X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=Documentation%2Farm64%2Ftagged-pointers.txt;h=d9995f1f51b3eb9e678a557a471e4d387db49ca8;hb=1846e7d725d986786e4fc427f8f3c39c105c2809;hp=264e9841563aa6ebb162b545fb3442b85f00c38b;hpb=4b647eeef8ef684754b58b46eb5bc7d9b55e7279;p=firefly-linux-kernel-4.4.55.git

diff --git a/Documentation/arm64/tagged-pointers.txt b/Documentation/arm64/tagged-pointers.txt
index 264e9841563a..d9995f1f51b3 100644
--- a/Documentation/arm64/tagged-pointers.txt
+++ b/Documentation/arm64/tagged-pointers.txt
@@ -18,17 +18,17 @@ this byte for application use, with the following caveats:
 	    parameters containing user virtual addresses *must* have
 	    their top byte cleared before trapping to the kernel.
 
-	(2) Tags are not guaranteed to be preserved when delivering
-	    signals. This means that signal handlers in applications
-	    making use of tags cannot rely on the tag information for
-	    user virtual addresses being maintained for fields inside
-	    siginfo_t. One exception to this rule is for signals raised
-	    in response to debug exceptions, where the tag information
+	(2) Non-zero tags are not preserved when delivering signals.
+	    This means that signal handlers in applications making use
+	    of tags cannot rely on the tag information for user virtual
+	    addresses being maintained for fields inside siginfo_t.
+	    One exception to this rule is for signals raised in response
+	    to watchpoint debug exceptions, where the tag information
 	    will be preserved.
 
 	(3) Special care should be taken when using tagged pointers,
 	    since it is likely that C compilers will not hazard two
-	    addresses differing only in the upper bits.
+	    virtual addresses differing only in the upper byte.
 
 The architecture prevents the use of a tagged PC, so the upper byte will
 be set to a sign-extension of bit 55 on exception return.