summaryrefslogtreecommitdiff
path: root/include/linux/uaccess.h
diff options
context:
space:
mode:
authorThomas Zimmermann <tzimmermann@suse.de>2022-07-14 09:57:37 +0200
committerThomas Zimmermann <tzimmermann@suse.de>2022-07-14 09:57:37 +0200
commitf83d9396d1f63048c423efa00e4e244da10a35fd (patch)
tree48da2cf9b20cc7049c92dd4a7dd74be11add86e5 /include/linux/uaccess.h
parent5ee8c8f930ba7d20717c4fc2d9f1ce0e757d1155 (diff)
parent0180290abb5ce5c870f84a00ffeda5802f641dce (diff)
Merge drm/drm-next into drm-misc-next-fixes
Backmerging from drm/drm-next for the final fixes that will go into v5.20. Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Diffstat (limited to 'include/linux/uaccess.h')
-rw-r--r--include/linux/uaccess.h22
1 files changed, 22 insertions, 0 deletions
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index 546179418ffa..5a328cf02b75 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -231,6 +231,28 @@ static inline bool pagefault_disabled(void)
*/
#define faulthandler_disabled() (pagefault_disabled() || in_atomic())
+#ifndef CONFIG_ARCH_HAS_SUBPAGE_FAULTS
+
+/**
+ * probe_subpage_writeable: probe the user range for write faults at sub-page
+ * granularity (e.g. arm64 MTE)
+ * @uaddr: start of address range
+ * @size: size of address range
+ *
+ * Returns 0 on success, the number of bytes not probed on fault.
+ *
+ * It is expected that the caller checked for the write permission of each
+ * page in the range either by put_user() or GUP. The architecture port can
+ * implement a more efficient get_user() probing if the same sub-page faults
+ * are triggered by either a read or a write.
+ */
+static inline size_t probe_subpage_writeable(char __user *uaddr, size_t size)
+{
+ return 0;
+}
+
+#endif /* CONFIG_ARCH_HAS_SUBPAGE_FAULTS */
+
#ifndef ARCH_HAS_NOCACHE_UACCESS
static inline __must_check unsigned long