| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <1316642115-20029-22-git-send-email-jim.cromie@gmail.com>
Date: Wed, 21 Sep 2011 15:55:10 -0600
From: jim.cromie@...il.com
To: jbaron@...hat.com
Cc: joe@...ches.com, bart.vanassche@...il.com, greg@...ah.com,
linux-kernel@...r.kernel.org, Jim Cromie <jim.cromie@...il.com>
Subject: [PATCH 21/26] dynamic_debug: add $DBGFS/dynamic_debug/pending file
From: Jim Cromie <jim.cromie@...il.com>
Add pending file so user can see queries that are pending. Output
format imitates that used to submit commands/queries. This simplifies
cut-paste-edit to delete pending queries when they're no longer wanted.
Signed-off-by: Jim Cromie <jim.cromie@...il.com>
---
lib/dynamic_debug.c | 191 ++++++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 188 insertions(+), 3 deletions(-)
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index d7b71a6..80b5322 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -64,6 +64,10 @@ struct ddebug_iter {
unsigned int idx;
};
+struct pending_iter {
+ struct pending_query *elem;
+};
+
static DEFINE_MUTEX(ddebug_lock);
static LIST_HEAD(ddebug_tables);
static int verbose = 0;
@@ -842,7 +846,8 @@ static void *ddebug_proc_start(struct seq_file *m, loff_t *pos)
int n = *pos;
if (verbose >= VERBOSE_PROC)
- pr_info("called m=%p *pos=%lld\n", m, (unsigned long long)*pos);
+ pr_info("called m=%p *pos=%lld\n",
+ m, (unsigned long long)*pos);
mutex_lock(&ddebug_lock);
@@ -963,7 +968,180 @@ static const struct file_operations ddebug_proc_fops = {
.write = ddebug_proc_write
};
-/* apply matching queries in pending-queries list */
+/*
+ * Set the iterator to point to the first pending_query object
+ * and return a pointer to that first object. Returns
+ * NULL if there are no pending_querys at all.
+ */
+static struct pending_query *pending_iter_first(struct pending_iter *iter)
+{
+ if (list_empty(&pending_queries)) {
+ iter->elem = NULL;
+ return NULL;
+ }
+ iter->elem = list_entry(pending_queries.next,
+ struct pending_query, link);
+ return iter->elem;
+}
+
+/*
+ * Advance the iterator to point to the next pending_query
+ * object from the one the iterator currently points at,
+ * and returns a pointer to the new pending_query. Returns
+ * NULL if the iterator has seen all the pending_querys.
+ */
+static struct pending_query *pending_iter_next(struct pending_iter *iter)
+{
+ if (iter->elem == NULL)
+ return NULL;
+ if (list_is_last(&iter->elem->link, &pending_queries)) {
+ iter->elem = NULL;
+ return NULL;
+ }
+ iter->elem = list_entry(iter->elem->link.next,
+ struct pending_query, link);
+ return iter->elem;
+}
+
+/*
+ * Seq_ops start method. Called at the start of every read() call on
+ * pending file from userspace. Takes the ddebug_lock and seeks the
+ * seq_file's iterator to the given position.
+ */
+static void *pending_proc_start(struct seq_file *m, loff_t *pos)
+{
+ struct pending_iter *iter = m->private;
+ struct pending_query *pq;
+ int n = *pos;
+
+ if (verbose >= VERBOSE_PROC)
+ pr_info("called m=%p *pos=%lld\n",
+ m, (unsigned long long)*pos);
+
+ mutex_lock(&ddebug_lock);
+
+ if (!n)
+ return SEQ_START_TOKEN;
+ if (n < 0)
+ return NULL;
+ pq = pending_iter_first(iter);
+ while (pq != NULL && --n > 0)
+ pq = pending_iter_next(iter);
+ return pq;
+}
+
+/*
+ * Seq_ops next method. Called several times within a read()
+ * call from userspace, with pending_lock held. Walks to the
+ * next pending_query object with a special case for the header line.
