svn commit: r193712 - head/sys/arm/arm

[Rafal Jaworowski]

Author: raj
Date: Mon Jun  8 12:15:39 2009
New Revision: 193712
URL: http://svn.freebsd.org/changeset/base/193712

Log:
  Invalidate cache in pmap_remove_all() on ARM.
  
  When pages are removed from virtual address space by calling pmap_remove_all()
  CPU caches were not invalidated, which led to read corruption when another
  page got mapped at this same virtual address at later time (the CPU was
  retrieving stale contents).
  
  Submitted by:	Piotr Ziecik
  Obtained from:	Semihalf

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

Modified: head/sys/arm/arm/pmap.c
==============================================================================
--- head/sys/arm/arm/pmap.c	Mon Jun  8 12:10:42 2009	(r193711)
+++ head/sys/arm/arm/pmap.c	Mon Jun  8 12:15:39 2009	(r193712)
@@ -3124,7 +3124,19 @@ pmap_remove_all(vm_page_t m)
 		if (flush == FALSE && (pv->pv_pmap == curpm ||
 		    pv->pv_pmap == pmap_kernel()))
 			flush = TRUE;
+
 		PMAP_LOCK(pv->pv_pmap);
+		/*
+		 * Cached contents were written-back in pmap_remove_write(),
+		 * but we still have to invalidate the cache entry to make
+		 * sure stale data are not retrieved when another page will be
+		 * mapped under this virtual address.
+		 */
+		if (pmap_is_current(pv->pv_pmap)) {
+			cpu_dcache_inv_range(pv->pv_va, PAGE_SIZE);
+			cpu_l2cache_inv_range(pv->pv_va, PAGE_SIZE);
+		}
+
 		l2b = pmap_get_l2_bucket(pv->pv_pmap, pv->pv_va);
 		KASSERT(l2b != NULL, ("No l2 bucket"));
 		ptep = &l2b->l2b_kva[l2pte_index(pv->pv_va)];