The branch main has been updated by andrew:
URL:
https://cgit.FreeBSD.org/src/commit/?id=4eec584d79c1e8375d863c7eec7229ac7ec3f13b
commit 4eec584d79c1e8375d863c7eec7229ac7ec3f13b
Author: Andrew Turner <and...@freebsd.org>
AuthorDate: 2024-06-12 13:08:13 +0000
Commit: Andrew Turner <and...@freebsd.org>
CommitDate: 2024-06-12 13:08:13 +0000
arm64: Clear td_frame when returning to userspace
When returning from an exception to userspace clear the saved td_frame.
On the next exception this should point to the frame, however this is
not guaranteed.
To ensure the trap frame pointer is either valid or NULL clear it
before returning to userspace in the EL0 synchronous exception handler.
Reviewed by: kib, markj
Sponsored by: Arm Ltd
Differential Revision: https://reviews.freebsd.org/D44807
---
sys/arm64/arm64/exception.S | 2 ++
1 file changed, 2 insertions(+)
diff --git a/sys/arm64/arm64/exception.S b/sys/arm64/arm64/exception.S
index 662684588e0c..3dff834e27a2 100644
--- a/sys/arm64/arm64/exception.S
+++ b/sys/arm64/arm64/exception.S
@@ -252,9 +252,11 @@ ENTRY(handle_el0_sync)
KMSAN_ENTER
ldr x0, [x18, #PC_CURTHREAD]
mov x1, sp
+ mov x22, x0
str x1, [x0, #TD_FRAME]
bl do_el0_sync
do_ast
+ str xzr, [x22, #TD_FRAME]
KMSAN_LEAVE
restore_registers 0
ERET