+ */
+static void *pending_proc_next(struct seq_file *m, void *p, loff_t *pos)
+{
+ struct pending_iter *iter = m->private;
+ struct pending_query *pq;
+
+ if (verbose >= VERBOSE_PROC_SHOW)
+ pr_info("called m=%p p=%p *pos=%lld\n",
+ m, p, (unsigned long long)*pos);
+
+ if (p == SEQ_START_TOKEN)
+ pq = pending_iter_first(iter);
+ else
+ pq = pending_iter_next(iter);
+ ++*pos;
+ return pq;
+}
+
+/*
+ * Seq_ops show method. Called several times within a read()
+ * call from userspace, with pending_lock held. Formats the
+ * current pending_query as a single human-readable line, with a
+ * special case for the header line.
+ */
+static int pending_proc_show(struct seq_file *m, void *p)
+{
+ struct pending_iter *iter = m->private;
+ struct pending_query *pq = iter->elem;
+ struct ddebug_query *q = &pq->query;
+ char flagsbuf[10];
+
+ if (verbose >= VERBOSE_PROC_SHOW)
+ pr_info("called m=%p p=%p\n", m, p);
+
+ if (p == SEQ_START_TOKEN) {
+ seq_puts(m, "# func file module format line flags mask\n");
+ return 0;
+ }
+
+ seq_printf(m, "%s%s%s%s%s%s%s%s line %d-%d %s\n",
+ q->module ? "module " : "",
+ q->module ? q->module : "",
+ q->function ? " func " : "",
+ q->function ? q->function : "",
+ q->filename ? " file " : "",
+ q->filename ? q->filename : "",
+ q->format ? " format " : "",
+ q->format ? q->format : "",
+ q->first_lineno, q->last_lineno,
+ ddebug_describe_flags(pq->flags, flagsbuf, sizeof(flagsbuf)));
+
+ return 0;
+}
+
+/*
+ * Seq_ops stop method. Called at the end of each read()
+ * call from userspace. Drops pending_lock.
+ */
+static void pending_proc_stop(struct seq_file *m, void *p)
+{
+ if (verbose >= VERBOSE_PROC)
+ pr_info("called m=%p p=%p\n", m, p);
+ mutex_unlock(&ddebug_lock);
+}
+
+static const struct seq_operations pending_proc_seqops = {
+ .start = pending_proc_start,
+ .next = pending_proc_next,
+ .show = pending_proc_show,
+ .stop = pending_proc_stop
+};
+
+/*
+ * File_ops->open method for <debugfs>/dynamic_debug/control. Does the seq_file
+ * setup dance, and also creates an iterator to walk the pending_querys.
+ * Note that we create a seq_file always, even for O_WRONLY files
+ * where it's not needed, as doing so simplifies the ->release method.
+ */
+static int pending_proc_open(struct inode *inode, struct file *file)
+{
+ struct pending_iter *iter;
+ int err;
+
+ if (verbose)
+ pr_info("called\n");
+
+ iter = kzalloc(sizeof(*iter), GFP_KERNEL);
+ if (iter == NULL)
+ return -ENOMEM;
+
+ err = seq_open(file, &pending_proc_seqops);
+ if (err) {
+ kfree(iter);
+ return err;
+ }
+ ((struct seq_file *) file->private_data)->private = iter;
+ return 0;
+}
+
+static const struct file_operations pending_proc_fops = {
+ .owner = THIS_MODULE,
+ .open = pending_proc_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release_private,
+};
+
+/* apply matching queries in pending-queries list. Called with lock held */
static void apply_pending_queries(struct ddebug_table *dt)
{
struct pending_query *pq, *pqnext;
@@ -1063,7 +1241,7 @@ static __initdata int ddebug_init_success;
static int __init dynamic_debug_init_debugfs(void)
{
- struct dentry *dir, *file;
+ struct dentry *dir, *file, *file2;
if (!ddebug_init_success)
return -ENODEV;
@@ -1077,6 +1255,13 @@ static int __init dynamic_debug_init_debugfs(void)
debugfs_remove(dir);
return -ENOMEM;
}
+ file2 = debugfs_create_file("pending", 0444, dir, NULL,
+ &pending_proc_fops);
+ if (!file2) {
+ debugfs_remove(file);
+ debugfs_remove(dir);
+ return -ENOMEM;
+ }
return 0;
}
--
1.7.4.4
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists