git: 4cb8ec6c6f81 - stable/14 - vm_map: add vm_map_find_locked(9)

The branch stable/14 has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=4cb8ec6c6f81243da158def4525f92c6dc7b964b

commit 4cb8ec6c6f81243da158def4525f92c6dc7b964b
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2024-09-15 06:29:28 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2024-10-05 07:08:54 +0000

    vm_map: add vm_map_find_locked(9)
    
    (cherry picked from commit 0ecbb28ce351652b3a2dae271eedf1eb3aa65400)
---
 sys/vm/vm_map.c | 50 +++++++++++++++++++++++++++++++++-----------------
 sys/vm/vm_map.h |  2 ++
 2 files changed, 35 insertions(+), 17 deletions(-)

diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c
index 97b96a46e4b2..28cf309f86c3 100644
--- a/sys/vm/vm_map.c
+++ b/sys/vm/vm_map.c
@@ -2113,9 +2113,24 @@ vm_map_find_aligned(vm_map_t map, vm_offset_t *addr, vm_size_t length,
  */
 int
 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
-	    vm_offset_t *addr,	/* IN/OUT */
-	    vm_size_t length, vm_offset_t max_addr, int find_space,
-	    vm_prot_t prot, vm_prot_t max, int cow)
+    vm_offset_t *addr,	/* IN/OUT */
+    vm_size_t length, vm_offset_t max_addr, int find_space,
+    vm_prot_t prot, vm_prot_t max, int cow)
+{
+	int rv;
+
+	vm_map_lock(map);
+	rv = vm_map_find_locked(map, object, offset, addr, length, max_addr,
+	    find_space, prot, max, cow);
+	vm_map_unlock(map);
+	return (rv);
+}
+
+int
+vm_map_find_locked(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
+    vm_offset_t *addr,	/* IN/OUT */
+    vm_size_t length, vm_offset_t max_addr, int find_space,
+    vm_prot_t prot, vm_prot_t max, int cow)
 {
 	vm_offset_t alignment, curr_min_addr, min_addr;
 	int gap, pidx, rv, try;
@@ -2123,7 +2138,7 @@ vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
 
 	KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 ||
 	    object == NULL,
-	    ("vm_map_find: non-NULL backing object for stack"));
+	    ("non-NULL backing object for stack"));
 	MPASS((cow & MAP_REMAP) == 0 || (find_space == VMFS_NO_SPACE &&
 	    (cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0));
 	if (find_space == VMFS_OPTIMAL_SPACE && (object == NULL ||
@@ -2146,7 +2161,6 @@ vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
 	    (map->flags & MAP_ASLR_IGNSTART) != 0)
 		curr_min_addr = min_addr = vm_map_min(map);
 	try = 0;
-	vm_map_lock(map);
 	if (cluster) {
 		curr_min_addr = map->anon_loc;
 		if (curr_min_addr == 0)
@@ -2217,8 +2231,7 @@ again:
 					MPASS(try == 1);
 					goto again;
 				}
-				rv = KERN_NO_SPACE;
-				goto done;
+				return (KERN_NO_SPACE);
 			}
 		}
 
@@ -2232,16 +2245,14 @@ again:
 				try = 0;
 				goto again;
 			}
-			goto done;
+			return (rv);
 		}
 	} else if ((cow & MAP_REMAP) != 0) {
-		if (!vm_map_range_valid(map, *addr, *addr + length)) {
-			rv = KERN_INVALID_ADDRESS;
-			goto done;
-		}
+		if (!vm_map_range_valid(map, *addr, *addr + length))
+			return (KERN_INVALID_ADDRESS);
 		rv = vm_map_delete(map, *addr, *addr + length);
 		if (rv != KERN_SUCCESS)
-			goto done;
+			return (rv);
 	}
 	if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) {
 		rv = vm_map_stack_locked(map, *addr, length, sgrowsiz, prot,
@@ -2250,10 +2261,15 @@ again:
 		rv = vm_map_insert(map, object, offset, *addr, *addr + length,
 		    prot, max, cow);
 	}
-	if (rv == KERN_SUCCESS && update_anon)
-		map->anon_loc = *addr + length;
-done:
-	vm_map_unlock(map);
+
+	/*
+	 * Update the starting address for clustered anonymous memory mappings
+	 * if a starting address was not previously defined or an ASLR restart
+	 * placed an anonymous memory mapping at a lower address.
+	 */
+	if (update_anon && rv == KERN_SUCCESS && (map->anon_loc == 0 ||
+	    *addr < map->anon_loc))
+		map->anon_loc = *addr;
 	return (rv);
 }
 
diff --git a/sys/vm/vm_map.h b/sys/vm/vm_map.h
index c0b3be886505..5d41f892e83d 100644
--- a/sys/vm/vm_map.h
+++ b/sys/vm/vm_map.h
@@ -475,6 +475,8 @@ boolean_t vm_map_check_protection (vm_map_t, vm_offset_t, vm_offset_t, vm_prot_t
 int vm_map_delete(vm_map_t, vm_offset_t, vm_offset_t);
 int vm_map_find(vm_map_t, vm_object_t, vm_ooffset_t, vm_offset_t *, vm_size_t,
     vm_offset_t, int, vm_prot_t, vm_prot_t, int);
+int vm_map_find_locked(vm_map_t, vm_object_t, vm_ooffset_t, vm_offset_t *,
+    vm_size_t, vm_offset_t, int, vm_prot_t, vm_prot_t, int);
 int vm_map_find_min(vm_map_t, vm_object_t, vm_ooffset_t, vm_offset_t *,
     vm_size_t, vm_offset_t, vm_offset_t, int, vm_prot_t, vm_prot_t, int);
 int vm_map_find_aligned(vm_map_t map, vm_offset_t *addr, vm_size_t length,