This patch continues fixing __ASSUME_* issues in preparation for
moving to a 2.6.32 minimum kernel version by addressing assumptions on
robust mutex and PI futex support availability. Those assumptions are
bug 9894, but to be clear this patch does not address all the issues
from that bug about wrong version assumptions, only those still
applicable for --enable-kernel=2.6.32 or later (with the expectation
that the move to that minimum kernel will obsolete the other parts of
the bug). The patch is independent of
<https://sourceware.org/ml/libc-alpha/2014-03/msg00585.html>, my other
pending-review patch preparing for the kernel version change; the two
together complete all the changes I believe are needed in preparation
regarding any macro in sysdeps/unix/sysv/linux/kernel-features.h that
would be affected by such a change. (I have not checked the
correctness of macros whose conditions are unaffected by such a
change, or macros only defined in other kernel-features.h files.)
As discussed in that bug, robust mutexes and PI futexes need
futex_atomic_cmpxchg_inatomic to be implemented, in addition to
certain syscalls needed for robust mutexes (and
architecture-independent kernel pieces for all the features in
question). That is, as I understand it, they need
futex_atomic_cmpxchg_inatomic to *work* (not return an ENOSYS error).
The issues identified in my analysis relate to ARM, M68K, MicroBlaze,
MIPS and SPARC.
On ARM, whether futex_atomic_cmpxchg_inatomic works depends on the
kernel configuration. As of 3.13, the condition for *not* working is
CONFIG_CPU_USE_DOMAINS && CONFIG_SMP. As of 2.6.32 it was simply
CONFIG_SMP that meant the feature was not implemented. I don't know
if there are any circumstances in which we can say "we can assume a
userspace glibc binary built with these options will never run on a
kernel with the problematic configuration", but at least for now I'm
just undefining the relevant __ASSUME_* macros for ARM.
On M68K, two of the three macros are undefined for kernels before
3.10, but as far as I can see __ASSUME_FUTEX_LOCK_PI is in the same
group needing futex_atomic_cmpxchg_inatomic support and so should be
undefined as well.
On MicroBlaze the required support was added in 2.6.33.
On MIPS, the support depends on cpu_has_llsc in the kernel - that is,
actual hardware LL/SC support (GCC and glibc for MIPS GNU/Linux rely
on the instructions being supported in some way, but it may be kernel
emulation; futex_atomic_cmpxchg_inatomic doesn't work with that
emulation). The same condition as in GCC for indicating LL/SC support
may not be available is used for undefining the macros in glibc,
__mips == 1 || defined _MIPS_ARCH_R5900. (Maybe we could in fact
desupport MIPS processors without the hardware support in glibc.)
On SPARC, 32-bit kernels don't support futex_atomic_cmpxchg_inatomic;
__arch64__ || __sparc_v9__ is used as the condition for binaries that
won't run on 32-bit kernels.
This patch is not tested beyond the sanity check of an x86_64 build.
[BZ #9894]
* sysdeps/unix/sysv/linux/kernel-features.h
[__sparc__ && !__arch64__ && !__sparc_v9__]
(__ASSUME_SET_ROBUST_LIST): Do not define.
[__sparc__ && !__arch64__ && !__sparc_v9__]
(__ASSUME_FUTEX_LOCK_PI): Likewise.
[__sparc__ && !__arch64__ && !__sparc_v9__] (__ASSUME_REQUEUE_PI):
Likewise.
* sysdeps/unix/sysv/linux/arm/kernel-features.h
(__ASSUME_FUTEX_LOCK_PI): Undefine.
(__ASSUME_REQUEUE_PI): Likewise.
(__ASSUME_SET_ROBUST_LIST): Likewise.
* sysdeps/unix/sysv/linux/m68k/kernel-features.h
[__LINUX_KERNEL_VERSION < 0x030a00] (__ASSUME_FUTEX_LOCK_PI):
Undefine.
