svn commit: r344391 - head/sys/kern
Andrew Turner
andrew at FreeBSD.org
Wed Feb 20 22:41:18 UTC 2019
Author: andrew
Date: Wed Feb 20 22:41:14 2019
New Revision: 344391
URL: https://svnweb.freebsd.org/changeset/base/344391
Log:
Unwire the kcov buffer when freeing the info struct.
Without this the physical memory will not be returned to the kernel.
While here call vm_object_reference on the object when mmapping the buffer.
This removed the need for buggy tracking of if it has been mapped or not.
This fixes issues where kcov could use all the system memory.
Reported by: tuexen
Reviewed by: kib
Sponsored by: DARPA, AFTL
Differential Revision: https://reviews.freebsd.org/D19252
Modified:
head/sys/kern/kern_kcov.c
Modified: head/sys/kern/kern_kcov.c
==============================================================================
--- head/sys/kern/kern_kcov.c Wed Feb 20 22:32:28 2019 (r344390)
+++ head/sys/kern/kern_kcov.c Wed Feb 20 22:41:14 2019 (r344391)
@@ -58,6 +58,7 @@ __FBSDID("$FreeBSD$");
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pager.h>
+#include <vm/vm_param.h>
MALLOC_DEFINE(M_KCOV_INFO, "kcovinfo", "KCOV info type");
@@ -347,6 +348,7 @@ kcov_mmap_single(struct cdev *dev, vm_ooffset_t *offse
info->mmap != false)
return (EINVAL);
+ vm_object_reference(info->bufobj);
info->mmap = true;
*offset = 0;
*object = info->bufobj;
@@ -393,13 +395,26 @@ kcov_alloc(struct kcov_info *info, size_t entries)
static void
kcov_free(struct kcov_info *info)
{
+ vm_page_t m;
+ size_t i;
if (info->kvaddr != 0) {
pmap_qremove(info->kvaddr, info->bufsize / PAGE_SIZE);
kva_free(info->kvaddr, info->bufsize);
}
- if (info->bufobj != NULL && !info->mmap)
+ if (info->bufobj != NULL) {
+ VM_OBJECT_WLOCK(info->bufobj);
+ m = vm_page_lookup(info->bufobj, 0);
+ for (i = 0; i < info->bufsize / PAGE_SIZE; i++) {
+ vm_page_lock(m);
+ vm_page_unwire_noq(m);
+ vm_page_unlock(m);
+
+ m = vm_page_next(m);
+ }
+ VM_OBJECT_WUNLOCK(info->bufobj);
vm_object_deallocate(info->bufobj);
+ }
free(info, M_KCOV_INFO);
}
More information about the svn-src-head
mailing list