits/syscall.h. This would be fine, because it'll definitely have been generated by the time we start compiling tests, except that the generated <builddir>/misc/bits/syscall.h is not visible in the include path, because nothing needed it till now. So we either get the bits/syscall.h from the host system, or the build fails. The fix is simple: add a shim header for bits/syscall.h. I put it in sysdeps/unix/sysv/linux/include instead of the top-level include/ because bits/syscall.h doesn't exist at all on other configurations as far as I can tell. This is known to affect nptl/tst-cond2[45]. Thanks to John David Anglin for noticing the problem. [BZ #21514] * sysdeps/unix/sysv/linux/include/bits/syscall.h: New shim header pointing to the generated file in <builddir>/misc/bits/syscall.h.
2017-06-01Fix more namespace issues in sys/ucontext.h (bug 21457).Joseph Myers
Continuing the fixes for namespace issues in sys/ucontext.h, this patch moves various symbols into the implementation namespace in the absence of __USE_MISC. As with previous changes, it is nonexhaustive, just covering more straightforward cases. Structure fields are generally changed to have a prefix __ in the absence of __USE_MISC, via a macro __ctx (used without a space before the open parenthesis, since the result is a single identifier). Various macros such as NGREG also have leading __ added. No changes are made to structure tags (and thus to C++ name mangling), except that in the (unused) file sysdeps/i386/sys/ucontext.h, structures defined inside other structures as the type for a field have their tags removed in the non-__USE_MISC case (those structure tags would not in any case have been visible in C++, because in C++ the scope of such a tag is limited to the containing structure). No changes are made to the contents of bits/sigcontext.h, or to whether it is included. Because of remaining namespace issues, this patch does not yet fix the bug or allow any XFAILs to be removed. Tested for x86_64 and x86, and with build-many-glibcs.py. [BZ #21457] * sysdeps/arm/sys/ucontext.h (NGREG): Rename to __NGREG and define NGREG to __NGREG if [__USE_MISC]. (gregset_t): Define using __NGREG. (__ctx): New macro. (mcontext_t): Use __ctx in defining fields. * sysdeps/i386/sys/ucontext.h (NGREG): Rename to __NGREG and define NGREG to __NGREG if [__USE_MISC]. (gregset_t): Define using __NGREG. (__ctx): New macro. (__ctxt): Likewise. (fpregset_t): Use __ctx and __ctxt in defining fields. (mcontext_t): Likewise. * sysdeps/m68k/sys/ucontext.h (NGREG): Rename to __NGREG and define NGREG to __NGREG if [__USE_MISC]. (gregset_t): Define using __NGREG. (__ctx): New macro. (mcontext_t): Use __ctx in defining fields. * sysdeps/mips/sys/ucontext.h (NGREG): Rename to __NGREG and define NGREG to __NGREG if [__USE_MISC]. (gregset_t): Define using __NGREG. (__ctx): New macro. (fpregset_t): Use __ctx in defining fields. (mcontext_t): Likewise. * sysdeps/unix/sysv/linux/alpha/sys/ucontext.h (NGREG): Rename to __NGREG and define NGREG to __NGREG if [__USE_MISC]. (gregset_t): Define using __NGREG. (NFPREG): Rename to __NFPREG and define NFPREG to __NFPREG if [__USE_MISC]. (fpregset_t): Define using __NFPREG. * sysdeps/unix/sysv/linux/m68k/sys/ucontext.h (NGREG): Rename to __NGREG and define NGREG to __NGREG if [__USE_MISC]. (gregset_t): Define using __NGREG. (__ctx): New macro. (fpregset_t): Use __ctx in defining fields. (mcontext_t): Likewise. * sysdeps/unix/sysv/linux/mips/sys/ucontext.h (NGREG): Rename to __NGREG and define NGREG to __NGREG if [__USE_MISC]. (NFPREG): Rename to __NFPREG and define NFPREG to __NFPREG if [__USE_MISC]. (gregset_t): Define using __NGREG. (__ctx): New macro. (fpregset_t): Use __ctx in defining fields. (mcontext_t): Likewise. * sysdeps/unix/sysv/linux/nios2/sys/ucontext.h (__ctx): New macro. (mcontext_t): Use __ctx in defining fields. * sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h (__ctx): New macro. [__WORDSIZE == 32] (NGREG): Rename to __NGREG and define NGREG to __NGREG if [__USE_MISC]. [__WORDSIZE == 32] (gregset_t): Define using __NGREG. [__WORDSIZE == 32] (fpregset_t): Use __ctx in defining fields. (mcontext_t): Likewise. [__WORDSIZE != 32] (NGREG): Rename to __NGREG and define NGREG to __NGREG if [__USE_MISC]. [__WORDSIZE != 32] (NFPREG): Rename to __NFPREG and define NFPREG to __NFPREG if [__USE_MISC]. [__WORDSIZE != 32] (NVRREG): Rename to __NVRREG and define NVRREG to __NVRREG if [__USE_MISC]. [__WORDSIZE != 32] (gregset_t): Define using __NGREG. [__WORDSIZE != 32] (fpregset_t): Define using __NFPREG. [__WORDSIZE != 32] (vscr_t): Use __ctx in defining fields. [__WORDSIZE != 32] (vrregset_t): Likewise. [__WORDSIZE != 32] (mcontext_t): Likewise. * sysdeps/unix/sysv/linux/s390/sys/ucontext.h (__ctx): New macro. (__psw_t): Use __ctx in defining fields. (NGREG): Rename to __NGREG and define NGREG to __NGREG if [__USE_MISC]. (gregset_t): Define using __NGREG. (fpreg_t): Use __ctx in defining fields. (fpregset_t): Likewise. (mcontext_t): Likewise. * sysdeps/unix/sysv/linux/sh/sys/ucontext.h (NGREG): Rename to __NGREG and define NGREG to __NGREG if [__USE_MISC]. (gregset_t): Define using __NGREG. (NFPREG): Rename to __NFPREG and define NFPREG to __NFPREG if [__USE_MISC]. (fpregset_t): Define using __NFPREG. (__ctx): New macro. (mcontext_t): Use __ctx in defining fields. * sysdeps/unix/sysv/linux/x86/sys/ucontext.h (__ctx): New macro. [__x86_64__] (NGREG): Rename to __NGREG and define NGREG to __NGREG if [__USE_MISC]. [__x86_64__] (gregset_t): Define using __NGREG. [__x86_64__] (struct _libc_fpxreg): Use __ctx in defining fields. [__x86_64__] (struct _libc_fpstate): Likewise. [__x86_64__] (mcontext_t): Likewise. [!__x86_64__] (NGREG): Rename to __NGREG and define NGREG to __NGREG if [__USE_MISC]. [!__x86_64__] (gregset_t): Define using __NGREG. [!__x86_64__] (struct _libc_fpreg): Use __ctx in defining fields. [!__x86_64__] (struct _libc_fpstate): Likewise. [!__x86_64__] (mcontext_t): Likewise.
2017-06-01Avoid tickling a linker bug from microblaze pt-vfork.S.Zack Weinberg
libpthread used to have its own vfork implementation that differed from libc's only in having a pointless micro-optimization. There is no longer any use to having a separate copy in libpthread, but the historical ABI requires a compatibility shim. microblaze was trying to be slightly too clever about how it did this, and tickled a linker bug. The linker bug should get fixed eventually, but there's no reason for us to keep tickling it in the meantime. This doesn't reuse the generic pt-vfork.c because microblaze doesn't have IFUNC support yet, and it doesn't reuse aarch64/pt-vfork.c because that fails to generate a tailcall (with GCC 7.1.1). * sysdeps/unix/sysv/linux/microblaze/pt-vfork.S: Don't include alpha/pt-vfork.S. Provide own compat shim for vfork and __vfork. * sysdeps/unix/sysv/linux/microblaze/vfork.S: Add __libc_vfork alias. * sysdeps/unix/sysv/linux/microblaze/localplt.data: libpthread.so no longer references __errno_location.