* sysdeps/unix/sysv/linux/microblaze/kernel-features.h
[__LINUX_KERNEL_VERSION < 0x020621] (__ASSUME_FUTEX_LOCK_PI):
Likewise.
[__LINUX_KERNEL_VERSION < 0x020621] (__ASSUME_REQUEUE_PI):
Likewise.
[__LINUX_KERNEL_VERSION < 0x020621] (__ASSUME_SET_ROBUST_LIST):
Likewise.
* sysdeps/unix/sysv/linux/mips/kernel-features.h
[__mips == 1 || _MIPS_ARCH_R5900] (__ASSUME_FUTEX_LOCK_PI):
Undefine.
[__mips == 1 || _MIPS_ARCH_R5900] (__ASSUME_REQUEUE_PI): Likewise.
[__mips == 1 || _MIPS_ARCH_R5900] (__ASSUME_SET_ROBUST_LIST):
Likewise.
In <https://sourceware.org/ml/libc-alpha/2013-12/msg00008.html>,
Aurelien noted issues with the definition of __ASSUME_ACCEPT4, which I
discussed in more detail in
<https://sourceware.org/ml/libc-alpha/2013-12/msg00014.html>; these
are now bug 16609.
As previously noted, __ASSUME_ACCEPT4 is used in two ways:
* In OS-independent code, to mean "accept4 can be assumed to work
rather than fail with ENOSYS". It doesn't matter whether it's
implemented with socketcall or a separate syscall.
* In Linux-specific code, to mean "the socketcall multiplex syscall
can be assumed to handle the accept4 operation. When used in
Linux-specific code, it *never* refers to anything relating to the
accept4 syscall, only to the socketcall multiplexer.
This patch splits the macro into separate __ASSUME_ACCEPT4_SOCKETCALL,
__ASSUME_ACCEPT4_SYSCALL and __ASSUME_ACCEPT4 to clarify the different
cases involved. A macro __ASSUME_SOCKETCALL is added for convenience
in writing logic relating to all socketcall architectures. In
addition, to address the issue of architectures where socketcall
support for accept4 was added before a separate syscall was added (and
so the separate syscall should not be used unless known to be present
or fallback to socketcall is available), a fourth macro
__ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL is added to indicate that the
syscall became available at the same time as socketcall support. This
is then used in the relevant places in a conditional determining
whether to undefine __NR_accept4 (the simple approach to avoiding the
syscall's presence causing problems; I didn't try to implement runtime
fallback from the syscall to socketcall).
Architecture-specific note: alpha defined __ASSUME_ACCEPT4 for 2.6.33
and later, but actually the syscall was added for alpha in 3.2, so
this patch uses the correct condition for __ASSUME_ACCEPT4_SYSCALL
there.
Tested x86_64, including that disassembly of the installed shared
libraries is unchanged by this patch.
[BZ #16609]
* sysdeps/unix/sysv/linux/kernel-features.h [__i386__ ||
__powerpc__ || __s390__ || __sh__ || __sparc__]
(__ASSUME_SOCKETCALL): Define.
[__LINUX_KERNEL_VERSION && __ASSUME_SOCKETCALL]
(__ASSUME_ACCEPT4_SOCKETCALL): Likewise.
[(__LINUX_KERNEL_VERSION >= 0x02061c && (__x86_64__ || __sparc__))
|| (__LINUX_KERNEL_VERSION >= 0x020625 && (__powerpc__ ||
__sh__))] (__ASSUME_ACCEPT4_SYSCALL): Likewise.
[__sparc__] (__ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL): Likewise.
[__ASSUME_ACCEPT4_SOCKETCALL || __ASSUME_ACCEPT4_SYSCALL]
(__ASSUME_ACCEPT4): Define instead of using previous
[__LINUX_KERNEL_VERSION >= 0x02061c && (__i386__ || __x86_64__ ||
__powerpc__ || __sparc__ || __s390__)] condition.
* sysdeps/unix/sysv/linux/aarch64/kernel-features.h
(__ASSUME_ACCEPT4): Change to __ASSUME_ACCEPT4_SYSCALL.
