From: Szabolcs Nagy <szabolcs.nagy@arm.com>
Date: Wed, 27 Dec 2023 18:36:10 +0000 (+0000)
Subject: aarch64: Add GCS support to vfork
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4b2f9ca4e7b1970fe5b7a9e2f82b38a37bdcd851;p=thirdparty%2Fglibc.git

aarch64: Add GCS support to vfork
---

diff --git a/sysdeps/unix/sysv/linux/aarch64/vfork.S b/sysdeps/unix/sysv/linux/aarch64/vfork.S
index e71e492da3..cfaf4a1ffb 100644
--- a/sysdeps/unix/sysv/linux/aarch64/vfork.S
+++ b/sysdeps/unix/sysv/linux/aarch64/vfork.S
@@ -33,8 +33,14 @@ ENTRY (__vfork)
 
 	cmn	x0, #4095
 	b.cs    .Lsyscall_error
+	cbz	x0, L(child)
 	RET
-
+L(child):
+	/* Return with indirect branch in the child to support GCS.
+	   Clear x30 to crash early if the child tries to ret.  */
+	mov	x1, x30
+	mov	x30, 0
+	br	x1
 PSEUDO_END (__vfork)
 libc_hidden_def (__vfork)