svn commit: r353876 - head/sys/kern

[Gleb Smirnoff]

Author: glebius
Date: Mon Oct 21 23:12:14 2019
New Revision: 353876
URL: https://svnweb.freebsd.org/changeset/base/353876

Log:
  Assert that any epoch tracker belongs to the thread stack.
  
  Reviewed by:	kib

Modified:
  head/sys/kern/subr_epoch.c

Modified: head/sys/kern/subr_epoch.c
==============================================================================
--- head/sys/kern/subr_epoch.c	Mon Oct 21 21:21:34 2019	(r353875)
+++ head/sys/kern/subr_epoch.c	Mon Oct 21 23:12:14 2019	(r353876)
@@ -366,9 +366,13 @@ _epoch_enter_preempt(epoch_t epoch, epoch_tracker_t et
 	struct thread *td;
 
 	MPASS(cold || epoch != NULL);
-	INIT_CHECK(epoch);
 	MPASS(epoch->e_flags & EPOCH_PREEMPT);
 	td = curthread;
+	MPASS((vm_offset_t)et >= td->td_kstack &&
+	    (vm_offset_t)et + sizeof(struct epoch_tracker) <
+	    td->td_kstack + td->td_kstack_pages * PAGE_SIZE);
+
+	INIT_CHECK(epoch);
 #ifdef EPOCH_TRACE
 	epoch_trace_enter(td, epoch, et, file, line);
 #endif