* sysdeps/unix/sysv/linux/accept4.c [__ASSUME_SOCKETCALL &&
!__ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL &&
!__ASSUME_ACCEPT4_SYSCALL] (__NR_accept4): Undefine.
[!__ASSUME_ACCEPT4]: Change condition to
[!__ASSUME_ACCEPT4_SOCKETCALL].
* sysdeps/unix/sysv/linux/alpha/kernel-features.h
(__ASSUME_ACCEPT4): Change to __ASSUME_ACCEPT4_SYSCALL. Correct
condition to [__LINUX_KERNEL_VERSION >= 0x030200].
* sysdeps/unix/sysv/linux/arm/kernel-features.h
[__LINUX_KERNEL_VERSION >= 0x020624] (__ASSUME_ACCEPT4): Change to
__ASSUME_ACCEPT4_SYSCALL.
* sysdeps/unix/sysv/linux/i386/accept4.S [__ASSUME_ACCEPT4]:
Change conditions to [__ASSUME_ACCEPT4_SOCKETCALL].
* sysdeps/unix/sysv/linux/ia64/kernel-features.h
[__LINUX_KERNEL_VERSION >= 0x030300] (__ASSUME_ACCEPT4): Change to
__ASSUME_ACCEPT4_SYSCALL.
* sysdeps/unix/sysv/linux/internal_accept4.S [__ASSUME_SOCKETCALL
&& !__ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL &&
!__ASSUME_ACCEPT4_SYSCALL] (__NR_accept4): Undefine.
[__ASSUME_ACCEPT4]: Change condition to
[__ASSUME_ACCEPT4_SOCKETCALL].
* sysdeps/unix/sysv/linux/m68k/kernel-features.h
(__ASSUME_SOCKETCALL): Define.
[__LINUX_KERNEL_VERSION >= 0x02061c] (__ASSUME_ACCEPT4): Remove.
* sysdeps/unix/sysv/linux/microblaze/kernel-features.h
(__ASSUME_SOCKETCALL): Define.
(__ASSUME_ACCEPT4): Remove.
[__LINUX_KERNEL_VERSION >= 0x020621] (__ASSUME_ACCEPT4_SYSCALL):
Define.
* sysdeps/unix/sysv/linux/mips/kernel-features.h
[__LINUX_KERNEL_VERSION >= 0x02061f] (__ASSUME_ACCEPT4_SYSCALL):
Likewise.
* sysdeps/unix/sysv/linux/tile/kernel-features.h
(__ASSUME_ACCEPT4): Change to __ASSUME_ACCEPT4_SYSCALL.
* sysdeps/unix/sysv/linux/hppa/kernel-features.h
[__LINUX_KERNEL_VERSION >= 0x020622] (__ASSUME_ACCEPT4_SYSCALL):
Define.
fchownat, and unlinkat.
(static-only-routines): Add fstatat and fstatat64.
(tests): Add tst-unlinkat, tst-fstatat, tst-futimesat, tst-renameat,
and tst-fchownat.
* io/Versions [GLIBC_2.4]: Add fchownat, __fxstatat, __fxstatat64,
and unlinkat.
* io/fcntl.h: Define AT_FDCWD, AT_SYMLINK_NOFOLLOW, and AT_REMOVEDIR.
* io/fstatat.c: New file.
* io/fstatat64.c: New file.
* io/sys/stat.h: Declare fstatat, fstatat64, __fxstatat, __fxstatat64
and define fstatat and fstatat64 inline functions.
* libio/stdio.h: Declare renameat.
* misc/Makefile (routines): Add futimesat.
* misc/Versions [GLIBC_2.4]: Add futimesat.
* posix/unistd.h: Declare fchownat and unlinkat.
* stdio-common/Makefile (routines): Add renameat.
