svn commit: r353306 - head/sys/riscv/riscv

[Mark Johnston]

Author: markj
Date: Tue Oct  8 14:54:35 2019
New Revision: 353306
URL: https://svnweb.freebsd.org/changeset/base/353306

Log:
  Clear PGA_WRITEABLE in riscv's pmap_remove_l3().
  
  pmap_remove_l3() may remove the last mapping of a page, in which case
  it must clear PGA_WRITEABLE.
  
  Reported by:	Jenkins, via lwhsu
  MFC after:	1 week
  Sponsored by:	The FreeBSD Foundation

Modified:
  head/sys/riscv/riscv/pmap.c

Modified: head/sys/riscv/riscv/pmap.c
==============================================================================
--- head/sys/riscv/riscv/pmap.c	Tue Oct  8 13:43:05 2019	(r353305)
+++ head/sys/riscv/riscv/pmap.c	Tue Oct  8 14:54:35 2019	(r353306)
@@ -2085,6 +2085,7 @@ static int
 pmap_remove_l3(pmap_t pmap, pt_entry_t *l3, vm_offset_t va, 
     pd_entry_t l2e, struct spglist *free, struct rwlock **lockp)
 {
+	struct md_page *pvh;
 	pt_entry_t old_l3;
 	vm_paddr_t phys;
 	vm_page_t m;
@@ -2104,6 +2105,12 @@ pmap_remove_l3(pmap_t pmap, pt_entry_t *l3, vm_offset_
 			vm_page_aflag_set(m, PGA_REFERENCED);
 		CHANGE_PV_LIST_LOCK_TO_VM_PAGE(lockp, m);
 		pmap_pvh_free(&m->md, pmap, va);
+		if (TAILQ_EMPTY(&m->md.pv_list) &&
+		    (m->flags & PG_FICTITIOUS) == 0) {
+			pvh = pa_to_pvh(VM_PAGE_TO_PHYS(m));
+			if (TAILQ_EMPTY(&pvh->pv_list))
+				vm_page_aflag_clear(m, PGA_WRITEABLE);
+		}
 	}
 
 	return (pmap_unuse_pt(pmap, va, l2e, free));