2017-05-31posix: Implement preadv2 and pwritev2Adhemerval Zanella
This patch adds support of preadv2 and pwritev2 which are similar to preadv/pwritev but with an extra flag argument. As for preadv/pwritev both interfaces are added a non-standard GNU API. For default 'posix' implementation trying to emulate the Linux supported flags is troublesome: * We can not temporary change the file state of the O_DSYNC and O_SYNC flags to emulate RWF_{D}SYNC (attempts to change the state of using fcntl are silently ignored). * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal semantic not provided by any other flag (O_NONBLOCK for instance). So default sysdeps/posix implementations fails with EOPNOTSUPP for any non supported flag (which are none currently) calls generic preadv/pwritev. Basically this implementation supports only preadv2 called as preadv (with flags sets to 0). The Linux one uses the preadv2/pwritev2 syscall if defined, otherwise it call preadv/writev. Instead of using the previous __ASSUME_* to unconditionally issue the syscall (and avoid building the fallback routine), it call pread/write if the preadv2/pwritev2 syscalls fails. The idea is just avoid adding another __ASSUME_* and checking each architecture on every kernel bump and simplify code conditionals. Checked on x86_64-linux-gnu and on i686-linux-gnu and a check with run-built-tests=no on aarch64-linux-gnu, alpha-linux-gnu, arm-linux-gnueabihf, ia64-linux-gnu, m68k-linux-gnu, microblaze-linux-gnu, mips{64,64n32}-linux-gnu, nios2-linux-gnu, powerpc{64,64le}-linux-gnu, s390{x}-linux-gnu, sparc{64,v9}-linux-gnu, tile{gx,pro}-linux-gnu, and sh4-linux-gnu (all using gcc 6.3). * NEWS: Add note about pwritev2 and preadv2 inclusion. * misc/Makefile (routines): Add preadv2, preadv64v2, pwritev2, and pwritev64v2. (tests): Add tst-preadvwritev2 and tst-preadvwritev64v2. * misc/Versions (GLIBC_2.26): Add preadv2, preadv64v2, pwritev2, and pwritev64v2. * misc/preadv2.c: New file. * misc/preadv64v2.c: Likewise. * misc/pwritev2.c: Likewise. * misc/pwritev64v2.c: Likewise. * misc/tst-preadvwritev2.c: Likewise. * misc/tst-preadvwritev64v2.c: Likewise. * manual/llio.texi: Add preadv2 and pwritev2 documentation. * misc/sys/uio.h [__USE_GNU && !__USE_FILE_OFFSET64] (preadv2): New prototype. [__USE_GNU && !__USE_FILE_OFFSET64] (pwritev2): Likewise. [__USE_GNU && __USE_FILE_OFFSET64] (preadv64v2): Likewise. [__USE_GNU && __USE_FILE_OFFSET64] (pwritev64v2): Likewise. * misc/tst-preadvwritev-common.c (PREADV): Define if not defined. (PWRITEV): Likewise. (do_test_with_offset): Use PREADV and PWRITEV macros and check for ENOSYS. * nptl/tst-cancel4.c (tf_pwritev2): New test. (tf_preadv2): Likewise. (tf_fsync): Add tf_pwritev2 and tf_preadv2. * sysdeps/posix/preadv2.c: Likewise. * sysdeps/posix/preadv64v2.c: Likewise. * sysdeps/posix/pwritev2.c: Likewise. * sysdeps/posix/pwritev64v2.c: Likewise. * sysdeps/unix/sysv/linux/kernel-features.h: Add comment for syscall support in kernel. * sysdeps/unix/sysv/linux/preadv2.c: Likewise. * sysdeps/unix/sysv/linux/preadv64v2.c: Likewise. * sysdeps/unix/sysv/linux/pwritev2.c: Likewise. * sysdeps/unix/sysv/linux/pwritev64v2.c: Likewise. * sysdeps/unix/sysv/linux/preadv.c (preadv): Add libc_hidden_def. * sysdeps/unix/sysv/linux/preadv64.c (preadv64): Likewise. * sysdeps/unix/sysv/linux/pwritev.c (pwritev): Likewise. * sysdeps/unix/sysv/linux/pwritev64.c (pwritev64): Likewise. * sysdeps/unix/sysv/linux/bits/uio.h: Add supported preadv2/pwritev2 support flags on Linux. * sysdeps/unix/sysv/linux/aarch64/libc.abilist (GLIBC_2.26): Add preadv2, preadv64v2, pwritev2, pwritev64v2. * sysdeps/unix/sysv/linux/alpha/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/unix/sysv/linux/arm/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/unix/sysv/linux/hppa/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/unix/sysv/linux/i386/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/unix/sysv/linux/ia64/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/unix/sysv/linux/microblaze/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/unix/sysv/linux/nios2/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist (GLIBC_2.26): Likewise. * sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/unix/sysv/linux/sh/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/sysv/linux/tile/tilegx/tilegx32/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/sysv/linux/tile/tilegx/tilegx64/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/unix/sysv/linux/x86_64/64/libc.abilist (GLIBC_2.26): Likewise. * sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist (GLIBC_2.26): Likewise.
2017-05-31Use test-driver in nptl/tst-fork3.cAndreas Schwab
2017-05-31Delay initialization of CPU features struct in static binariesSiddhesh Poyarekar
Allow the CPU features structure set up to be overridden by tunables by delaying it to until after tunables are initialized. The initialization is already delayed in dynamically linked glibc, it is only in static binaries that the initialization is set early to allow it to influence IFUNC relocations that happen in libc-start. It is a bit too early however and there is a good place between tunables initialization and IFUNC relocations where this can be done. Verified that this does not regress the testsuite. * csu/libc-start.c [!ARCH_INIT_CPU_FEATURES]: Define ARCH_INIT_CPU_FEATURES. (LIBC_START_MAIN): Call it. * sysdeps/unix/sysv/linux/aarch64/libc-start.c (__libc_start_main): Remove. (ARCH_INIT_CPU_FEATURES): New macro. * sysdeps/x86/libc-start.c (__libc_start_main): Remove. (ARCH_INIT_CPU_FEATURES): New macro.
