CVS commit: src/external/cddl/osnet/dev/dtrace/aarch64

["Taylor R Campbell" <riastradh%netbsd.org@localhost>]

Module Name:    src
Committed By:   riastradh
Date:           Wed Feb 12 06:05:23 UTC 2020

Modified Files:
        src/external/cddl/osnet/dev/dtrace/aarch64: dtrace_subr.c

Log Message:
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!)


To generate a diff of this commit:
cvs rdiff -u -r1.2 -r1.3 \
    src/external/cddl/osnet/dev/dtrace/aarch64/dtrace_subr.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.