* stdio-common/Versions [GLIBC_2.4]: Add renameat.
* sysdeps/generic/fchownat.c: New file.
* sysdeps/generic/futimesat.c: New file.
* sysdeps/generic/fxstatat.c: New file.
* sysdeps/generic/fxstatat64.c: New file.
* sysdeps/generic/renameat.c: New file.
* sysdeps/generic/unlinkat.c: New file.
* sysdeps/unix/sysv/linux/fchownat.c: New file.
* sysdeps/unix/sysv/linux/futimesat.c: New file.
* sysdeps/unix/sysv/linux/fxstatat.c: New file.
* sysdeps/unix/sysv/linux/fxstatat64.c: New file.
* sysdeps/unix/sysv/linux/renameat.c: New file.
* sysdeps/unix/sysv/linux/unlinkat.c: New file.
* sysdeps/unix/sysv/linux/alpha/fxstatat.c: New file.
* sysdeps/unix/sysv/linux/i386/fchownat.c: New file.
* sysdeps/unix/sysv/linux/i386/fxstatat.c: New file.
* sysdeps/unix/sysv/linux/m68k/fchownat.c: New file.
* sysdeps/unix/sysv/linux/m68k/fxstatat.c: New file.
* sysdeps/unix/sysv/linux/powerpc/fchownat.c: New file.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fxstatat.c: New file.
* sysdeps/unix/sysv/linux/s390/s390-32/fchownat.c: New file.
* sysdeps/unix/sysv/linux/s390/s390-32/fxstatat.c: New file.
* sysdeps/unix/sysv/linux/sh/fchownat.c: New file.
* sysdeps/unix/sysv/linux/sh/fxstatat.c: New file.
* sysdeps/unix/sysv/linux/sparc/sparc32/fchownat.c: New file.
* sysdeps/unix/sysv/linux/sparc/sparc32/fxstatat.c: New file.
* sysdeps/unix/sysv/linux/sparc/sparc64/fxstatat.c: New file.
* sysdeps/unix/sysv/linux/wordsize-64/fxstatat.c: New file.
* sysdeps/unix/sysv/linux/wordsize-64/fxstatat64.c: New file.
* time/sys/time.h: Declare futimesat.
* include/fcntl.h: Declare __atfct_seterrno.
* sysdeps/unix/sysv/linux/openat.c (__atfct_seterrno): New function.
Split out from openat code and called.
(do_test): Allow openat to fail with ENOSYS. Handle AT_FDCWD.
* sysdeps/generic/openat.c: Handle AT_FDCWD.
* sysdeps/generic/openat64.c: Likewise.
* io/tst-unlinkat.c: New file.
* io/tst-fstatat.c: New file.
* io/tst-futimesat.c: New file.
* io/tst-renameat.c: New file.
* io/tst-fchownat.c: New file.
* io/tst-openat.c: Don't fail if openat is not implemented.
* sysdeps/unix/sysv/linux/powerpc/chown.c: Don't provide backward
compatibility code if new kernel is guaranteed.
* time/sys/time.h: Add a few nonnull attributes.
2003-07-25 Jakub Jelinek <jakub@redhat.com>
* sysdeps/unix/sysv/linux/a.out.h: Replace with i386 version.
Include bits/a.out.h.
* sysdeps/unix/sysv/linux/Makefile (sysdep_headers): Add
bits/a.out.h.
* sysdeps/unix/sysv/linux/bits/a.out.h: New file.
* sysdeps/unix/sysv/linux/i386/bits/a.out.h: New file.
* sysdeps/unix/sysv/linux/m68k/bits/a.out.h: New file.
* sysdeps/unix/sysv/linux/x86_64/bits/a.out.h: New file.
* sysdeps/unix/sysv/linux/alpha/a.out.h: New file.
* sysdeps/unix/sysv/linux/alpha/bits/a.out.h: New file.
