[PATCH] Fix 32bit truncate on x86-64

From: Andi Kleen <ak@muc.de>

Another potential data corruption fix.

The 32bit truncate64 on x86-64 did silently truncate
offsets >32bit. That broke mysql for example. Fix that.

From Chris Wilson

arch/x86_64/ia32/ia32entry.S

@@ -396,8 +396,8 @@ ia32_sys_call_table:
 	.quad stub32_vfork            /* 190 */
 	.quad compat_sys_getrlimit
 	.quad sys32_mmap2
-	.quad sys_truncate
-	.quad sys_ftruncate
+	.quad sys32_truncate64
+	.quad sys32_ftruncate64
 	.quad sys32_stat64		/* 195 */
 	.quad sys32_lstat64
 	.quad sys32_fstat64

arch/x86_64/ia32/sys_ia32.c

@@ -110,6 +110,21 @@ int cp_compat_stat(struct kstat *kbuf, struct compat_stat *ubuf)
 	return 0;
 }
 
+extern long sys_truncate(char *, loff_t);
+extern long sys_ftruncate(int, loff_t);
+
+asmlinkage long
+sys32_truncate64(char * filename, unsigned long offset_low, unsigned long offset_high)
+{
+       return sys_truncate(filename, ((loff_t) offset_high << 32) | offset_low);
+}
+
+asmlinkage long
+sys32_ftruncate64(unsigned int fd, unsigned long offset_low, unsigned long offset_high)
+{
+       return sys_ftruncate(fd, ((loff_t) offset_high << 32) | offset_low);
+}
+
 /* Another set for IA32/LFS -- x86_64 struct stat is different due to 
    support for 64bit inode numbers. */