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authorKim Phillips <kim.phillips@freescale.com>2012-07-13 18:04:23 -0500
committerHerbert Xu <herbert@gondor.apana.org.au>2012-08-20 16:35:40 +0800
commitce026cb9cbf1d529652394ea91fb8a459072be91 (patch)
treef31bc59d6e055691b80190e8d55a5515d794aa46
parent76f16f83ee520d6c10356b0f6ff592441a6f08bd (diff)
downloadlinux-ce026cb9cbf1d529652394ea91fb8a459072be91.tar.bz2
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)
head = ACCESS_ONCE(jrp->head);
- spin_lock_bh(&jrp->outlock);
+ spin_lock(&jrp->outlock);
sw_idx = tail = jrp->tail;
hw_idx = jrp->out_ring_read_index;
@@ -115,7 +115,7 @@ static void caam_jr_dequeue(unsigned long devarg)
jrp->tail = tail;
}
- spin_unlock_bh(&jrp->outlock);
+ spin_unlock(&jrp->outlock);
/* Finally, execute user's callback */
usercall(dev, userdesc, userstatus, userarg);
@@ -236,14 +236,14 @@ int caam_jr_enqueue(struct device *dev, u32 *desc,
return -EIO;
}
- spin_lock(&jrp->inplock);
+ spin_lock_bh(&jrp->inplock);
head = jrp->head;
tail = ACCESS_ONCE(jrp->tail);
if (!rd_reg32(&jrp->rregs->inpring_avail) ||
CIRC_SPACE(head, tail, JOBR_DEPTH) <= 0) {
- spin_unlock(&jrp->inplock);
+ spin_unlock_bh(&jrp->inplock);
dma_unmap_single(dev, desc_dma, desc_size, DMA_TO_DEVICE);
return -EBUSY;
}
@@ -265,7 +265,7 @@ int caam_jr_enqueue(struct device *dev, u32 *desc,
wr_reg32(&jrp->rregs->inpring_jobadd, 1);
- spin_unlock(&jrp->inplock);
+ spin_unlock_bh(&jrp->inplock);
return 0;
}