* sysdeps/unix/sysv/linux/sparc/a.out.h: New file.
* sysdeps/unix/sysv/linux/sparc/bits/a.out.h: New file.
changed from [USE_TLS && HAVE___THREAD].
* sysdeps/i386/dl-machine.h (elf_machine_type_class, elf_machine_rel):
Disable TLS relocs if [RTLD_BOOTSTRAP && !USE___THREAD].
* sysdeps/x86_64/dl-machine.h
(elf_machine_type_class, elf_machine_rela): Likewise.
* sysdeps/sh/dl-machine.h (elf_machine_type_class, elf_machine_rela):
Likewise.
* include/link.h (struct link_map): Remove member l_tls_tp_initialized.
* elf/rtld.c (_dl_start_final, dl_main): Don't use it.
(_dl_start): Conditionalize PT_TLS check on [USE___THREAD].
* sysdeps/i386/dl-tls.h (__TLS_GET_ADDR): Use ___tls_get_addr_internal
instead of ___tls_get_addr.
(___tls_get_addr_internal): Add attribute_hidden to decl.
* sysdeps/generic/ldsodefs.h (struct rtld_global): New variable
_dl_error_catch_tsd.
* elf/rtld.c (startup_error_tsd): New function.
(dl_main): Point _dl_error_catch_tsd at that.
* elf/dl-error.c: Don't use libc-tsd.h for DL_ERROR,
use new function pointer instead.
* elf/dl-tsd.c: New file.
* elf/Makefile (routines): Add it.
2002-10-07 Roland McGrath <roland@redhat.com>
* elf/dl-misc.c (_dl_debug_vdprintf): Use INTERNAL_SYSCALL macro for
writev if it's available. Otherwise if [RTLD_PRIVATE_ERRNO] then
take _dl_load_lock around calling __writev.
* sysdeps/unix/sysv/linux/i386/sysdep.h (INTERNAL_SYSCALL): New macro.
(INLINE_SYSCALL): Use that.
* sysdeps/generic/dl-sysdep.h: New file.
* sysdeps/mach/hurd/dl-sysdep.h: New file.
* sysdeps/generic/ldsodefs.h: Include <dl-sysdep.h>.
* include/errno.h [IS_IN_rtld]: Include <dl-sysdep.h> to define ...
[RTLD_PRIVATE_ERRNO]: Use a hidden global variable for errno and
access it directly.
* elf/dl-minimal.c (__errno_location): Removed.
* sysdeps/unix/i386/sysdep.S (__syscall_errno) [RTLD_PRIVATE_ERRNO]:
Use GOTOFF access for errno.
* sysdeps/unix/sysv/linux/i386/sysdep.h
[RTLD_PRIVATE_ERRNO] (SYSCALL_ERROR_HANDLER): Likewise.
* sysdeps/unix/x86_64/sysdep.S (__syscall_errno) [RTLD_PRIVATE_ERRNO]:
Use PC-relative access for errno.
* sysdeps/unix/sysv/linux/x86_64/sysdep.h
[RTLD_PRIVATE_ERRNO] (SYSCALL_ERROR_HANDLER): Likewise.
* include/tls.h: New file.
(USE___THREAD): New macro.
Define to 1 under [USE_TLS && HAVE___THREAD] and only when compiling
libc or libpthread.
* sysdeps/unix/sysv/linux/i386/sysdep.h [USE___THREAD]: Conditional
changed from [USE_TLS && HAVE___THREAD].
* sysdeps/unix/sysv/linux/x86_64/sysdep.h: Likewise.
* sysdeps/unix/i386/sysdep.S: Likewise.
* sysdeps/unix/x86_64/sysdep.S: Likewise.
* include/errno.h: Likewise.
* include/netdb.h: Likewise.
* include/resolv.h: Likewise.
* sysdeps/generic/errno.c: New file.
* csu/Makefile (aux): New variable, list errno.
