[PATCH] staging: dgap: implement error handling in dgap_tty_register()

Daeseok Youn
2014-04-25T07:05:30Z

- alloc_tty_driver() is deprecated so it is changed to
tty_alloc_driver()
- Pointers which are allocated by alloc_tty_driver() and kzalloc()
can be NULL so it need to check NULL for them.
- If one of those is failed, it need to add proper handler for
avoiding memory leak.

Signed-off-by: Daeseok Youn <daeseok.youn@gmail.com>
---
drivers/staging/dgap/dgap.c | 49 +++++++++++++++++++++++++++++++++++--------
1 files changed, 40 insertions(+), 9 deletions(-)

diff --git a/drivers/staging/dgap/dgap.c b/drivers/staging/dgap/dgap.c
index 3c9278a..5c8823a 100644
--- a/drivers/staging/dgap/dgap.c
+++ b/drivers/staging/dgap/dgap.c
@@ -875,7 +875,11 @@ static int dgap_firmware_load(struct pci_dev *pdev, int card_type)
return -EINVAL;
}

- dgap_tty_register(brd);
+ ret = dgap_tty_register(brd);
+ if (ret) {
+ pr_err("dgap: failed to register tty driver\n");
+ return ret;
+ }
dgap_finalize_board_init(brd);

if (fw_info[card_type].bios_name) {
@@ -1200,7 +1204,9 @@ static int dgap_tty_register(struct board_t *brd)
{
int rc = 0;

- brd->SerialDriver = alloc_tty_driver(MAXPORTS);
+ brd->SerialDriver = tty_alloc_driver(MAXPORTS, 0);
+ if (IS_ERR(brd->SerialDriver))
+ return PTR_ERR(brd->SerialDriver);

snprintf(brd->SerialName, MAXTTYNAMELEN, "tty_dgap_%d_", brd->boardnum);
brd->SerialDriver->name = brd->SerialName;
@@ -1218,8 +1224,10 @@ static int dgap_tty_register(struct board_t *brd)
/* The kernel wants space to store pointers to tty_structs */
brd->SerialDriver->ttys =
kzalloc(MAXPORTS * sizeof(struct tty_struct *), GFP_KERNEL);
- if (!brd->SerialDriver->ttys)
- return -ENOMEM;
+ if (!brd->SerialDriver->ttys) {
+ rc = -ENOMEM;
+ goto free_serial_drv;
+ }

/*
* Entry points for driver. Called by the kernel from
@@ -1232,7 +1240,11 @@ static int dgap_tty_register(struct board_t *brd)
* again, separately so we don't get the LD confused about what major
* we are when we get into the dgap_tty_open() routine.
*/
- brd->PrintDriver = alloc_tty_driver(MAXPORTS);
+ brd->PrintDriver = tty_alloc_driver(MAXPORTS, 0);
+ if (IS_ERR(brd->PrintDriver)) {
+ rc = PTR_ERR(brd->PrintDriver);
+ goto free_serial_ttys;
+ }

snprintf(brd->PrintName, MAXTTYNAMELEN, "pr_dgap_%d_", brd->boardnum);
brd->PrintDriver->name = brd->PrintName;
@@ -1250,8 +1262,10 @@ static int dgap_tty_register(struct board_t *brd)
/* The kernel wants space to store pointers to tty_structs */
brd->PrintDriver->ttys =
kzalloc(MAXPORTS * sizeof(struct tty_struct *), GFP_KERNEL);
- if (!brd->PrintDriver->ttys)
- return -ENOMEM;
+ if (!brd->PrintDriver->ttys) {
+ rc = -ENOMEM;
+ goto free_print_drv;
+ }

/*
* Entry points for driver. Called by the kernel from
@@ -1263,7 +1277,8 @@ static int dgap_tty_register(struct board_t *brd)
/* Register tty devices */
rc = tty_register_driver(brd->SerialDriver);
if (rc < 0)
- return rc;
+ goto free_print_ttys;
+
brd->dgap_Major_Serial_Registered = TRUE;
dgap_BoardsByMajor[brd->SerialDriver->major] = brd;
brd->dgap_Serial_Major = brd->SerialDriver->major;
@@ -1273,13 +1288,29 @@ static int dgap_tty_register(struct board_t *brd)
/* Register Transparent Print devices */
rc = tty_register_driver(brd->PrintDriver);
if (rc < 0)
- return rc;
+ goto unregister_serial_drv;
+
brd->dgap_Major_TransparentPrint_Registered = TRUE;
dgap_BoardsByMajor[brd->PrintDriver->major] = brd;
brd->dgap_TransparentPrint_Major = brd->PrintDriver->major;
}

return rc;
+
+unregister_serial_drv:
+ tty_unregister_driver(brd->SerialDriver);
+free_print_ttys:
+ kfree(brd->PrintDriver->ttys);
+ brd->PrintDriver->ttys = NULL;
+free_print_drv:
+ put_tty_driver(brd->PrintDriver);
+free_serial_ttys:
+ kfree(brd->SerialDriver->ttys);
+ brd->SerialDriver->ttys = NULL;
+free_serial_drv:
+ put_tty_driver(brd->SerialDriver);
+
+ return rc;
}

/*
--
1.7.4.4