[PATCH 2/2] firewire-core: obsolete cast of function callback

Takashi Sakamoto
2020-05-20T06:47:43Z

This commit obsoletes cast of function callback to assist attempt of
Control Flow Integrity builds.

Reported-by: Oscar Carter <oscar.carter@gmx.com>
Reference: https://lore.kernel.org/lkml/20200519173425.4724-1-oscar.carter@gmx.com/
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
---
drivers/firewire/core-cdev.c | 44 +++++++++++++++++++-----------------
1 file changed, 23 insertions(+), 21 deletions(-)

diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
index 6e291d8f3a27..f1e83396dd22 100644
--- a/drivers/firewire/core-cdev.c
+++ b/drivers/firewire/core-cdev.c
@@ -957,7 +957,6 @@ static int ioctl_create_iso_context(struct client *client, union ioctl_arg *arg)
{
struct fw_cdev_create_iso_context *a = &arg->create_iso_context;
struct fw_iso_context *context;
- fw_iso_callback_t cb;
int ret;

BUILD_BUG_ON(FW_CDEV_ISO_CONTEXT_TRANSMIT != FW_ISO_CONTEXT_TRANSMIT ||
@@ -965,32 +964,35 @@ static int ioctl_create_iso_context(struct client *client, union ioctl_arg *arg)
FW_CDEV_ISO_CONTEXT_RECEIVE_MULTICHANNEL !=
FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL);

- switch (a->type) {
- case FW_ISO_CONTEXT_TRANSMIT:
- if (a->speed > SCODE_3200 || a->channel > 63)
- return -EINVAL;
-
- cb = iso_callback;
- break;
+ if (a->type != FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL) {
+ fw_iso_callback_t cb;

- case FW_ISO_CONTEXT_RECEIVE:
- if (a->header_size < 4 || (a->header_size & 3) ||
- a->channel > 63)
- return -EINVAL;
+ switch (a->type) {
+ case FW_ISO_CONTEXT_TRANSMIT:
+ if (a->speed > SCODE_3200 || a->channel > 63)
+ return -EINVAL;

- cb = iso_callback;
- break;
+ cb = iso_callback;
+ break;

- case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
- cb = (fw_iso_callback_t)iso_mc_callback;
- break;
+ case FW_ISO_CONTEXT_RECEIVE:
+ if (a->header_size < 4 || (a->header_size & 3) ||
+ a->channel > 63)
+ return -EINVAL;

- default:
- return -EINVAL;
- }
+ cb = iso_callback;
+ break;
+ default:
+ return -EINVAL;
+ }

- context = fw_iso_context_create(client->device->card, a->type,
+ context = fw_iso_context_create(client->device->card, a->type,
a->channel, a->speed, a->header_size, cb, client);
+ } else {
+ context = fw_iso_mc_context_create(client->device->card,
+ a->type, a->channel, a->speed, a->header_size,
+ iso_mc_callback, client);
+ }
if (IS_ERR(context))
return PTR_ERR(context);
if (client->version < FW_CDEV_VERSION_AUTO_FLUSH_ISO_OVERFLOW)
--
2.25.1