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-Tag: glibc-2.41~49
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=1cf59c2603be88e3c97e68b1f219647f20310215;p=thirdparty%2Fglibc.git

aarch64: Add GCS support to vfork

Reviewed-by: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
---

diff --git a/sysdeps/unix/sysv/linux/aarch64/vfork.S b/sysdeps/unix/sysv/linux/aarch64/vfork.S
index 27618567f1..d5943a7485 100644
--- a/sysdeps/unix/sysv/linux/aarch64/vfork.S
+++ b/sysdeps/unix/sysv/linux/aarch64/vfork.S
@@ -33,8 +33,13 @@ 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.
+	   Compilers insert BTI instruction after vfork() to make
+	   sure return via BR works on systems with BTI.  */
+	br	x30
 PSEUDO_END (__vfork)
 libc_hidden_def (__vfork)