From 8223717ce62c1ad0becc34ce69fe2d1771f3ba05 Mon Sep 17 00:00:00 2001 From: Konstantin Belousov Date: Tue, 30 Mar 2021 18:40:02 +0300 Subject: [PATCH] x86: clear %db registers in new process MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Reported by: Michał Górny PR: 254661 Reviewed by: emaste, jhb MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential revision: https://reviews.freebsd.org/D29496 --- sys/amd64/amd64/vm_machdep.c | 8 ++++++++ sys/i386/i386/vm_machdep.c | 8 ++++++++ 2 files changed, 16 insertions(+) diff --git a/sys/amd64/amd64/vm_machdep.c b/sys/amd64/amd64/vm_machdep.c index f64259decbff..98d212dc8771 100644 --- a/sys/amd64/amd64/vm_machdep.c +++ b/sys/amd64/amd64/vm_machdep.c @@ -229,6 +229,14 @@ cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags) copy_thread(td1, td2); + /* Reset debug registers in the new process */ + pcb2->pcb_dr0 = 0; + pcb2->pcb_dr1 = 0; + pcb2->pcb_dr2 = 0; + pcb2->pcb_dr3 = 0; + pcb2->pcb_dr6 = 0; + pcb2->pcb_dr7 = 0; + /* Point mdproc and then copy over p1's contents */ mdp2 = &p2->p_md; bcopy(&p1->p_md, mdp2, sizeof(*mdp2)); diff --git a/sys/i386/i386/vm_machdep.c b/sys/i386/i386/vm_machdep.c index c04fb57db4b1..ed40ebe5d1c8 100644 --- a/sys/i386/i386/vm_machdep.c +++ b/sys/i386/i386/vm_machdep.c @@ -241,6 +241,14 @@ cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags) copy_thread(td1, td2); + /* Reset debug registers in the new process */ + pcb2->pcb_dr0 = 0; + pcb2->pcb_dr1 = 0; + pcb2->pcb_dr2 = 0; + pcb2->pcb_dr3 = 0; + pcb2->pcb_dr6 = 0; + pcb2->pcb_dr7 = 0; + /* Point mdproc and then copy over td1's contents */ mdp2 = &p2->p_md; bcopy(&p1->p_md, mdp2, sizeof(*mdp2));