- Push down the acquisition and release of Giant into pmap_protect() on

   those architectures without pmap locking.
 - Eliminate the acquisition and release of Giant from vm_map_protect().

(Translation: mprotect(2) runs to completion without touching Giant on
alpha, amd64, i386 and ia64.)

6 files changed, 20 insertions, 2 deletions

diff --git a/sys/arm/arm/pmap.c b/sys/arm/arm/pmap.c
index 8a03f769e326..d776a0a36212 100644
--- a/sys/arm/arm/pmap.c
+++ b/sys/arm/arm/pmap.c
@@ -3014,7 +3014,9 @@ pmap_protect(pmap_t pm, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
 	int flush;
 
 	if ((prot & VM_PROT_READ) == 0) {
+		mtx_lock(&Giant);
 		pmap_remove(pm, sva, eva);
+		mtx_unlock(&Giant);
 		return;
 	}
 
@@ -3026,6 +3028,7 @@ pmap_protect(pmap_t pm, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
 		return;
 	}
 
+	mtx_lock(&Giant);
 
 	/*
 	 * OK, at this point, we know we're doing write-protect operation.
@@ -3091,6 +3094,7 @@ pmap_protect(pmap_t pm, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
 			pmap_tlb_flushD(pm);
 	}
 
+	mtx_unlock(&Giant);
 }
 
 
diff --git a/sys/powerpc/aim/mmu_oea.c b/sys/powerpc/aim/mmu_oea.c
index c0368605454c..4db44cb677e7 100644
--- a/sys/powerpc/aim/mmu_oea.c
+++ b/sys/powerpc/aim/mmu_oea.c
@@ -1459,10 +1459,13 @@ pmap_protect(pmap_t pm, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
 	    ("pmap_protect: non current pmap"));
 
 	if ((prot & VM_PROT_READ) == VM_PROT_NONE) {
+		mtx_lock(&Giant);
 		pmap_remove(pm, sva, eva);
+		mtx_unlock(&Giant);
 		return;
 	}
 
+	mtx_lock(&Giant);
 	vm_page_lock_queues();
 	for (; sva < eva; sva += PAGE_SIZE) {
 		pvo = pmap_pvo_find_va(pm, sva, &pteidx);
@@ -1490,6 +1493,7 @@ pmap_protect(pmap_t pm, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
 			pmap_pte_change(pt, &pvo->pvo_pte, pvo->pvo_vaddr);
 	}
 	vm_page_unlock_queues();
+	mtx_unlock(&Giant);
 }
 
 /*
diff --git a/sys/powerpc/powerpc/mmu_oea.c b/sys/powerpc/powerpc/mmu_oea.c
index c0368605454c..4db44cb677e7 100644
--- a/sys/powerpc/powerpc/mmu_oea.c
+++ b/sys/powerpc/powerpc/mmu_oea.c
@@ -1459,10 +1459,13 @@ pmap_protect(pmap_t pm, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
 	    ("pmap_protect: non current pmap"));
 
 	if ((prot & VM_PROT_READ) == VM_PROT_NONE) {
+		mtx_lock(&Giant);
 		pmap_remove(pm, sva, eva);
+		mtx_unlock(&Giant);
 		return;
 	}
 
+	mtx_lock(&Giant);
 	vm_page_lock_queues();
 	for (; sva < eva; sva += PAGE_SIZE) {
 		pvo = pmap_pvo_find_va(pm, sva, &pteidx);
@@ -1490,6 +1493,7 @@ pmap_protect(pmap_t pm, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
 			pmap_pte_change(pt, &pvo->pvo_pte, pvo->pvo_vaddr);
 	}
 	vm_page_unlock_queues();
+	mtx_unlock(&Giant);
 }
 
 /*
diff --git a/sys/powerpc/powerpc/pmap.c b/sys/powerpc/powerpc/pmap.c
index c0368605454c..4db44cb677e7 100644
--- a/sys/powerpc/powerpc/pmap.c
+++ b/sys/powerpc/powerpc/pmap.c
@@ -1459,10 +1459,13 @@ pmap_protect(pmap_t pm, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
 	    ("pmap_protect: non current pmap"));
 
 	if ((prot & VM_PROT_READ) == VM_PROT_NONE) {
+		mtx_lock(&Giant);
 		pmap_remove(pm, sva, eva);
+		mtx_unlock(&Giant);
 		return;
 	}
 
+	mtx_lock(&Giant);
 	vm_page_lock_queues();
 	for (; sva < eva; sva += PAGE_SIZE) {
 		pvo = pmap_pvo_find_va(pm, sva, &pteidx);
@@ -1490,6 +1493,7 @@ pmap_protect(pmap_t pm, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
 			pmap_pte_change(pt, &pvo->pvo_pte, pvo->pvo_vaddr);
 	}
 	vm_page_unlock_queues();
+	mtx_unlock(&Giant);
 }
 
 /*
diff --git a/sys/sparc64/sparc64/pmap.c b/sys/sparc64/sparc64/pmap.c
index 304d81b98861..91ec4ff7d073 100644
--- a/sys/sparc64/sparc64/pmap.c
+++ b/sys/sparc64/sparc64/pmap.c
@@ -1208,13 +1208,16 @@ pmap_protect(pmap_t pm, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
 	    pm->pm_context[PCPU_GET(cpuid)], sva, eva, prot);
 
 	if ((prot & VM_PROT_READ) == VM_PROT_NONE) {
+		mtx_lock(&Giant);
 		pmap_remove(pm, sva, eva);
+		mtx_unlock(&Giant);
 		return;
 	}
 
 	if (prot & VM_PROT_WRITE)
 		return;
 
+	mtx_lock(&Giant);
 	vm_page_lock_queues();
 	if (eva - sva > PMAP_TSB_THRESH) {
 		tsb_foreach(pm, NULL, sva, eva, pmap_protect_tte);
@@ -1227,6 +1230,7 @@ pmap_protect(pmap_t pm, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
 		tlb_range_demap(pm, sva, eva - 1);
 	}
 	vm_page_unlock_queues();
+	mtx_unlock(&Giant);
 }
 
 /*
diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c
index b5c69174b4e0..baacf706c100 100644
--- a/sys/vm/vm_map.c
+++ b/sys/vm/vm_map.c
@@ -1394,14 +1394,12 @@ vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end,
 		 * here -- CHECK THIS XXX
 		 */
 		if (current->protection != old_prot) {
-			mtx_lock(&Giant);
 #define MASK(entry)	(((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \
 							VM_PROT_ALL)
 			pmap_protect(map->pmap, current->start,
 			    current->end,
 			    current->protection & MASK(current));
 #undef	MASK
-			mtx_unlock(&Giant);
 		}
 		vm_map_simplify_entry(map, current);
 		current = current->next;