Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 63379c13 authored by Helge Deller's avatar Helge Deller
Browse files

parisc: implement full version of access_ok() 



Up to now PA-RISC could live with a trivial version of access_ok().
Our fault handlers can correctly handle fault cases.

But testcases showed that we need a better access check else we won't
always return correct errno failure codes to userspace.

Problem showed up during 32bit userspace tests in which writev() used a
32bit memory area and length which would then wrap around on 64bit
kernel.

Signed-off-by: default avatarHelge Deller <deller@gmx.de>
parent 3a7452b4

arch/parisc/include/asm/uaccess.h

+42 −4
Original line number Diff line number Diff line
@@ -4,11 +4,14 @@ 
/*

 * 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
@@ -33,12 +36,43 @@ extern int __get_user_bad(void); 
extern int __put_kernel_bad(void);

extern int __put_user_bad(void);



static inline long access_ok(int type, const void __user * addr,

		unsigned long size)



/*

 * 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)

{

	return 1;

	unsigned long __newaddr = addr + size;

	return (__newaddr < addr || __newaddr > limit || size > limit);

}



/**

 * 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
@@ -219,7 +253,11 @@ extern long lstrnlen_user(const char __user *,long); 
/*

 * Complex access routines -- macros

 */

#define user_addr_max() (~0UL)

#ifdef CONFIG_COMPAT

#define user_addr_max() (TASK_SIZE)

#else

#define user_addr_max() (DEFAULT_TASK_SIZE)

#endif



#define strnlen_user lstrnlen_user

#define strlen_user(str) lstrnlen_user(str, 0x7fffffffL)