[PATCH net 4/5] bnxt_en: Check abort error state in bnxt_open_nic().

[Michael Chan <michael.chan@broadcom.com>]

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bnxt_open_nic() is called during configuration changes that require
the NIC to be closed and then opened.  This call is protected by
rtnl_lock.  Firmware reset can be happening at the same time.  Only
critical portions of the entire firmware reset sequence are protected
by the rtnl_lock.  It is possible that bnxt_open_nic() can be called
when the firmware reset sequence is aborting.  In that case,
bnxt_open_nic() needs to check if the ABORT_ERR flag is set and
abort if it is.  The configuration change that resulted in the
bnxt_open_nic() call will fail but the NIC will be brought to a
consistent IF_DOWN state.

Without this patch, if bnxt_open_nic() were to continue in this error
state, it may crash like this:

[ 1648.659736] BUG: unable to handle kernel NULL pointer dereference at           (null)
[ 1648.659768] IP: [<ffffffffc01e9b3a>] bnxt_alloc_mem+0x50a/0x1140 [bnxt_en]
[ 1648.659796] PGD 101e1b3067 PUD 101e1b2067 PMD 0
[ 1648.659813] Oops: 0000 [#1] SMP
[ 1648.659825] Modules linked in: xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter sunrpc dell_smbios dell_wmi_descriptor dcdbas amd64_edac_mod edac_mce_amd kvm_amd kvm irqbypass crc32_pclmul ghash_clmulni_intel aesni_intel lrw gf128mul glue_helper ablk_helper vfat cryptd fat pcspkr ipmi_ssif sg k10temp i2c_piix4 wmi ipmi_si ipmi_devintf ipmi_msghandler tpm_crb acpi_power_meter sch_fq_codel ip_tables xfs libcrc32c sd_mod crc_t10dif crct10dif_generic mgag200 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm ahci drm libahci megaraid_sas crct10dif_pclmul crct10dif_common
[ 1648.660063]  tg3 libata crc32c_intel bnxt_en(OE) drm_panel_orientation_quirks devlink ptp pps_core dm_mirror dm_region_hash dm_log dm_mod fuse
[ 1648.660105] CPU: 13 PID: 3867 Comm: ethtool Kdump: loaded Tainted: G           OE  ------------   3.10.0-1152.el7.x86_64 #1
[ 1648.660911] Hardware name: Dell Inc. PowerEdge R7515/0R4CNN, BIOS 1.2.14 01/28/2020
[ 1648.661662] task: ffff94e64cbc9080 ti: ffff94f55df1c000 task.ti: ffff94f55df1c000
[ 1648.662409] RIP: 0010:[<ffffffffc01e9b3a>]  [<ffffffffc01e9b3a>] bnxt_alloc_mem+0x50a/0x1140 [bnxt_en]
[ 1648.663171] RSP: 0018:ffff94f55df1fba8  EFLAGS: 00010202
[ 1648.663927] RAX: 0000000000000000 RBX: ffff94e6827e0000 RCX: 0000000000000000
[ 1648.664684] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff94e6827e08c0
[ 1648.665433] RBP: ffff94f55df1fc20 R08: 00000000000001ff R09: 0000000000000008
[ 1648.666184] R10: 0000000000000d53 R11: ffff94f55df1f7ce R12: ffff94e6827e08c0
[ 1648.666940] R13: ffff94e6827e08c0 R14: ffff94e6827e08c0 R15: ffffffffb9115e40
[ 1648.667695] FS:  00007f8aadba5740(0000) GS:ffff94f57eb40000(0000) knlGS:0000000000000000
[ 1648.668447] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1648.669202] CR2: 0000000000000000 CR3: 0000001022772000 CR4: 0000000000340fe0
[ 1648.669966] Call Trace:
[ 1648.670730]  [<ffffffffc01f1d5d>] ? bnxt_need_reserve_rings+0x9d/0x170 [bnxt_en]
[ 1648.671496]  [<ffffffffc01fa7ea>] __bnxt_open_nic+0x8a/0x9a0 [bnxt_en]
[ 1648.672263]  [<ffffffffc01f7479>] ? bnxt_close_nic+0x59/0x1b0 [bnxt_en]
[ 1648.673031]  [<ffffffffc01fb11b>] bnxt_open_nic+0x1b/0x50 [bnxt_en]
[ 1648.673793]  [<ffffffffc020037c>] bnxt_set_ringparam+0x6c/0xa0 [bnxt_en]
[ 1648.674550]  [<ffffffffb8a5f564>] dev_ethtool+0x1334/0x21a0
[ 1648.675306]  [<ffffffffb8a719ff>] dev_ioctl+0x1ef/0x5f0
[ 1648.676061]  [<ffffffffb8a324bd>] sock_do_ioctl+0x4d/0x60
[ 1648.676810]  [<ffffffffb8a326bb>] sock_ioctl+0x1eb/0x2d0
[ 1648.677548]  [<ffffffffb8663230>] do_vfs_ioctl+0x3a0/0x5b0
[ 1648.678282]  [<ffffffffb8b8e678>] ? __do_page_fault+0x238/0x500
[ 1648.679016]  [<ffffffffb86634e1>] SyS_ioctl+0xa1/0xc0
[ 1648.679745]  [<ffffffffb8b93f92>] system_call_fastpath+0x25/0x2a
[ 1648.680461] Code: 9e 60 01 00 00 0f 1f 40 00 45 8b 8e 48 01 00 00 31 c9 45 85 c9 0f 8e 73 01 00 00 66 0f 1f 44 00 00 49 8b 86 a8 00 00 00 48 63 d1 <48> 8b 14 d0 48 85 d2 0f 84 46 01 00 00 41 8b 86 44 01 00 00 c7
[ 1648.681986] RIP  [<ffffffffc01e9b3a>] bnxt_alloc_mem+0x50a/0x1140 [bnxt_en]
[ 1648.682724]  RSP <ffff94f55df1fba8>
[ 1648.683451] CR2: 0000000000000000

Fixes: ec5d31e3c15d ("bnxt_en: Handle firmware reset status during IF_UP.")
Reviewed-by: Vasundhara Volam <vasundhara-v.volam@broadcom.com>
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 8012386b4a0f..0165f70dba74 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -9779,7 +9779,10 @@ int bnxt_open_nic(struct bnxt *bp, bool irq_re_init, bool link_re_init)
 {
 	int rc = 0;
 
-	rc = __bnxt_open_nic(bp, irq_re_init, link_re_init);
+	if (test_bit(BNXT_STATE_ABORT_ERR, &bp->state))
+		rc = -EIO;
+	if (!rc)
+		rc = __bnxt_open_nic(bp, irq_re_init, link_re_init);
 	if (rc) {
 		netdev_err(bp->dev, "nic open fail (rc: %x)\n", rc);
 		dev_close(bp->dev);
-- 
2.18.1


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