2017-05-30Add reallocarray functionDennis Wölfing
The reallocarray function is an extension from OpenBSD. It is an integer-overflow-safe replacement for realloc(p, X*Y) and malloc(X*Y) (realloc(NULL, X*Y)). It can therefore help in preventing certain security issues in code. This is an updated version of a patch originally submitted by Rüdiger Sonderfeld in May 2014 [1]. Checked on i686-linux-gnu and x86_64-linux-gnu. [1] <https://sourceware.org/ml/libc-alpha/2014-05/msg00481.html>. 2017-05-30 Dennis Wölfing <denniswoelfing@gmx.de> Rüdiger Sonderfeld <ruediger@c-plusplus.de> * include/stdlib.h (__libc_reallocarray): New declaration. * malloc/Makefile (routines): Add reallocarray. (tests): Add tst-reallocarray.c. * malloc/Versions: Add reallocarray and __libc_reallocarray. * malloc/malloc-internal.h (check_mul_overflow_size_t): New inline function. * malloc/malloc.h (reallocarray): New declaration. * stdlib/stdlib.h (reallocarray): Likewise. * malloc/reallocarray.c: New file. * malloc/tst-reallocarray.c: New test file. * manual/memory.texi: Document reallocarray. * sysdeps/unix/sysv/linux/aarch64/libc.abilist: Add reallocarray. * sysdeps/unix/sysv/linux/alpha/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/arm/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/hppa/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/i386/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/ia64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/microblaze/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/nios2/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/sh/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/tilepro/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise.
2017-05-30x86_64: Remove redundant REX bytes from memchr.SH.J. Lu
By x86-64 specification, 32-bit destination registers are zero-extended to 64 bits. There is no need to use 64-bit registers when only the lower 32 bits are non-zero. * sysdeps/x86_64/memchr.S (MEMCHR): Use 32-bit registers for the lower 32 bits.
2017-05-29m68k: handle default PIEAndreas Schwab
2017-05-25Add memchr tests for n == 0H.J. Lu
* string/test-memchr.c (test_main): Add tests for n == 0.
2017-05-25Move tst-mutex*8* to tests-internalTulio Magno Quites Machado Filho
The following tests depend on ENABLE_LOCK_ELISION, which is only available on tests-internal. - nptl/tst-mutex8 - nptl/tst-mutex8-static - nptl/tst-mutexpi8 - nptl/tst-mutexpi8-static * nptl/Makefile (tests): Move nptl/tst-mutex8, nptl/tst-mutex8-static, nptl/tst-mutexpi8 and nptl/tst-mutexpi8-static to... (tests-internal): ... here.
2017-05-25Make __tunables_init hidden and avoid PLTH.J. Lu
Since __tunables_init is internal to ld.so, we should mark it hidden to avoid PLT. We should also avoid PLT when calling __tunable_set_val within ld.so. 2017-05-25 Siddhesh Poyarekar <siddhesh@sourceware.org> H.J. Lu <hongjiu.lu@intel.com> * elf/dl-tunables.c (__tunable_set_val): Make a hidden alias. * elf/dl-tunables.h (__tunables_init): Mark it hidden in rtld. (__tunable_set_val): Likewise.
2017-05-25Support dl-tunables.list in subdirectoriesH.J. Lu
We can put processor specific tunables in dl-tunables.list under sysdeps instead of in elf/dl-tunables.list. * Makeconfig ($(common-objpfx)dl-tunable-list.h): Also check dl-tunables.list in subdirectories.
