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authorH.J. Lu <hjl.tools@gmail.com>2015-12-17 11:46:49 -0800
committerH.J. Lu <hjl.tools@gmail.com>2015-12-17 11:47:06 -0800
commit8ead7a9b94a085e6fba69b8b22e2ba0e2677f0d5 (patch)
tree8836dfa3fb66beb56c403595a928fc739d01d38c /sysdeps/unix/sysv/linux
parent2094350c9c9c1b87cf34b193ad6541e4a29b62dc (diff)
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Provide x32 times
Since times returns 64-bit clock_t on x32, we need to provide x32 times
by redefining INTERNAL_SYSCALL_NCS and INTERNAL_SYSCALL_ERROR_P with
64-bit return type for syscall.  All system calls returning 64-bit
integer, which are lseek, time and times, must be handled specially for
x32.  lseek is handled by x32 lseek.S and time doesn't check syscall
return.  times is the only missed one.  Before this patch, there are

0000000 <__times>:
   0:	b8 64 00 00 40       	mov    $0x40000064,%eax
   5:	0f 05                	syscall
   7:	48 63 d0             	movslq %eax,%rdx
                                ^^^^^^^^^^ Incorrect signed extension
   a:	48 83 fa f2          	cmp    $0xfffffffffffffff2,%rdx
   e:	75 07                	jne    17 <__times+0x17>
  10:	3d 00 f0 ff ff       	cmp    $0xfffff000,%eax
                                ^^^^^^^^^^^^^^^^^^^^^ 32-bit compare
  15:	77 11                	ja     28 <__times+0x28>
  17:	48 83 fa ff          	cmp    $0xffffffffffffffff,%rdx
  1b:	b8 00 00 00 00       	mov    $0x0,%eax
  20:	48 0f 45 c2          	cmovne %rdx,%rax
  24:	c3                   	retq

After this patch, there are

00000000 <__times>:
   0:	b8 64 00 00 40       	mov    $0x40000064,%eax
   5:	0f 05                	syscall
   7:	48 83 f8 f2          	cmp    $0xfffffffffffffff2,%rax
   b:	75 08                	jne    15 <__times+0x15>
   d:	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax
  13:	77 13                	ja     28 <__times+0x28>
  15:	48 83 f8 ff          	cmp    $0xffffffffffffffff,%rax
  19:	ba 00 00 00 00       	mov    $0x0,%edx
  1e:	48 0f 44 c2          	cmove  %rdx,%rax
  22:	c3                   	retq

The incorrect signed extension and 32-bit compare are gone.

	[BZ #19363]
	* sysdeps/unix/sysv/linux/x86_64/x32/times.c: New file.
Diffstat (limited to 'sysdeps/unix/sysv/linux')
-rw-r--r--sysdeps/unix/sysv/linux/x86_64/x32/times.c38
1 files changed, 38 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/times.c b/sysdeps/unix/sysv/linux/x86_64/x32/times.c
new file mode 100644
index 0000000000..3002d92385
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/times.c
@@ -0,0 +1,38 @@
+/* Linux times.  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>
+
+/* Linux times system call returns 64-bit integer.  */
+#undef INTERNAL_SYSCALL_NCS
+#define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \
+  ({									      \
+    unsigned long long int resultvar;					      \
+    LOAD_ARGS_##nr (args)						      \
+    LOAD_REGS_##nr							      \
+    asm volatile (							      \
+    "syscall\n\t"							      \
+    : "=a" (resultvar)							      \
+    : "0" (name) ASM_ARGS_##nr : "memory", REGISTERS_CLOBBERED_BY_SYSCALL);   \
+    (long long int) resultvar; })
+
+#undef INTERNAL_SYSCALL_ERROR_P
+#define INTERNAL_SYSCALL_ERROR_P(val, err) \
+  ((unsigned long long int) (val) >= -4095LL)
+
+#include <sysdeps/unix/sysv/linux/times.c>