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.
Support for /proc/self/task/$tid/comm as added in Linux 2.6.33,
therefore since the test tst-setgetname relies on this functionality
to operate we must skip the test in kernels < 2.6.33. We wrap the
checks with __ASSUME_PROC_PID_TASK_COMM such that in the future when
we move arch_minimum_kernel to 2.6.33 we can remove this code.
Fix BZ #15305.
On kernel versions earlier than 2.6.29, the Linux kernel exported a
sysctl called restrict_chown for xfs, which could be used to allow
chown to users other than the owner. 2.6.29 removed this support,
causing the open_not_cancel_2 to fail and thus modify errno. The fix
is to save and restore errno so that the caller sees it as unmodified.
Additionally, since the code to check the sysctl is not useful on
newer kernels, we add an ifdef so that in future the code block gets
rmeoved completely.
* sysdeps/unix/sysv/linux/kernel-features.h
(__ASSUME_CLONE_THREAD_FLAGS): Set on sparc when 2.5.64 and later.
(__ASSUME_TGKILL): Set on sparc when 2.6.1 and later, simplify
expression.
(__ASSUME_FADVISE64_64_SYSCALL): Set on sparc when 2.6.1 and
later.
fopen should set the FD_CLOEXEC flag if requested evenif the kernel does
not support an aotmic operation.
freopen should reuse the file descriptor for the stream. This is
especially important for calls to change the standard streams (stin,
stdout, stderr).
The syscall conventions on some Linux archs prevented F_GETOWN from working
correctly in some situations. This can be rectified when using the new
F_GETOWN_EX command.
* misc/Versions: Export preadv, preadv64, pwritev, pwritev64 for
GLIBC_2.10.
* misc/sys/uio.h: Declare preadv, preadv64, pwritev, pwritev64.
* sysdeps/unix/sysv/linux/kernel-features.h: Add entries for preadv
and pwritev.
* misc/preadv.c: New file.
* misc/preadv64.c: New file.
* misc/pwritev.c: New file.
* misc/pwritev64.c: New file.
* sysdeps/posx/preadv.c: New file.
* sysdeps/posx/preadv64.c: New file.
* sysdeps/posx/pwritev.c: New file.
* sysdeps/posx/pwritev64.c: New file.
* sysdeps/unix/sysv/linux/preadv.c: New file.
* sysdeps/unix/sysv/linux/preadv64.c: New file.
* sysdeps/unix/sysv/linux/pwritev.c: New file.
* sysdeps/unix/sysv/linux/pwritev64.c: New file.
* sysdeps/unix/sysv/linux/wordsize-64/preadv64.c: New file.
* sysdeps/unix/sysv/linux/wordsize-64/pwritev64.c: New file.
__ASSUME_COMPLETE_READV_WRITEV.
* sysdeps/unix/sysv/linux/readv.c: No need for userlevel fallback
with modern kernels.
* sysdeps/unix/sysv/linux/writev.c: Likewise.
* sysdeps/posix/readv.c: Since read is a cancellation point we have
to free a possible malloced buffer in case of cancellation.
* sysdeps/posix/writev.c: Likewise for write.
c2009-04-01 Ulrich Drepper <drepper@redhat.com>
__ASSUME_PACCEPT, __ASSUME_IN_NONBLOCK, and __ASSUME_PACCEPT if
appropriate.
* nscd/connections.c: Avoid fcntl calls to set close-on-exec flag and
non-blocking mode by using socket, paccept, and inotify_init1.
__ASSUME_PPOLL, __ASSUME_ATFCTS, __ASSUME_SET_ROBUST_LIST,
__ASSUME_UTIMENSAT, __ASSUME_FALLOCATE): Update per-arch conditions
when each feature was introduced.
* sysdeps/unix/sysv/linux/dl-vdso.c: Don't include dl-hash.h.
* sysdeps/unix/sysv/linux/dl-vdso.h: Don't include dl-hash.h if NDEBUG.
(CHECK_HASH): New macro.
(PREPARE_VERSION): Use it.
* sysdeps/unix/sysv/linux/pselect.c (__generic_pselect): Only provide
prototype if not __ASSUME_PSELECT.
* sysdeps/unix/sysv/linux/ppoll.c (__generic_ppoll): Only provide
prototype if not __ASSUME_PPOLL.
* sysdeps/unix/sysv/linux/dl-osinfo.h (ROUND): #undef after use.
* sysdeps/unix/clock_settime.c (freq, __pthread_clock_settime,
hp_timing_settime): Don't define or declare if HANDLED_CPUTIME
is defined.
