diff options
| author | Damien Zammit <damien@zamaudio.com> | 2024-02-23 08:15:11 +0000 |
|---|---|---|
| committer | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2024-02-23 14:14:52 +0100 |
| commit | e5872f2d6a0129dfc4a564b8af8a0f45dcdce86c (patch) | |
| tree | 54df87f9773f4293d5ccd06750f601db72674759 | |
| parent | 082831b9a62c7582635c564791d329e2477e2de4 (diff) | |
vm_map: Add comment and assert for vm_map_deletemaster
This will prevent calling vm_map_delete without the map locked
unless ref_count is zero.
Message-ID: <20240223081505.458240-1-damien@zamaudio.com>
| -rw-r--r-- | vm/vm_map.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/vm/vm_map.c b/vm/vm_map.c index c237afbe..7db76b7b 100644 --- a/vm/vm_map.c +++ b/vm/vm_map.c @@ -551,10 +551,12 @@ void vm_map_deallocate(vm_map_t map) c = --map->ref_count; simple_unlock(&map->ref_lock); + /* Check the refcount */ if (c > 0) { return; } + /* If no more references, call vm_map_delete without locking the map */ projected_buffer_collect(map); (void) vm_map_delete(map, map->min_offset, map->max_offset); @@ -2029,6 +2031,11 @@ kern_return_t vm_map_delete( panic("vm_map_delete(%lx-%lx) falls in physical memory area!\n", (unsigned long) start, (unsigned long) end); /* + * Must be called with map lock taken unless refcount is zero + */ + assert((map->ref_count > 0 && have_lock(map->lock)) || (map->ref_count == 0)); + + /* * Find the start of the region, and clip it */ |