git: 4a5ec55af6d0 - main - amd64: expicitly re-init td_frame in copy_thread()

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=4a5ec55af6d0bfa659f67483e346d55f90ba0856

commit 4a5ec55af6d0bfa659f67483e346d55f90ba0856
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2022-07-21 16:26:26 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2022-08-02 18:11:09 +0000

    amd64: expicitly re-init td_frame in copy_thread()
    
    Otherwise we are using whatever the value was left from the previous
    thread run on kernel entry from usermode. Typically it would be the
    desired value as is, but it is not guaranteed.
    
    Reviewed by:    markj
    Tested by:      pho
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Differential revision:  https://reviews.freebsd.org/D35888
---
 sys/amd64/amd64/vm_machdep.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sys/amd64/amd64/vm_machdep.c b/sys/amd64/amd64/vm_machdep.c
index c9c498180c7e..cc90e659ff11 100644
--- a/sys/amd64/amd64/vm_machdep.c
+++ b/sys/amd64/amd64/vm_machdep.c
@@ -170,6 +170,8 @@ copy_thread(struct thread *td1, struct thread *td2)
 		    cpu_max_ext_state_size);
 	}
 
+	td2->td_frame = (struct trapframe *)td2->td_md.md_stack_base - 1;
+
 	/*
 	 * Set registers for trampoline to user mode.  Leave space for the
 	 * return address on stack.  These are the kernel mode register values.