#include <linux/rcupdate.h>
#include <linux/marker.h>
#include <linux/err.h>
+#include <linux/slab.h>
extern struct marker __start___markers[];
extern struct marker __stop___markers[];
/* Set to 1 to enable marker debug output */
-const int marker_debug;
+static const int marker_debug;
/*
* markers_mutex nests inside module_mutex. Markers mutex protects the builtin
struct marker_entry {
struct hlist_node hlist;
char *format;
- void (*call)(const struct marker *mdata, /* Probe wrapper */
- void *call_private, const char *fmt, ...);
+ /* Probe wrapper */
+ void (*call)(const struct marker *mdata, void *call_private, ...);
struct marker_probe_closure single;
struct marker_probe_closure *multi;
int refcount; /* Number of times armed. 0 if disarmed. */
* marker_probe_cb Callback that prepares the variable argument list for probes.
* @mdata: pointer of type struct marker
* @call_private: caller site private data
- * @fmt: format string
* @...: Variable argument list.
*
* Since we do not use "typical" pointer based RCU in the 1 argument case, we
* need to put a full smp_rmb() in this branch. This is why we do not use
* rcu_dereference() for the pointer read.
*/
-void marker_probe_cb(const struct marker *mdata, void *call_private,
- const char *fmt, ...)
+void marker_probe_cb(const struct marker *mdata, void *call_private, ...)
{
va_list args;
char ptype;
/*
- * disabling preemption to make sure the teardown of the callbacks can
- * be done correctly when they are in modules and they insure RCU read
- * coherency.
+ * preempt_disable does two things : disabling preemption to make sure
+ * the teardown of the callbacks can be done correctly when they are in
+ * modules and they insure RCU read coherency.
*/
preempt_disable();
- ptype = ACCESS_ONCE(mdata->ptype);
+ ptype = mdata->ptype;
if (likely(!ptype)) {
marker_probe_func *func;
/* Must read the ptype before ptr. They are not data dependant,
* so we put an explicit smp_rmb() here. */
smp_rmb();
- func = ACCESS_ONCE(mdata->single.func);
+ func = mdata->single.func;
/* Must read the ptr before private data. They are not data
* dependant, so we put an explicit smp_rmb() here. */
smp_rmb();
- va_start(args, fmt);
- func(mdata->single.probe_private, call_private, fmt, &args);
+ va_start(args, call_private);
+ func(mdata->single.probe_private, call_private, mdata->format,
+ &args);
va_end(args);
} else {
struct marker_probe_closure *multi;
int i;
/*
+ * Read mdata->ptype before mdata->multi.
+ */
+ smp_rmb();
+ multi = mdata->multi;
+ /*
* multi points to an array, therefore accessing the array
* depends on reading multi. However, even in this case,
* we must insure that the pointer is read _before_ the array
* in the fast path, so put the explicit barrier here.
*/
smp_read_barrier_depends();
- multi = ACCESS_ONCE(mdata->multi);
for (i = 0; multi[i].func; i++) {
- va_start(args, fmt);
- multi[i].func(multi[i].probe_private, call_private, fmt,
- &args);
+ va_start(args, call_private);
+ multi[i].func(multi[i].probe_private, call_private,
+ mdata->format, &args);
va_end(args);
}
}
* marker_probe_cb Callback that does not prepare the variable argument list.
* @mdata: pointer of type struct marker
* @call_private: caller site private data
- * @fmt: format string
* @...: Variable argument list.
*
* Should be connected to markers "MARK_NOARGS".
*/
-void marker_probe_cb_noarg(const struct marker *mdata,
- void *call_private, const char *fmt, ...)
+void marker_probe_cb_noarg(const struct marker *mdata, void *call_private, ...)
{
va_list args; /* not initialized */
char ptype;
preempt_disable();
- ptype = ACCESS_ONCE(mdata->ptype);
+ ptype = mdata->ptype;
if (likely(!ptype)) {
marker_probe_func *func;
/* Must read the ptype before ptr. They are not data dependant,
* so we put an explicit smp_rmb() here. */
smp_rmb();
- func = ACCESS_ONCE(mdata->single.func);
+ func = mdata->single.func;
/* Must read the ptr before private data. They are not data
* dependant, so we put an explicit smp_rmb() here. */
smp_rmb();
- func(mdata->single.probe_private, call_private, fmt, &args);
+ func(mdata->single.probe_private, call_private, mdata->format,
+ &args);
} else {
struct marker_probe_closure *multi;
int i;
/*
+ * Read mdata->ptype before mdata->multi.
