From: Pan Xinhui <[email protected]>
There is one filed gsm->num to store mux's index of gsm_mux[]. So use
gsm->num to remove itself from gsm_mux[] instead of the for-loop
traverse in gsm_cleanup_mux().
Signed-off-by: Pan Xinhui <[email protected]>
---
drivers/tty/n_gsm.c | 14 +++++---------
1 files changed, 5 insertions(+), 9 deletions(-)
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 9aff371..cf28054 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -2037,18 +2037,14 @@ static void gsm_cleanup_mux(struct gsm_mux *gsm)
gsm->dead = 1;
- spin_lock(&gsm_mux_lock);
- for (i = 0; i < MAX_MUX; i++) {
- if (gsm_mux[i] == gsm) {
- gsm_mux[i] = NULL;
- break;
- }
- }
- spin_unlock(&gsm_mux_lock);
/* open failed before registering => nothing to do */
- if (i == MAX_MUX)
+ if (gsm_mux[gsm->num] != gsm)
return;
+ spin_lock(&gsm_mux_lock);
+ gsm_mux[gsm->num] = NULL;
+ spin_unlock(&gsm_mux_lock);
+
/* In theory disconnecting DLCI 0 is sufficient but for some
modems this is apparently not the case. */
if (dlci) {
--
1.7.1
On Mon, 14 Dec 2015 15:08:03 +0800
Pan Xinhui <[email protected]> wrote:
> From: Pan Xinhui <[email protected]>
>
> There is one filed gsm->num to store mux's index of gsm_mux[]. So use
> gsm->num to remove itself from gsm_mux[] instead of the for-loop
> traverse in gsm_cleanup_mux().
>
> Signed-off-by: Pan Xinhui <[email protected]>
> ---
> drivers/tty/n_gsm.c | 14 +++++---------
> 1 files changed, 5 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
> index 9aff371..cf28054 100644
> --- a/drivers/tty/n_gsm.c
> +++ b/drivers/tty/n_gsm.c
> @@ -2037,18 +2037,14 @@ static void gsm_cleanup_mux(struct gsm_mux *gsm)
>
> gsm->dead = 1;
>
> - spin_lock(&gsm_mux_lock);
> - for (i = 0; i < MAX_MUX; i++) {
> - if (gsm_mux[i] == gsm) {
> - gsm_mux[i] = NULL;
> - break;
> - }
> - }
> - spin_unlock(&gsm_mux_lock);
> /* open failed before registering => nothing to do */
> - if (i == MAX_MUX)
> + if (gsm_mux[gsm->num] != gsm)
> return;
>
> + spin_lock(&gsm_mux_lock);
> + gsm_mux[gsm->num] = NULL;
> + spin_unlock(&gsm_mux_lock);
Its a highly theoretical and probably impossible corner case but I can't
help thinking the lock should be held for the if () as well as NULLing
this out.
Alan