2017-05-25float128: Add wrappers to override ldbl-128 as float128.Paul E. Murphy
This change defines float128_private.h which contains macros used to override long double naming conventions when building a ldbl file. * math/math.h [__HAVE_FLOAT128 && __GLIBC_USE (IEC_60559_TYPES_EXT)] (SNANF128): New macro. * math/e_sqrtf128.c: New file. * math/s_fmaxmag_template.c: Include math_private.h in order to make inline expansion of fabs128(). * math/s_fminmag_template.c: Likewise. * sysdeps/ieee754/float128/e_acosf128.c: New file. * sysdeps/ieee754/float128/e_acoshf128.c: New file. * sysdeps/ieee754/float128/e_asinf128.c: New file. * sysdeps/ieee754/float128/e_atan2f128.c: New file. * sysdeps/ieee754/float128/e_atanhf128.c: New file. * sysdeps/ieee754/float128/e_coshf128.c: New file. * sysdeps/ieee754/float128/e_exp10f128.c: New file. * sysdeps/ieee754/float128/e_expf128.c: New file. * sysdeps/ieee754/float128/e_fmodf128.c: New file. * sysdeps/ieee754/float128/e_gammaf128_r.c: New file. * sysdeps/ieee754/float128/e_hypotf128.c: New file. * sysdeps/ieee754/float128/e_ilogbf128.c: New file. * sysdeps/ieee754/float128/e_j0f128.c: New file. * sysdeps/ieee754/float128/e_j1f128.c: New file. * sysdeps/ieee754/float128/e_jnf128.c: New file. * sysdeps/ieee754/float128/e_lgammaf128_r.c: New file. * sysdeps/ieee754/float128/e_log10f128.c: New file. * sysdeps/ieee754/float128/e_log2f128.c: New file. * sysdeps/ieee754/float128/e_logf128.c: New file. * sysdeps/ieee754/float128/e_powf128.c: New file. * sysdeps/ieee754/float128/e_rem_pio2f128.c: New file. * sysdeps/ieee754/float128/e_remainderf128.c: New file. * sysdeps/ieee754/float128/e_scalbf128.c: New file. * sysdeps/ieee754/float128/e_sinhf128.c: New file. * sysdeps/ieee754/float128/float128_private.h: New file. * sysdeps/ieee754/float128/gamma_productf128.c: New file. * sysdeps/ieee754/float128/ieee754_float128.h: New file. * sysdeps/ieee754/float128/k_cosf128.c: New file. * sysdeps/ieee754/float128/k_sincosf128.c: New file. * sysdeps/ieee754/float128/k_sinf128.c: New file. * sysdeps/ieee754/float128/k_tanf128.c: New file. * sysdeps/ieee754/float128/lgamma_negf128.c: New file. * sysdeps/ieee754/float128/lgamma_productf128.c: New file. * sysdeps/ieee754/float128/s_asinhf128.c: New file. * sysdeps/ieee754/float128/s_atanf128.c: New file. * sysdeps/ieee754/float128/s_cbrtf128.c: New file. * sysdeps/ieee754/float128/s_ceilf128.c: New file. * sysdeps/ieee754/float128/s_copysignf128.c: New file. * sysdeps/ieee754/float128/s_cosf128.c: New file. * sysdeps/ieee754/float128/s_erff128.c: New file. * sysdeps/ieee754/float128/s_expm1f128.c: New file. * sysdeps/ieee754/float128/s_fabsf128.c: New file. * sysdeps/ieee754/float128/s_finitef128.c: New file. * sysdeps/ieee754/float128/s_floorf128.c: New file. * sysdeps/ieee754/float128/s_fmaf128.c: New file. * sysdeps/ieee754/float128/s_fpclassifyf128.c: New file. * sysdeps/ieee754/float128/s_frexpf128.c: New file. * sysdeps/ieee754/float128/s_fromfpf128.c: New file. * sysdeps/ieee754/float128/s_fromfpxf128.c: New file. * sysdeps/ieee754/float128/s_getpayloadf128.c: New file. * sysdeps/ieee754/float128/s_isinff128.c: New file. * sysdeps/ieee754/float128/s_isnanf128.c: New file. * sysdeps/ieee754/float128/s_issignalingf128.c: New file. * sysdeps/ieee754/float128/s_llrintf128.c: New file. * sysdeps/ieee754/float128/s_llroundf128.c: New file. * sysdeps/ieee754/float128/s_log1pf128.c: New file. * sysdeps/ieee754/float128/s_logbf128.c: New file. * sysdeps/ieee754/float128/s_lrintf128.c: New file. * sysdeps/ieee754/float128/s_lroundf128.c: New file. * sysdeps/ieee754/float128/s_modff128.c: New file. * sysdeps/ieee754/float128/s_nearbyintf128.c: New file. * sysdeps/ieee754/float128/s_nextafterf128.c: New file. * sysdeps/ieee754/float128/s_nexttowardf128.c: New file. * sysdeps/ieee754/float128/s_nextupf128.c: New file. * sysdeps/ieee754/float128/s_remquof128.c: New file. * sysdeps/ieee754/float128/s_rintf128.c: New file. * sysdeps/ieee754/float128/s_roundevenf128.c: New file. * sysdeps/ieee754/float128/s_roundf128.c: New file. * sysdeps/ieee754/float128/s_scalblnf128.c: New file. * sysdeps/ieee754/float128/s_scalbnf128.c: New file. * sysdeps/ieee754/float128/s_setpayloadf128.c: New file. * sysdeps/ieee754/float128/s_setpayloadsigf128.c: New file. * sysdeps/ieee754/float128/s_signbitf128.c: New file. * sysdeps/ieee754/float128/s_significandf128.c: New file. * sysdeps/ieee754/float128/s_sincosf128.c: New file. * sysdeps/ieee754/float128/s_sinf128.c: New file. * sysdeps/ieee754/float128/s_tanf128.c: New file. * sysdeps/ieee754/float128/s_tanhf128.c: New file. * sysdeps/ieee754/float128/s_totalorderf128.c: New file. * sysdeps/ieee754/float128/s_totalordermagf128.c: New file. * sysdeps/ieee754/float128/s_truncf128.c: New file. * sysdeps/ieee754/float128/s_ufromfpf128.c: New file. * sysdeps/ieee754/float128/s_ufromfpxf128.c: New file. * sysdeps/ieee754/float128/t_sincosf128.c: New file. * sysdeps/ieee754/float128/x2y2m1f128.c: New file. * sysdeps/ieee754/ldbl-128ibm/bits/iscanonical.h: (__iscanonicalf128): Define as a macro.
