ARM: fix uaccess_with_memcpy() with SW_DOMAIN_PAN
The uaccess_with_memcpy() code is currently incompatible with the SW
PAN code: it takes locks within the region that we've changed the DACR,
potentially sleeping as a result. As we do not save and restore the
DACR across co-operative sleep events, can lead to an incorrect DACR
value later in this code path.
Reported-by: Peter Rosin <peda@axentia.se>
Tested-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h
index 8cc85a4..35c9db8 100644
--- a/arch/arm/include/asm/uaccess.h
+++ b/arch/arm/include/asm/uaccess.h
@@ -510,10 +510,14 @@
static inline unsigned long __must_check
__copy_to_user(void __user *to, const void *from, unsigned long n)
{
+#ifndef CONFIG_UACCESS_WITH_MEMCPY
unsigned int __ua_flags = uaccess_save_and_enable();
n = arm_copy_to_user(to, from, n);
uaccess_restore(__ua_flags);
return n;
+#else
+ return arm_copy_to_user(to, from, n);
+#endif
}
extern unsigned long __must_check