svn commit: r367714 - head/sys/kern

[Mateusz Guzik]

Author: mjg
Date: Mon Nov 16 03:12:21 2020
New Revision: 367714
URL: https://svnweb.freebsd.org/changeset/base/367714

Log:
  select: call seltdfini on process and thread exit
  
  Since thread_zone is marked NOFREE the thread_fini callback is never
  executed, meaning memory allocated by seltdinit is never released.
  
  Adding the call to thread_dtor is not sufficient as exiting processes
  cache the main thread.

Modified:
  head/sys/kern/kern_exit.c
  head/sys/kern/kern_thread.c

Modified: head/sys/kern/kern_exit.c
==============================================================================
--- head/sys/kern/kern_exit.c	Mon Nov 16 03:09:18 2020	(r367713)
+++ head/sys/kern/kern_exit.c	Mon Nov 16 03:12:21 2020	(r367714)
@@ -355,6 +355,7 @@ exit1(struct thread *td, int rval, int signo)
 	PROC_UNLOCK(p);
 
 	umtx_thread_exit(td);
+	seltdfini(td);
 
 	/*
 	 * Reset any sigio structures pointing to us as a result of

Modified: head/sys/kern/kern_thread.c
==============================================================================
--- head/sys/kern/kern_thread.c	Mon Nov 16 03:09:18 2020	(r367713)
+++ head/sys/kern/kern_thread.c	Mon Nov 16 03:12:21 2020	(r367714)
@@ -329,6 +329,7 @@ thread_ctor(void *mem, int size, void *arg, int flags)
 	audit_thread_alloc(td);
 #endif
 	umtx_thread_alloc(td);
+	MPASS(td->td_sel == NULL);
 	return (0);
 }
 
@@ -369,6 +370,7 @@ thread_dtor(void *mem, int size, void *arg)
 	osd_thread_exit(td);
 	td_softdep_cleanup(td);
 	MPASS(td->td_su == NULL);
+	seltdfini(td);
 }
 
 /*
@@ -405,7 +407,7 @@ thread_fini(void *mem, int size)
 	turnstile_free(td->td_turnstile);
 	sleepq_free(td->td_sleepqueue);
 	umtx_thread_fini(td);
-	seltdfini(td);
+	MPASS(td->td_sel == NULL);
 }
 
 /*