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authorKim Phillips <kim.phillips@freescale.com>2012-07-13 19:04:23 -0400
committerHerbert Xu <herbert@gondor.apana.org.au>2012-08-20 04:35:40 -0400
commitce026cb9cbf1d529652394ea91fb8a459072be91 (patch)
treef31bc59d6e055691b80190e8d55a5515d794aa46
parent76f16f83ee520d6c10356b0f6ff592441a6f08bd (diff)
crypto: caam - fix possible deadlock condition
commit "crypto: caam - use non-irq versions of spinlocks for job rings" made two bad assumptions: (a) The caam_jr_enqueue lock isn't used in softirq context. Not true: jr_enqueue can be interrupted by an incoming net interrupt and the received packet may be sent for encryption, via caam_jr_enqueue in softirq context, thereby inducing a deadlock. This is evidenced when running netperf over an IPSec tunnel between two P4080's, with spinlock debugging turned on: [ 892.092569] BUG: spinlock lockup on CPU#7, netperf/10634, e8bf5f70 [ 892.098747] Call Trace: [ 892.101197] [eff9fc10] [c00084c0] show_stack+0x48/0x15c (unreliable) [ 892.107563] [eff9fc50] [c0239c2c] do_raw_spin_lock+0x16c/0x174 [ 892.113399] [eff9fc80] [c0596494] _raw_spin_lock+0x3c/0x50 [ 892.118889] [eff9fc90] [c0445e74] caam_jr_enqueue+0xf8/0x250 [ 892.124550] [eff9fcd0] [c044a644] aead_decrypt+0x6c/0xc8 [ 892.129625] BUG: spinlock lockup on CPU#5, swapper/5/0, e8bf5f70 [ 892.129629] Call Trace: [ 892.129637] [effa7c10] [c00084c0] show_stack+0x48/0x15c (unreliable) [ 892.129645] [effa7c50] [c0239c2c] do_raw_spin_lock+0x16c/0x174 [ 892.129652] [effa7c80] [c0596494] _raw_spin_lock+0x3c/0x50 [ 892.129660] [effa7c90] [c0445e74] caam_jr_enqueue+0xf8/0x250 [ 892.129666] [effa7cd0] [c044a644] aead_decrypt+0x6c/0xc8 [ 892.129674] [effa7d00] [c0509724] esp_input+0x178/0x334 [ 892.129681] [effa7d50] [c0519778] xfrm_input+0x77c/0x818 [ 892.129688] [effa7da0] [c050e344] xfrm4_rcv_encap+0x20/0x30 [ 892.129697] [effa7db0] [c04b90c8] ip_local_deliver+0x190/0x408 [ 892.129703] [effa7de0] [c04b966c] ip_rcv+0x32c/0x898 [ 892.129709] [effa7e10] [c048b998] __netif_receive_skb+0x27c/0x4e8 [ 892.129715] [effa7e80] [c048d744] netif_receive_skb+0x4c/0x13c [ 892.129726] [effa7eb0] [c03c28ac] _dpa_rx+0x1a8/0x354 [ 892.129732] [effa7ef0] [c03c2ac4] ingress_rx_default_dqrr+0x6c/0x108 [ 892.129742] [effa7f10] [c0467ae0] qman_poll_dqrr+0x170/0x1d4 [ 892.129748] [effa7f40] [c03c153c] dpaa_eth_poll+0x20/0x94 [ 892.129754] [effa7f60] [c048dbd0] net_rx_action+0x13c/0x1f4 [ 892.129763] [effa7fa0] [c003d1b8] __do_softirq+0x108/0x1b0 [ 892.129769] [effa7ff0] [c000df58] call_do_softirq+0x14/0x24 [ 892.129775] [ebacfe70] [c0004868] do_softirq+0xd8/0x104 [ 892.129780] [ebacfe90] [c003d5a4] irq_exit+0xb8/0xd8 [ 892.129786] [ebacfea0] [c0004498] do_IRQ+0xa4/0x1b0 [ 892.129792] [ebacfed0] [c000fad8] ret_from_except+0x0/0x18 [ 892.129798] [ebacff90] [c0009010] cpu_idle+0x94/0xf0 [ 892.129804] [ebacffb0] [c059ff88] start_secondary+0x42c/0x430 [ 892.129809] [ebacfff0] [c0001e28] __secondary_start+0x30/0x84 [ 892.281474] [ 892.282959] [eff9fd00] [c0509724] esp_input+0x178/0x334 [ 892.288186] [eff9fd50] [c0519778] xfrm_input+0x77c/0x818 [ 892.293499] [eff9fda0] [c050e344] xfrm4_rcv_encap+0x20/0x30 [ 892.299074] [eff9fdb0] [c04b90c8] ip_local_deliver+0x190/0x408 [ 892.304907] [eff9fde0] [c04b966c] ip_rcv+0x32c/0x898 [ 892.309872] [eff9fe10] [c048b998] __netif_receive_skb+0x27c/0x4e8 [ 892.315966] [eff9fe80] [c048d744] netif_receive_skb+0x4c/0x13c [ 892.321803] [eff9feb0] [c03c28ac] _dpa_rx+0x1a8/0x354 [ 892.326855] [eff9fef0] [c03c2ac4] ingress_rx_default_dqrr+0x6c/0x108 [ 892.333212] [eff9ff10] [c0467ae0] qman_poll_dqrr+0x170/0x1d4 [ 892.338872] [eff9ff40] [c03c153c] dpaa_eth_poll+0x20/0x94 [ 892.344271] [eff9ff60] [c048dbd0] net_rx_action+0x13c/0x1f4 [ 892.349846] [eff9ffa0] [c003d1b8] __do_softirq+0x108/0x1b0 [ 892.355338] [eff9fff0] [c000df58] call_do_softirq+0x14/0x24 [ 