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From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: [for-next][PATCH 04/12] ftrace: Have the cached module list show in set_ftrace_filter
Date: Thu, 29 Jun 2017 20:38:35 -0400	[thread overview]
Message-ID: <20170630004022.255706520@goodmis.org> (raw)
In-Reply-To: 20170630003831.946074263@goodmis.org

[-- Attachment #1: 0004-ftrace-Have-the-cached-module-list-show-in-set_ftrac.patch --]
[-- Type: text/plain, Size: 6698 bytes --]

From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

When writing in a module filter into set_ftrace_filter for a module that is
not yet loaded, it it cached, and will be executed when the module is loaded
(although that is not implemented yet at this commit). Display the list of
cached modules to be traced.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 include/linux/ftrace.h |   3 +-
 kernel/trace/ftrace.c  | 112 +++++++++++++++++++++++++++++++++++++++++++------
 2 files changed, 102 insertions(+), 13 deletions(-)

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 1b6992e994e6..9fb9a67dc9d4 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -446,7 +446,8 @@ enum {
 	FTRACE_ITER_PRINTALL	= (1 << 2),
 	FTRACE_ITER_DO_PROBES	= (1 << 3),
 	FTRACE_ITER_PROBE	= (1 << 4),
-	FTRACE_ITER_ENABLED	= (1 << 5),
+	FTRACE_ITER_MOD		= (1 << 5),
+	FTRACE_ITER_ENABLED	= (1 << 6),
 };
 
 void arch_ftrace_update_code(int command);
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 1867edec6269..bfdbce78064b 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3112,6 +3112,7 @@ ftrace_allocate_pages(unsigned long num_to_init)
 struct ftrace_iterator {
 	loff_t				pos;
 	loff_t				func_pos;
+	loff_t				mod_pos;
 	struct ftrace_page		*pg;
 	struct dyn_ftrace		*func;
 	struct ftrace_func_probe	*probe;
@@ -3119,6 +3120,8 @@ struct ftrace_iterator {
 	struct trace_parser		parser;
 	struct ftrace_hash		*hash;
 	struct ftrace_ops		*ops;
+	struct trace_array		*tr;
+	struct list_head		*mod_list;
 	int				pidx;
 	int				idx;
 	unsigned			flags;
@@ -3203,13 +3206,13 @@ static void *t_probe_start(struct seq_file *m, loff_t *pos)
 	if (!(iter->flags & FTRACE_ITER_DO_PROBES))
 		return NULL;
 
-	if (iter->func_pos > *pos)
+	if (iter->mod_pos > *pos)
 		return NULL;
 
 	iter->probe = NULL;
 	iter->probe_entry = NULL;
 	iter->pidx = 0;
-	for (l = 0; l <= (*pos - iter->func_pos); ) {
+	for (l = 0; l <= (*pos - iter->mod_pos); ) {
 		p = t_probe_next(m, &l);
 		if (!p)
 			break;
@@ -3248,6 +3251,82 @@ t_probe_show(struct seq_file *m, struct ftrace_iterator *iter)
 }
 
 static void *
+t_mod_next(struct seq_file *m, loff_t *pos)
+{
+	struct ftrace_iterator *iter = m->private;
+	struct trace_array *tr = iter->tr;
+
+	(*pos)++;
+	iter->pos = *pos;
+
+	iter->mod_list = iter->mod_list->next;
+
+	if (iter->mod_list == &tr->mod_trace ||
+	    iter->mod_list == &tr->mod_notrace) {
+		iter->flags &= ~FTRACE_ITER_MOD;
+		return NULL;
+	}
+
+	iter->mod_pos = *pos;
+
+	return iter;
+}
+
+static void *t_mod_start(struct seq_file *m, loff_t *pos)
+{
+	struct ftrace_iterator *iter = m->private;
+	void *p = NULL;
+	loff_t l;
+
+	if (iter->func_pos > *pos)
+		return NULL;
+
+	iter->mod_pos = iter->func_pos;
+
+	/* probes are only available if tr is set */
+	if (!iter->tr)
+		return NULL;
+
+	for (l = 0; l <= (*pos - iter->func_pos); ) {
+		p = t_mod_next(m, &l);
+		if (!p)
+			break;
+	}
+	if (!p) {
+		iter->flags &= ~FTRACE_ITER_MOD;
+		return t_probe_start(m, pos);
+	}
+
+	/* Only set this if we have an item */
+	iter->flags |= FTRACE_ITER_MOD;
+
+	return iter;
+}
+
+static int
+t_mod_show(struct seq_file *m, struct ftrace_iterator *iter)
+{
+	struct ftrace_mod_load *ftrace_mod;
+	struct trace_array *tr = iter->tr;
+
+	if (WARN_ON_ONCE(!iter->mod_list) ||
+			 iter->mod_list == &tr->mod_trace ||
+			 iter->mod_list == &tr->mod_notrace)
+		return -EIO;
+
+	ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list);
+
+	if (ftrace_mod->func)
+		seq_printf(m, "%s", ftrace_mod->func);
+	else
+		seq_putc(m, '*');
+
+	seq_printf(m, ":mod:%s\n", ftrace_mod->module);
+
+	return 0;
+}
+
+static void *
 t_func_next(struct seq_file *m, loff_t *pos)
 {
 	struct ftrace_iterator *iter = m->private;
@@ -3288,7 +3367,7 @@ static void *
 t_next(struct seq_file *m, void *v, loff_t *pos)
 {
 	struct ftrace_iterator *iter = m->private;
-	loff_t l = *pos; /* t_hash_start() must use original pos */
+	loff_t l = *pos; /* t_probe_start() must use original pos */
 	void *ret;
 
 	if (unlikely(ftrace_disabled))
@@ -3297,16 +3376,19 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
 	if (iter->flags & FTRACE_ITER_PROBE)
 		return t_probe_next(m, pos);
 
