[PATCH] atm: idt77252: Convert timers to use timer_setup()

[Kees Cook]

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly. This required adding a pointer back
to vc_map, and adjusting the locking around removal a bit.

Cc: Chas Williams <3ch...@gmail.com>
Cc: linux-atm-gene...@lists.sourceforge.net
Cc: netdev@vger.kernel.org
Cc: Thomas Gleixner <t...@linutronix.de>
Signed-off-by: Kees Cook <keesc...@chromium.org>
---
This requires commit 686fef928bba ("timer: Prepare to change timer
callback argument type") in v4.14-rc3, but should be otherwise
stand-alone.
---
 drivers/atm/idt77252.c | 21 ++++++++++++---------
 drivers/atm/idt77252.h |  3 +++
 2 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/drivers/atm/idt77252.c b/drivers/atm/idt77252.c
index 47f3c4ae0594..0e3b9c44c808 100644
--- a/drivers/atm/idt77252.c
+++ b/drivers/atm/idt77252.c
@@ -2073,21 +2073,19 @@ idt77252_rate_logindex(struct idt77252_dev *card, int 
pcr)
 }
 
 static void
-idt77252_est_timer(unsigned long data)
+idt77252_est_timer(struct timer_list *t)
 {
-       struct vc_map *vc = (struct vc_map *)data;
+       struct rate_estimator *est = from_timer(est, t, timer);
+       struct vc_map *vc = est->vc;
        struct idt77252_dev *card = vc->card;
-       struct rate_estimator *est;
        unsigned long flags;
        u32 rate, cps;
        u64 ncells;
        u8 lacr;
 
        spin_lock_irqsave(&vc->lock, flags);
-       est = vc->estimator;
-       if (!est)
+       if (!vc->estimator)
                goto out;
-
        ncells = est->cells;
 
        rate = ((u32)(ncells - est->last_cells)) << (7 - est->interval);
@@ -2126,10 +2124,11 @@ idt77252_init_est(struct vc_map *vc, int pcr)
        est->maxcps = pcr < 0 ? -pcr : pcr;
        est->cps = est->maxcps;
        est->avcps = est->cps << 5;
+       est->vc = vc;
 
        est->interval = 2;              /* XXX: make this configurable */
        est->ewma_log = 2;              /* XXX: make this configurable */
-       setup_timer(&est->timer, idt77252_est_timer, (unsigned long)vc);
+       timer_setup(&est->timer, idt77252_est_timer, 0);
        mod_timer(&est->timer, jiffies + ((HZ / 4) << est->interval));
 
        return est;
@@ -2209,16 +2208,20 @@ static int
 idt77252_init_ubr(struct idt77252_dev *card, struct vc_map *vc,
                  struct atm_vcc *vcc, struct atm_qos *qos)
 {
+       struct rate_estimator *est = NULL;
        unsigned long flags;
        int tcr;
 
        spin_lock_irqsave(&vc->lock, flags);
        if (vc->estimator) {
-               del_timer(&vc->estimator->timer);
-               kfree(vc->estimator);
+               est = vc->estimator;
                vc->estimator = NULL;
        }
        spin_unlock_irqrestore(&vc->lock, flags);
+       if (est) {
+               del_timer_sync(&est->timer);
+               kfree(est);
+       }
 
        tcr = atm_pcr_goal(&qos->txtp);
        if (tcr == 0)
diff --git a/drivers/atm/idt77252.h b/drivers/atm/idt77252.h
index 3a82cc23a053..9339197d701c 100644
--- a/drivers/atm/idt77252.h
+++ b/drivers/atm/idt77252.h
@@ -184,6 +184,8 @@ struct aal1 {
        unsigned char           sequence;
 };
 
+struct vc_map;
+
 struct rate_estimator {
        struct timer_list       timer;
        unsigned int            interval;
@@ -193,6 +195,7 @@ struct rate_estimator {
        long                    avcps;
        u32                     cps;
        u32                     maxcps;
+       struct vc_map           *vc;
 };
 
 struct vc_map {
-- 
2.7.4


-- 
Kees Cook
Pixel Security