Module Name: src
Committed By: riastradh
Date: Sun Dec 19 11:21:45 UTC 2021
Modified Files:
src/sys/external/bsd/drm2/include/linux: rwsem.h
src/sys/external/bsd/drm2/linux: linux_rwsem.c
Log Message:
linux: Teach rw semaphores about lockdebug.
To generate a diff of this commit:
cvs rdiff -u -r1.3 -r1.4 src/sys/external/bsd/drm2/include/linux/rwsem.h
cvs rdiff -u -r1.2 -r1.3 src/sys/external/bsd/drm2/linux/linux_rwsem.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/external/bsd/drm2/include/linux/rwsem.h
diff -u src/sys/external/bsd/drm2/include/linux/rwsem.h:1.3 src/sys/external/bsd/drm2/include/linux/rwsem.h:1.4
--- src/sys/external/bsd/drm2/include/linux/rwsem.h:1.3 Sun Dec 19 11:21:30 2021
+++ src/sys/external/bsd/drm2/include/linux/rwsem.h Sun Dec 19 11:21:45 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: rwsem.h,v 1.3 2021/12/19 11:21:30 riastradh Exp $ */
+/* $NetBSD: rwsem.h,v 1.4 2021/12/19 11:21:45 riastradh Exp $ */
/*-
* Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -60,6 +60,7 @@ struct rw_semaphore {
struct lwp *rws_writer;
unsigned rws_readers;
bool rws_writewanted;
+ bool rws_debug;
};
void init_rwsem(struct rw_semaphore *);
Index: src/sys/external/bsd/drm2/linux/linux_rwsem.c
diff -u src/sys/external/bsd/drm2/linux/linux_rwsem.c:1.2 src/sys/external/bsd/drm2/linux/linux_rwsem.c:1.3
--- src/sys/external/bsd/drm2/linux/linux_rwsem.c:1.2 Sun Dec 19 11:21:38 2021
+++ src/sys/external/bsd/drm2/linux/linux_rwsem.c Sun Dec 19 11:21:45 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: linux_rwsem.c,v 1.2 2021/12/19 11:21:38 riastradh Exp $ */
+/* $NetBSD: linux_rwsem.c,v 1.3 2021/12/19 11:21:45 riastradh Exp $ */
/*-
* Copyright (c) 2021 The NetBSD Foundation, Inc.
@@ -27,12 +27,13 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: linux_rwsem.c,v 1.2 2021/12/19 11:21:38 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: linux_rwsem.c,v 1.3 2021/12/19 11:21:45 riastradh Exp $");
#include <sys/types.h>
#include <sys/condvar.h>
#include <sys/lwp.h>
+#include <sys/lockdebug.h>
#include <sys/rwlock.h>
#include <machine/limits.h>
@@ -41,6 +42,40 @@ __KERNEL_RCSID(0, "$NetBSD: linux_rwsem.
#include <linux/rwsem.h>
+#define RWSEM_WANTLOCK(RWSEM) \
+ LOCKDEBUG_WANTLOCK((RWSEM)->rws_debug, (RWSEM), \
+ (uintptr_t)__builtin_return_address(0), 0)
+#define RWSEM_LOCKED_EX(RWSEM) \
+ LOCKDEBUG_LOCKED((RWSEM)->rws_debug, (RWSEM), NULL, \
+ (uintptr_t)__builtin_return_address(0), 0)
+#define RWSEM_LOCKED_SH(RWSEM) \
+ LOCKDEBUG_LOCKED((RWSEM)->rws_debug, (RWSEM), NULL, \
+ (uintptr_t)__builtin_return_address(0), 1)
+#define RWSEM_UNLOCKED_EX(RWSEM) \
+ LOCKDEBUG_UNLOCKED((RWSEM)->rws_debug, (RWSEM), \
+ (uintptr_t)__builtin_return_address(0), 0)
+#define RWSEM_UNLOCKED_SH(RWSEM) \