+	if (iter->flags & FTRACE_ITER_MOD)
+		return t_mod_next(m, pos);
+
 	if (iter->flags & FTRACE_ITER_PRINTALL) {
 		/* next must increment pos, and t_probe_start does not */
 		(*pos)++;
-		return t_probe_start(m, &l);
+		return t_mod_start(m, &l);
 	}
 
 	ret = t_func_next(m, pos);
 
 	if (!ret)
-		return t_probe_start(m, &l);
+		return t_mod_start(m, &l);
 
 	return ret;
 }
@@ -3315,7 +3397,7 @@ static void reset_iter_read(struct ftrace_iterator *iter)
 {
 	iter->pos = 0;
 	iter->func_pos = 0;
-	iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE);
+	iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE | FTRACE_ITER_MOD);
 }
 
 static void *t_start(struct seq_file *m, loff_t *pos)
@@ -3344,15 +3426,15 @@ static void *t_start(struct seq_file *m, loff_t *pos)
 	    ftrace_hash_empty(iter->hash)) {
 		iter->func_pos = 1; /* Account for the message */
 		if (*pos > 0)
-			return t_probe_start(m, pos);
+			return t_mod_start(m, pos);
 		iter->flags |= FTRACE_ITER_PRINTALL;
 		/* reset in case of seek/pread */
 		iter->flags &= ~FTRACE_ITER_PROBE;
 		return iter;
 	}
 
-	if (iter->flags & FTRACE_ITER_PROBE)
-		return t_probe_start(m, pos);
+	if (iter->flags & FTRACE_ITER_MOD)
+		return t_mod_start(m, pos);
 
 	/*
 	 * Unfortunately, we need to restart at ftrace_pages_start
@@ -3368,7 +3450,7 @@ static void *t_start(struct seq_file *m, loff_t *pos)
 	}
 
 	if (!p)
-		return t_probe_start(m, pos);
+		return t_mod_start(m, pos);
 
 	return iter;
 }
@@ -3402,6 +3484,9 @@ static int t_show(struct seq_file *m, void *v)
 	if (iter->flags & FTRACE_ITER_PROBE)
 		return t_probe_show(m, iter);
 
+	if (iter->flags & FTRACE_ITER_MOD)
+		return t_mod_show(m, iter);
+
 	if (iter->flags & FTRACE_ITER_PRINTALL) {
 		if (iter->flags & FTRACE_ITER_NOTRACE)
 			seq_puts(m, "#### no functions disabled ####\n");
@@ -3528,17 +3613,20 @@ ftrace_regex_open(struct ftrace_ops *ops, int flag,
 
 	iter->ops = ops;
 	iter->flags = flag;
+	iter->tr = tr;
 
 	mutex_lock(&ops->func_hash->regex_lock);
 
 	if (flag & FTRACE_ITER_NOTRACE) {
 		hash = ops->func_hash->notrace_hash;
-		mod_head = tr ? &tr->mod_trace : NULL;
+		mod_head = tr ? &tr->mod_notrace : NULL;
 	} else {
 		hash = ops->func_hash->filter_hash;
-		mod_head = tr ? &tr->mod_notrace : NULL;
+		mod_head = tr ? &tr->mod_trace : NULL;
 	}
 
+	iter->mod_list = mod_head;
+
 	if (file->f_mode & FMODE_WRITE) {
 		const int size_bits = FTRACE_HASH_DEFAULT_BITS;
 
-- 
2.10.2

  parent reply	other threads:[~2017-06-30  0:42 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-06-30  0:38 [for-next][PATCH 00/12] tracing: More updates for 4.13 Steven Rostedt
2017-06-30  0:38 ` [for-next][PATCH 01/12] ftrace: Add missing comment for FTRACE_OPS_FL_RCU Steven Rostedt
2017-06-30  0:38 ` [for-next][PATCH 02/12] tracing: Show address when function names are not found Steven Rostedt
2017-06-30  0:38 ` [for-next][PATCH 03/12] ftrace: Add :mod: caching infrastructure to trace_array Steven Rostedt
2017-06-30  0:38 ` Steven Rostedt [this message]
2017-06-30  0:38 ` [for-next][PATCH 05/12] ftrace: Implement cached modules tracing on module load Steven Rostedt
2017-06-30  0:38 ` [for-next][PATCH 06/12] ftrace: Have cached module filters be an active filter Steven Rostedt
2017-06-30  0:38 ` [for-next][PATCH 07/12] sh/ftrace: Remove only user of ftrace_arch_read_dyn_info() Steven Rostedt
2017-06-30  0:38   ` Steven Rostedt
2017-06-30  0:38 ` [for-next][PATCH 08/12] ftrace: Remove unused function ftrace_arch_read_dyn_info() Steven Rostedt
2017-06-30  0:38 ` [for-next][PATCH 09/12] ftrace: Decrement count for dyn_ftrace_total_info file Steven Rostedt
2017-06-30  0:38 ` [for-next][PATCH 10/12] tracing: Add support for recording tgid of tasks Steven Rostedt
2017-06-30  0:38 ` [for-next][PATCH 11/12] tracing: Add support for display of tgid in trace output Steven Rostedt
2017-06-30  0:38 ` [for-next][PATCH 12/12] ftrace: Unlock hash mutex on failed allocation in process_mod_list() Steven Rostedt

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