From: H.J. Lu <hjl.tools@gmail.com>
Date: Tue, 22 May 2012 19:43:46 +0000 (-0700)
Subject: Add x32 arch_prctl
X-Git-Tag: glibc-2.16-tps~203
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=da0331a873dbb62462c151c3d824da2f6fe2e770;p=thirdparty%2Fglibc.git

Add x32 arch_prctl
---

diff --git a/ChangeLog b/ChangeLog
index 2682acc8668..7b4157079fa 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2012-05-22  H.J. Lu  <hongjiu.lu@intel.com>
 
+	* sysdeps/unix/sysv/linux/x86_64/x32/Makefile (sysdep_routines):
+	Add arch_prctl.
+	* sysdeps/unix/sysv/linux/x86_64/x32/arch_prctl.c: New file.
+
 	* sysdeps/unix/sysv/linux/wordsize-64/posix_fallocate.c
 	(posix_fallocate): Use INTERNAL_SYSCALL_TYPES if it is defined.
 	* sysdeps/unix/sysv/linux/x86_64/sysdep.h (INLINE_SYSCALL_TYPES):
diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/Makefile b/sysdeps/unix/sysv/linux/x86_64/x32/Makefile
index 5f77df7c7a8..aa78238a0d7 100644
--- a/sysdeps/unix/sysv/linux/x86_64/x32/Makefile
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/Makefile
@@ -1,3 +1,7 @@
+ifeq ($(subdir),misc)
+sysdep_routines += arch_prctl
+endif
+
 ifeq ($(subdir),posix)
 sysdep_routines += getcpu sched_getcpu-static
 endif
diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/arch_prctl.c b/sysdeps/unix/sysv/linux/x86_64/x32/arch_prctl.c
new file mode 100644
index 00000000000..6933306de94
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/arch_prctl.c
@@ -0,0 +1,62 @@
+/* arch_prctl call for Linux/x32.
+   Copyright (C) 2012 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <sys/prctl.h>
+#include <sys/syscall.h>
+#include <sysdep.h>
+
+/* Since x32 arch_prctl stores 32-bit base address of segment registers
+   %fs and %gs as unsigned 64-bit value via ARCH_GET_FS and ARCH_GET_GS,
+   we use an unsigned 64-bit variable to hold the base address and copy
+   it to ADDR after the system call returns.  */
+
+int
+__arch_prctl (int code, uintptr_t *addr)
+{
+  int res;
+  uint64_t addr64;
+  void *prctl_arg = addr;
+
+  switch (code)
+    {
+    case ARCH_GET_FS:
+    case ARCH_GET_GS:
+      prctl_arg = &addr64;
+      break;
+    }
+
+  res = INLINE_SYSCALL (arch_prctl, 2, code, prctl_arg);
+  if (res == 0)
+    switch (code)
+      {
+      case ARCH_GET_FS:
+      case ARCH_GET_GS:
+	 /* Check for a large value that overflows.  */
+	if ((uintptr_t) addr64 != addr64)
+	  {
+	    __set_errno (EOVERFLOW);
+	    return -1;
+	  }
+	*addr = (uintptr_t) addr64;
+	break;
+      }
+
+  return res;
+}
+weak_alias (__arch_prctl, arch_prctl)