From: deraadt <deraadt@openbsd.org>
Date: Wed, 2 Feb 2022 04:05:16 +0000 (+0000)
Subject: acpi_addtask() calls malloc() w/ M_NOWAIT (because some calls come from
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=f48369e00dd0c5bcc6b1c49c8787d8007deeb4e2;p=openbsd

acpi_addtask() calls malloc() w/ M_NOWAIT (because some calls come from
interrupt context), this however means occasional resource shortage will
result in callbacks registration failing, and unknown consequences for
the task-submitting caller.
Changing this to use pools with a low water mark, decreases the odds
of that problem occuring.
ok kettenis
---

diff --git a/sys/dev/acpi/acpi.c b/sys/dev/acpi/acpi.c
index acbaa1b07c0..6644c52464a 100644
--- a/sys/dev/acpi/acpi.c
+++ b/sys/dev/acpi/acpi.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: acpi.c,v 1.407 2022/02/01 18:09:00 deraadt Exp $ */
+/* $OpenBSD: acpi.c,v 1.408 2022/02/02 04:05:16 deraadt Exp $ */
 /*
  * Copyright (c) 2005 Thorsten Lockert <tholo@sigmasoft.com>
  * Copyright (c) 2005 Jordan Hargrave <jordan@openbsd.org>
@@ -21,6 +21,7 @@
 #include <sys/buf.h>
 #include <sys/device.h>
 #include <sys/malloc.h>
+#include <sys/pool.h>
 #include <sys/fcntl.h>
 #include <sys/ioccom.h>
 #include <sys/event.h>
@@ -74,6 +75,8 @@ int	acpi_poll_enabled;
 int	acpi_hasprocfvs;
 int	acpi_haspci;
 
+struct pool acpiwqpool;
+
 #define ACPIEN_RETRIES 15
 
 struct aml_node *acpi_pci_match(struct device *, struct pci_attach_args *);
@@ -1007,6 +1010,10 @@ acpi_attach_common(struct acpi_softc *sc, paddr_t base)
 	}
 	rsdp = (struct acpi_rsdp *)handle.va;
 
+	pool_init(&acpiwqpool, sizeof(struct acpi_taskq), 0, IPL_BIO, 0,
+	    "acpiwqpl", NULL);
+	pool_setlowat(&acpiwqpool, 16);
+
 	SIMPLEQ_INIT(&sc->sc_tables);
 	SIMPLEQ_INIT(&sc->sc_wakedevs);
 #if NACPIPWRRES > 0
@@ -1798,9 +1805,11 @@ acpi_addtask(struct acpi_softc *sc, void (*handler)(void *, int),
 	struct acpi_taskq *wq;
 	int s;
 
-	wq = malloc(sizeof(*wq), M_DEVBUF, M_ZERO | M_NOWAIT);
-	if (wq == NULL)
+	wq = pool_get(&acpiwqpool, PR_ZERO | PR_NOWAIT);
+	if (wq == NULL) {
+		printf("unable to create task");
 		return;
+	}
 	wq->handler = handler;
 	wq->arg0 = arg0;
 	wq->arg1 = arg1;
@@ -1829,7 +1838,7 @@ acpi_dotask(struct acpi_softc *sc)
 
 	wq->handler(wq->arg0, wq->arg1);
 
-	free(wq, M_DEVBUF, sizeof(*wq));
+	pool_put(&acpiwqpool, wq);
 
 	/* We did something */
 	return (1);