diff mbox series

[v3,06/23] aarch64: Add GCS support to vfork

Message ID 20241023083920.466015-7-yury.khrustalev@arm.com
State New
Headers show
Series aarch64: Add support for Guarded Control Stack extension | expand

Commit Message

Yury Khrustalev Oct. 23, 2024, 8:39 a.m. UTC 
From: Szabolcs Nagy <szabolcs.nagy@arm.com>

---
 sysdeps/unix/sysv/linux/aarch64/vfork.S | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
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Patch

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)