From: Helge Deller <deller@gmx.de>
Date: Tue, 19 Nov 2013 22:31:35 +0000 (+0100)
Subject: Revert "parisc: implement full version of access_ok()"
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=a0ffa8f06f77a6197405521324501614d281bee1;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

Revert "parisc: implement full version of access_ok()"

This reverts commit 63379c135331c724d40a87b98eb62d2122981341.

It broke userspace and adding more checking is not needed.
Even checking if a syscall would access memory in page zero doesn't
makes sense since it may lead to some syscalls returning -EFAULT
where we would return other error codes on other platforms.
In summary, just drop this change and return to always return 1.

Signed-off-by: Helge Deller <deller@gmx.de>
---

diff --git a/arch/parisc/include/asm/uaccess.h b/arch/parisc/include/asm/uaccess.h
index 63f4dd0b49c2..4006964d8e12 100644
--- a/arch/parisc/include/asm/uaccess.h
+++ b/arch/parisc/include/asm/uaccess.h
@@ -4,14 +4,11 @@
 /*
  * User space memory access functions
  */
-#include <asm/processor.h>
 #include <asm/page.h>
 #include <asm/cache.h>
 #include <asm/errno.h>
 #include <asm-generic/uaccess-unaligned.h>
 
-#include <linux/sched.h>
-
 #define VERIFY_READ 0
 #define VERIFY_WRITE 1
 
@@ -36,43 +33,12 @@ extern int __get_user_bad(void);
 extern int __put_kernel_bad(void);
 extern int __put_user_bad(void);
 
-
-/*
- * Test whether a block of memory is a valid user space address.
- * Returns 0 if the range is valid, nonzero otherwise.
- */
-static inline int __range_not_ok(unsigned long addr, unsigned long size,
-				 unsigned long limit)
+static inline long access_ok(int type, const void __user * addr,
+		unsigned long size)
 {
-	unsigned long __newaddr = addr + size;
-	return (__newaddr < addr || __newaddr > limit || size > limit);
+	return 1;
 }
 
-/**
- * access_ok: - Checks if a user space pointer is valid
- * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE.  Note that
- *        %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
- *        to write to a block, it is always safe to read from it.
- * @addr: User space pointer to start of block to check
- * @size: Size of block to check
- *
- * Context: User context only.  This function may sleep.
- *
- * Checks if a pointer to a block of memory in user space is valid.
- *
- * Returns true (nonzero) if the memory block may be valid, false (zero)
- * if it is definitely invalid.
- *
- * Note that, depending on architecture, this function probably just
- * checks that the pointer is in the user space range - after calling
- * this function, memory access functions may still return -EFAULT.
- */
-#define access_ok(type, addr, size)					\
-(	__chk_user_ptr(addr),						\
-	!__range_not_ok((unsigned long) (__force void *) (addr),	\
-			size, user_addr_max())				\
-)
-
 #define put_user __put_user
 #define get_user __get_user
 
@@ -253,11 +219,7 @@ extern long lstrnlen_user(const char __user *,long);
 /*
  * Complex access routines -- macros
  */
-#ifdef CONFIG_COMPAT
-#define user_addr_max() (TASK_SIZE)
-#else
-#define user_addr_max() (DEFAULT_TASK_SIZE)
-#endif
+#define user_addr_max() (~0UL)
 
 #define strnlen_user lstrnlen_user
 #define strlen_user(str) lstrnlen_user(str, 0x7fffffffL)