Clang issues a warning for double alias redirection, indicating that thei
original symbol is used even if a weak definition attempts to override it.
For instance, in the construction:
int __internal_impl (...) {}
weak_alias (__internal_impl, external_impl);
#if SOMETHING
weak_alias (external_impl, another_external_impl)
#endif
Clang warns that another_external_impl always resolves to __internal_impl,
even if external_impl is a weak reference. Using the internal symbol for
both aliases resolves this warning.
This issue also occurs with certain libc_hidden_def usage:
int __internal_impl (...) {}
weak_alias (__internal_impl, __internal_alias)
libc_hidden_weak (__internal_alias)
In this case, using a strong_alias is sufficient to avoid the warning
(since the alias is internal, there is no need to use a weak alias).
However, for the constructions like:
int __internal_impl (...) {}
weak_alias (__internal_impl, __internal_alias)
libc_hidden_def (__internal_alias)
weak_alias (__internal_impl, external_alias)
libc_hidden_def (external_alias)
Clang warns that the internal external_alias will always resolve to
__GI___internal_impl, even if a weak definition of __GI_internal_impl is
overridden. For this case, a new macro named static_weak_alias is used
to create a strong alias for SHARED, or a weak_alias otherwise.
With these changes, there is no need to check and enable the
-Wno-ignored-attributes suppression when using clang.
Checked with a build on affected ABIs, and a full check on aarch64,
armhf, i686, and x86_64.
Reviewed-by: Sam James <sam@gentoo.org>
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.
I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah. I don't
know why I run into these diagnostics whereas others evidently do not.
remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
This patch consolidates the recv Linux syscall implementation on
sysdeps/unix/sysv/linux/recv.c. The changes are:
1. Remove recv from auto-generation syscalls.list on the architecture
that uses __NR_recv.
2. Define __NR_recv for architectures that supports it. It was done
instead of defining in default kernel-features.h because current Linux
practice for new ports is to implement only __NR_recvfrom [1] and it will
require adding new kernel-features for ports that do not require it
(aarch64 for instance).
3. Remove __ASSUME_RECVFROM_FOR_RECV_SYSCALL and decide to use
__NR_recvfrom for recv generation based on __ASSUME_RECVFROM_SYSCALL.
Checked on i686-linux-gnu, x86_64-linux-gnu, x86_64-linux-gnux32,
aarch64-linux-gnu, arm-linux-gnueabihf, and powerpc64le-linux-gnu.
* sysdeps/unix/sysv/linux/alpha/syscalls.list: Remove recv from
auto-generation list.
* sysdeps/unix/sysv/linux/arm/syscalls.list: Likewise.
* sysdeps/unix/sysv/linux/hppa/syscalls.list: Likewise.
* sysdeps/unix/sysv/linux/ia64/syscalls.list: Likewise.
* sysdeps/unix/sysv/linux/mips/syscalls.list: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/syscalls.list: Likewise.
* sysdeps/unix/sysv/linux/alpha/kernel-features.h
(__ASSUME_RECV_SYSCALL): New define.
* sysdeps/unix/sysv/linux/arm/kernel-features.h
(__ASSUME_RECV_SYSCALL): Likewise.
* sysdeps/unix/sysv/linux/hppa/kernel-features.h
(__ASSUME_RECV_SYSCALL): Likewise.
* sysdeps/unix/sysv/linux/ia64/kernel-features.h
(__ASSUME_RECV_SYSCALL): Likewise.
* sysdeps/unix/sysv/linux/mips/kernel-features.h
(__ASSUME_RECV_SYSCALL): Likewise.
* sysdeps/unix/sysv/linux/i386/kernel-features.h
(__ASSUME_RECVFROM_FOR_RECV_SYSCALL): Remove define.
* sysdeps/unix/sysv/linux/m68k/kernel-features.h
(__ASSUME_RECVFROM_FOR_RECV_SYSCALL): Remove define.
* sysdeps/unix/sysv/linux/s390/kernel-features.h
(__ASSUME_RECVFROM_FOR_RECV_SYSCALL): Remove define.
* sysdeps/unix/sysv/linux/generic/recv.c: Remove file.
* sysdeps/unix/sysv/linux/mips/mips64/recv.c: Likewise.
* sysdeps/unix/sysv/linux/x86_64/recv.c: Likewise.
* sysdeps/unix/sysv/linux/recv.c: Simplify includes.
(__libc_recv): Use __ASSUME_RECVFROM_SYSCALL instead of
__ASSUME_RECVFROM_FOR_RECV_SYSCALL to issue recvfrom syscall.
[1] include/asm-generic/unistd.h (__ARCH_WANT_SYSCALL_DEPRECATED)
this patch calls direct system calls for socket operations in the same way as power does. The system calls were introduced in kernel commit https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=977108f89c989b1eeb5c8d938e1e71913391eb5f.
