This one is not right.
On Wed, Sep 25, 2013 at 07:08:53PM -0400, Lidza Louina wrote:
> This patch changes error handling to the
> tty_driver allocations in dgap_tty_register.
>
> Before, it didn't handle the possibility of an
> alloc_tty_driver failure. This patch makes
> dgap_register_driver return -ENOMEM if that fails.
>
> This patch also adds handling to the possibility that
> the brd->SerialDriver->ttys or brd->PrintDriver->ttys
> allocation will fail. It now calls put_tty_driver on
> that driver after it fails and returns -ENOMEM.
>
> Signed-off-by: Lidza Louina <lidza.louina@xxxxxxxxx>
> ---
> drivers/staging/dgap/dgap_tty.c | 26 ++++++++++++++++++--------
> 1 file changed, 18 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/staging/dgap/dgap_tty.c b/drivers/staging/dgap/dgap_tty.c
> index 59fda2e..3e12ddb 100644
> --- a/drivers/staging/dgap/dgap_tty.c
> +++ b/drivers/staging/dgap/dgap_tty.c
> @@ -220,6 +220,8 @@ int dgap_tty_register(struct board_t *brd)
> DPR_INIT(("tty_register start"));
>
> brd->SerialDriver = alloc_tty_driver(MAXPORTS);
> + if (!brd->SerialDriver)
> + return -ENOMEM;
>
> snprintf(brd->SerialName, MAXTTYNAMELEN, "tty_dgap_%d_", brd->boardnum);
> brd->SerialDriver->name = brd->SerialName;
> @@ -234,9 +236,10 @@ int dgap_tty_register(struct board_t *brd)
>
> /* The kernel wants space to store pointers to tty_structs */
> brd->SerialDriver->ttys = dgap_driver_kzmalloc(MAXPORTS * sizeof(struct tty_struct *), GFP_KERNEL);
> - if (!brd->SerialDriver->ttys)
> - return(-ENOMEM);
> -
> + if (!brd->SerialDriver->ttys){
> + rc = -ENOMEM;
> + goto err_put_tty_serial;
> + }
> #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,28)
> brd->SerialDriver->refcount = brd->TtyRefCnt;
> #endif
> @@ -253,6 +256,8 @@ int dgap_tty_register(struct board_t *brd)
> * we are when we get into the dgap_tty_open() routine.
> */
> brd->PrintDriver = alloc_tty_driver(MAXPORTS);
> + if (!brd->PrintDriver)
> + return -ENOMEM;
if (!brd->PrintDriver) {
rc = -ENOMEM:
goto err_free_serial_ttys;
}
>
> snprintf(brd->PrintName, MAXTTYNAMELEN, "pr_dgap_%d_", brd->boardnum);
> brd->PrintDriver->name = brd->PrintName;
> @@ -267,9 +272,10 @@ int dgap_tty_register(struct board_t *brd)
>
> /* The kernel wants space to store pointers to tty_structs */
> brd->PrintDriver->ttys = dgap_driver_kzmalloc(MAXPORTS * sizeof(struct tty_struct *), GFP_KERNEL);
> - if (!brd->PrintDriver->ttys)
> - return(-ENOMEM);
> -
> + if (!brd->PrintDriver->ttys){
> + rc = -ENOMEM;
> + goto err_put_tty_print;
> + }
> #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,28)
> brd->PrintDriver->refcount = brd->TtyRefCnt;
> #endif
> @@ -285,7 +291,7 @@ int dgap_tty_register(struct board_t *brd)
> rc = tty_register_driver(brd->SerialDriver);
> if (rc < 0) {
> APR(("Can't register tty device (%d)\n", rc));
> - return(rc);
> + goto err_put_tty_serial;
goto err_free_print_ttys;
> }
> brd->dgap_Major_Serial_Registered = TRUE;
> dgap_BoardsByMajor[brd->SerialDriver->major] = brd;
> @@ -297,7 +303,7 @@ int dgap_tty_register(struct board_t *brd)
> rc = tty_register_driver(brd->PrintDriver);
> if (rc < 0) {
> APR(("Can't register Transparent Print device (%d)\n", rc));
> - return(rc);
> + goto err_put_tty_print;
goto err_unregister_serial;
> }
> brd->dgap_Major_TransparentPrint_Registered = TRUE;
> dgap_BoardsByMajor[brd->PrintDriver->major] = brd;
> @@ -307,6 +313,10 @@ int dgap_tty_register(struct board_t *brd)
> DPR_INIT(("DGAP REGISTER TTY: MAJORS: %d %d\n", brd->SerialDriver->major,
> brd->PrintDriver->major));
Your patch frees everything by mistake on the success path. It should
be:
return 0;
err_unregister_serial:
tty_unregister_driver(brd->SerialDriver);
err_free_print_ttys:
kfree(brd->PrintDriver->ttys);
err_put_tty_print:
put_tty_driver(brd->PrintDriver);
err_free_serial_ttys:
kfree(brd->SerialDriver->ttys);
err_put_tty_serial:
put_tty_driver(brd->SerialDriver);
return rc;
}
regards,
dan carpenter
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