ath9k: Fix possible double free of PAPRD skb's
This patch reverts the following commit
ath9k: remove bfs_paprd_timestamp from struct ath_buf_state
Under high interference/noisy environment conditions where PAPRD frames
fails heavily introduces a possibility of double freeing skb's and causes
kernel panic after some time.This patch reverts back to the original approach
of using paprd_timestamp before freeing the PAPRD frame skb's
[ 194.193705] Pid: 0, comm: swapper Tainted: G D WC
2.6.35-22-generic #33-Ubuntu
[ 194.193712] Call Trace:
[ 194.193722] [<c05c6468>] ? printk+0x2d/0x35
[ 194.193732] [<c05c63c3>] panic+0x5a/0xd2
[ 194.193741] [<c05ca3ed>] oops_end+0xcd/0xd0
[ 194.193750] [<c0105f74>] die+0x54/0x80
[ 194.193758] [<c05c9a16>] do_trap+0x96/0xc0
[ 194.193837] [<c0103fb0>] ? do_invalid_op+0x0/0xa0
[ 194.193846] [<c010403b>] do_invalid_op+0x8b/0xa0
[ 194.193856] [<c020bd4c>] ? kfree+0xec/0xf0
[ 194.193866] [<c012ce18>] ? default_spin_lock_flags+0x8/0x10
[ 194.193877] [<c01de47a>] ? free_one_page+0x12a/0x2d0
[ 194.193888] [<c01e04dc>] ? __free_pages+0x1c/0x40
[ 194.193897] [<c05c97a7>] error_code+0x73/0x78
[ 194.193906] [<c020bd4c>] ? kfree+0xec/0xf0
[ 194.193915] [<c04ecdd0>] ? skb_release_data+0x70/0xa0
[ 194.193924] [<c04ecdd0>] skb_release_data+0x70/0xa0
[ 194.193933] [<c04ec997>] __kfree_skb+0x17/0x90
[ 194.193941] [<c04eca31>] consume_skb+0x21/0x40
[ 194.193964] [<f85e0b70>] ieee80211_tx_status+0x760/0x860 [mac80211]
[ 194.193979] [<f85caddf>] ath_tx_complete_buf+0x1bf/0x2c0 [ath9k]
[ 194.193988] [<c05c8b9f>] ? _raw_spin_lock_irqsave+0x2f/0x50
[ 194.193997] [<c04ec40e>] ? skb_queue_tail+0x3e/0x50
[ 194.194010] [<f85cc803>] ath_tx_complete_aggr+0x823/0x940 [ath9k]
[ 194.194021] [<c0108a28>] ? sched_clock+0x8/0x10
[ 194.194030] [<c016bf14>] ? sched_clock_local+0xa4/0x180
[ 194.194040] [<c0139f57>] ? enqueue_sleeper+0x1e7/0x2b0
[ 194.194051] [<c013a194>] ? enqueue_entity+0x174/0x200
[ 194.194064] [<f85ce83d>] ath_tx_edma_tasklet+0x2bd/0x3b0 [ath9k]
[ 194.194074] [<c05c8b9f>] ? _raw_spin_lock_irqsave+0x2f/0x50
[ 194.194088] [<f85c7b9f>] ath9k_tasklet+0x9f/0x190 [ath9k]
[ 194.194097] [<c01505d7>] tasklet_action+0xa7/0xb0
[ 194.194107] [<c015127c>] __do_softirq+0x9c/0x1b0
[ 194.194117] [<c01a7f64>] ? irq_to_desc+0x14/0x20
[ 194.194126] [<c0124fc4>] ? ack_apic_level+0x64/0x1f0
[ 194.194136] [<c01513d5>] do_softirq+0x45/0x50
[ 194.194145] [<c0151545>] irq_exit+0x65/0x70
[ 194.194153] [<c05cf665>] do_IRQ+0x55/0xc0
[ 194.194162] [<c016a6c7>] ? hrtimer_start+0x27/0x30
[ 194.194171] [<c0103630>] common_interrupt+0x30/0x38
[ 194.194181] [<c012c21a>] ? native_safe_halt+0xa/0x10
[ 194.194268] [<c010a2f9>] default_idle+0x49/0xb0
[ 194.194277] [<c0101fcc>] cpu_idle+0x8c/0xd0
[ 194.194286] [<c05b2431>] rest_init+0x71/0x80
[ 194.194295] [<c081981a>] start_kernel+0x36e/0x374
[ 194.194305] [<c08199dd>] ? pass_all_bootoptions+0x0/0xa
[ 194.194314] [<c08190d7>] i386_start_kernel+0xd7/0xdf
[ 194.194364] panic occurred, switching back to text console
Signed-off-by: Mohammed Shafi Shajakhan <mshajakhan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index 3681caf5..23838e3 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -218,6 +218,7 @@
struct ath_buf_state {
u8 bf_type;
u8 bfs_paprd;
+ unsigned long bfs_paprd_timestamp;
enum ath9k_internal_frame_type bfs_ftype;
};
@@ -593,7 +594,6 @@
struct work_struct paprd_work;
struct work_struct hw_check_work;
struct completion paprd_complete;
- bool paprd_pending;
u32 intrstatus;
u32 sc_flags; /* SC_OP_* */
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 9040c2f..da5c645 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -342,7 +342,6 @@
tx_info->control.rates[1].idx = -1;
init_completion(&sc->paprd_complete);
- sc->paprd_pending = true;
txctl.paprd = BIT(chain);
if (ath_tx_start(hw, skb, &txctl) != 0) {
@@ -353,7 +352,6 @@
time_left = wait_for_completion_timeout(&sc->paprd_complete,
msecs_to_jiffies(ATH_PAPRD_TIMEOUT));
- sc->paprd_pending = false;
if (!time_left)
ath_dbg(ath9k_hw_common(sc->sc_ah), ATH_DBG_CALIBRATE,
diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 33a37ed..07b7804 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -1725,6 +1725,9 @@
ar9003_hw_set_paprd_txdesc(sc->sc_ah, bf->bf_desc,
bf->bf_state.bfs_paprd);
+ if (txctl->paprd)
+ bf->bf_state.bfs_paprd_timestamp = jiffies;
+
ath_tx_send_normal(sc, txctl->txq, tid, &bf_head);
}
@@ -1886,7 +1889,9 @@
bf->bf_buf_addr = 0;
if (bf->bf_state.bfs_paprd) {
- if (!sc->paprd_pending)
+ if (time_after(jiffies,
+ bf->bf_state.bfs_paprd_timestamp +
+ msecs_to_jiffies(ATH_PAPRD_TIMEOUT)))
dev_kfree_skb_any(skb);
else
complete(&sc->paprd_complete);