From eaaf9f7fce3e921720a1f3cee4fd97b3b4ef1dcd Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Wed, 25 Jun 2014 03:30:03 +0000 Subject: [PATCH] Now that vm_map_insert() sets MAP_ENTRY_GROWS_{DOWN,UP} on the stack entries that it creates (r267645), we can place the check that blocks map entry coalescing on stack entries in vm_map_simplify_entry() where it properly belongs. Reviewed by: kib --- sys/vm/vm_map.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c index 9bb9bd10fbc2..47313a6cd601 100644 --- a/sys/vm/vm_map.c +++ b/sys/vm/vm_map.c @@ -1292,12 +1292,12 @@ vm_map_insert(vm_map_t map, vm_object_t object, vm_ooffset_t offset, map->size += new_entry->end - new_entry->start; /* - * It may be possible to merge the new entry with the next and/or - * previous entries. However, due to MAP_STACK_* being a hack, a - * panic can result from merging such entries. + * Try to coalesce the new entry with both the previous and next + * entries in the list. Previously, we only attempted to coalesce + * with the previous entry when object is NULL. Here, we handle the + * other cases, which are less common. */ - if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0) - vm_map_simplify_entry(map, new_entry); + vm_map_simplify_entry(map, new_entry); if (cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) { vm_map_pmap_enter(map, start, prot, @@ -1512,7 +1512,8 @@ vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry) vm_map_entry_t next, prev; vm_size_t prevsize, esize; - if (entry->eflags & (MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_IS_SUB_MAP)) + if ((entry->eflags & (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP | + MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_IS_SUB_MAP)) != 0) return; prev = entry->prev;