Revert {send,sendm,recv,recvm}msg conformance changes

After some discussion in libc-alpha about this POSIX compliance fix, I see
that GLIBC should indeed revert back to previous definition of msghdr and
cmsghdr and implementation of sendmsg, recvmsg, sendmmsg, recvmmsg due some
reasons:

 * The possible issue where the syscalls wrapper add the compatibility
   layer is quite limited in scope and range.  And kernel current
   also add some limits to the values on the internal msghdr and
   cmsghdr fields:

     - msghdr::msg_iovlen larger than UIO_MAXIOV (1024) returns
       EMSGSIZE.
     - msghdr::msg_controllen larger than INT_MAX returns ENOBUFS.

 * There is a small performance hit for recvmsg/sendmsg/recmmsg which
   is neglectable, but it is a big hit for sendmmsg since now instead
   of calling the syscall for the packed structure, GLIBC is calling
   multiple sendmsg.  This defeat the very existence of the syscall.

 * It currently breaks libsanitizer build on GCC [1] (I fixed on compiler-rt).
   However the fix is incomplete because it does add any runtime check
   since libsanitizer currently does not have any facility to intercept
   symbols with multiple version [2].

   This, along with incorret dlsym/dlvsym return for versioned symbol due
   another bug [3], makes hard to interpose versioned symbols.

   Also, current approach of fixing GCC PR#71445 leads to half-baked
   solutions without versioned symbol interposing.

This patch basically reverts commits 2f0dc39029ae08, 222c2d7f4357d66,
af7f7c7ec8dea1.  I decided to not revert abf29edd4a3918 (Adjust
kernel-features.h defaults for recvmsg and sendmsg) mainly because it
does not really address the POSIX compliance original issue and also
adds some cleanups.

Tested on x86, i386, s390, s390x, aarch64, and powerpc64le.

[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71445
[2] https://github.com/google/sanitizers/issues/628
[3] https://sourceware.org/bugzilla/show_bug.cgi?id=14932

	* conform/data/sys/socket.h-data (msghdr.msg_iovlen): Add xfail-.
	(msghdr.msg_controllen): Likewise.
	(cmsghdr.cmsg_len): Likewise.
	* nptl/Makefile (libpthread-routines): Remove ptw-oldrecvmsg and
	ptw-oldsendmsg.
	(CFLAGS-oldrecvmsg.c): Remove rule.
	(CFLAGS-oldsendmsg.c): Likewise.
	(CFLAGS-recvmsg.c): Add rule.
	(CFLAGS-sendmsg.c): Likewise.
	* sysdeps/unix/sysv/linux/Makefile (sysdep_routines): Remove
	oldrecvmsg, oldsendmsg, oldrecvmmsg, oldsendmmsg.
	(CFLAGS-recvmsg.c): Remove rule.
	(CFLAGS-sendmsg.c): Likewise.
	(CFLAGS-oldrecvmsg.c): Likewise.
	(CFLAGS-oldsendmsg.c): Likewise.
	(CFLAGS-recvmmsg.c): Likewise.
	* sysdeps/unix/sysv/linux/bits/socket.h (msghdr.msg_iovlen): Revert
	to kernel defined interfaces.
	(msghdr.msg_controllen): Likewise.
	(cmsghdr.cmsg_len): Likewise.
	(msghdr.__glibc_reserved1): Remove member.
	(msghdr.__glibc_reserved2): Likewise.
	(cmsghdr.__glibc_reserved1): Likewise.
	* sysdeps/unix/sysv/linux/oldrecvmmsg.c: Remove file.
	* sysdeps/unix/sysv/linux/oldrecvmsg.c: Likewise.
	* sysdeps/unix/sysv/linux/oldsendmmsg.c: Likewise.
	* sysdeps/unix/sysv/linux/oldsendmsg.c: Likewise.
	* sysdeps/unix/sysv/linux/recvmmsg.c: Revert back to previous
	version.
	* sysdeps/unix/sysv/linux/recvmsg.c: Likewise.
	* sysdeps/unix/sysv/linux/sendmmsg.c: Likewise.
	* sysdeps/unix/sysv/linux/sendmsg.c: Likewise.
	* sysdeps/unix/sysv/linux/aarch64/Versions [libc] (GLIBC_2.24):
	Remove recvmsg and sendmsg.
	* sysdeps/unix/sysv/linux/alpha/Versions [libc] (GLIBC_2.24):
	Likewise.
	* sysdeps/unix/sysv/linux/hppa/Versions [libc] (GLIBC_2.24):
	Likewise.
	* sysdeps/unix/sysv/linux/i386/Versions [libc] (GLIBC_2.24): Likewise.
	* sysdeps/unix/sysv/linux/m68k/Versions [libc] (GLIBC_2.24): Likewise.
	* sysdeps/unix/sysv/linux/microblaze/Versions [libc] (GLIBC_2.24):
	Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/Versions [libc] (GLIBC_2.24):
	Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n32/Versions
	[libc] (GLIBC_2.24): Likewise.
	* sysdeps/unix/sysv/linux/nios2/Versions [libc] (GLIBC_2.24):
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/Versions [libc] (GLIBC_2.24):
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/Versions
	[libc] (GLIBC_2.24): Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/Versions [libc] (GLIBC_2.24):
	Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-64/Versions [libc] (GLIBC_2.24):
	Likewise.
	* sysdeps/unix/sysv/linux/sh/Versions [libc] (GLIBC_2.24): Likewise.
	* sysdeps/unix/sysv/linux/sparc/Versions [libc] (GLIBC_2.24):
	Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/Versions [libc] (GLIBC_2.24):
	Likewise.
	* sysdeps/unix/sysv/linux/tile/Versions [libc] (GLIBC_2.24):
	Likewise.
	* sysdeps/unix/sysv/linux/x86_64/Versions [libc] (GLIBC_2.24):
	Likewise.
	* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/Versions: Remove file
	* sysdeps/unix/sysv/linux/x86_64/64/Versions: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n64/Versions: Likewise.
	* sysdeps/unix/sysv/linux/aarch64/libc.abilist: Remove new 2.24
	version for {recv,send,recm,sendm}msg.
	* 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/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/nios2/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/tile/tilepro/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise.

