On Sun, Jan 16, 2022 at 09:22:50AM -0300, Martin Pieuchot wrote:
> IMHO this approach of let's try if it works now and revert if it isn't
> doesn't help us make progress. I'd be more confident seeing diffs that
> assert for the right lock in the functions called by uvm_mapanon() and
> documentation about which lock is protecting which field of the data
> structures.
I picked `vm_map's `size' as first underdocumented member.
All accesses to it are protected by vm_map_lock(), either through the
function itself or implicitly by already requiring the calling function
to lock the map.
So annotate functions using `size' wrt. the required lock.
Index: uvm_map.c
===================================================================
RCS file: /cvs/src/sys/uvm/uvm_map.c,v
retrieving revision 1.282
diff -u -p -r1.282 uvm_map.c
--- uvm_map.c 21 Dec 2021 22:21:32 -0000 1.282
+++ uvm_map.c 21 Jan 2022 13:03:05 -0000
@@ -805,6 +805,8 @@ uvm_map_sel_limits(vaddr_t *min, vaddr_t
* Fills in *start_ptr and *end_ptr to be the first and last entry describing
* the space.
* If called with prefilled *start_ptr and *end_ptr, they are to be correct.
+ *
+ * map must be at least read-locked.
*/
int
uvm_map_isavail(struct vm_map *map, struct uvm_addr_state *uaddr,
@@ -2206,6 +2208,8 @@ uvm_unmap_kill_entry(struct vm_map *map,
* If remove_holes, then remove ET_HOLE entries as well.
* If markfree, entry will be properly marked free, otherwise, no replacement
* entry will be put in the tree (corrupting the tree).
+ *
+ * map must be locked.
*/
void
uvm_unmap_remove(struct vm_map *map, vaddr_t start, vaddr_t end,
@@ -2976,6 +2980,9 @@ uvm_tree_sanity(struct vm_map *map, char
UVM_ASSERT(map, addr == vm_map_max(map), file, line);
}
+/*
+ * map must be at least read-locked.
+ */
void
uvm_tree_size_chk(struct vm_map *map, char *file, int line)
{
Index: uvm_map.h
===================================================================
RCS file: /cvs/src/sys/uvm/uvm_map.h,v
retrieving revision 1.71
diff -u -p -r1.71 uvm_map.h
--- uvm_map.h 15 Dec 2021 12:53:53 -0000 1.71
+++ uvm_map.h 21 Jan 2022 12:51:26 -0000
@@ -272,7 +272,7 @@ struct vm_map {
struct uvm_map_addr addr; /* [v] Entry tree, by addr */
- vsize_t size; /* virtual size */
+ vsize_t size; /* [v] virtual size */
int ref_count; /* [a] Reference count */
int flags; /* flags */
struct mutex flags_lock; /* flags lock */
