svn commit: r363266 - in head/sys: amd64/amd64 i386/i386 mips/mips powerpc/aim powerpc/booke

[Conrad Meyer]

Author: cem
Date: Thu Jul 16 23:29:26 2020
New Revision: 363266
URL: https://svnweb.freebsd.org/changeset/base/363266

Log:
  Revert r240317 to prevent leaking pmap entries
  
  Subsequent to r240317, kmem_free() was replaced with kva_free() (r254025).
  kva_free() releases the KVA allocation for the mapped region, but no longer
  clears the pmap (pagetable) entries.
  
  An affected pmap_unmapdev operation would leave the still-pmap'd VA space
  free for allocation by other KVA consumers.  However, this bug easily
  avoided notice for ~7 years because most devices (1) never call
  pmap_unmapdev and (2) on amd64, mostly fit within the DMAP and do not need
  KVA allocations.  Other affected arch are less popular: i386, MIPS, and
  PowerPC.  Arm64, arm32, and riscv are not affected.
  
  Reported by:	Don Morris <dgmorris AT earthlink.net>
  Submitted by:	Don Morris (amd64 part)
  Reviewed by:	kib, markj, Don (!amd64 parts)
  MFC after:	I don't intend to, but you might want to
  Sponsored by:	Dell Isilon
  Differential Revision:	https://reviews.freebsd.org/D25689

Modified:
  head/sys/amd64/amd64/pmap.c
  head/sys/i386/i386/pmap.c
  head/sys/mips/mips/pmap.c
  head/sys/powerpc/aim/mmu_oea.c
  head/sys/powerpc/aim/mmu_oea64.c
  head/sys/powerpc/aim/mmu_radix.c
  head/sys/powerpc/booke/pmap.c

Modified: head/sys/amd64/amd64/pmap.c
==============================================================================
--- head/sys/amd64/amd64/pmap.c	Thu Jul 16 23:05:18 2020	(r363265)
+++ head/sys/amd64/amd64/pmap.c	Thu Jul 16 23:29:26 2020	(r363266)
@@ -8279,8 +8279,10 @@ pmap_unmapdev(vm_offset_t va, vm_size_t size)
 			return;
 		}
 	}
-	if (pmap_initialized)
+	if (pmap_initialized) {
+		pmap_qremove(va, atop(size));
 		kva_free(va, size);
+	}
 }
 
 /*

Modified: head/sys/i386/i386/pmap.c
==============================================================================
--- head/sys/i386/i386/pmap.c	Thu Jul 16 23:05:18 2020	(r363265)
+++ head/sys/i386/i386/pmap.c	Thu Jul 16 23:29:26 2020	(r363266)
@@ -5538,8 +5538,10 @@ __CONCAT(PMTYPE, unmapdev)(vm_offset_t va, vm_size_t s
 			return;
 		}
 	}
-	if (pmap_initialized)
+	if (pmap_initialized) {
+		pmap_qremove(va, atop(size));
 		kva_free(va, size);
+	}
 }
 
 /*

Modified: head/sys/mips/mips/pmap.c
==============================================================================
--- head/sys/mips/mips/pmap.c	Thu Jul 16 23:05:18 2020	(r363265)
+++ head/sys/mips/mips/pmap.c	Thu Jul 16 23:29:26 2020	(r363266)
@@ -3264,6 +3264,7 @@ pmap_unmapdev(vm_offset_t va, vm_size_t size)
 	base = trunc_page(va);
 	offset = va & PAGE_MASK;
 	size = roundup(size + offset, PAGE_SIZE);
+	pmap_qremove(base, atop(size));
 	kva_free(base, size);
 #endif
 }

Modified: head/sys/powerpc/aim/mmu_oea.c
==============================================================================
--- head/sys/powerpc/aim/mmu_oea.c	Thu Jul 16 23:05:18 2020	(r363265)
+++ head/sys/powerpc/aim/mmu_oea.c	Thu Jul 16 23:29:26 2020	(r363266)
@@ -2673,6 +2673,7 @@ moea_unmapdev(vm_offset_t va, vm_size_t size)
 		base = trunc_page(va);
 		offset = va & PAGE_MASK;
 		size = roundup(offset + size, PAGE_SIZE);
+		moea_qremove(base, atop(size));
 		kva_free(base, size);
 	}
 }

Modified: head/sys/powerpc/aim/mmu_oea64.c
==============================================================================
--- head/sys/powerpc/aim/mmu_oea64.c	Thu Jul 16 23:05:18 2020	(r363265)
+++ head/sys/powerpc/aim/mmu_oea64.c	Thu Jul 16 23:29:26 2020	(r363266)
@@ -2869,6 +2869,7 @@ moea64_unmapdev(vm_offset_t va, vm_size_t size)
 	offset = va & PAGE_MASK;
 	size = roundup2(offset + size, PAGE_SIZE);
 
+	moea64_qremove(base, atop(size));
 	kva_free(base, size);
 }
 

Modified: head/sys/powerpc/aim/mmu_radix.c
==============================================================================
--- head/sys/powerpc/aim/mmu_radix.c	Thu Jul 16 23:05:18 2020	(r363265)
+++ head/sys/powerpc/aim/mmu_radix.c	Thu Jul 16 23:29:26 2020	(r363266)
@@ -5846,8 +5846,10 @@ mmu_radix_unmapdev(vm_offset_t va, vm_size_t size)
 	size = round_page(offset + size);
 	va = trunc_page(va);
 
-	if (pmap_initialized)
+	if (pmap_initialized) {
+		mmu_radix_qremove(va, atop(size));
 		kva_free(va, size);
+	}
 }
 
 static __inline void

Modified: head/sys/powerpc/booke/pmap.c
==============================================================================
--- head/sys/powerpc/booke/pmap.c	Thu Jul 16 23:05:18 2020	(r363265)
+++ head/sys/powerpc/booke/pmap.c	Thu Jul 16 23:29:26 2020	(r363266)
@@ -2322,6 +2322,7 @@ mmu_booke_unmapdev(vm_offset_t va, vm_size_t size)
 		base = trunc_page(va);
 		offset = va & PAGE_MASK;
 		size = roundup(offset + size, PAGE_SIZE);
+		mmu_booke_qremove(base, atop(size));
 		kva_free(base, size);
 	}
 #endif