When incoming packet qualifies for rx_copybreak, we copy the data to newly
allocated skb. We do not free/unmap the original buffer. At this point driver
assumes this buffer is unallocated. When enic_rq_alloc_buf() is called for
buffer allocation, it checks if buf->os_buf is NULL. If its not NULL that means
buffer can be re-used.
When vnic_rq_clean() is called for freeing all rq buffers, and if the
rx_copybreak reused buffer falls outside the used desc, we do not free the
buffer. The following trace is observer when dma-debug is enabled.
Fix is to walk through complete ring and clean if buffer is present.
[ 40.555386] ------------[ cut here ]------------
[ 40.555396] WARNING: CPU: 0 PID: 491 at lib/dma-debug.c:971
dma_debug_device_change+0x188/0x1f0()
[ 40.555400] pci 0000:06:00.0: DMA-API: device driver has pending DMA
allocations while released from device [count=4]
One of leaked entries details: [device
address=0x00000000ff4cc040] [size=9018 bytes] [mapped with DMA_FROM_DEVICE]
[mapped as single]
[ 40.555402] Modules linked in: nfsv3 nfs_acl rpcsec_gss_krb5 auth_rpcgss
oid_registry nfsv4 dns_resolver coretemp intel_rapl iosf_mbi
x86_pkg_temp_thermal intel_powerclamp kvm_intel kvm crct10dif_pclmul
crc32_pclmul ghash_clmulni_intel aesni_intel aes_x86_64 lrw joydev mousedev
gf128mul hid_generic glue_helper mgag200 usbhid ttm hid drm_kms_helper drm
ablk_helper syscopyarea sysfillrect sysimgblt i2c_algo_bit i2c_core iTCO_wdt
cryptd mac_hid evdev pcspkr sb_edac edac_core tpm_tis iTCO_vendor_support
ipmi_si wmi tpm ipmi_msghandler shpchp lpc_ich processor acpi_power_meter hwmon
button ac sch_fq_codel nfs lockd grace sunrpc fscache sd_mod ehci_pci ehci_hcd
megaraid_sas usbcore scsi_mod usb_common enic(-) crc32c_generic crc32c_intel
btrfs xor raid6_pq ext4 crc16 mbcache jbd2
[ 40.555467] CPU: 0 PID: 491 Comm: rmmod Not tainted
4.1.0-rc7-ARCH-01305-gf59b71f #118
[ 40.555469] Hardware name: Cisco Systems Inc UCSB-B200-M4/UCSB-B200-M4, BIOS
B200M4.2.2.2.23.061220140128 06/12/2014
[ 40.555471] 0000000000000000 00000000e2f8a5b7 ffff880275f8bc48
ffffffff8158d6f0
[ 40.555474] 0000000000000000 ffff880275f8bca0 ffff880275f8bc88
ffffffff8107b04a
[ 40.555477] ffff8802734e0000 0000000000000004 ffff8804763fb3c0
ffff88027600b650
[ 40.555480] Call Trace:
[ 40.555488] [<ffffffff8158d6f0>] dump_stack+0x4f/0x7b
[ 40.555492] [<ffffffff8107b04a>] warn_slowpath_common+0x8a/0xc0
[ 40.555494] [<ffffffff8107b0d5>] warn_slowpath_fmt+0x55/0x70
[ 40.555498] [<ffffffff812fa408>] dma_debug_device_change+0x188/0x1f0
[ 40.555503] [<ffffffff8109aaef>] notifier_call_chain+0x4f/0x80
[ 40.555506] [<ffffffff8109aecb>] __blocking_notifier_call_chain+0x4b/0x70
[ 40.555510] [<ffffffff8109af06>] blocking_notifier_call_chain+0x16/0x20
[ 40.555514] [<ffffffff813f8066>] __device_release_driver+0xf6/0x120
[ 40.555518] [<ffffffff813f8b08>] driver_detach+0xc8/0xd0
[ 40.555523] [<ffffffff813f7c59>] bus_remove_driver+0x59/0xe0
[ 40.555527] [<ffffffff813f93a0>] driver_unregister+0x30/0x70
[ 40.555534] [<ffffffff8131532d>] pci_unregister_driver+0x2d/0xa0
[ 40.555542] [<ffffffffa0200ec2>] enic_cleanup_module+0x10/0x14e [enic]
[ 40.555547] [<ffffffff8110158f>] SyS_delete_module+0x1cf/0x280
[ 40.555551] [<ffffffff811e284e>] ? ____fput+0xe/0x10
[ 40.555554] [<ffffffff810980ec>] ? task_work_run+0xbc/0xf0
[ 40.555558] [<ffffffff815930ee>] system_call_fastpath+0x12/0x71
[ 40.555561] ---[ end trace 4988cadc77c2b236 ]---
[ 40.555562] Mapped at:
[ 40.555563] [<ffffffff812fa865>] debug_dma_map_page+0x95/0x150
[ 40.555566] [<ffffffffa01f4a88>] enic_rq_alloc_buf+0x1b8/0x360 [enic]
[ 40.555570] [<ffffffffa01f7658>] enic_open+0xf8/0x820 [enic]
[ 40.555574] [<ffffffff8148d50e>] __dev_open+0xce/0x150
[ 40.555579] [<ffffffff8148d851>] __dev_change_flags+0xa1/0x170
Signed-off-by: Govindarajulu Varadarajan <_gov...@gmx.com>
---
drivers/net/ethernet/cisco/enic/vnic_rq.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/drivers/net/ethernet/cisco/enic/vnic_rq.c
b/drivers/net/ethernet/cisco/enic/vnic_rq.c
index 36a2ed6..c4b2183 100644
--- a/drivers/net/ethernet/cisco/enic/vnic_rq.c
+++ b/drivers/net/ethernet/cisco/enic/vnic_rq.c
@@ -188,16 +188,15 @@ void vnic_rq_clean(struct vnic_rq *rq,
struct vnic_rq_buf *buf;
u32 fetch_index;
unsigned int count = rq->ring.desc_count;
+ int i;
buf = rq->to_clean;
- while (vnic_rq_desc_used(rq) > 0) {
-
+ for (i = 0; i < rq->ring.desc_count; i++) {
(*buf_clean)(rq, buf);
-
- buf = rq->to_clean = buf->next;
- rq->ring.desc_avail++;
+ buf = buf->next;
}
+ rq->ring.desc_avail = rq->ring.desc_count - 1;
/* Use current fetch_index as the ring starting point */
fetch_index = ioread32(&rq->ctrl->fetch_index);
--
2.4.2
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
