git: 54d34bfbdf08 - main - Introduce sys/kassert.h

From: Konstantin Belousov <kib_at_FreeBSD.org>
Date: Tue, 01 Feb 2022 04:53:22 UTC
The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=54d34bfbdf08d383b0ecb9a721434ac732620c79

commit 54d34bfbdf08d383b0ecb9a721434ac732620c79
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2022-01-29 03:37:15 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2022-02-01 03:14:14 +0000

    Introduce sys/kassert.h
    
    It contains assert-related definitions previously provided by
    sys/systm.h.  The new header is leaner than whole systm.h.
    Include kassert.h from systm.h for compatibility.
    
    The copyright assignment to Eivind Eklund was suggested by Kirk McKusick
    and is based in the commit 5526d2d920eb17b1507499f35b275b486f7fe8d0.
    
    Suggested by:   jhb
    Reviewed by:    alc, imp, jhb
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Differential revision:  https://reviews.freebsd.org/D34089
---
 sys/sys/kassert.h | 149 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 sys/sys/systm.h   | 115 ++---------------------------------------
 2 files changed, 154 insertions(+), 110 deletions(-)

diff --git a/sys/sys/kassert.h b/sys/sys/kassert.h
new file mode 100644
index 000000000000..bb6847dc404f
--- /dev/null
+++ b/sys/sys/kassert.h
@@ -0,0 +1,149 @@
+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (c) 1999 Eivind Eklund <eivind@FreeBSD.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef _SYS_KASSERT_H_
+#define	_SYS_KASSERT_H_
+
+#include <sys/cdefs.h>
+
+#ifdef _KERNEL
+extern const char *panicstr;	/* panic message */
+extern bool panicked;
+#define	KERNEL_PANICKED()	__predict_false(panicked)
+
+#ifdef	INVARIANTS		/* The option is always available */
+#define	VNASSERT(exp, vp, msg) do {					\
+	if (__predict_false(!(exp))) {					\
+		vn_printf(vp, "VNASSERT failed: %s not true at %s:%d (%s)\n",\
+		   #exp, __FILE__, __LINE__, __func__);	 		\
+		kassert_panic msg;					\
+	}								\
+} while (0)
+#define	VNPASS(exp, vp)	do {						\
+	const char *_exp = #exp;					\
+	VNASSERT(exp, vp, ("condition %s not met at %s:%d (%s)",	\
+	    _exp, __FILE__, __LINE__, __func__));			\
+} while (0)
+#define	__assert_unreachable() \
+	panic("executing segment marked as unreachable at %s:%d (%s)\n", \
+	    __FILE__, __LINE__, __func__)
+#else	/* INVARIANTS */
+#define	VNASSERT(exp, vp, msg) do { \
+} while (0)
+#define	VNPASS(exp, vp) do { \
+} while (0)
+#define	__assert_unreachable()	__unreachable()
+#endif	/* INVARIANTS */
+
+#ifndef CTASSERT	/* Allow lint to override */
+#define	CTASSERT(x)	_Static_assert(x, "compile-time assertion failed")
+#endif
+
+/*
+ * These functions need to be declared before the KASSERT macro is invoked in
+ * !KASSERT_PANIC_OPTIONAL builds, so their declarations are sort of out of
+ * place compared to other function definitions in this header.  On the other
+ * hand, this header is a bit disorganized anyway.
+ */
+void	panic(const char *, ...) __dead2 __printflike(1, 2);
+void	vpanic(const char *, __va_list) __dead2 __printflike(1, 0);
+#endif	/* _KERNEL */
+
+#if defined(_STANDALONE)
+/*
+ * Until we have more experience with KASSERTS that are called
+ * from the boot loader, they are off. The bootloader does this
+ * a little differently than the kernel (we just call printf atm).
+ * we avoid most of the common functions in the boot loader, so
+ * declare printf() here too.
+ */
+int	printf(const char *, ...) __printflike(1, 2);
+#  define kassert_panic printf
+#else /* !_STANDALONE */
+#  if defined(WITNESS) || defined(INVARIANT_SUPPORT)
+#    ifdef KASSERT_PANIC_OPTIONAL
+void	kassert_panic(const char *fmt, ...)  __printflike(1, 2);
+#    else
+#      define kassert_panic	panic
+#    endif /* KASSERT_PANIC_OPTIONAL */
+#  endif /* defined(WITNESS) || defined(INVARIANT_SUPPORT) */
+#endif /* _STANDALONE */
+
+#if (defined(_KERNEL) && defined(INVARIANTS)) || defined(_STANDALONE)
+#define	KASSERT(exp,msg) do {						\
+	if (__predict_false(!(exp)))					\
+		kassert_panic msg;					\
+} while (0)
+#else /* !(KERNEL && INVARIANTS) && !_STANDALONE */
+#define	KASSERT(exp,msg) do { \
+} while (0)
+#endif /* (_KERNEL && INVARIANTS) || _STANDALONE */
+
+#ifdef _KERNEL
+/*
+ * Helpful macros for quickly coming up with assertions with informative
+ * panic messages.
+ */
+#define MPASS(ex)		MPASS4(ex, #ex, __FILE__, __LINE__)
+#define MPASS2(ex, what)	MPASS4(ex, what, __FILE__, __LINE__)
+#define MPASS3(ex, file, line)	MPASS4(ex, #ex, file, line)
+#define MPASS4(ex, what, file, line)					\
+	KASSERT((ex), ("Assertion %s failed at %s:%d", what, file, line))
+
+/*
+ * Assert that a pointer can be loaded from memory atomically.
+ *
+ * This assertion enforces stronger alignment than necessary.  For example,
+ * on some architectures, atomicity for unaligned loads will depend on
+ * whether or not the load spans multiple cache lines.
+ */
+#define	ASSERT_ATOMIC_LOAD_PTR(var, msg)				\
+	KASSERT(sizeof(var) == sizeof(void *) &&			\
+	    ((uintptr_t)&(var) & (sizeof(void *) - 1)) == 0, msg)
+/*
+ * Assert that a thread is in critical(9) section.
+ */
+#define	CRITICAL_ASSERT(td)						\
+	KASSERT((td)->td_critnest >= 1, ("Not in critical section"))
+
+/*
+ * If we have already panic'd and this is the thread that called
+ * panic(), then don't block on any mutexes but silently succeed.
+ * Otherwise, the kernel will deadlock since the scheduler isn't
+ * going to run the thread that holds any lock we need.
+ */
+#define	SCHEDULER_STOPPED_TD(td)  ({					\
+	MPASS((td) == curthread);					\
+	__predict_false((td)->td_stopsched);				\
+})
+#define	SCHEDULER_STOPPED() SCHEDULER_STOPPED_TD(curthread)
+#endif /* _KERNEL */
+
+#endif	/* _SYS_KASSERT_H_ */
diff --git a/sys/sys/systm.h b/sys/sys/systm.h
index 25a2d0c41e82..f2ffa7e6b815 100644
--- a/sys/sys/systm.h
+++ b/sys/sys/systm.h
@@ -44,6 +44,7 @@
 #include <machine/atomic.h>
 #include <machine/cpufunc.h>
 #include <sys/callout.h>
+#include <sys/kassert.h>
 #include <sys/queue.h>
 #include <sys/stdint.h>		/* for people using printf mainly */
 
