PR/58666 CVS commit: src/sys/arch/x86/x86

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

The following reply was made to PR kern/58666; it has been noted by GNATS.

From: "Taylor R Campbell" <riastradh%netbsd.org@localhost>
To: gnats-bugs%gnats.NetBSD.org@localhost
Cc: 
Subject: PR/58666 CVS commit: src/sys/arch/x86/x86
Date: Tue, 8 Oct 2024 21:09:08 +0000

 Module Name:	src
 Committed By:	riastradh
 Date:		Tue Oct  8 21:09:08 UTC 2024
 
 Modified Files:
 	src/sys/arch/x86/x86: pmap.c
 
 Log Message:
 x86/pmap: Use UVM_KMF_WAITVA to ensure pmap_pdp_alloc never fails.
 
 This is used as the backing page allocator for pmap_pdp_pool, and
 pmap_ctor assumes that PR_WAITOK allocations from it don't fail and
 unconditionally writes to the resulting kva, which if null leads
 nowhere good.
 
 It is unclear to me why uvm_km_alloc can accept any combination of
 the options UVM_KMF_NOWAIT and UVM_KMF_WAITVA.  It seems to me that
 at least one should be required (and they should be exclusive), and
 any other use should trip an assertion.
 
 PR kern/58666: panic: lock error: Reader / writer lock:
 rw_vector_enter,357: locking against myself
 
 
 To generate a diff of this commit:
 cvs rdiff -u -r1.426 -r1.427 src/sys/arch/x86/x86/pmap.c
 
 Please note that diffs are not public domain; they are subject to the
 copyright notices on the relevant files.