__ASSUME_TMPFS_NAME.
* sysdeps/unix/sysv/linux/shm_open.c [!__ASSUME_TMPFS_NAME]
(where_is_shmfs): Don't test for obsolete shm filesystem name.
* sysdeps/unix/sysv/linux/getsysstats.c: Don't search for proc
mount point. We assume procfs is mounted at /proc in many other
places already.
(struct shmid_ds): Use it for shm_nattch field.
2005-11-18 Jakub Jelinek <jakub@redhat.com>
* sysdeps/unix/sysv/linux/futimesat.c (futimesat): If FILE is NULL,
set access and modification times of the file referenced by FD.
* sysdeps/generic/futimesat.c (futimesat): Don't return EINVAL if
FILE is NULL. Don't check FD if FILE is absolute path.
2005-11-19 Ulrich Drepper <drepper@redhat.com>
* nscd/nscd_gethst_r.c (nscd_gethst_r): Avoid unnecesary read call
if there are no aliases.
* sysdeps/unix/sysv/linux/Makefile (CFLAGS-connections.c,
CFLAGS-pwdcache.c, CFLAGS-grpcache.c, CFLAGS-hstcache.c,
CFLAGS-aicache.c, CFLAGS-initgrcache.c): Add -DHAVE_SENDFILE.
* sysdeps/unix/sysv/linux/kernel-features.h (__ASSUME_SENDFILE):
Define.
* nscd/pwdcache.c [HAVE_SENDFILE]: Include <sys/sendfile.h> and
<kernel-features.h>.
[HAVE_SENDFILE] (cache_addpw): Use sendfile to transmit positive
result.
* nscd/grpcache.c: Likewise.
* nscd/hstcache.c: Likewise.
* nscd/aicache.c: Likewise.
* nscd/initgrcache.c: Likewise.
* nscd/connectionc.c: Likewise.
2005-04-28 Roland McGrath <roland@redhat.com>
[BZ #796]
* sysdeps/unix/sysv/linux/dl-sysdep.h: New file.
Define NEED_DL_SYSINFO_DSO for all platforms.
* sysdeps/generic/dl-sysdep.h: Remove multiple inclusion protection.
* sysdeps/alpha/dl-sysdep.h: Likewise.
Use #include_next instead of duplicating generic file's contents.
* sysdeps/ia64/dl-sysdep.h: Likewise.
* sysdeps/sparc/dl-sysdep.h: Likewise.
2005-03-22 Steven Munroe <sjmunroe@us.ibm.com>
* sysdeps/powerpc/powerpc64/memset.S (memset): Make ___memset local.
2005-03-07 Steven Munroe <sjmunroe@us.ibm.com>
[BZ #781]
* sysdeps/unix/sysv/linux/kernel-features.h
(__ASSUME_TGKILL): Define for powerpc32/64 starting with 2.6.1.
(__ASSUME_UTIMES): Define for powerpc32/64 starting with 2.6.1.
(__ASSUME_FADVISE64_64_SYSCALL): Define for powerpc32 only starting
with 2.6.1.
(__ASSUME_WAITID_SYSCALL): Don't define for powerpc32/64.
(WSTOPPED, WEXITED, WCONTINUED, WNOWAIT): New macros.
* sysdeps/unix/sysv/linux/kernel-features.h (__ASSUME_WAITID_SYSCALL):
New macro.
* sysdeps/unix/sysv/linux/waitid.c: New file. Use new syscall when
available, or fall back to the waitpid-based generic code.
2004-08-15 Roland McGrath <roland@redhat.com>
[BZ #227]
* sysdeps/unix/sysv/linux/kernel-features.h
(__ASSUME_BRK_PAGE_ROUNDED): New macro.
* sysdeps/unix/sysv/linux/dl-sysdep.c (frob_brk)
[! __ASSUME_BRK_PAGE_ROUNDED]: Adjust the break up if it falls within
the partial page after the dynamic linker's own data segment.
2004-03-01 Ulrich Drepper <drepper@redhat.com>
* sysdeps/unix/sysv/linux/kernel-features.h: Add support for
__ASSUME_GETDENTS32_D_TYPE.
* sysdeps/unix/sysv/linux/getdents.c: For 2.6.4+ kernels you
getdents syscall again since it provides d_type information.
* manual/install.texi (Tools for Compilation): Autoconf 2.53 is
required.
2004-01-14 Steven Munroe <sjmunroe@us.ibm.com>
* include/libc-symbols.h [HAVE_ASM_GLOBAL_DOT_NAME]
(_symbol_version): Use C_SYMBOL_DOT_NAME to create '.'ed symbols.
