diff options
Diffstat (limited to 'drivers/usb/gadget/function/f_fs.c')
-rw-r--r-- | drivers/usb/gadget/function/f_fs.c | 67 |
1 files changed, 49 insertions, 18 deletions
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index 94ccf43368df..5fd4fc49aef9 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -614,7 +614,7 @@ static int ffs_ep0_open(struct inode *inode, struct file *file) file->private_data = ffs; ffs_data_opened(ffs); - return 0; + return stream_open(inode, file); } static int ffs_ep0_release(struct inode *inode, struct file *file) @@ -1156,7 +1156,7 @@ ffs_epfile_open(struct inode *inode, struct file *file) file->private_data = epfile; ffs_data_opened(epfile->ffs); - return 0; + return stream_open(inode, file); } static int ffs_aio_cancel(struct kiocb *kiocb) @@ -1729,16 +1729,24 @@ static void ffs_data_put(struct ffs_data *ffs) static void ffs_data_closed(struct ffs_data *ffs) { + struct ffs_epfile *epfiles; + unsigned long flags; + ENTER(); if (atomic_dec_and_test(&ffs->opened)) { if (ffs->no_disconnect) { ffs->state = FFS_DEACTIVATED; - if (ffs->epfiles) { - ffs_epfiles_destroy(ffs->epfiles, - ffs->eps_count); - ffs->epfiles = NULL; - } + spin_lock_irqsave(&ffs->eps_lock, flags); + epfiles = ffs->epfiles; + ffs->epfiles = NULL; + spin_unlock_irqrestore(&ffs->eps_lock, + flags); + + if (epfiles) + ffs_epfiles_destroy(epfiles, + ffs->eps_count); + if (ffs->setup_state == FFS_SETUP_PENDING) __ffs_ep0_stall(ffs); } else { @@ -1785,17 +1793,34 @@ static struct ffs_data *ffs_data_new(const char *dev_name) static void ffs_data_clear(struct ffs_data *ffs) { + struct ffs_epfile *epfiles; + unsigned long flags; + ENTER(); ffs_closed(ffs); BUG_ON(ffs->gadget); - if (ffs->epfiles) - ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count); + spin_lock_irqsave(&ffs->eps_lock, flags); + epfiles = ffs->epfiles; + ffs->epfiles = NULL; + spin_unlock_irqrestore(&ffs->eps_lock, flags); - if (ffs->ffs_eventfd) + /* + * potential race possible between ffs_func_eps_disable + * & ffs_epfile_release therefore maintaining a local + * copy of epfile will save us from use-after-free. + */ + if (epfiles) { + ffs_epfiles_destroy(epfiles, ffs->eps_count); + ffs->epfiles = NULL; + } + + if (ffs->ffs_eventfd) { eventfd_ctx_put(ffs->ffs_eventfd); + ffs->ffs_eventfd = NULL; + } kfree(ffs->raw_descs_data); kfree(ffs->raw_strings); @@ -1808,7 +1833,6 @@ static void ffs_data_reset(struct ffs_data *ffs) ffs_data_clear(ffs); - ffs->epfiles = NULL; ffs->raw_descs_data = NULL; ffs->raw_descs = NULL; ffs->raw_strings = NULL; @@ -1937,12 +1961,15 @@ static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count) static void ffs_func_eps_disable(struct ffs_function *func) { - struct ffs_ep *ep = func->eps; - struct ffs_epfile *epfile = func->ffs->epfiles; - unsigned count = func->ffs->eps_count; + struct ffs_ep *ep; + struct ffs_epfile *epfile; + unsigned short count; unsigned long flags; spin_lock_irqsave(&func->ffs->eps_lock, flags); + count = func->ffs->eps_count; + epfile = func->ffs->epfiles; + ep = func->eps; while (count--) { /* pending requests get nuked */ if (likely(ep->ep)) @@ -1960,14 +1987,18 @@ static void ffs_func_eps_disable(struct ffs_function *func) static int ffs_func_eps_enable(struct ffs_function *func) { - struct ffs_data *ffs = func->ffs; - struct ffs_ep *ep = func->eps; - struct ffs_epfile *epfile = ffs->epfiles; - unsigned count = ffs->eps_count; + struct ffs_data *ffs; + struct ffs_ep *ep; + struct ffs_epfile *epfile; + unsigned short count; unsigned long flags; int ret = 0; spin_lock_irqsave(&func->ffs->eps_lock, flags); + ffs = func->ffs; + ep = func->eps; + epfile = ffs->epfiles; + count = ffs->eps_count; while(count--) { ep->ep->driver_data = ep; |