fix put_user for 80386
PATCH 1/1 fix put_user for 80386
Hi,
Linus noticed that put_user doesn't to the manual page table lookup that is required for cpus without a working WP flag. The solution is simple: if CONFIG_X86_WP_WORKS_OK is not set, then the put_user macros must call __copy_to_user_ll(). That function contains the required checks. This is already implemented for __put_user_size(), somehow I overlooked __put_user_{1,2,4,8,X}.
What do you think?
Patch against 2.6.11-mm2, test booted with bochs.
--
Manfred
include/asm-i386/uaccess.h +17 -0
@@ -217,6 +217,8 @@* * Returns zero on success, or -EFAULT on error. */ +#ifdef CONFIG_X86_WP_WORKS_OK +#define put_user (x,ptr) \ ({ int __ret_pu; \ __chk_user_ptr(ptr); \
@@ -230,6 +232,21 @@ __ret_pu; \ }) +#else +#define put_user (x,ptr) \ +({ \ + int __ret_pu; \ + __typeof__(*(ptr)) __pus_tmp = x; \ + __ret_pu=0; \ + if(unlikely(__copy_to_user_ll(ptr, &__pus_tmp, \ + sizeof(*(ptr))) != 0)) \ + __ret_pu=-EFAULT; \ + __ret_pu; \ + }) + + +#endif +/** * __get_user: - Get a simple variable from user space, with less checking. * @x: Variable to store result.