1 files changed, 21 insertions, 51 deletions

diff --git a/sysdeps/unix/sysv/linux/sendmmsg.c b/sysdeps/unix/sysv/linux/sendmmsg.c
index 9b193438ce..6e0d46be9e 100644
--- a/sysdeps/unix/sysv/linux/sendmmsg.c
+++ b/sysdeps/unix/sysv/linux/sendmmsg.c
@@ -16,10 +16,12 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
+#include <errno.h>
 #include <sys/socket.h>
-#include <socketcall.h>
+
 #include <sysdep-cancel.h>
-#include <shlib-compat.h>
+#include <sys/syscall.h>
+#include <kernel-features.h>
 
 /* Do not use the sendmmsg syscall on socketcall architectures unless
    it was added at the same time as the socketcall support or can be
@@ -30,53 +32,31 @@
 # undef __NR_sendmmsg
 #endif
 
-#if __WORDSIZE == 64
-static inline int
-send_mmsghdr (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags)
-{
-  /* Emulate kernel interface for vlen size.  */
-  if (vlen > IOV_MAX)
-    vlen = IOV_MAX;
-  if (vlen == 0)
-    return 0;
-  /* POSIX specifies that both msghdr::msg_iovlen and msghdr::msg_controllen
-     to be int and socklen_t respectively,  however Linux defines it as both
-     size_t.  So for 64-bit it requires some adjustments by copying to
-     temporary header and zeroing the pad fields.
-     The problem is sendmmsg's msghdr may points to an already-filled control
-     buffer and modifying it is not part of sendmmsg contract (the data may
-     be in ro map).  So interact over the msghdr calling the sendmsg that
-     adjust the header using a temporary buffer.  */
-  for (unsigned int i = 0; i < vlen; i++)
-    {
-      ssize_t ret = __sendmsg (fd, &vmessages[i].msg_hdr, flags);
-      if (ret < 0)
-	return -1;
-      vmessages[i].msg_len = ret;
-    }
-  return 1;
-}
-#endif
-
+#ifdef __NR_sendmmsg
 int
 __sendmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags)
 {
-#if __WORDSIZE == 64
-  return send_mmsghdr (fd, vmessages, vlen, flags);
-#elif defined __NR_sendmmsg
   return SYSCALL_CANCEL (sendmmsg, fd, vmessages, vlen, flags);
+}
+libc_hidden_def (__sendmmsg)
+weak_alias (__sendmmsg, sendmmsg)
 #elif defined __NR_socketcall
+# include <socketcall.h>
 # ifdef __ASSUME_SENDMMSG_SOCKETCALL
+int
+__sendmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags)
+{
   return SOCKETCALL_CANCEL (sendmmsg, fd, vmessages, vlen, flags);
+}
 # else
-  static int have_sendmmsg;
+static int have_sendmmsg;
+
+int
+__sendmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags)
+{
   if (__glibc_likely (have_sendmmsg >= 0))
     {
-#  if __WORDSIZE == 64
-      int ret = send_mmsghdr (fd, vmessages, vlen, flags);
-#  else
       int ret = SOCKETCALL_CANCEL (sendmmsg, fd, vmessages, vlen, flags);
-#  endif
       /* The kernel returns -EINVAL for unknown socket operations.
 	 We need to convert that error to an ENOSYS error.  */
       if (__builtin_expect (ret < 0, 0)
@@ -104,20 +84,10 @@ __sendmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags)
     }
   __set_errno (ENOSYS);
   return -1;
-# endif /* __ASSUME_SENDMMSG_SOCKETCALL  */
-#else /* defined __NR_socketcall  */
-# define STUB 1
-  __set_errno (ENOSYS);
-  return -1;
-#endif
 }
-#ifdef STUB
-stub_warning (sendmmsg)
-#endif
-
+# endif /* __ASSUME_SENDMMSG_SOCKETCALL  */
 libc_hidden_def (__sendmmsg)
-#if __WORDSIZE == 64
-versioned_symbol (libc, __sendmmsg, sendmmsg, GLIBC_2_24);
-#else
 weak_alias (__sendmmsg, sendmmsg)
+#else
+# include <socket/sendmmsg.c>
 #endif