On Sun, Sep 13, 2020 at 04:49:48PM +0200, Sebastien Marie wrote:
> On Sun, Sep 13, 2020 at 03:29:57PM +0200, Martin Pieuchot wrote:
> > I'm no longer able to reproduce the corruption while building lang/go
> > with the diff below. Something relevant to threading change in go since
> > march?
> >
> > Can someone try this diff and tell me if go and/or rust still fail?
>
> quickly tested with rustc build (nightly here), and it is failing at random
> places (not always at the same) with memory errors (signal 11, compiler ICE
> signal 6...)
>
A first hint.
With the help of deraadt@, it was found that disabling
uvm_map_inentry() call in usertrap() is enough to avoid the crashes.
To be clear, I am using the following diff:
diff 3e16148d8fe176d83ff415f6c03a79618da4401e /data/semarie/repos/openbsd/src
blob - 7f195a5309280943e0138953c61fffcb6a80c6bf
file + sys/arch/amd64/conf/GENERIC.MP
--- sys/arch/amd64/conf/GENERIC.MP
+++ sys/arch/amd64/conf/GENERIC.MP
@@ -4,6 +4,8 @@ include "arch/amd64/conf/GENERIC"
option MULTIPROCESSOR
#option MP_LOCKDEBUG
-#option WITNESS
+option WITNESS
+
+pseudo-device dt
cpu* at mainbus?
blob - fc23bc67e305a1a1edc7d6f08ecb982dccdc4a45
file + sys/uvm/uvm_map.c
--- sys/uvm/uvm_map.c
+++ sys/uvm/uvm_map.c
@@ -1893,16 +1893,16 @@ uvm_map_inentry(struct proc *p, struct p_inentry *ie,
boolean_t ok = TRUE;
if (uvm_map_inentry_recheck(serial, addr, ie)) {
- KERNEL_LOCK();
ok = uvm_map_inentry_fix(p, ie, addr, fn, serial);
if (!ok) {
+ KERNEL_LOCK();
printf(fmt, p->p_p->ps_comm, p->p_p->ps_pid, p->p_tid,
addr, ie->ie_start, ie->ie_end);
p->p_p->ps_acflag |= AMAP;
sv.sival_ptr = (void *)PROC_PC(p);
trapsignal(p, SIGSEGV, 0, SEGV_ACCERR, sv);
+ KERNEL_UNLOCK();
}
- KERNEL_UNLOCK();
}
return (ok);
}
blob - 4a4c6275aa766fe2e4f5c9d913d1257f41a9d578
file + sys/arch/amd64/amd64/trap.c
--- sys/arch/amd64/amd64/trap.c
+++ sys/arch/amd64/amd64/trap.c
@@ -343,10 +343,12 @@ usertrap(struct trapframe *frame)
p->p_md.md_regs = frame;
refreshcreds(p);
+#if 0
if (!uvm_map_inentry(p, &p->p_spinentry, PROC_STACK(p),
"[%s]%d/%d sp=%lx inside %lx-%lx: not MAP_STACK\n",
uvm_map_inentry_sp, p->p_vmspace->vm_map.sserial))
goto out;
+#endif
switch (type) {
case T_PROTFLT: /* protection fault */
Thanks.
--
Sebastien Marie
