| Message ID | 20200429074627.5955-4-mcgrof@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | block: fix blktrace debugfs use after free | expand |
On Wed, Apr 29, 2020 at 07:46:24AM +0000, Luis Chamberlain wrote: > Move the work to create the debugfs directory used into a helper. > It will make further checks easier to read. This commit introduces > no functional changes. > > Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Looks good, Reviewed-by: Christoph Hellwig <hch@lst.de>
On 2020-04-29 00:46, Luis Chamberlain wrote: > +static struct dentry *blk_trace_debugfs_dir(struct blk_user_trace_setup *buts, > + struct blk_trace *bt) > +{ > + struct dentry *dir = NULL; > + > + dir = debugfs_lookup(buts->name, blk_debugfs_root); > + if (!dir) > + bt->dir = dir = debugfs_create_dir(buts->name, blk_debugfs_root); > + > + return dir; > +} Initializing 'dir' is not necessary since the first statement overwrites 'dir'. Anyway: Reviewed-by: Bart Van Assche <bvanassche@acm.org>
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index ca39dc3230cb..2c6e6c386ace 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -468,6 +468,18 @@ static void blk_trace_setup_lba(struct blk_trace *bt, } } +static struct dentry *blk_trace_debugfs_dir(struct blk_user_trace_setup *buts, + struct blk_trace *bt) +{ + struct dentry *dir = NULL; + + dir = debugfs_lookup(buts->name, blk_debugfs_root); + if (!dir) + bt->dir = dir = debugfs_create_dir(buts->name, blk_debugfs_root); + + return dir; +} + /* * Setup everything required to start tracing */ @@ -509,9 +521,7 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, ret = -ENOENT; - dir = debugfs_lookup(buts->name, blk_debugfs_root); - if (!dir) - bt->dir = dir = debugfs_create_dir(buts->name, blk_debugfs_root); + dir = blk_trace_debugfs_dir(buts, bt); bt->dev = dev; atomic_set(&bt->dropped, 0);
Move the work to create the debugfs directory used into a helper. It will make further checks easier to read. This commit introduces no functional changes. Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> --- kernel/trace/blktrace.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-)