892.360910] [e7169950] [c0004868] do_softirq+0xd8/0x104 [ 892.366135] [e7169970] [c003d5a4] irq_exit+0xb8/0xd8 [ 892.371101] [e7169980] [c0004498] do_IRQ+0xa4/0x1b0 [ 892.375979] [e71699b0] [c000fad8] ret_from_except+0x0/0x18 [ 892.381466] [e7169a70] [c0445e74] caam_jr_enqueue+0xf8/0x250 [ 892.387127] [e7169ab0] [c044ad4c] aead_givencrypt+0x6ac/0xa70 [ 892.392873] [e7169b20] [c050a0b8] esp_output+0x2b4/0x570 [ 892.398186] [e7169b80] [c0519b9c] xfrm_output_resume+0x248/0x7c0 [ 892.404194] [e7169bb0] [c050e89c] xfrm4_output_finish+0x18/0x28 [ 892.410113] [e7169bc0] [c050e8f4] xfrm4_output+0x48/0x98 [ 892.415427] [e7169bd0] [c04beac0] ip_local_out+0x48/0x98 [ 892.420740] [e7169be0] [c04bec7c] ip_queue_xmit+0x16c/0x490 [ 892.426314] [e7169c10] [c04d6128] tcp_transmit_skb+0x35c/0x9a4 [ 892.432147] [e7169c70] [c04d6f98] tcp_write_xmit+0x200/0xa04 [ 892.437808] [e7169cc0] [c04c8ccc] tcp_sendmsg+0x994/0xcec [ 892.443213] [e7169d40] [c04eebfc] inet_sendmsg+0xd0/0x164 [ 892.448617] [e7169d70] [c04792f8] sock_sendmsg+0x8c/0xbc [ 892.453931] [e7169e40] [c047aecc] sys_sendto+0xc0/0xfc [ 892.459069] [e7169f10] [c047b934] sys_socketcall+0x110/0x25c [ 892.464729] [e7169f40] [c000f480] ret_from_syscall+0x0/0x3c (b) since the caam_jr_dequeue lock is only used in bh context, then semantically it should use _bh spin_lock types. spin_lock_bh semantics are to disable back-halves, and used when a lock is shared between softirq (bh) context and process and/or h/w IRQ context. Since the lock is only used within softirq context, and this tasklet is atomic, there is no need to do the additional work to disable back halves. This patch adds back-half disabling protection to caam_jr_enqueue spin_locks to fix (a), and drops it from caam_jr_dequeue to fix (b). Signed-off-by: Kim Phillips <kim.phillips@freescale.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
-rw-r--r--drivers/crypto/caam/jr.c10
1 files changed, 5 insertions, 5 deletions
diff --git a/drivers/crypto/caam/jr.c b/drivers/crypto/caam/jr.c
index 53c8c51d5881..93d14070141a 100644
--- a/drivers/crypto/caam/jr.c
+++ b/drivers/crypto/caam/jr.c
@@ -63,7 +63,7 @@ static void caam_jr_dequeue(unsigned long devarg)
63 63
64 head = ACCESS_ONCE(jrp->head); 64 head = ACCESS_ONCE(jrp->head);
65 65
66 spin_lock_bh(&jrp->outlock); 66 spin_lock(&jrp->outlock);
67 67
68 sw_idx = tail = jrp->tail; 68 sw_idx = tail = jrp->tail;
69 hw_idx = jrp->out_ring_read_index; 69 hw_idx = jrp->out_ring_read_index;
@@ -115,7 +115,7 @@ static void caam_jr_dequeue(unsigned long devarg)
115 jrp->tail = tail; 115 jrp->tail = tail;
116 } 116 }
117 117
118 spin_unlock_bh(&jrp->outlock); 118 spin_unlock(&jrp->outlock);
119 119
120 /* Finally, execute user's callback */ 120 /* Finally, execute user's callback */
121 usercall(dev, userdesc, userstatus, userarg); 121 usercall(dev, userdesc, userstatus, userarg);
@@ -236,14 +236,14 @@ int caam_jr_enqueue(struct device *dev, u32 *desc,
236 return -EIO; 236 return -EIO;
237 } 237 }
238 238
239 spin_lock(&jrp->inplock); 239 spin_lock_bh(&jrp->inplock);
240 240
241 head = jrp->head; 241 head = jrp->head;
242 tail = ACCESS_ONCE(jrp->tail); 242 tail = ACCESS_ONCE(jrp->tail);
243 243
244 if (!rd_reg32(&jrp->rregs->inpring_avail) || 244 if (!rd_reg32(&jrp->rregs->inpring_avail) ||
245 CIRC_SPACE(head, tail, JOBR_DEPTH) <= 0) { 245 CIRC_SPACE(head, tail, JOBR_DEPTH) <= 0) {
246 spin_unlock(&jrp->inplock); 246 spin_unlock_bh(&jrp->inplock);
247 dma_unmap_single(dev, desc_dma, desc_size, DMA_TO_DEVICE); 247 dma_unmap_single(dev, desc_dma, desc_size, DMA_TO_DEVICE);
248 return -EBUSY; 248 return -EBUSY;
249 } 249 }
@@ -265,7 +265,7 @@ int caam_jr_enqueue(struct device *dev, u32 *desc,
265 265
266 wr_reg32(&jrp->rregs->inpring_jobadd, 1); 266 wr_reg32(&jrp->rregs->inpring_jobadd, 1);
267 267
268 spin_unlock(&jrp->inplock); 268 spin_unlock_bh(&jrp->inplock);
269 269
270 return 0; 270 return 0;
271} 271}