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SubjectRe: [PATCH] lock assertion macros for 2.5.30
On Wed, Aug 07, 2002 at 07:19:21PM -0300, Rik van Riel wrote:
> Looks good to me. Would be even better if you removed MUST_NOT_HOLD ;)

Ok, here's yet another version. I've removed the conversion of the
scsi layer's ASSERT_LOCK macros as well as the silly version of
MUST_NOT_HOLD. Other things people seem interested in:
o sleeping function assertions
o lock ordering enforcement
o lock recursion detection
o more assertion checks in other parts of the kernel

Should any of the above be included in this patch? If so, I can try
to hack one or more of them together, otherwise maybe this is ok to go
in?

Thanks,
Jesse


diff -Naur -X /home/jbarnes/dontdiff linux-2.5.30/fs/inode.c linux-2.5.30-lockassert/fs/inode.c
--- linux-2.5.30/fs/inode.c Thu Aug 1 14:16:45 2002
+++ linux-2.5.30-lockassert/fs/inode.c Thu Aug 8 10:03:13 2002
@@ -193,6 +193,8 @@
*/
void __iget(struct inode * inode)
{
+ MUST_HOLD(&inode_lock);
+
if (atomic_read(&inode->i_count)) {
atomic_inc(&inode->i_count);
return;
diff -Naur -X /home/jbarnes/dontdiff linux-2.5.30/include/asm-i386/semaphore.h linux-2.5.30-lockassert/include/asm-i386/semaphore.h
--- linux-2.5.30/include/asm-i386/semaphore.h Thu Aug 1 14:16:16 2002
+++ linux-2.5.30-lockassert/include/asm-i386/semaphore.h Thu Aug 8 10:03:13 2002
@@ -40,6 +40,7 @@
#include <asm/atomic.h>
#include <linux/wait.h>
#include <linux/rwsem.h>
+#include <linux/config.h>

struct semaphore {
atomic_t count;
@@ -55,6 +56,12 @@
, (int)&(name).__magic
#else
# define __SEM_DEBUG_INIT(name)
+#endif
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+# define MUST_HOLD_SEM(sem) do { BUG_ON(atomic_read(&((sem)->count))); } while(0)
+#else
+# define MUST_HOLD_SEM(sem) do { } while(0)
#endif

#define __SEMAPHORE_INITIALIZER(name,count) \
diff -Naur -X /home/jbarnes/dontdiff linux-2.5.30/include/asm-i386/spinlock.h linux-2.5.30-lockassert/include/asm-i386/spinlock.h
--- linux-2.5.30/include/asm-i386/spinlock.h Thu Aug 1 14:16:14 2002
+++ linux-2.5.30-lockassert/include/asm-i386/spinlock.h Thu Aug 8 10:03:13 2002
@@ -157,6 +157,7 @@
#define RW_LOCK_UNLOCKED (rwlock_t) { RW_LOCK_BIAS RWLOCK_MAGIC_INIT }

#define rwlock_init(x) do { *(x) = RW_LOCK_UNLOCKED; } while(0)
+#define rwlock_is_locked(x) ((x)->lock != RW_LOCK_BIAS)

/*
* On x86, we implement read-write locks as a 32-bit counter
diff -Naur -X /home/jbarnes/dontdiff linux-2.5.30/include/asm-ia64/semaphore.h linux-2.5.30-lockassert/include/asm-ia64/semaphore.h
--- linux-2.5.30/include/asm-ia64/semaphore.h Thu Aug 1 14:16:24 2002
+++ linux-2.5.30-lockassert/include/asm-ia64/semaphore.h Thu Aug 8 10:03:13 2002
@@ -6,6 +6,7 @@
* Copyright (C) 1998-2000 David Mosberger-Tang <davidm@hpl.hp.com>
*/

+#include <linux/config.h>
#include <linux/wait.h>
#include <linux/rwsem.h>

@@ -24,6 +25,12 @@
# define __SEM_DEBUG_INIT(name) , (long) &(name).__magic
#else
# define __SEM_DEBUG_INIT(name)
+#endif
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+# define MUST_HOLD_SEM(sem) do { BUG_ON(atomic_read(&((sem)->count)); } while(0)
+#else
+# define MUST_HOLD_SEM(sem) do { } while(0)
#endif

#define __SEMAPHORE_INITIALIZER(name,count) \
diff -Naur -X /home/jbarnes/dontdiff linux-2.5.30/include/asm-ia64/spinlock.h linux-2.5.30-lockassert/include/asm-ia64/spinlock.h
--- linux-2.5.30/include/asm-ia64/spinlock.h Thu Aug 1 14:16:06 2002
+++ linux-2.5.30-lockassert/include/asm-ia64/spinlock.h Thu Aug 8 10:03:13 2002
@@ -109,6 +109,7 @@
#define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0 }