2017-05-24aarch64: Thunderx specific memcpy and memmoveSteve Ellcey
* sysdeps/aarch64/memcpy.S (MEMMOVE, MEMCPY): New macros. (memmove): Use MEMMOVE for name. (memcpy): Use MEMCPY for name. Change internal labels to external labels. * sysdeps/aarch64/multiarch/Makefile: New file. * sysdeps/aarch64/multiarch/ifunc-impl-list.c: Likewise. * sysdeps/aarch64/multiarch/init-arch.h: Likewise. * sysdeps/aarch64/multiarch/memcpy.c: Likewise. * sysdeps/aarch64/multiarch/memcpy_generic.S: Likewise. * sysdeps/aarch64/multiarch/memcpy_thunderx.S: Likewise. * sysdeps/aarch64/multiarch/memmove.c: Likewise.
2017-05-24arm: Fix typo in array countSiddhesh Poyarekar
I just noticed that the array count for the hwcap flags list in ARM is off by 10, i.e. 37 instead of 27. Following patch fixes this. * sysdeps/unix/sysv/linux/arm/dl-procinfo.c (_dl_arm_cap_flags): Fix array subscript. * sysdeps/unix/sysv/linux/arm/dl-procinfo.h (_DL_HWCAP_COUNT): Fix count.
2017-05-24x86: Don't include cacheinfo.c in ld.soH.J. Lu
Since cacheinfo.c isn't used by ld.so, there is no need to include it in ld.so. * sysdeps/x86/cacheinfo.c: Skip if not in libc.
2017-05-24x86: Use __get_cpu_features to get cpu_featuresH.J. Lu
Remove is_intel, is_amd and max_cpuid macros. Use __get_cpu_features to get cpu_features instead. * sysdeps/x86/cacheinfo.c (is_intel): Removed. (is_amd): Likewise. (max_cpuid): Likewise. (__cache_sysconf): Use __get_cpu_features to get cpu_features. (init_cacheinfo): Likewise.
2017-05-23Fix sigstack namespace (bug 21511).Joseph Myers
The sigstack function was removed in the 2001 edition of POSIX, and the sigstack structure in the 2008 edition. signal.h wrongly includes those declarations even for newer POSIX versions. This patch fixes the conditions, and conform/ expectations, accordingly. This patch makes the minimum change to when these declarations are present, leaving them visible for __USE_MISC as they would previously have been visible by default. Arguably these legacy declarations should only be visible when an old standard is specifically requested, but implementing that would require arranging for the various sigstack implementations to be able to see the struct sigstack type despite it not being in _GNU_SOURCE in that case. Tested for x86_64. [BZ #21511] * signal/signal.h: Include <bits/types/struct_sigstack.h> only if [(__USE_XOPEN_EXTENDED && !__USE_XOPEN2K8) || __USE_MISC]. (sigstack): Declare only if [(__USE_XOPEN_EXTENDED && !__USE_XOPEN2K) || __USE_MISC]. * conform/data/signal.h-data (struct sigstack): Expect type only if [!XOPEN2K8 && !POSIX2008]. (sigstack): Expect function only if [XPG42 || UNIX98].
2017-05-23Fix sys/ucontext.h namespace from signal.h etc. inclusion (bug 21457).Joseph Myers
The various sys/ucontext.h headers include <signal.h> and all the headers split out of <bits/sigstack.h>. (Except that the powerpc version does not include <signal.h>.) None of the standard versions defining ucontext.h require or permit such inclusions; rather, they all say that the stack_t and sigset_t types from signal.h are defined. This patch fixes the headers to include just the bits/ headers for those types (and the existing includes of bits/sigcontext.h). Since bits/types/sigset_t.h is now being included instead of bits/types/__sigset_t.h, __sigset_t uses in the headers are replaced by direct use of the public sigset_t type. sysdeps/unix/sysv/linux/x86/bits/sigcontext.h was relying on the prior inclusion of <signal.h> to define types such as __uint32_t, so gets a bits/types.h include added to provide those types. Although one could keep some or all of the includes under a __USE_MISC conditional, that seems unnecessary to me, especially given the lack of a <signal.h> include in the powerpc version meaning that portable programs already cannot rely on such an include. Tested for x86_64 and x86, and with build-many-glibcs.py. As with other such fixes, more namespace issues remain so this does not permit any XFAILs to be removed or bugs to be closed. [BZ #21457] * sysdeps/arm/sys/ucontext.h: Do not include <signal.h>, <bits/sigstack.h>, <bits/types/struct_sigstack.h> or <bits/ss_flags.h>. Include <bits/types/sigset_t.h> instead of <bits/types/__sigset_t.h>. (ucontext_t): Use sigset_t instead of __sigset_t. * sysdeps/generic/sys/ucontext.h: Do not include <signal.h>, <bits/sigstack.h>, <bits/types/struct_sigstack.h> or <bits/ss_flags.h>. Include <bits/types/sigset_t.h> instead of <bits/types/__sigset_t.h>. (ucontext_t): Use sigset_t instead of __sigset_t. * sysdeps/i386/sys/ucontext.h: Do not include <signal.h>, <bits/sigstack.h>, <bits/types/struct_sigstack.h> or <bits/ss_flags.h>. Include <bits/types/sigset_t.h> instead of <bits/types/__sigset_t.h>. (ucontext_t): Use sigset_t instead of __sigset_t. * sysdeps/m68k/sys/ucontext.h: Do not include <signal.h>, <bits/sigstack.h>, <bits/types/struct_sigstack.h> or <bits/ss_flags.h>. Include <bits/types/sigset_t.h> instead of <bits/types/__sigset_t.h>. (ucontext_t): Use sigset_t instead of __sigset_t. * sysdeps/mips/sys/ucontext.h: Do not include <signal.h>, <bits/sigstack.h>, <bits/types/struct_sigstack.h> or <bits/ss_flags.h>. Include <bits/types/sigset_t.h> instead of <bits/types/__sigset_t.h>. (ucontext_t): Use sigset_t instead of __sigset_t. * sysdeps/unix/sysv/linux/aarch64/sys/ucontext.h: Do not include <signal.h>, <bits/sigstack.h>, <bits/types/struct_sigstack.h> or <bits/ss_flags.h>. Include <bits/types/sigset_t.h> instead of <bits/types/__sigset_t.h>. (ucontext_t): Use sigset_t instead of __sigset_t. * sysdeps/unix/sysv/linux/alpha/sys/ucontext.h: Do not include <signal.h>, <bits/sigstack.h>, <bits/types/struct_sigstack.h> or <bits/ss_flags.h>. Include <bits/types/sigset_t.h> instead of <bits/types/__sigset_t.h>. (ucontext_t): Use sigset_t instead of __sigset_t. * sysdeps/unix/sysv/linux/arm/sys/ucontext.h: Do not include <signal.h>, <bits/sigstack.h>, <bits/types/struct_sigstack.h> or <bits/ss_flags.h>. Include <bits/types/sigset_t.h> instead of <bits/types/__sigset_t.h>. (ucontext_t): Use sigset_t instead of __sigset_t. * sysdeps/unix/sysv/linux/hppa/sys/ucontext.h: Do not include <signal.h>, <bits/sigstack.h>, <bits/types/struct_sigstack.h> or <bits/ss_flags.h>. Include <bits/types/sigset_t.h> instead of <bits/types/__sigset_t.h>. (ucontext_t): Use sigset_t instead of __sigset_t. * sysdeps/unix/sysv/linux/ia64/sys/ucontext.h: Do not include <signal.h>, <bits/sigstack.h>, <bits/types/struct_sigstack.h> or <bits/ss_flags.h>. Include <bits/types/sigset_t.h>. * sysdeps/unix/sysv/linux/m68k/sys/ucontext.h: Do not include <signal.h>, <bits/sigstack.h>, <bits/types/struct_sigstack.h> or <bits/ss_flags.h>. Include <bits/types/sigset_t.h> instead of <bits/types/__sigset_t.h>. (ucontext_t): Use sigset_t instead of __sigset_t. * sysdeps/unix/sysv/linux/mips/sys/ucontext.h: Do not include <signal.h>, <bits/sigstack.h>, <bits/types/struct_sigstack.h> or <bits/ss_flags.h>. Include <bits/types/sigset_t.h> instead of <bits/types/__sigset_t.h>. (ucontext_t): Use sigset_t