CVS commit: [netbsd-9] src/sys/arch/x86/x86

["Martin Husemann" <martin%netbsd.org@localhost>]

Module Name:    src
Committed By:   martin
Date:           Mon Nov 18 18:08:51 UTC 2024

Modified Files:
        src/sys/arch/x86/x86 [netbsd-9]: pmap.c

Log Message:
Pull up following revision(s) (requested by riastradh in ticket #1924):

        sys/arch/x86/x86/pmap.c: revision 1.427

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 -r1.334.2.7 -r1.334.2.8 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.