+ LOCKDEBUG_UNLOCKED((RWSEM)->rws_debug, (RWSEM), \
+ (uintptr_t)__builtin_return_address(0), 1)
+
+#ifdef LOCKDEBUG
+static void
+rwsem_dump(const volatile void *cookie, lockop_printer_t pr)
+{
+ const volatile struct rw_semaphore *rwsem = cookie;
+
+ pr("%-13s: %p", "writer", rwsem->rws_writer);
+ pr("%-13s: %u", "readers", rwsem->rws_readers);
+ pr("%-13s: %s", "writewanted", rwsem->rws_writewanted ? "yes" : "no");
+}
+
+static lockops_t rwsem_lockops = {
+ .lo_name = "Linux read/write semaphore",
+ .lo_type = LOCKOPS_SLEEP,
+ .lo_dump = rwsem_dump,
+};
+#endif
+
void
init_rwsem(struct rw_semaphore *rwsem)
{
@@ -49,6 +84,11 @@ init_rwsem(struct rw_semaphore *rwsem)
cv_init(&rwsem->rws_cv, "lnxrwsem");
rwsem->rws_writer = NULL;
rwsem->rws_readers = 0;
+
+#ifdef LOCKDEBUG
+ rwsem->rws_debug = LOCKDEBUG_ALLOC(rwsem, &rwsem_lockops,
+ (uintptr_t)__builtin_return_address(0));
+#endif
}
void
@@ -57,6 +97,11 @@ destroy_rwsem(struct rw_semaphore *rwsem
KASSERT(rwsem->rws_readers == 0);
KASSERT(rwsem->rws_writer == NULL);
+
+#ifdef LOCKDEBUG
+ LOCKDEBUG_FREE(rwsem->rws_debug, rwsem);
+#endif
+
cv_destroy(&rwsem->rws_cv);
mutex_destroy(&rwsem->rws_lock);
}
@@ -65,12 +110,16 @@ void
down_read(struct rw_semaphore *rwsem)
{
+ RWSEM_WANTLOCK(rwsem);
+
mutex_enter(&rwsem->rws_lock);
while (rwsem->rws_writer || rwsem->rws_writewanted)
cv_wait(&rwsem->rws_cv, &rwsem->rws_lock);
KASSERT(rwsem->rws_readers < UINT_MAX);
rwsem->rws_readers++;
mutex_exit(&rwsem->rws_lock);
+
+ RWSEM_LOCKED_SH(rwsem);
}
bool
@@ -94,6 +143,9 @@ down_read_trylock(struct rw_semaphore *r
}
mutex_exit(&rwsem->rws_lock);
+ if (ret)
+ RWSEM_LOCKED_SH(rwsem);
+
return ret;
}
@@ -101,6 +153,8 @@ void
up_read(struct rw_semaphore *rwsem)
{
+ RWSEM_UNLOCKED_SH(rwsem);
+
mutex_enter(&rwsem->rws_lock);
KASSERT(rwsem->rws_readers);
KASSERT(rwsem->rws_writer == NULL);
@@ -113,6 +167,8 @@ void
down_write(struct rw_semaphore *rwsem)
{
+ RWSEM_WANTLOCK(rwsem);
+
mutex_enter(&rwsem->rws_lock);
/* If another writer is waiting, get in the queue. */
@@ -138,12 +194,16 @@ down_write(struct rw_semaphore *rwsem)
rwsem->rws_writer = curlwp;
mutex_exit(&rwsem->rws_lock);
+
+ RWSEM_LOCKED_EX(rwsem);
}
void
up_write(struct rw_semaphore *rwsem)
{
+ RWSEM_UNLOCKED_EX(rwsem);
+
mutex_enter(&rwsem->rws_lock);
KASSERT(rwsem->rws_writer == curlwp);
KASSERT(rwsem->rws_readers == 0);
@@ -156,6 +216,8 @@ void
downgrade_write(struct rw_semaphore *rwsem)
{
+ RWSEM_UNLOCKED_EX(rwsem);
+
mutex_enter(&rwsem->rws_lock);
KASSERT(rwsem->rws_writer == curlwp);
KASSERT(rwsem->rws_readers == 0);
@@ -163,4 +225,6 @@ downgrade_write(struct rw_semaphore *rws
rwsem->rws_readers = 1;
cv_broadcast(&rwsem->rws_cv);
mutex_exit(&rwsem->rws_lock);
+
+ RWSEM_LOCKED_SH(rwsem);
}
