Module Name: src
Committed By: riastradh
Date: Sat Aug 20 11:34:08 UTC 2022
Modified Files:
src/sys/arch/aarch64/aarch64: fpu.c
src/sys/arch/arm/vfp: vfp_init.c
src/sys/arch/x86/x86: fpu.c
Log Message:
fpu_kern_enter/leave: Disable IPL assertions.
These don't work because mutex_enter/exit on a spin lock may raise an
IPL but not lower it, if another spin lock was already held. For
example,
mutex_enter(some_lock_at_IPL_VM);
printf("foo\n");
fpu_kern_enter();
...
fpu_kern_leave();
mutex_exit(some_lock_at_IPL_VM);
will trigger the panic, because printf takes a lock at IPL_HIGH where
the IPL wil remain until the mutex_exit. (This was a nightmare to
track down before I remembered that detail of spin lock IPL
semantics...)
To generate a diff of this commit:
cvs rdiff -u -r1.12 -r1.13 src/sys/arch/aarch64/aarch64/fpu.c
cvs rdiff -u -r1.77 -r1.78 src/sys/arch/arm/vfp/vfp_init.c
cvs rdiff -u -r1.78 -r1.79 src/sys/arch/x86/x86/fpu.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/aarch64/aarch64/fpu.c
diff -u src/sys/arch/aarch64/aarch64/fpu.c:1.12 src/sys/arch/aarch64/aarch64/fpu.c:1.13
--- src/sys/arch/aarch64/aarch64/fpu.c:1.12 Fri Apr 1 19:57:22 2022
+++ src/sys/arch/aarch64/aarch64/fpu.c Sat Aug 20 11:34:08 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: fpu.c,v 1.12 2022/04/01 19:57:22 riastradh Exp $ */
+/* $NetBSD: fpu.c,v 1.13 2022/08/20 11:34:08 riastradh Exp $ */
/*-
* Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -31,7 +31,7 @@
#include <sys/cdefs.h>
-__KERNEL_RCSID(1, "$NetBSD: fpu.c,v 1.12 2022/04/01 19:57:22 riastradh Exp $");
+__KERNEL_RCSID(1, "$NetBSD: fpu.c,v 1.13 2022/08/20 11:34:08 riastradh Exp $");
#include <sys/param.h>
#include <sys/types.h>
@@ -214,7 +214,14 @@ fpu_kern_enter(void)
*/
s = splvm();
ci = curcpu();
+#if 0
+ /*
+ * Can't assert this because if the caller holds a spin lock at
+ * IPL_VM, and previously held and released a spin lock at
+ * higher IPL, the IPL remains raised above IPL_VM.
+ */
KASSERTMSG(ci->ci_cpl <= IPL_VM || cold, "cpl=%d", ci->ci_cpl);
+#endif
KASSERT(ci->ci_kfpu_spl == -1);
ci->ci_kfpu_spl = s;
@@ -242,7 +249,14 @@ fpu_kern_leave(void)
ci = curcpu();
+#if 0
+ /*
+ * Can't assert this because if the caller holds a spin lock at
+ * IPL_VM, and previously held and released a spin lock at
+ * higher IPL, the IPL remains raised above IPL_VM.
+ */
KASSERT(ci->ci_cpl == IPL_VM || cold);
+#endif
KASSERT(ci->ci_kfpu_spl != -1);
/*
Index: src/sys/arch/arm/vfp/vfp_init.c
diff -u src/sys/arch/arm/vfp/vfp_init.c:1.77 src/sys/arch/arm/vfp/vfp_init.c:1.78
--- src/sys/arch/arm/vfp/vfp_init.c:1.77 Fri Apr 1 19:57:22 2022
+++ src/sys/arch/arm/vfp/vfp_init.c Sat Aug 20 11:34:08 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: vfp_init.c,v 1.77 2022/04/01 19:57:22 riastradh Exp $ */
+/* $NetBSD: vfp_init.c,v 1.78 2022/08/20 11:34:08 riastradh Exp $ */
/*
* Copyright (c) 2008 ARM Ltd
@@ -32,7 +32,7 @@
#include "opt_cputypes.h"
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfp_init.c,v 1.77 2022/04/01 19:57:22 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfp_init.c,v 1.78 2022/08/20 11:34:08 riastradh Exp $");
#include <sys/param.h>
#include <sys/types.h>
@@ -695,7 +695,14 @@ fpu_kern_enter(void)
*/
s = splvm();
ci = curcpu();
+#if 0
+ /*
+ * Can't assert this because if the caller holds a spin lock at
+ * IPL_VM, and previously held and released a spin lock at
+ * higher IPL, the IPL remains raised above IPL_VM.
+ */
KASSERTMSG(ci->ci_cpl <= IPL_VM || cold, "cpl=%d", ci->ci_cpl);
+#endif
KASSERT(ci->ci_kfpu_spl == -1);
ci->ci_kfpu_spl = s;
@@ -721,7 +728,14 @@ fpu_kern_leave(void)
return;
}
+#if 0
+ /*
+ * Can't assert this because if the caller holds a spin lock at
+ * IPL_VM, and previously held and released a spin lock at
+ * higher IPL, the IPL remains raised above IPL_VM.
+ */
KASSERT(ci->ci_cpl == IPL_VM || cold);
+#endif
KASSERT(ci->ci_kfpu_spl != -1);
/*
Index: src/sys/arch/x86/x86/fpu.c
diff -u src/sys/arch/x86/x86/fpu.c:1.78 src/sys/arch/x86/x86/fpu.c:1.79
--- src/sys/arch/x86/x86/fpu.c:1.78 Tue May 24 06:28:00 2022
+++ src/sys/arch/x86/x86/fpu.c Sat Aug 20 11:34:08 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: fpu.c,v 1.78 2022/05/24 06:28:00 andvar Exp $ */
+/* $NetBSD: fpu.c,v 1.79 2022/08/20 11:34:08 riastradh Exp $ */
/*
* Copyright (c) 2008, 2019 The NetBSD Foundation, Inc. All
@@ -96,7 +96,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: fpu.c,v 1.78 2022/05/24 06:28:00 andvar Exp $");
+__KERNEL_RCSID(0, "$NetBSD: fpu.c,v 1.79 2022/08/20 11:34:08 riastradh Exp $");
#include "opt_multiprocessor.h"
@@ -380,8 +380,15 @@ fpu_kern_enter(void)
s = splvm();
ci = curcpu();
+#if 0
+ /*
+ * Can't assert this because if the caller holds a spin lock at
+ * IPL_VM, and previously held and released a spin lock at
+ * higher IPL, the IPL remains raised above IPL_VM.
+ */
KASSERTMSG(ci->ci_ilevel <= IPL_VM || cold, "ilevel=%d",
ci->ci_ilevel);
+#endif
KASSERT(ci->ci_kfpu_spl == -1);
ci->ci_kfpu_spl = s;
@@ -414,7 +421,14 @@ fpu_kern_leave(void)
struct cpu_info *ci = curcpu();
int s;
+#if 0
+ /*
+ * Can't assert this because if the caller holds a spin lock at
+ * IPL_VM, and previously held and released a spin lock at
+ * higher IPL, the IPL remains raised above IPL_VM.
+ */
KASSERT(ci->ci_ilevel == IPL_VM || cold);
+#endif
KASSERT(ci->ci_kfpu_spl != -1);
/*
