From: Dave Anderson <anderson@redhat.com>
Date: Wed, 23 Jan 2008 15:19:03 -0500
Subject: [misc] kprobes: inatomic __get_user and __put_user
Message-id: 4797A137.2080100@redhat.com
O-Subject: [RHEL5.2 PATCH 3/4] kprobes: BZ #232489: need kprobes improvement patches
Bugzilla: 232489

BZ #232489: need kprobes improvement patches
https://bugzilla.redhat.com/show_bug.cgi?id=232489
linux-2.6.git-e68c825bb016703eda94aac99be96de73b482d61

Direct backport of this powerpc commit, which will only
be used by Systemtap-generated modules to allow atomic
access to userspace:

   commit e68c825bb016703eda94aac99be96de73b482d61
   Author: Benjamin Herrenschmidt <benh@kernel.crashing.org>
   Date:   Wed Apr 11 16:13:19 2007 +1000

   [POWERPC] Add inatomic versions of __get_user and __put_user

   Those are needed by things like alignment exception fixup handlers
   since those can now be triggered by copy_tofrom_user_inatomic.

   Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
   Signed-off-by: Paul Mackerras <paulus@samba.org>

Tested on ppc64 by: Ananth N Mavinakayanahalli (ananth@in.ibm.com)

diff --git a/include/asm-powerpc/uaccess.h b/include/asm-powerpc/uaccess.h
index d83fc29..c5e12cf 100644
--- a/include/asm-powerpc/uaccess.h
+++ b/include/asm-powerpc/uaccess.h
@@ -110,12 +110,18 @@ struct exception_table_entry {
 	__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
 #define __put_user(x, ptr) \
 	__put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
+
 #ifndef __powerpc64__
 #define __get_user64(x, ptr) \
 	__get_user64_nocheck((x), (ptr), sizeof(*(ptr)))
 #define __put_user64(x, ptr) __put_user(x, ptr)
 #endif
 
+#define __get_user_inatomic(x, ptr) \
+	__get_user_nosleep((x), (ptr), sizeof(*(ptr)))
+#define __put_user_inatomic(x, ptr) \
+	__put_user_nosleep((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
+
 #define __get_user_unaligned __get_user
 #define __put_user_unaligned __put_user
 
@@ -198,6 +204,16 @@ do {								\
 	__pu_err;							\
 })
 
+#define __put_user_nosleep(x, ptr, size)			\
+({								\
+	long __pu_err;						\
+	__typeof__(*(ptr)) __user *__pu_addr = (ptr);		\
+	__chk_user_ptr(ptr);					\
+	__put_user_size((x), __pu_addr, (size), __pu_err);	\
+	__pu_err;						\
+})
+
+
 extern long __get_user_bad(void);
 
 #define __get_user_asm(x, addr, err, op)		\
@@ -297,6 +313,18 @@ do {								\
 	__gu_err;							\
 })
 
+#define __get_user_nosleep(x, ptr, size)			\
+({								\
+	long __gu_err;						\
+	unsigned long __gu_val;					\
+	const __typeof__(*(ptr)) __user *__gu_addr = (ptr);	\
+	__chk_user_ptr(ptr);					\
+	__get_user_size(__gu_val, __gu_addr, (size), __gu_err);	\
+	(x) = (__typeof__(*(ptr)))__gu_val;			\
+	__gu_err;						\
+})
+
+
 /* more complex routines */
 
 extern unsigned long __copy_tofrom_user(void __user *to,