OS-8288 Pull in 13902 and 13915 early (#370)release-20210701

Portions contributed by: Jerry Jelinek <gjelinek@gmail.com>

6 files changed, 38 insertions, 13 deletions

diff --git a/usr/src/uts/common/brand/lx/os/lx_misc.c b/usr/src/uts/common/brand/lx/os/lx_misc.c
index 726c3c7915..8d48d2ea59 100644
--- a/usr/src/uts/common/brand/lx/os/lx_misc.c
+++ b/usr/src/uts/common/brand/lx/os/lx_misc.c
@@ -121,7 +121,7 @@ lx_exec()
 	lwpd->br_ntv_stack_current = 0;
 
 	installctx(lwptot(lwp), lwp, lx_save, lx_restore, NULL, NULL, lx_save,
-	    NULL);
+	    NULL, NULL);
 
 	/*
 	 * clear out the tls array
@@ -499,7 +499,7 @@ lx_initlwp(klwp_t *lwp, void *lwpbd)
 	lwpd->br_lpid = NULL;
 
 	installctx(lwptot(lwp), lwp, lx_save, lx_restore, NULL, NULL,
-	    lx_save, NULL);
+	    lx_save, NULL, NULL);
 
 	/*
 	 * Install branded system call hooks for this LWP:
diff --git a/usr/src/uts/common/disp/thread.c b/usr/src/uts/common/disp/thread.c
index bf1f121b67..c9e0216dbe 100644
--- a/usr/src/uts/common/disp/thread.c
+++ b/usr/src/uts/common/disp/thread.c
@@ -21,7 +21,7 @@
 
 /*
  * Copyright (c) 1991, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright 2019 Joyent, Inc.
+ * Copyright 2021 Joyent, Inc.
  */
 
 #include <sys/types.h>
@@ -1025,7 +1025,28 @@ reapq_add(kthread_t *t)
 }
 
 /*
+ * Provide an allocation function for callers of installctx() that, for
+ * reasons of incomplete context-op initialization, must call installctx()
+ * in a kpreempt_disable() block.  The caller, therefore, must call this
+ * without being in such a block.
+ */
+struct ctxop *
+installctx_preallocate(void)
+{
+	/*
+	 * NOTE: We could ASSERT/VERIFY that we are not in a place where
+	 * a KM_SLEEP allocation could block indefinitely.
+	 *
+	 * ASSERT(curthread->t_preempt == 0);
+	 */
+
+	return (kmem_alloc(sizeof (struct ctxop), KM_SLEEP));
+}
+
+/*
  * Install thread context ops for the current thread.
+ * The caller can pass in a preallocated struct ctxop, eliminating the need
+ * for the requirement of entering with kernel preemption still enabled.
  */
 void
 installctx(
@@ -1036,11 +1057,12 @@ installctx(
 	void	(*fork)(void *, void *),
 	void	(*lwp_create)(void *, void *),
 	void	(*exit)(void *),
-	void	(*free)(void *, int))
+	void	(*free)(void *, int),
+	struct ctxop *ctx)
 {
-	struct ctxop *ctx;
+	if (ctx == NULL)
+		ctx = kmem_alloc(sizeof (struct ctxop), KM_SLEEP);
 
-	ctx = kmem_alloc(sizeof (struct ctxop), KM_SLEEP);
 	ctx->save_op = save;
 	ctx->restore_op = restore;
 	ctx->fork_op = fork;
diff --git a/usr/src/uts/common/fs/zfs/spa_misc.c b/usr/src/uts/common/fs/zfs/spa_misc.c
index dd44829a43..af87d4611c 100644
--- a/usr/src/uts/common/fs/zfs/spa_misc.c
+++ b/usr/src/uts/common/fs/zfs/spa_misc.c
@@ -322,7 +322,8 @@ int zfs_deadman_enabled = -1;
  * the FPU state?  This is currently off by default due to stability issues in
  * the kernel FPU routines; e.g., see bug 13717.
  */
-int zfs_fpu_enabled = 0;
+/* XXX SmartOS now includes fixes for 13902 and 13915, so re-enable it. */
+int zfs_fpu_enabled = 1;
 #endif
 
 /*
diff --git a/usr/src/uts/common/os/kcpc.c b/usr/src/uts/common/os/kcpc.c
index 977d243400..33486aaff3 100644
--- a/usr/src/uts/common/os/kcpc.c
+++ b/usr/src/uts/common/os/kcpc.c
@@ -21,6 +21,7 @@
 
 /*
  * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright 2021 Joyent, Inc.
  */
 
 #include <sys/param.h>
@@ -318,7 +319,7 @@ kcpc_bind_thread(kcpc_set_t *set, kthread_t *t, int *subcode)
 	 * Add a device context to the subject thread.
 	 */
 	installctx(t, ctx, kcpc_save, kcpc_restore, NULL,
-	    kcpc_lwp_create, NULL, kcpc_free);
+	    kcpc_lwp_create, NULL, kcpc_free, NULL);
 
 	/*
 	 * Ask the backend to program the hardware.
@@ -1424,7 +1425,7 @@ kcpc_lwp_create(kthread_t *t, kthread_t *ct)
 	}
 
 	installctx(ct, cctx, kcpc_save, kcpc_restore,
-	    NULL, kcpc_lwp_create, NULL, kcpc_free);
+	    NULL, kcpc_lwp_create, NULL, kcpc_free, NULL);
 }
 
 /*
diff --git a/usr/src/uts/common/os/schedctl.c b/usr/src/uts/common/os/schedctl.c
index 18b396a765..34f72995a2 100644
--- a/usr/src/uts/common/os/schedctl.c
+++ b/usr/src/uts/common/os/schedctl.c
@@ -22,7 +22,7 @@
 /*
  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
- * Copyright 2016 Joyent, Inc.
+ * Copyright 2021 Joyent, Inc.
  */
 
 #include <sys/types.h>
@@ -113,7 +113,7 @@ schedctl(void)
 		bzero(ssp, sizeof (*ssp));
 
 		installctx(t, ssp, schedctl_save, schedctl_restore,
-		    schedctl_fork, NULL, NULL, NULL);
+		    schedctl_fork, NULL, NULL, NULL, NULL);
 
 		thread_lock(t);	/* protect against ts_tick and ts_update */
 		t->t_schedctl = ssp;
diff --git a/usr/src/uts/common/sys/proc.h b/usr/src/uts/common/sys/proc.h
index bb6f62f83f..90007bda1b 100644
--- a/usr/src/uts/common/sys/proc.h
+++ b/usr/src/uts/common/sys/proc.h
@@ -21,7 +21,7 @@
 
 /*
  * Copyright (c) 1988, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright 2018 Joyent, Inc.
+ * Copyright 2021 Joyent, Inc.
  * Copyright 2020 Oxide Computer Company
  */
 
@@ -720,8 +720,9 @@ extern	void	thread_free(kthread_t *);
 extern	void	thread_rele(kthread_t *);
 extern	void	thread_join(kt_did_t);
 extern	int	reaper(void);
+extern	struct ctxop *installctx_preallocate(void);
 extern	void	installctx(kthread_t *, void *, void (*)(), void (*)(),
-    void (*)(), void (*)(), void (*)(), void (*)());
+    void (*)(), void (*)(), void (*)(), void (*)(), struct ctxop *);
 extern	int	removectx(kthread_t *, void *, void (*)(), void (*)(),
     void (*)(), void (*)(), void (*)(), void (*)());
 extern	void	savectx(kthread_t *);