[PATCH 10/21] dynamic_debug: call apply_pending_queries from ddebug_add_module

From: Jim Cromie
Date: Mon Jul 11 2011 - 03:47:43 EST


When a module is loaded, ddebug_add_module calls apply_pending_queries
to scan pending_queries list and call ddebug_change to apply them.
Matching rules are removed from pending_queries.

With this change, the loaded module's pr_debugs are enabled when
its module_init is invoked, which is not possible otherwize.

With verbose=1, kernel logs look like:

apply_pending_queries: check: pc8736x_gpio <-> q->function="(null)" q->filename="(null)" \
q->module="pc8736x_gpio" q->format="(null)" q->lineno=0-0 q->flags=0x1 q->mask=0xffffffff
...
ddebug_change: changed .../drivers/char/pc8736x_gpio.c:342 [pc8736x_gpio]pc8736x_gpio_cleanup p
ddebug_change: changed .../drivers/char/pc8736x_gpio.c:319 [pc8736x_gpio]pc8736x_gpio_init p
...
platform pc8736x_gpio.0: NatSemi pc8736x GPIO Driver Initializing
platform pc8736x_gpio.0: GPIO ioport 6600 reserved

Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>
---
lib/dynamic_debug.c | 41 +++++++++++++++++++++++++++++++++++++++++
1 files changed, 41 insertions(+), 0 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index b049ef2..cc8e157 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -124,6 +124,16 @@ static char *show_ddebug_query(const struct ddebug_query *q)
return prbuf_query;
}

+static char *show_pending_query(struct pending_query *pq)
+{
+ struct ddebug_query *dq = &pq->query;
+ char *tmp = show_ddebug_query(dq);
+
+ sprintf(tmp + strlen(tmp), " q->flags=0x%x q->mask=0x%x",
+ pq->flags, pq->mask);
+ return prbuf_query;
+}
+
/*
* Search the tables for _ddebug's which match the given
* `query' and apply the `flags' and `mask' to them. Tells
@@ -846,6 +856,34 @@ static const struct file_operations ddebug_proc_fops = {
.write = ddebug_proc_write
};

+/* apply matching queries in pending-queries list */
+static void apply_pending_queries(struct ddebug_table *dt)
+{
+ struct pending_query *pq, *pqnext;
+ int nfound;
+
+ if (verbose)
+ pr_info("pending_ct: %d\n", pending_ct);
+
+ list_for_each_entry_safe(pq, pqnext, &pending_queries, link) {
+
+ if (verbose)
+ pr_info("check: %s <-> %s\n",
+ dt->mod_name, show_pending_query(pq));
+
+ nfound = ddebug_change(&pq->query, pq->flags, pq->mask);
+
+ if (nfound) {
+ mutex_lock(&ddebug_lock);
+ list_del(&pq->link);
+ mutex_unlock(&ddebug_lock);
+ kfree(pq);
+ pending_ct--;
+ } else if (verbose)
+ pr_info("no-match: %s\n", show_pending_query(pq));
+ }
+
+}
/*
* Allocate a new ddebug_table for the given module
* and add it to the global list.
@@ -874,6 +912,9 @@ int ddebug_add_module(struct _ddebug *tab, unsigned int n,

if (verbose)
pr_info("%u debug prints in module %s\n", n, dt->mod_name);
+
+ apply_pending_queries(dt);
+
return 0;
}
EXPORT_SYMBOL_GPL(ddebug_add_module);
--
1.7.4.1

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