instead of __sigset_t. * sysdeps/unix/sysv/linux/nios2/sys/ucontext.h: Do not include <signal.h>, <bits/sigstack.h>, <bits/types/struct_sigstack.h> or <bits/ss_flags.h>. Include <bits/types/sigset_t.h> instead of <bits/types/__sigset_t.h>. (ucontext_t): Use sigset_t instead of __sigset_t. * sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h: Do not include <bits/sigstack.h>, <bits/types/struct_sigstack.h> or <bits/ss_flags.h>. * sysdeps/unix/sysv/linux/s390/sys/ucontext.h: Do not include <signal.h>, <bits/sigstack.h>, <bits/types/struct_sigstack.h> or <bits/ss_flags.h>. Include <bits/types/sigset_t.h> instead of <bits/types/__sigset_t.h>. (ucontext_t): Use sigset_t instead of __sigset_t. * sysdeps/unix/sysv/linux/sh/sys/ucontext.h: Do not include <signal.h>, <bits/sigstack.h>, <bits/types/struct_sigstack.h> or <bits/ss_flags.h>. Include <bits/types/sigset_t.h> instead of <bits/types/__sigset_t.h>. (ucontext_t): Use sigset_t instead of __sigset_t. * sysdeps/unix/sysv/linux/sparc/sys/ucontext.h: Do not include <signal.h>, <bits/sigstack.h>, <bits/types/struct_sigstack.h> or <bits/ss_flags.h>. Include <bits/types/sigset_t.h> instead of <bits/types/__sigset_t.h>. (ucontext_t): Use sigset_t instead of __sigset_t. * sysdeps/unix/sysv/linux/tile/sys/ucontext.h: Do not include <signal.h>, <bits/sigstack.h>, <bits/types/struct_sigstack.h> or <bits/ss_flags.h>. Include <bits/types/sigset_t.h> instead of <bits/types/__sigset_t.h>. (ucontext_t): Use sigset_t instead of __sigset_t. * sysdeps/unix/sysv/linux/x86/bits/sigcontext.h: Include <bits/types.h>. * sysdeps/unix/sysv/linux/x86/sys/ucontext.h: Do not include <signal.h>, <bits/sigstack.h>, <bits/types/struct_sigstack.h> or <bits/ss_flags.h>. Include <bits/types/sigset_t.h> instead of <bits/types/__sigset_t.h>. (ucontext_t): Use sigset_t instead of __sigset_t.
2017-05-22Fix a bug in 'Remove __need macros from signal.h' (a992f506)Zack Weinberg
siginfo-arch.h is included in two different places, so the default definitions of the macros that it might or might not define need to be done conditionally afterward, not unconditionally beforehand. * sysdeps/unix/sysv/linux/bits/siginfo-consts.h (__SI_ASYNCIO_AFTER_SIGIO): Define default after including bits/siginfo-arch.h, only if not already defined. * sysdeps/unix/sysv/linux/bits/types/siginfo_t.h (__SI_ALIGNMENT, __SI_BAND_TYPE, __SI_CLOCK_T) (__SI_ERRNO_THEN_CODE, __SI_HAVE_SIGSYS, __SI_SEGFAULT_ADDL): Likewise. * sysdeps/unix/sysv/linux/ia64/bits/siginfo-arch.h * sysdeps/unix/sysv/linux/mips/bits/siginfo-arch.h * sysdeps/unix/sysv/linux/sparc/bits/siginfo-arch.h * sysdeps/unix/sysv/linux/tile/bits/siginfo-arch.h * sysdeps/unix/sysv/linux/x86/bits/siginfo-arch.h: Unconditionally define __SI_* macros.
2017-05-22libio: Avoid dup already opened file descriptor [BZ#21393]Adhemerval Zanella
As described in BZ#21398 (close as dup of 21393) report current freopen implementation fails when one tries to freopen STDIN_FILENO, STDOUT_FILENO, or STDERR_FILENO. Although on bug report the discussion leads to argue if a close followed by a freopen on the standard file is a valid operation, the underlying issue is not really the check for dup3 returned value, but rather calling it if the returned file descriptor is equal as the input one. So for a quality of implementation this patch avoid calling dup3 for the aforementioned case. It also adds a dup3 error case check for the two possible failures, with one being Linux only: EINTR and EBUSY. The EBUSY issue is better explained on this stackoverflow thread [1], but in a short it is due the internal Linux implementation which allows a race condition window for dup2 due the logic dissociation of file descriptor allocation and actual VFS 'install' operation. For both outliers failures all allocated memory is freed and a NULL FILE* is returned. With this patch the example on BZ#21398 is now actually possible (I used as the testcase for the bug report). Checked on x86_64-linux-gnu. [BZ #21393] * libio/freopen.c (freopen): Avoid dup already opened file descriptor and add a check for dup3 failure. * libio/freopen64.c (freopen64): Likewise. * libio/tst-freopen.c (do_test): Rename to do_test_basic and use libsupport. (do_test_bz21398): New test. * manual/stdio.texi (freopen): Add documentation of EBUSY failure. [1] http://stackoverflow.com/questions/23440216/race-condition-when-using-dup2