[src/trunk]: src/external/cddl/osnet/dev/dtrace/aarch64 Change the address ra...

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/bee022498d2e
branches:  trunk
changeset: 744749:bee022498d2e
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Wed Feb 12 06:05:23 2020 +0000

description:
Change the address ranges that aarch64 considers toxic for dtrace.

`Toxic' means dtrace forbids D scripts from even attempting to read
or write at them.

Previously we considered [0, VM_MIN_KERNEL_ADDRESS) toxic, but
VM_MIN_KERNEL_ADDRESS is only the minimum address of the kernel map;
the direct-mapped region lies below it, and with PMAP_MAP_POOLPAGE we
allocate virtual pages for pool backing directly from physical pages
through the direct-mapped region.  Also, this did not consider I/O
mappings to be toxic, which they probably should be.

Instead, treat:

[0, AARCH64_KSEG_START)
and
[VM_KERNEL_IO_ADDRESS, 0xfff...ff)

as toxic.  (The upper bound for 0xfff...ff ought to be inclusive, not
exclusive, but I think we'll need another mechanism for expressing
that to dtrace!)

diffstat:

 external/cddl/osnet/dev/dtrace/aarch64/dtrace_subr.c |  5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diffs (22 lines):

diff -r 11acf9fe8838 -r bee022498d2e external/cddl/osnet/dev/dtrace/aarch64/dtrace_subr.c
--- a/external/cddl/osnet/dev/dtrace/aarch64/dtrace_subr.c      Wed Feb 12 05:44:26 2020 +0000
+++ b/external/cddl/osnet/dev/dtrace/aarch64/dtrace_subr.c      Wed Feb 12 06:05:23 2020 +0000
@@ -28,7 +28,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: dtrace_subr.c,v 1.2 2020/02/12 01:09:38 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: dtrace_subr.c,v 1.3 2020/02/12 06:05:23 riastradh Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -128,7 +128,8 @@
 dtrace_toxic_ranges(void (*func)(uintptr_t base, uintptr_t limit))
 {
 
-       (*func)(0, (uintptr_t)VM_MIN_KERNEL_ADDRESS);
+       (*func)(0, (uintptr_t)AARCH64_KSEG_START);
+       (*func)((uintptr_t)VM_KERNEL_IO_ADDRESS, ~(uintptr_t)0);
 }
 
 static void