There are no direct recv, send, accept syscalls available on s390. Thus
recvfrom, sendto, accept4 are called instead of the socketcall by defining __ASSUME_*_FOR_*_SYSCALL macros. See recv.c, send.c, accept.c in sysdeps/unix/sysv/linux/ folder.
The socketcalls in syscalls.list for s390-64 are removed. They were never used on s390x.
ChangeLog:
* sysdeps/unix/sysv/linux/s390/kernel-features.h:
(__ASSUME_*_SYSCALL) Define new macros.
* sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list:
Remove socketcall syscalls.
* sysdeps/unix/sysv/linux/accept.c (__libc_accept):
Use accept4 if defined __ASSUME_ACCEPT4_FOR_ACCEPT_SYSCALL.
* sysdeps/unix/sysv/linux/recv.c (__libc_recv):
Use recvfrom if defined __ASSUME_RECVFROM_FOR_RECV_SYSCALL.
* sysdeps/unix/sysv/linux/send.c (__libc_send):
Use sendto if defined __ASSUME_SENDTO_FOR_SEND_SYSCALL.
Explicit system calls for the socket operations were added in Linux kernel
in commit 86250b9d12ca for powerpc. This patch make use of those instead of
calling socketcall to save number of cycles on networking syscalls.
2015-08-25 Rajalakshmi Srinivasaraghavan <raji@linux.vnet.ibm.com>
* sysdeps/unix/sysv/linux/powerpc/kernel-features.h: Define new macros.
* sysdeps/unix/sysv/linux/accept.c: Call direct system call.
* sysdeps/unix/sysv/linux/bind.c: Call direct system call.
* sysdeps/unix/sysv/linux/connect.c: Call direct system call.
* sysdeps/unix/sysv/linux/getpeername.c: Call direct system call.
* sysdeps/unix/sysv/linux/getsockname.c: Call direct system call.
* sysdeps/unix/sysv/linux/getsockopt.c: Call direct system call.
* sysdeps/unix/sysv/linux/listen.c: Call direct system call.
* sysdeps/unix/sysv/linux/recv.c: Call direct system call.
* sysdeps/unix/sysv/linux/recvfrom.c: Call direct system call.
* sysdeps/unix/sysv/linux/recvmsg.c: Call direct system call.
* sysdeps/unix/sysv/linux/send.c: Call direct system call.
* sysdeps/unix/sysv/linux/sendmsg.c: Call direct system call.
* sysdeps/unix/sysv/linux/sendto.c: Call direct system call.
* sysdeps/unix/sysv/linux/setsockopt.c: Call direct system call.
* sysdeps/unix/sysv/linux/shutdown.c: Call direct system call.
* sysdeps/unix/sysv/linux/socket.c: Call direct system call.
* sysdeps/unix/sysv/linux/socketpair.c: Call direct system call.
mq_notify (in the 1996 edition of POSIX) brings in references to recv
and socket (not in POSIX until the 2001 edition). This patch fixes
this by using __recv and __socket, exporting them from libc at version
GLIBC_PRIVATE.
Tested for x86_64 and x86 (testsuite and comparison of installed
stripped shared libraries; PLT / dynamic symbol table changes render
the comparison not particularly useful for libc).
[BZ #18546]
* socket/recv.c (__recv): Use libc_hidden_def.
* socket/socket.c (__socket): Likewise.
* sysdeps/mach/hurd/recv.c (__recv): Likewise.
* sysdeps/mach/hurd/socket.c (__socket): Likewise.
* sysdeps/unix/sysv/linux/generic/recv.c (__recv): Likewise.
* sysdeps/unix/sysv/linux/recv.c (__recv): Use libc_hidden_weak.
* sysdeps/unix/sysv/linux/socket.c (__socket): Use
libc_hidden_def.
* sysdeps/unix/sysv/linux/x86_64/recv.c (__recv): Use
libc_hidden_weak.
* include/sys/socket.h (__socket): Do not use attribute_hidden.
Use libc_hidden_proto.
(__recv): Likewise.
* socket/Versions (libc): Export __recv and __socket at version
GLIBC_PRIVATE.
* sysdeps/unix/sysv/linux/mq_notify.c (helper_thread): Call __recv
instead of recv.
(init_mq_netlink): Call __socket instead of socket.
* conform/Makefile (test-xfail-POSIX/mqueue.h/linknamespace):
Remove variable.
This patch removes the socket.S implementation for all ports and replace
it by a C implementation using socketcall. For ports that implement
the syscall directly, there is no change.
The patch idea is to simplify the socket function implementation that
uses the socketcall to be based on C implemetation instead of a pseudo
assembly implementation with arch specific parts. The patch then remove
the assembly implementatation for the ports which uses socketcall
(i386, microblaze, mips, powerpc, sparc, m68k, s390 and sh).
I have cross-build GLIBC for afore-mentioned ports and tested on both
i386 and ppc32 without regressions.
