re: kern/51093:

[matthew green <mrg%eterna.com.au@localhost>]

The following reply was made to PR kern/51093; it has been noted by GNATS.

From: matthew green <mrg%eterna.com.au@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: kern-bug-people%netbsd.org@localhost, gnats-admin%netbsd.org@localhost,
    netbsd-bugs%netbsd.org@localhost
Subject: re: kern/51093: 
Date: Tue, 26 Apr 2016 05:46:44 +1000

 can you show the dmesg of the usb controller and devices you have?
 
 > Stopped in pid 1185.1 (x64) at  netbsd:vmem_alloc+0x3e: movq    0(%rax),%rdi
 > vmem_alloc() at netbsd:vmem_alloc+0x3e
 > uvm_km_kmem_alloc() at netbsd:uvm_km_kmem_alloc+0x46
 > kmem_intr_alloc() at netbsd:kmem_intr_alloc+0x6d
 > uhidopen() at netbsd:uhidopen+0xaf
 > cdev_open() at netbsd:cdev_open+0xbe
 > spec_open() at netbsd:spec_open+0x265
 
 and:
 
 > rax         36
 
 is a NULL deref, i guess.  usually when kmem_alloc fails it's cuz
 some prior user broke something (freed to the wrong size?).  which
 makes it a little harder to track down.
 
 can you try a DEBUG kernel?  and if possible, also a test with the
 kmguard feature enabled.  see the "OPTIONS" section of kmem_alloc(9)
 manual for details on enabling kmguard.
 
 thanks.
 
 
 .mrg.