d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

When MAP_STACK_GROWS_{DOWN,UP} are passed to vm_map_insert() set the

Browse Source 
corresponding flag(s) in the new map entry.  Previously, the caller was
responsible for setting them after vm_map_insert() returned.

Pass MAP_STACK_GROWS_DOWN to vm_map_insert() from vm_map_growstack() when
extending the stack in the downward direction.

Together these changes slightly simplify the caller's task when creating a
downward growing stack.  In particular, the caller no longer needs to clip
the previous entry, because the new stack entry can't possibly coalesce
with the previous entry.

Reviewed by:	kib
Sponsored by:	EMC / Isilon Storage Division
This commit is contained in:
Alan Cox 2014-06-19 16:26:16 +00:00
parent 50fe38b6b8
commit 712efe66e2
1 changed files with 14 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
sys/vm/vm_map.c
View File

@ -1159,6 +1159,10 @@ vm_map_insert(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
protoeflags |= MAP_ENTRY_NOSYNC;
if (cow & MAP_DISABLE_COREDUMP)
protoeflags |= MAP_ENTRY_NOCOREDUMP;
if (cow & MAP_STACK_GROWS_DOWN)
protoeflags |= MAP_ENTRY_GROWS_DOWN;
if (cow & MAP_STACK_GROWS_UP)
protoeflags |= MAP_ENTRY_GROWS_UP;
if (cow & MAP_VN_WRITECOUNT)
protoeflags |= MAP_ENTRY_VN_WRITECNT;
if (cow & MAP_INHERIT_SHARE)
@ -3445,17 +3449,17 @@ vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize,
/* Now set the avail_ssize amount. */
if (rv == KERN_SUCCESS) {
if (prev_entry != &map->header)
vm_map_clip_end(map, prev_entry, bot);
new_entry = prev_entry->next;
if (new_entry->end != top || new_entry->start != bot)
panic("Bad entry start/end for new stack entry");
new_entry->avail_ssize = max_ssize - init_ssize;
if (orient & MAP_STACK_GROWS_DOWN)
new_entry->eflags |= MAP_ENTRY_GROWS_DOWN;
if (orient & MAP_STACK_GROWS_UP)
new_entry->eflags |= MAP_ENTRY_GROWS_UP;
KASSERT((orient & MAP_STACK_GROWS_DOWN) == 0 ||
(new_entry->eflags & MAP_ENTRY_GROWS_DOWN) != 0,
("new entry lacks MAP_ENTRY_GROWS_DOWN"));
KASSERT((orient & MAP_STACK_GROWS_UP) == 0 ||
(new_entry->eflags & MAP_ENTRY_GROWS_UP) != 0,
("new entry lacks MAP_ENTRY_GROWS_UP"));
}
return (rv);
@ -3675,21 +3679,21 @@ Retry:
}
rv = vm_map_insert(map, NULL, 0, addr, stack_entry->start,
next_entry->protection, next_entry->max_protection, 0);
next_entry->protection, next_entry->max_protection,
MAP_STACK_GROWS_DOWN);
/* Adjust the available stack space by the amount we grew. */
if (rv == KERN_SUCCESS) {
if (prev_entry != &map->header)
vm_map_clip_end(map, prev_entry, addr);
new_entry = prev_entry->next;
KASSERT(new_entry == stack_entry->prev, ("foo"));
KASSERT(new_entry->end == stack_entry->start, ("foo"));
KASSERT(new_entry->start == addr, ("foo"));
KASSERT((new_entry->eflags & MAP_ENTRY_GROWS_DOWN) !=
0, ("new entry lacks MAP_ENTRY_GROWS_DOWN"));
grow_amount = new_entry->end - new_entry->start;
new_entry->avail_ssize = stack_entry->avail_ssize -
grow_amount;
stack_entry->eflags &= ~MAP_ENTRY_GROWS_DOWN;
new_entry->eflags |= MAP_ENTRY_GROWS_DOWN;
}
} else {
/*