@@ -53,9 +54,6 @@ __NULLABILITY_PRAGMA_PUSH
 extern int cold;		/* nonzero if we are doing a cold boot */
 extern int suspend_blocked;	/* block suspend due to pending shutdown */
 extern int rebooting;		/* kern_reboot() has been called. */
-extern const char *panicstr;	/* panic message */
-extern bool panicked;
-#define	KERNEL_PANICKED()	__predict_false(panicked)
 extern char version[];		/* system version */
 extern char compiler_version[];	/* compiler version */
 extern char copyright[];	/* system copyright */
@@ -86,86 +84,8 @@ enum VM_GUEST { VM_GUEST_NO = 0, VM_GUEST_VM, VM_GUEST_XEN, VM_GUEST_HV,
 		VM_GUEST_VMWARE, VM_GUEST_KVM, VM_GUEST_BHYVE, VM_GUEST_VBOX,
 		VM_GUEST_PARALLELS, VM_LAST };
 
-#ifdef	INVARIANTS		/* The option is always available */
-#define	VNASSERT(exp, vp, msg) do {					\
-	if (__predict_false(!(exp))) {					\
-		vn_printf(vp, "VNASSERT failed: %s not true at %s:%d (%s)\n",\
-		   #exp, __FILE__, __LINE__, __func__);	 		\
-		kassert_panic msg;					\
-	}								\
-} while (0)
-#define	VNPASS(exp, vp)	do {						\
-	const char *_exp = #exp;					\
-	VNASSERT(exp, vp, ("condition %s not met at %s:%d (%s)",	\
-	    _exp, __FILE__, __LINE__, __func__));			\
-} while (0)
-#define	__assert_unreachable() \
-	panic("executing segment marked as unreachable at %s:%d (%s)\n", \
-	    __FILE__, __LINE__, __func__)
-#else
-#define	VNASSERT(exp, vp, msg) do { \
-} while (0)
-#define	VNPASS(exp, vp) do { \
-} while (0)
-#define	__assert_unreachable()	__unreachable()
-#endif
-
-#ifndef CTASSERT	/* Allow lint to override */
-#define	CTASSERT(x)	_Static_assert(x, "compile-time assertion failed")
-#endif
 #endif /* KERNEL */
 
