3.10-stable patches

added patches:
	tracing-change-remove_event_file_dir-to-clear-d_subdirs-i_private.patch

diff --git a/queue-3.10/series b/queue-3.10/series
index 565ecada592915e397c6c457a7123f71a7ce3dda..3778680c733d8600c5683d8e95cb1ba2b7f03dd0 100644 (file)
--- a/queue-3.10/series
+++ b/queue-3.10/series
@@ -28,3 +28,4 @@ tracing-change-event_enable-disable_read-to-verify-i_private-null.patch
 tracing-change-event_filter_read-write-to-verify-i_private-null.patch
 tracing-change-f_start-to-take-event_mutex-and-verify-i_private-null.patch
 tracing-introduce-remove_event_file_dir.patch
+tracing-change-remove_event_file_dir-to-clear-d_subdirs-i_private.patch

diff --git a/queue-3.10/tracing-change-remove_event_file_dir-to-clear-d_subdirs-i_private.patch b/queue-3.10/tracing-change-remove_event_file_dir-to-clear-d_subdirs-i_private.patch
new file mode 100644 (file)
index 0000000..1122cab
--- /dev/null
+++ b/queue-3.10/tracing-change-remove_event_file_dir-to-clear-d_subdirs-i_private.patch
@@ -0,0 +1,111 @@
+From bf682c3159c4d298d1126a56793ed3f5e80395f7 Mon Sep 17 00:00:00 2001
+From: Oleg Nesterov <oleg@redhat.com>
+Date: Sun, 28 Jul 2013 20:35:27 +0200
+Subject: tracing: Change remove_event_file_dir() to clear "d_subdirs"->i_private
+
+From: Oleg Nesterov <oleg@redhat.com>
+
+commit bf682c3159c4d298d1126a56793ed3f5e80395f7 upstream.
+
+Change remove_event_file_dir() to clear ->i_private for every
+file we are going to remove.
+
+We need to check file->dir != NULL because event_create_dir()
+can fail. debugfs_remove_recursive(NULL) is fine but the patch
+moves it under the same check anyway for readability.
+
+spin_lock(d_lock) and "d_inode != NULL" check are not needed
+afaics, but I do not understand this code enough.
+
+tracing_open_generic_file() and tracing_release_generic_file()
+can go away, ftrace_enable_fops and ftrace_event_filter_fops()
+use tracing_open_generic() but only to check tracing_disabled.
+
+This fixes all races with event_remove() or instance_delete().
+f_op->read/write/whatever can never use the freed file/call,
+all event/* files were changed to check and use ->i_private
+under event_mutex.
+
+Note: this doesn't not fix other problems, event_remove() can
+destroy the active ftrace_event_call, we need more changes but
+those changes are completely orthogonal.
+
+Link: http://lkml.kernel.org/r/20130728183527.GB16723@redhat.com
+
+Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
+Signed-off-by: Oleg Nesterov <oleg@redhat.com>
+Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ kernel/trace/trace_events.c |   47 ++++++++++++++------------------------------
+ 1 file changed, 15 insertions(+), 32 deletions(-)
+
+--- a/kernel/trace/trace_events.c
++++ b/kernel/trace/trace_events.c
+@@ -426,39 +426,23 @@ static void *event_file_data(struct file
+ 
+ static void remove_event_file_dir(struct ftrace_event_file *file)
+ {
+-      list_del(&file->list);
+-      debugfs_remove_recursive(file->dir);
+-      remove_subsystem(file->system);
+-      kmem_cache_free(file_cachep, file);
+-}
++      struct dentry *dir = file->dir;
++      struct dentry *child;
+ 
+-/*
+- * Open and update trace_array ref count.
+- * Must have the current trace_array passed to it.
+- */
+-static int tracing_open_generic_file(struct inode *inode, struct file *filp)
+-{
+-      struct ftrace_event_file *file = inode->i_private;
+-      struct trace_array *tr = file->tr;
+-      int ret;
+-
+-      if (trace_array_get(tr) < 0)
+-              return -ENODEV;
+-
+-      ret = tracing_open_generic(inode, filp);
+-      if (ret < 0)
+-              trace_array_put(tr);
+-      return ret;
+-}
+-
+-static int tracing_release_generic_file(struct inode *inode, struct file *filp)
+-{
+-      struct ftrace_event_file *file = inode->i_private;
+-      struct trace_array *tr = file->tr;
++      if (dir) {
++              spin_lock(&dir->d_lock);        /* probably unneeded */
++              list_for_each_entry(child, &dir->d_subdirs, d_u.d_child) {
++                      if (child->d_inode)     /* probably unneeded */
++                              child->d_inode->i_private = NULL;
++              }
++              spin_unlock(&dir->d_lock);
+ 
+-      trace_array_put(tr);
++              debugfs_remove_recursive(dir);
++      }
+ 
+-      return 0;
++      list_del(&file->list);
++      remove_subsystem(file->system);
++      kmem_cache_free(file_cachep, file);
+ }
+ 
+ /*
+@@ -1303,10 +1287,9 @@ static const struct file_operations ftra
+ };
+ 
+ static const struct file_operations ftrace_enable_fops = {
+-      .open = tracing_open_generic_file,
++      .open = tracing_open_generic,
+       .read = event_enable_read,
+       .write = event_enable_write,
+-      .release = tracing_release_generic_file,
+       .llseek = default_llseek,
+ };
+