CVS commit: src/sys/arch/amd64/amd64

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

Module Name:    src
Committed By:   riastradh
Date:           Sun May 23 08:59:08 UTC 2021

Modified Files:
        src/sys/arch/amd64/amd64: db_disasm.c

Log Message:
ddb/amd64: Don't go out of the way to detect invalid addresses.

db_disasm had logic to detect invalid addresses before trying to
disassemble them.  But when disassembling a null instruction address,
the logic to detect invalid addresses itself tried to dereference an
invalid address.

db_get_value can already handle this situation gracefully, so there is
no need for this faulty fault-avoidance logic.

Fixes double-fault in ddb on calling null function pointers.  With
any luck, this should make diagnosing such bugs easier in the future!


To generate a diff of this commit:
cvs rdiff -u -r1.27 -r1.28 src/sys/arch/amd64/amd64/db_disasm.c

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