Message ID | 1401959173-13117-6-git-send-email-u.kleine-koenig@pengutronix.de (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h index 75d95799b6e6..fd42da46828d 100644 --- a/arch/arm/include/asm/uaccess.h +++ b/arch/arm/include/asm/uaccess.h @@ -224,7 +224,7 @@ static inline void set_fs(mm_segment_t fs) #define access_ok(type,addr,size) (__range_ok(addr,size) == 0) #define user_addr_max() \ - (segment_eq(get_fs(), USER_DS) ? TASK_SIZE : ~0UL) + (segment_eq(get_fs(), KERNEL_DS) ? ~0UL : get_fs()) /* * The "__xxx" versions of the user access functions do not verify the
With CONFIG_MMU=y get_fs() returns current_thread_info()->addr_limit which is initialized as USER_DS (which in turn is defined to TASK_SIZE) for userspace processes. At least theoretically current_thread_info()->addr_limit is changable by set_fs() to a different limit, so checking for KERNEL_DS is more robust. With !CONFIG_MMU get_fs returns KERNEL_DS. To see what the old variant did you'd have to find out that USER_DS == KERNEL_DS which isn't needed any more with the variant this patch introduces. So it's a bit easier to understand, too. Also if the limit was changed this limit should be returned, not TASK_SIZE. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> --- Cc: Ben Hutchings <ben@decadent.org.uk> BTW, alpha, m68k, openrisc and sparc use the same definition of user_addr_max as arm before this patch. arch/arm/include/asm/uaccess.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)