CVS commit: src/sys/uvm

["Chuck Silvers" <chs%netbsd.org@localhost>]

Module Name:    src
Committed By:   chs
Date:           Mon Aug  5 17:36:42 UTC 2019

Modified Files:
        src/sys/uvm: uvm_fault.c

Log Message:
fix two bugs reported in
https://syzkaller.appspot.com/bug?id=8840dce484094a926e1ec388ffb83acb2fa291c9

 - in uvm_fault_check(), if the map entry is wired, handle the fault the same way
   that we would handle UVM_FAULT_WIRE.  faulting on wired mappings is valid
   if the mapped object was truncated and then later grown again.

 - in uvm_fault_unwire_locked(), we must hold the locks for the vm_map_entry
   while calling pmap_extract() in order to avoid races with the mapped object
   being truncated while we are unwiring it.

Reported-by: syzbot+2e0ae2fc35ab7301c7b8%syzkaller.appspotmail.com@localhost


To generate a diff of this commit:
cvs rdiff -u -r1.206 -r1.207 src/sys/uvm/uvm_fault.c

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