+ */
+ smp_rmb();
+ multi = mdata->multi;
+ /*
* multi points to an array, therefore accessing the array
* depends on reading multi. However, even in this case,
* we must insure that the pointer is read _before_ the array
* in the fast path, so put the explicit barrier here.
*/
smp_read_barrier_depends();
- multi = ACCESS_ONCE(mdata->multi);
for (i = 0; multi[i].func; i++)
- multi[i].func(multi[i].probe_private, call_private, fmt,
- &args);
+ multi[i].func(multi[i].probe_private, call_private,
+ mdata->format, &args);
}
preempt_enable();
}
hlist_del(&e->hlist);
/* Make sure the call_rcu has been executed */
if (e->rcu_pending)
- rcu_barrier();
+ rcu_barrier_sched();
kfree(e);
return 0;
}
hlist_del(&(*entry)->hlist);
/* Make sure the call_rcu has been executed */
if ((*entry)->rcu_pending)
- rcu_barrier();
+ rcu_barrier_sched();
kfree(*entry);
*entry = e;
trace_mark(core_marker_format, "name %s format %s",
/*
* Disable a marker and its probe callback.
- * Note: only after a synchronize_sched() issued after setting elem->call to the
- * empty function insures that the original callback is not used anymore. This
- * insured by preemption disabling around the call site.
+ * Note: only waiting an RCU period after setting elem->call to the empty
+ * function insures that the original callback is not used anymore. This insured
+ * by preempt_disable around the call site.
*/
static void disable_marker(struct marker *elem)
{
elem->ptype = 0; /* single probe */
/*
* Leave the private data and id there, because removal is racy and
- * should be done only after a synchronize_sched(). These are never used
- * until the next initialization anyway.
+ * should be done only after an RCU period. These are never used until
+ * the next initialization anyway.
*/
}
/*
* Update probes, removing the faulty probes.
- * Issues a synchronize_sched() when no reference to the module passed
- * as parameter is found in the probes so the probe module can be
- * safely unloaded from now on.
*
* Internal callback only changed before the first probe is connected to it.
* Single probe private data can only be changed on 0 -> 1 and 2 -> 1
* make sure it's executed now.
*/
if (entry->rcu_pending)
- rcu_barrier();
+ rcu_barrier_sched();
old = marker_entry_add_probe(entry, probe, probe_private);
if (IS_ERR(old)) {
ret = PTR_ERR(old);
entry->rcu_pending = 1;
/* write rcu_pending before calling the RCU callback */
smp_wmb();
- call_rcu(&entry->rcu, free_old_closure);
+ call_rcu_sched(&entry->rcu, free_old_closure);
end:
mutex_unlock(&markers_mutex);
return ret;
if (!entry)
goto end;
if (entry->rcu_pending)
- rcu_barrier();
+ rcu_barrier_sched();
old = marker_entry_remove_probe(entry, probe, probe_private);
mutex_unlock(&markers_mutex);
marker_update_probes(); /* may update entry */
entry->rcu_pending = 1;
/* write rcu_pending before calling the RCU callback */
smp_wmb();
- call_rcu(&entry->rcu, free_old_closure);
+ call_rcu_sched(&entry->rcu, free_old_closure);
remove_marker(name); /* Ignore busy error message */
ret = 0;
end:
goto end;
}
if (entry->rcu_pending)
- rcu_barrier();
+ rcu_barrier_sched();
old = marker_entry_remove_probe(entry, NULL, probe_private);
mutex_unlock(&markers_mutex);
marker_update_probes(); /* may update entry */
entry->rcu_pending = 1;
/* write rcu_pending before calling the RCU callback */
smp_wmb();
- call_rcu(&entry->rcu, free_old_closure);
+ call_rcu_sched(&entry->rcu, free_old_closure);
remove_marker(entry->name); /* Ignore busy error message */
end:
mutex_unlock(&markers_mutex);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff