crypto: omap - Fix inconsistent locking of device lists

lockdep complains that in omap-aes, the list_lock is taken both with
softirqs enabled at probe time, and also in softirq context, which
could lead to a deadlock:

    ================================
    WARNING: inconsistent lock state
    5.14.0-rc1-00035-gc836005b01c5-dirty #69 Not tainted
    --------------------------------
    inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
    ksoftirqd/0/7 [HC0[0]:SC1[3]:HE1:SE0] takes:
    bf00e014 (list_lock){+.?.}-{2:2}, at: omap_aes_find_dev+0x18/0x54 [omap_aes_driver]
    {SOFTIRQ-ON-W} state was registered at:
      _raw_spin_lock+0x40/0x50
      omap_aes_probe+0x1d4/0x664 [omap_aes_driver]
      platform_probe+0x58/0xb8
      really_probe+0xbc/0x314
      __driver_probe_device+0x80/0xe4
      driver_probe_device+0x30/0xc8
      __driver_attach+0x70/0xf4
      bus_for_each_dev+0x70/0xb4
      bus_add_driver+0xf0/0x1d4
      driver_register+0x74/0x108
      do_one_initcall+0x84/0x2e4
      do_init_module+0x5c/0x240
      load_module+0x221c/0x2584
      sys_finit_module+0xb0/0xec
      ret_fast_syscall+0x0/0x2c
      0xbed90b30
    irq event stamp: 111800
    hardirqs last  enabled at (111800): [<c02a21e4>] __kmalloc+0x484/0x5ec
    hardirqs last disabled at (111799): [<c02a21f0>] __kmalloc+0x490/0x5ec
    softirqs last  enabled at (111776): [<c01015f0>] __do_softirq+0x2b8/0x4d0
    softirqs last disabled at (111781): [<c0135948>] run_ksoftirqd+0x34/0x50

    other info that might help us debug this:
     Possible unsafe locking scenario:

           CPU0
           ----
      lock(list_lock);
      <Interrupt>
        lock(list_lock);

     *** DEADLOCK ***

    2 locks held by ksoftirqd/0/7:
     #0: c0f5e8c8 (rcu_read_lock){....}-{1:2}, at: netif_receive_skb+0x6c/0x260
     #1: c0f5e8c8 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0x2c/0xdc

    stack backtrace:
    CPU: 0 PID: 7 Comm: ksoftirqd/0 Not tainted 5.14.0-rc1-00035-gc836005b01c5-dirty #69
    Hardware name: Generic AM43 (Flattened Device Tree)
    [<c010e6e0>] (unwind_backtrace) from [<c010b9d0>] (show_stack+0x10/0x14)
    [<c010b9d0>] (show_stack) from [<c017c640>] (mark_lock.part.17+0x5bc/0xd04)
    [<c017c640>] (mark_lock.part.17) from [<c017d9e4>] (__lock_acquire+0x960/0x2fa4)
    [<c017d9e4>] (__lock_acquire) from [<c0180980>] (lock_acquire+0x10c/0x358)
    [<c0180980>] (lock_acquire) from [<c093d324>] (_raw_spin_lock_bh+0x44/0x58)
    [<c093d324>] (_raw_spin_lock_bh) from [<bf00b258>] (omap_aes_find_dev+0x18/0x54 [omap_aes_driver])
    [<bf00b258>] (omap_aes_find_dev [omap_aes_driver]) from [<bf00b328>] (omap_aes_crypt+0x94/0xd4 [omap_aes_driver])
    [<bf00b328>] (omap_aes_crypt [omap_aes_driver]) from [<c08ac6d0>] (esp_input+0x1b0/0x2c8)
    [<c08ac6d0>] (esp_input) from [<c08c9e90>] (xfrm_input+0x410/0x1290)
    [<c08c9e90>] (xfrm_input) from [<c08b6374>] (xfrm4_esp_rcv+0x54/0x11c)
    [<c08b6374>] (xfrm4_esp_rcv) from [<c0838840>] (ip_protocol_deliver_rcu+0x48/0x3bc)
    [<c0838840>] (ip_protocol_deliver_rcu) from [<c0838c50>] (ip_local_deliver_finish+0x9c/0xdc)
    [<c0838c50>] (ip_local_deliver_finish) from [<c0838dd8>] (ip_local_deliver+0x148/0x1b0)
    [<c0838dd8>] (ip_local_deliver) from [<c0838f5c>] (ip_rcv+0x11c/0x180)
    [<c0838f5c>] (ip_rcv) from [<c077e3a4>] (__netif_receive_skb_one_core+0x54/0x74)
    [<c077e3a4>] (__netif_receive_skb_one_core) from [<c077e588>] (netif_receive_skb+0xa8/0x260)
    [<c077e588>] (netif_receive_skb) from [<c068d6d4>] (cpsw_rx_handler+0x224/0x2fc)
    [<c068d6d4>] (cpsw_rx_handler) from [<c0688ccc>] (__cpdma_chan_process+0xf4/0x188)
    [<c0688ccc>] (__cpdma_chan_process) from [<c068a0c0>] (cpdma_chan_process+0x3c/0x5c)
    [<c068a0c0>] (cpdma_chan_process) from [<c0690e14>] (cpsw_rx_mq_poll+0x44/0x98)
    [<c0690e14>] (cpsw_rx_mq_poll) from [<c0780810>] (__napi_poll+0x28/0x268)
    [<c0780810>] (__napi_poll) from [<c0780c64>] (net_rx_action+0xcc/0x204)
    [<c0780c64>] (net_rx_action) from [<c0101478>] (__do_softirq+0x140/0x4d0)
    [<c0101478>] (__do_softirq) from [<c0135948>] (run_ksoftirqd+0x34/0x50)
    [<c0135948>] (run_ksoftirqd) from [<c01583b8>] (smpboot_thread_fn+0xf4/0x1d8)
    [<c01583b8>] (smpboot_thread_fn) from [<c01546dc>] (kthread+0x14c/0x174)
    [<c01546dc>] (kthread) from [<c010013c>] (ret_from_fork+0x14/0x38)
    ...

The omap-des and omap-sham drivers appear to have a similar issue.

Fix this by using spin_{,un}lock_bh() around device list access in all
the probe and remove functions.

Signed-off-by: Ben Hutchings <ben.hutchings@mind.be>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 4 insertions, 4 deletions

diff --git a/drivers/crypto/omap-des.c b/drivers/crypto/omap-des.c
index bc8631363d72..be77656864e3 100644
--- a/drivers/crypto/omap-des.c
+++ b/drivers/crypto/omap-des.c
@@ -1033,9 +1033,9 @@ static int omap_des_probe(struct platform_device *pdev)
 
 
 	INIT_LIST_HEAD(&dd->list);
-	spin_lock(&list_lock);
+	spin_lock_bh(&list_lock);
 	list_add_tail(&dd->list, &dev_list);
-	spin_unlock(&list_lock);
+	spin_unlock_bh(&list_lock);
 
 	/* Initialize des crypto engine */
 	dd->engine = crypto_engine_alloc_init(dev, 1);
@@ -1094,9 +1094,9 @@ static int omap_des_remove(struct platform_device *pdev)
 	if (!dd)
 		return -ENODEV;
 
-	spin_lock(&list_lock);
+	spin_lock_bh(&list_lock);
 	list_del(&dd->list);
-	spin_unlock(&list_lock);
+	spin_unlock_bh(&list_lock);
 
 	for (i = dd->pdata->algs_info_size - 1; i >= 0; i--)
 		for (j = dd->pdata->algs_info[i].registered - 1; j >= 0; j--)