During the work of KVM's dirty page logging optimization, we encountered the need of copy_in_user() for 32-bit ppc and x86: these will be used for manipulating dirty bitmaps in user space.
So we implement copy_in_user() for 32-bit with __copy_tofrom_user(). Signed-off-by: Takuya Yoshikawa <[email protected]> Signed-off-by: Fernando Luis Vazquez Cao <[email protected]> CC: Alexander Graf <[email protected]> CC: Benjamin Herrenschmidt <[email protected]> CC: Paul Mackerras <[email protected]> --- arch/powerpc/include/asm/uaccess.h | 17 +++++++++++++++++ 1 files changed, 17 insertions(+), 0 deletions(-) diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h index bd0fb84..3a01ce8 100644 --- a/arch/powerpc/include/asm/uaccess.h +++ b/arch/powerpc/include/asm/uaccess.h @@ -359,6 +359,23 @@ static inline unsigned long copy_to_user(void __user *to, return n; } +static inline unsigned long copy_in_user(void __user *to, + const void __user *from, unsigned long n) +{ + unsigned long over; + + if (likely(access_ok(VERIFY_READ, from, n) && + access_ok(VERIFY_WRITE, to, n))) + return __copy_tofrom_user(to, from, n); + if (((unsigned long)from < TASK_SIZE) || + ((unsigned long)to < TASK_SIZE)) { + over = max((unsigned long)from, (unsigned long)to) + + n - TASK_SIZE; + return __copy_tofrom_user(to, from, n - over) + over; + } + return n; +} + #else /* __powerpc64__ */ #define __copy_in_user(to, from, size) \ -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
