From d9a921b0ea019ba7768eb6cc81ece94e587f1660 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Wed, 16 Dec 2015 06:50:42 -0800
Subject: [PATCH] Properly handle x32 syscall

X32 syscall() may return 64-bit integer as lseek, time and times.  Its
return type should be __syscall_slong_t instead of long int.  We need
to properly return 64-bit error value.

Before the patch:

Dump of assembler code for function syscall:
   0x000dab20 <+0>:	mov    %rdi,%rax
   0x000dab23 <+3>:	mov    %rsi,%rdi
   0x000dab26 <+6>:	mov    %rdx,%rsi
   0x000dab29 <+9>:	mov    %rcx,%rdx
   0x000dab2c <+12>:	mov    %r8,%r10
   0x000dab2f <+15>:	mov    %r9,%r8
   0x000dab32 <+18>:	mov    0x8(%rsp),%r9
   0x000dab37 <+23>:	syscall
   0x000dab39 <+25>:	cmp    $0xfffffffffffff001,%rax
   0x000dab3f <+31>:	jae    0xdab42 <syscall+34>
   0x000dab41 <+33>:	retq
   0x000dab42 <+34>:	mov    0x2b3367(%rip),%rcx        # 0x38deb0
   0x000dab49 <+41>:	neg    %eax
   0x000dab4b <+43>:	mov    %eax,%fs:(%rcx)
   0x000dab4e <+46>:	or     $0xffffffff,%eax
                        ^^^^^^^^^^^^^^^^^^ This is 32-bit error return.
   0x000dab51 <+49>:	retq
End of assembler dump.

After the patch:

Dump of assembler code for function syscall:
   0x000daaf0 <+0>:	mov    %rdi,%rax
   0x000daaf3 <+3>:	mov    %rsi,%rdi
   0x000daaf6 <+6>:	mov    %rdx,%rsi
   0x000daaf9 <+9>:	mov    %rcx,%rdx
   0x000daafc <+12>:	mov    %r8,%r10
   0x000daaff <+15>:	mov    %r9,%r8
   0x000dab02 <+18>:	mov    0x8(%rsp),%r9
   0x000dab07 <+23>:	syscall
   0x000dab09 <+25>:	cmp    $0xfffffffffffff001,%rax
   0x000dab0f <+31>:	jae    0xdab12 <syscall+34>
   0x000dab11 <+33>:	retq
   0x000dab12 <+34>:	mov    0x2b3397(%rip),%rcx        # 0x38deb0
   0x000dab19 <+41>:	neg    %eax
   0x000dab1b <+43>:	mov    %eax,%fs:(%rcx)
   0x000dab1e <+46>:	or     $0xffffffffffffffff,%rax
   0x000dab22 <+50>:	retq
End of assembler dump.

	[BZ #19371]
	* manual/startup.texi (syscall): Use __syscall_slong_t for
	return type.
	* posix/unistd.h (syscall): Likewise.
	* sysdeps/unix/sysv/linux/x86_64/x32/syscall.S: New file.
---
 manual/startup.texi                          |  2 +-
 posix/unistd.h                               |  2 +-
 sysdeps/unix/sysv/linux/x86_64/x32/syscall.S | 33 ++++++++++++++++++++++++++++
 3 files changed, 35 insertions(+), 2 deletions(-)
 create mode 100644 sysdeps/unix/sysv/linux/x86_64/x32/syscall.S

diff --git a/manual/startup.texi b/manual/startup.texi
index 9a091a5..56d10fc 100644
--- a/manual/startup.texi
+++ b/manual/startup.texi
@@ -724,7 +724,7 @@ anyway.
 
 @comment unistd.h
 @comment ???
-@deftypefun {long int} syscall (long int @var{sysno}, @dots{})
+@deftypefun {__syscall_slong_t} syscall (long int @var{sysno}, @dots{})
 @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
 
 @code{syscall} performs a generic system call.
diff --git a/posix/unistd.h b/posix/unistd.h
index 1b52930..bb61ad7 100644
--- a/posix/unistd.h
+++ b/posix/unistd.h
@@ -1058,7 +1058,7 @@ extern void *sbrk (intptr_t __delta) __THROW;
 
    In Mach, all system calls take normal arguments and always return an
    error code (zero for success).  */
-extern long int syscall (long int __sysno, ...) __THROW;
+extern __syscall_slong_t syscall (long int __sysno, ...) __THROW;
 
 #endif	/* Use misc.  */
 
diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/syscall.S b/sysdeps/unix/sysv/linux/x86_64/x32/syscall.S
new file mode 100644
index 0000000..cc5255f
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/syscall.S
@@ -0,0 +1,33 @@
+/* The syscall system call.  Linux/x32 version.
+   Copyright (C) 2015 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 <sysdep.h>
+
+/* Return -1LL in a full 64 bits.  */
+#undef SYSCALL_ERROR_HANDLER
+#define SYSCALL_ERROR_HANDLER	\
+0:				\
+	SYSCALL_SET_ERRNO;	\
+	orq $-1, %rax;		\
+	ret;
+
+/* Always use our own error handler.  */
+#undef SYSCALL_ERROR_LABEL
+#define SYSCALL_ERROR_LABEL 0f
+
+#include <sysdeps/unix/sysv/linux/x86_64/syscall.S>
-- 
2.5.0