-/*
- * These functions need to be declared before the KASSERT macro is invoked in
- * !KASSERT_PANIC_OPTIONAL builds, so their declarations are sort of out of
- * place compared to other function definitions in this header.  On the other
- * hand, this header is a bit disorganized anyway.
- */
-void	panic(const char *, ...) __dead2 __printflike(1, 2);
-void	vpanic(const char *, __va_list) __dead2 __printflike(1, 0);
-
-
-#if defined(_STANDALONE)
-struct ucred;
-/*
- * Until we have more experience with KASSERTS that are called
- * from the boot loader, they are off. The bootloader does this
- * a little differently than the kernel (we just call printf atm).
- * we avoid most of the common functions in the boot loader, so
- * declare printf() here too.
- */
-int	printf(const char *, ...) __printflike(1, 2);
-#  define kassert_panic printf
-#else /* !_STANDALONE */
-#  if defined(WITNESS) || defined(INVARIANT_SUPPORT)
-#    ifdef KASSERT_PANIC_OPTIONAL
-void	kassert_panic(const char *fmt, ...)  __printflike(1, 2);
-#    else
-#      define kassert_panic	panic
-#    endif /* KASSERT_PANIC_OPTIONAL */
-#  endif /* defined(WITNESS) || defined(INVARIANT_SUPPORT) */
-#endif /* _STANDALONE */
-
-#if defined(INVARIANTS) || defined(_STANDALONE)
-#define	KASSERT(exp,msg) do {						\
-	if (__predict_false(!(exp)))					\
-		kassert_panic msg;					\
-} while (0)
-#else /* !INVARIANTS && !_STANDALONE */
-#define	KASSERT(exp,msg) do { \
-} while (0)
-#endif /* INVARIANTS || _STANDALONE */
-
-/*
- * Helpful macros for quickly coming up with assertions with informative
- * panic messages.
- */
-#define MPASS(ex)		MPASS4(ex, #ex, __FILE__, __LINE__)
-#define MPASS2(ex, what)	MPASS4(ex, what, __FILE__, __LINE__)
-#define MPASS3(ex, file, line)	MPASS4(ex, #ex, file, line)
-#define MPASS4(ex, what, file, line)					\
-	KASSERT((ex), ("Assertion %s failed at %s:%d", what, file, line))
-
 /*
  * Align variables.
  */
@@ -173,40 +93,15 @@ void	kassert_panic(const char *fmt, ...)  __printflike(1, 2);
 #define	__read_frequently	__section(".data.read_frequently")
 #define	__exclusive_cache_line	__aligned(CACHE_LINE_SIZE) \
 				    __section(".data.exclusive_cache_line")
+#if defined(_STANDALONE)
+struct ucred;
+#endif
+
 #ifdef _KERNEL
 #include <sys/param.h>		/* MAXCPU */
 #include <sys/pcpu.h>		/* curthread */
 #include <sys/kpilite.h>
 
-/*
- * Assert that a pointer can be loaded from memory atomically.
- *
- * This assertion enforces stronger alignment than necessary.  For example,
- * on some architectures, atomicity for unaligned loads will depend on
- * whether or not the load spans multiple cache lines.
- */
-#define	ASSERT_ATOMIC_LOAD_PTR(var, msg)				\
-	KASSERT(sizeof(var) == sizeof(void *) &&			\
-	    ((uintptr_t)&(var) & (sizeof(void *) - 1)) == 0, msg)
-
-/*
- * Assert that a thread is in critical(9) section.
- */
-#define	CRITICAL_ASSERT(td)						\
-	KASSERT((td)->td_critnest >= 1, ("Not in critical section"))
-
-/*
- * If we have already panic'd and this is the thread that called
- * panic(), then don't block on any mutexes but silently succeed.
- * Otherwise, the kernel will deadlock since the scheduler isn't
- * going to run the thread that holds any lock we need.
- */
-#define	SCHEDULER_STOPPED_TD(td)  ({					\
-	MPASS((td) == curthread);					\
-	__predict_false((td)->td_stopsched);				\
-})
-#define	SCHEDULER_STOPPED() SCHEDULER_STOPPED_TD(curthread)
-
 extern int osreldate;
 
 extern const void *zero_region;	/* address space maps to a zeroed page	*/