diff options
author | David Thompson <davthompson@nvidia.com> | 2024-03-25 14:36:27 -0400 |
---|---|---|
committer | Jakub Kicinski <kuba@kernel.org> | 2024-03-26 20:51:11 -0700 |
commit | f7442a634ac06b953fc1f7418f307b25acd4cfbc (patch) | |
tree | 10d1d635e14d0d3a535264d1f7d4daa0f22fad84 /drivers/net | |
parent | 646fc4bd0a6bd942361a8a66a5c54ee90febb7f9 (diff) |
mlxbf_gige: call request_irq() after NAPI initialized
The mlxbf_gige driver encounters a NULL pointer exception in
mlxbf_gige_open() when kdump is enabled. The sequence to reproduce
the exception is as follows:
a) enable kdump
b) trigger kdump via "echo c > /proc/sysrq-trigger"
c) kdump kernel executes
d) kdump kernel loads mlxbf_gige module
e) the mlxbf_gige module runs its open() as the
the "oob_net0" interface is brought up
f) mlxbf_gige module will experience an exception
during its open(), something like:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
Mem abort info:
ESR = 0x0000000086000004
EC = 0x21: IABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x04: level 0 translation fault
user pgtable: 4k pages, 48-bit VAs, pgdp=00000000e29a4000
[0000000000000000] pgd=0000000000000000, p4d=0000000000000000
Internal error: Oops: 0000000086000004 [#1] SMP
CPU: 0 PID: 812 Comm: NetworkManager Tainted: G OE 5.15.0-1035-bluefield #37-Ubuntu
Hardware name: https://www.mellanox.com BlueField-3 SmartNIC Main Card/BlueField-3 SmartNIC Main Card, BIOS 4.6.0.13024 Jan 19 2024
pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : 0x0
lr : __napi_poll+0x40/0x230
sp : ffff800008003e00
x29: ffff800008003e00 x28: 0000000000000000 x27: 00000000ffffffff
x26: ffff000066027238 x25: ffff00007cedec00 x24: ffff800008003ec8
x23: 000000000000012c x22: ffff800008003eb7 x21: 0000000000000000
x20: 0000000000000001 x19: ffff000066027238 x18: 0000000000000000
x17: ffff578fcb450000 x16: ffffa870b083c7c0 x15: 0000aaab010441d0
x14: 0000000000000001 x13: 00726f7272655f65 x12: 6769675f6662786c
x11: 0000000000000000 x10: 0000000000000000 x9 : ffffa870b0842398
x8 : 0000000000000004 x7 : fe5a48b9069706ea x6 : 17fdb11fc84ae0d2
x5 : d94a82549d594f35 x4 : 0000000000000000 x3 : 0000000000400100
x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff000066027238
Call trace:
0x0
net_rx_action+0x178/0x360
__do_softirq+0x15c/0x428
__irq_exit_rcu+0xac/0xec
irq_exit+0x18/0x2c
handle_domain_irq+0x6c/0xa0
gic_handle_irq+0xec/0x1b0
call_on_irq_stack+0x20/0x2c
do_interrupt_handler+0x5c/0x70
el1_interrupt+0x30/0x50
el1h_64_irq_handler+0x18/0x2c
el1h_64_irq+0x7c/0x80
__setup_irq+0x4c0/0x950
request_threaded_irq+0xf4/0x1bc
mlxbf_gige_request_irqs+0x68/0x110 [mlxbf_gige]
mlxbf_gige_open+0x5c/0x170 [mlxbf_gige]
__dev_open+0x100/0x220
__dev_change_flags+0x16c/0x1f0
dev_change_flags+0x2c/0x70
do_setlink+0x220/0xa40
__rtnl_newlink+0x56c/0x8a0
rtnl_newlink+0x58/0x84
rtnetlink_rcv_msg+0x138/0x3c4
netlink_rcv_skb+0x64/0x130
rtnetlink_rcv+0x20/0x30
netlink_unicast+0x2ec/0x360
netlink_sendmsg+0x278/0x490
__sock_sendmsg+0x5c/0x6c
____sys_sendmsg+0x290/0x2d4
___sys_sendmsg+0x84/0xd0
__sys_sendmsg+0x70/0xd0
__arm64_sys_sendmsg+0x2c/0x40
invoke_syscall+0x78/0x100
el0_svc_common.constprop.0+0x54/0x184
do_el0_svc+0x30/0xac
el0_svc+0x48/0x160
el0t_64_sync_handler+0xa4/0x12c
el0t_64_sync+0x1a4/0x1a8
Code: bad PC value
---[ end trace 7d1c3f3bf9d81885 ]---
Kernel panic - not syncing: Oops: Fatal exception in interrupt
Kernel Offset: 0x2870a7a00000 from 0xffff800008000000
PHYS_OFFSET: 0x80000000
CPU features: 0x0,000005c1,a3332a5a
Memory Limit: none
---[ end Kernel panic - not syncing: Oops: Fatal exception in interrupt ]---
The exception happens because there is a pending RX interrupt before the
call to request_irq(RX IRQ) executes. Then, the RX IRQ handler fires
immediately after this request_irq() completes. The RX IRQ handler runs
"napi_schedule()" before NAPI is fully initialized via "netif_napi_add()"
and "napi_enable()", both which happen later in the open() logic.
The logic in mlxbf_gige_open() must fully initialize NAPI before any calls
to request_irq() execute.
Fixes: f92e1869d74e ("Add Mellanox BlueField Gigabit Ethernet driver")
Signed-off-by: David Thompson <davthompson@nvidia.com>
Reviewed-by: Asmaa Mnebhi <asmaa@nvidia.com>
Link: https://lore.kernel.org/r/20240325183627.7641-1-davthompson@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net')
-rw-r--r-- | drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_main.c | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_main.c b/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_main.c index cef0e2d3f1a7..77134ca92938 100644 --- a/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_main.c +++ b/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_main.c @@ -139,13 +139,10 @@ static int mlxbf_gige_open(struct net_device *netdev) control |= MLXBF_GIGE_CONTROL_PORT_EN; writeq(control, priv->base + MLXBF_GIGE_CONTROL); - err = mlxbf_gige_request_irqs(priv); - if (err) - return err; mlxbf_gige_cache_stats(priv); err = mlxbf_gige_clean_port(priv); if (err) - goto free_irqs; + return err; /* Clear driver's valid_polarity to match hardware, * since the above call to clean_port() resets the @@ -166,6 +163,10 @@ static int mlxbf_gige_open(struct net_device *netdev) napi_enable(&priv->napi); netif_start_queue(netdev); + err = mlxbf_gige_request_irqs(priv); + if (err) + goto napi_deinit; + /* Set bits in INT_EN that we care about */ int_en = MLXBF_GIGE_INT_EN_HW_ACCESS_ERROR | MLXBF_GIGE_INT_EN_TX_CHECKSUM_INPUTS | @@ -182,14 +183,17 @@ static int mlxbf_gige_open(struct net_device *netdev) return 0; +napi_deinit: + netif_stop_queue(netdev); + napi_disable(&priv->napi); + netif_napi_del(&priv->napi); + mlxbf_gige_rx_deinit(priv); + tx_deinit: mlxbf_gige_tx_deinit(priv); phy_deinit: phy_stop(phydev); - -free_irqs: - mlxbf_gige_free_irqs(priv); return err; } |