* sysdeps/unix/sysv/linux/i386/sysdep.S (errno, _errno): Remove defns.
* sysdeps/unix/sysv/linux/m68k/sysdep.S: Likewise.
* sysdeps/unix/sysv/linux/x86_64/sysdep.S: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/sysdep.S: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/sysdep.S: Likewise.
* sysdeps/unix/sysv/linux/arm/sysdep.S: Likewise.
* sysdeps/unix/sysv/linux/cris/sysdep.S: Likewise.
* sysdeps/unix/sysv/linux/hppa/sysdep.c: Likewise.
* sysdeps/unix/sysv/linux/ia64/sysdep.S: Likewise.
* sysdeps/unix/sysv/linux/powerpc/sysdep.c: Likewise.
* sysdeps/unix/sysv/linux/sparc/sysdep.S: Likewise.
* sysdeps/unix/sysv/linux/sh/sysdep.S: Likewise.
* sysdeps/unix/alpha/sysdep.S: Likewise.
* sysdeps/generic/start.c: Likewise.
* sysdeps/unix/start.c: Likewise.
* sysdeps/unix/arm/start.c: Likewise.
* sysdeps/unix/bsd/ultrix4/mips/start.S: Likewise.
* sysdeps/unix/sparc/start.c: Likewise.
* sysdeps/unix/sysv/irix4/start.c: Likewise.
* sysdeps/unix/sysv/linux/mips/sysdep.S: File removed.
* manual/search.texi (Tree Search Function, Hash Search Function):
Mention search.h clearly.
2002-10-05 Roland McGrath <roland@redhat.com>
* elf/dl-fxstat64.c: File removed.
* elf/dl-xstat64.c: File removed.
* elf/Makefile (rtld-routines): Remove them.
* sysdeps/unix/sysv/linux/xstat64.c: Remove RTLD_STAT64 conditionals.
Instead, use strong_alias instead of versioned_symbol in the
!SHLIB_COMPAT case.
* sysdeps/unix/sysv/linux/fxstat64.c: Likewise.
* sysdeps/unix/sysv/linux/lxstat64.c: Likewise.
* include/shlib-compat.h
(SHLIB_COMPAT): Require that IS_IN_##lib be defined nonzero.
[! NOT_IN_libc] (IS_IN_libc): Define it.
* cppflags-iterator.mk (CPPFLAGS-$(cpp-src)): Use -Dx=1 not just -Dx.
* elf/Makefile (CPPFLAGS-.os): Likewise.
* sunrpc/rpc_main.c (main): Don't declare with noreturn attribute.
Return the status instead of calling exit.
* Makeconfig (CFLAGS): Prepend -std=gnu99.
* Makerules (+make-deps): Use $(CFLAGS) only for .c sources.
Remove superfluous rm command, whose @ plus make bugs hid
all these commands from the make output.
* include/stubs-prologue.h: New file. Give #error under #ifdef _LIBC.
* Makefile ($(inst_includedir)/gnu/stubs.h): Depend on it.
Use that file's contents instead of literal echo's for the prologue.
* include/features.h: Include <gnu/stubs.h> unconditionally.
* include/gnu/stubs.h: New file.
2002-09-30 Roland McGrath <roland@redhat.com>
* elf/rtld-Rules: New file.
* elf/Makefile ($(objpfx)librtld.map, $(objpfx)librtld.mk,
$(objpfx)rtld-libc.a): New targets.
(generated): Add them.
(reloc-link): Remove -o $@ from the variable.
($(objpfx)dl-allobjs.os): Add -o $@ after $(reloc-link).
(distribute): Add rtld-Rules.
(CPPFLAGS-.os): Define this instead of CFLAGS-.os.
* Makerules ($(+sysdir_pfx)sysd-rules): Emit rules for rtld-% targets.
(common-mostlyclean, common-clean): Clean up rtld-* files.
* sysdeps/unix/make-syscalls.sh: Add rtld-*.os target name to rules.
