| Message ID | 1434003776-31840-3-git-send-email-_govind@gmx.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Govindarajulu Varadarajan <_govind@gmx.com> Date: Thu, 11 Jun 2015 11:52:56 +0530 > 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. ... > Signed-off-by: Govindarajulu Varadarajan <_govind@gmx.com> Applied. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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);
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 <_govind@gmx.com> --- drivers/net/ethernet/cisco/enic/vnic_rq.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)