From: Noah Goldstein <goldstein.w.n@gmail.com>
Date: Fri, 3 Jun 2022 23:52:37 +0000 (-0500)
Subject: x86: ZERO_UPPER_VEC_REGISTERS_RETURN_XTEST expect no transactions
X-Git-Tag: glibc-2.36~174
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c28db9cb29a7d6cf3ce08fd8445e6b7dea03f35b;p=thirdparty%2Fglibc.git

x86: ZERO_UPPER_VEC_REGISTERS_RETURN_XTEST expect no transactions

Give fall-through path to `vzeroupper` and taken-path to `vzeroall`.

Generally even on machines with RTM the expectation is the
string-library functions will not be called in transactions.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
---

diff --git a/sysdeps/x86_64/sysdep.h b/sysdeps/x86_64/sysdep.h
index 4f512d5566b..7f5defa4ecd 100644
--- a/sysdeps/x86_64/sysdep.h
+++ b/sysdeps/x86_64/sysdep.h
@@ -99,11 +99,11 @@ lose:									      \
    to avoid RTM abort triggered by VZEROUPPER inside transactionally.  */
 #define ZERO_UPPER_VEC_REGISTERS_RETURN_XTEST \
 	xtest;							\
-	jz	1f;						\
-	vzeroall;						\
+	jnz	1f;						\
+	vzeroupper;						\
 	ret;							\
 1:								\
-	vzeroupper;						\
+	vzeroall;						\
 	ret
 
 /* Can be used to replace vzeroupper that is not directly before a