(_default_symbol_version): Use C_SYMBOL_DOT_NAME to create '.'ed
symbols.
* sysdeps/powerpc/Makefile: Add rtld-global-offsets.sym to
gen-as-const-headers.
* sysdeps/powerpc/elf/rtld-global-offsets.sym: New file.
* sysdeps/powerpc/sysdep.h: Define v# symbols for vector registers.
Define PPC_FEATURE_* masks for Aux Vector AT_HWCAP.
* sysdeps/unix/sysv/linux/kernel-features.h
(__ASSUME_SWAPCONTEXT_SYSCALL): Define for PPC and 2.6.0 kernels.
* sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h [!__WORDSIZE == 32]:
Declare mcontext_t inline and include altivec state for 64-bit.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/Versions: Add GLIBC_2.3.4
versions for setcontext, getcontext, and swapcontext.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/Versions: Add GLIBC_2.3.4
versions for setcontext, getcontext, swapcontext, and makecontext.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/getcontext.S
(__getcontext): Upgrade to save Altivec regs and version GLIBC_2_3_4.
[SHLIB_COMPAT (libc, GLIBC_2_3, GLIBC_2_3_4)](__novec_getcontext):
Compatible with GLIBC_2.3.3 release.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/makecontext.S
(__makecontext): Use parm save area instead of compiler_dw to hold
context pointer.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/setcontext.S
(__setcontext): Upgrade to restore Altivec regs and version
GLIBC_2_3_4.
[SHLIB_COMPAT (libc, GLIBC_2_3, GLIBC_2_3_4)](__novec_setcontext):
Compatible with GLIBC_2.3.3 release.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/swapcontext.S
(__swapcontext): Upgrade to swap Altivec regs and version GLIBC_2_3_4.
[SHLIB_COMPAT (libc, GLIBC_2_3, GLIBC_2_3_4)](__novec_swapcontext):
Compatible with GLIBC_2.3.3 release.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/ucontext_i.h
(SIGCONTEXT_V_REGS_PTR, SIGCONTEXT_V_RESERVE): Defined.
2004-01-12 Steven Munroe <sjmunroe@us.ibm.com>
* sysdeps/unix/sysv/linux/powerpc/powerpc32/Versions: Add GLIBC_2.3.4
versions for setcontext, getcontext, swapcontext, and makecontext.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/getcontext.S
(__getcontext): Upgrade to save Altivec regs and version GLIBC_2_3_4.
[SHLIB_COMPAT (libc, GLIBC_2_3_3, GLIBC_2_3_4)](__novec_getcontext):
Compatible with GLIBC_2.3.3 release.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/makecontext.S
(__makecontext): Upgrade to align for Altivec regs and version
GLIBC_2_3_4.
[SHLIB_COMPAT (libc, GLIBC_2_3_3, GLIBC_2_3_4)](__novec_makecontext):
Compatible with GLIBC_2.3.3 release.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/setcontext.S
(__setcontext): Upgrade to restore Altivec regs and version
GLIBC_2_3_4.
[SHLIB_COMPAT (libc, GLIBC_2_3_3, GLIBC_2_3_4)](__novec_setcontext):
Compatible with GLIBC_2.3.3 release.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/swapcontext.S
(__swapcontext): Upgrade to swap Altivec regs and version GLIBC_2_3_4.
[SHLIB_COMPAT (libc, GLIBC_2_3_3, GLIBC_2_3_4)]
(__novec_swapcontext): Compatible with GLIBC_2.3.3 release.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/ucontext_i.h:
(_UC_VSCR, _UC_VRSAVE): Define.
(_FRAME_BACKCHAIN, _FRAME_LR_SAVE,_FRAME_PARM_SAVE1,_FRAME_PARM_SAVE2,
_FRAME_PARM_SAVE3, _FRAME_PARM_SAVE4): Defined.
2003-12-11 Ulrich Drepper <drepper@redhat.com>
* sysdeps/unix/sysv/linux/kernel-features.h: Remove __ASSUME_VSYSCALL.
There might always be processes which have no vDSO.
* sysdeps/generic/dl-sysdep.c: Remove __ASSUME_VSYSCALL uses.
* sysdeps/unix/sysv/linux/i386/sigaction.c: Likewise.
Joseph Myers
Carlos O'Donell
Allan McRae
Siddhesh Poyarekar
David S. Miller
Paul Eggert
Ulrich Drepper
Ulrich Drepper
Andreas Schwab
Roland McGrath
Jakub Jelinek
Andreas Jaeger
Richard Henderson