From: Yoav Zach <yoav_zach@yahoo.com>
Date: Thu, 23 Jun 2005 07:09:58 +0000 (-0700)
Subject: [PATCH] Don't force O_LARGEFILE for 32 bit processes on ia64
X-Git-Tag: v2.6.13-rc1~68^2~419
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ef3daeda7b58f046f94b26637d500354038d39f4;p=linux-2.6

[PATCH] Don't force O_LARGEFILE for 32 bit processes on ia64

In ia64 kernel, the O_LARGEFILE flag is forced when opening a file.  This
is problematic for execution of 32 bit processes, which are not largefile
aware, either by SW emulation or by HW execution.

For such processes, the problem is two-fold:

1) When trying to open a file that is larger than 4G
   the operation should fail, but it's not
2) Writing to offset larger than 4G should fail, but
   it's not

The proposed patch takes advantage of the way 32 bit processes are
identified in ia64 systems.  Such processes have PER_LINUX32 for their
personality.  With the patch, the ia64 kernel will not enforce the
O_LARGEFILE flag if the current process has PER_LINUX32 set.  The behavior
for all other architectures remains unchanged.

Signed-off-by: Yoav Zach <yoav.zach@intel.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/fs/open.c b/fs/open.c
index 963bd81a44..2ebb72c1a8 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -21,6 +21,7 @@
 #include <linux/vfs.h>
 #include <asm/uaccess.h>
 #include <linux/fs.h>
+#include <linux/personality.h>
 #include <linux/pagemap.h>
 #include <linux/syscalls.h>
 
@@ -935,9 +936,9 @@ asmlinkage long sys_open(const char __user * filename, int flags, int mode)
 	char * tmp;
 	int fd, error;
 
-#if BITS_PER_LONG != 32
-	flags |= O_LARGEFILE;
-#endif
+	if (force_o_largefile())
+		flags |= O_LARGEFILE;
+
 	tmp = getname(filename);
 	fd = PTR_ERR(tmp);
 	if (!IS_ERR(tmp)) {
diff --git a/include/asm-ia64/fcntl.h b/include/asm-ia64/fcntl.h
index d193981bb1..c9f8d835d0 100644
--- a/include/asm-ia64/fcntl.h
+++ b/include/asm-ia64/fcntl.h
@@ -81,4 +81,6 @@ struct flock {
 
 #define F_LINUX_SPECIFIC_BASE	1024
 
+#define force_o_largefile() ( ! (current->personality & PER_LINUX32) )
+
 #endif /* _ASM_IA64_FCNTL_H */
diff --git a/include/linux/fcntl.h b/include/linux/fcntl.h
index 704fb76b63..8a7c82151d 100644
--- a/include/linux/fcntl.h
+++ b/include/linux/fcntl.h
@@ -25,6 +25,10 @@
 
 #ifdef __KERNEL__
 
+#ifndef force_o_largefile
+#define force_o_largefile() (BITS_PER_LONG != 32)
+#endif
+
 #if BITS_PER_LONG == 32
 #define IS_GETLK32(cmd)		((cmd) == F_GETLK)
 #define IS_SETLK32(cmd)		((cmd) == F_SETLK)