#define rwlock_init(x) do { *(x) = RW_LOCK_UNLOCKED; } while(0)
+#define rwlock_is_locked(x) ((x)->read_counter != 0 || (x)->write_lock != 0)

#define _raw_read_lock(rw) \
do { \
diff -Naur -X /home/jbarnes/dontdiff linux-2.5.30/include/linux/rwsem-spinlock.h linux-2.5.30-lockassert/include/linux/rwsem-spinlock.h
--- linux-2.5.30/include/linux/rwsem-spinlock.h Thu Aug 1 14:16:28 2002
+++ linux-2.5.30-lockassert/include/linux/rwsem-spinlock.h Thu Aug 8 10:03:13 2002
@@ -46,6 +46,12 @@
#define __RWSEM_DEBUG_INIT /* */
#endif

+#ifdef CONFIG_DEBUG_SPINLOCK
+#define MUST_HOLD_RWSEM(sem) BUG_ON(!(sem)->activity))
+#else
+#define MUST_HOLD_RWSEM(sem) do { } while (0)
+#endif
+
#define __RWSEM_INITIALIZER(name) \
{ 0, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) __RWSEM_DEBUG_INIT }

diff -Naur -X /home/jbarnes/dontdiff linux-2.5.30/include/linux/rwsem.h linux-2.5.30-lockassert/include/linux/rwsem.h
--- linux-2.5.30/include/linux/rwsem.h Thu Aug 1 14:16:18 2002
+++ linux-2.5.30-lockassert/include/linux/rwsem.h Thu Aug 8 10:03:13 2002
@@ -7,6 +7,7 @@
#ifndef _LINUX_RWSEM_H
#define _LINUX_RWSEM_H

+#include <linux/config.h>
#include <linux/linkage.h>

#define RWSEM_DEBUG 0
diff -Naur -X /home/jbarnes/dontdiff linux-2.5.30/include/linux/spinlock.h linux-2.5.30-lockassert/include/linux/spinlock.h
--- linux-2.5.30/include/linux/spinlock.h Thu Aug 1 14:16:25 2002
+++ linux-2.5.30-lockassert/include/linux/spinlock.h Thu Aug 8 10:04:23 2002
@@ -117,7 +117,19 @@
#define _raw_write_lock(lock) (void)(lock) /* Not "unused variable". */
#define _raw_write_unlock(lock) do { } while(0)

-#endif /* !SMP */
+#endif /* !CONFIG_SMP */
+
+/*
+ * Simple lock assertions for debugging and documenting where locks need
+ * to be held.
+ */
+#if defined(CONFIG_DEBUG_SPINLOCK) && defined(CONFIG_SMP)
+#define MUST_HOLD(lock) BUG_ON(!spin_is_locked(lock))
+#define MUST_HOLD_RW(lock) BUG_ON(!rwlock_is_locked(lock))
+#else
+#define MUST_HOLD(lock) do { } while(0)
+#define MUST_HOLD_RW(lock) do { } while(0)
+#endif /* CONFIG_DEBUG_SPINLOCK && CONFIG_SMP */

#ifdef CONFIG_PREEMPT

diff -Naur -X /home/jbarnes/dontdiff linux-2.5.30/kernel/acct.c linux-2.5.30-lockassert/kernel/acct.c
--- linux-2.5.30/kernel/acct.c Thu Aug 1 14:16:27 2002
+++ linux-2.5.30-lockassert/kernel/acct.c Thu Aug 8 10:03:13 2002
@@ -160,6 +160,8 @@
{
struct file *old_acct = NULL;

+ MUST_HOLD(&acct_globals.lock);
+
if (acct_globals.file) {
old_acct = acct_globals.file;
del_timer(&acct_globals.timer);
diff -Naur -X /home/jbarnes/dontdiff linux-2.5.30/kernel/printk.c linux-2.5.30-lockassert/kernel/printk.c
--- linux-2.5.30/kernel/printk.c Thu Aug 1 14:16:25 2002
+++ linux-2.5.30-lockassert/kernel/printk.c Thu Aug 8 10:03:13 2002
@@ -337,6 +337,8 @@
unsigned long cur_index, start_print;
static int msg_level = -1;

+ MUST_HOLD_SEM(&console_sem);
+
if (((long)(start - end)) > 0)
BUG();

-
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