diff options
| author | Mike Marciniszyn <mike.marciniszyn@cornelisnetworks.com> | 2021-11-29 14:19:58 -0500 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@nvidia.com> | 2021-12-07 13:22:54 -0400 |
| commit | b6d57e24ce6cc3df8a8845e1b193e88a65d501b1 (patch) | |
| tree | 22a47921d1c101e6afea67689bb94fa8f084f8de /drivers/infiniband | |
| parent | 9292f8f9a2ac42eb320bced7153aa2e63d8cc13a (diff) | |
IB/hfi1: Insure use of smp_processor_id() is preempt disabled
The following BUG has just surfaced with our 5.16 testing:
BUG: using smp_processor_id() in preemptible [00000000] code: mpicheck/1581081
caller is sdma_select_user_engine+0x72/0x210 [hfi1]
CPU: 0 PID: 1581081 Comm: mpicheck Tainted: G S 5.16.0-rc1+ #1
Hardware name: Intel Corporation S2600WT2R/S2600WT2R, BIOS SE5C610.86B.01.01.0016.033120161139 03/31/2016
Call Trace:
<TASK>
dump_stack_lvl+0x33/0x42
check_preemption_disabled+0xbf/0xe0
sdma_select_user_engine+0x72/0x210 [hfi1]
? _raw_spin_unlock_irqrestore+0x1f/0x31
? hfi1_mmu_rb_insert+0x6b/0x200 [hfi1]
hfi1_user_sdma_process_request+0xa02/0x1120 [hfi1]
? hfi1_write_iter+0xb8/0x200 [hfi1]
hfi1_write_iter+0xb8/0x200 [hfi1]
do_iter_readv_writev+0x163/0x1c0
do_iter_write+0x80/0x1c0
vfs_writev+0x88/0x1a0
? recalibrate_cpu_khz+0x10/0x10
? ktime_get+0x3e/0xa0
? __fget_files+0x66/0xa0
do_writev+0x65/0x100
do_syscall_64+0x3a/0x80
Fix this long standing bug by moving the smp_processor_id() to after the
rcu_read_lock().
The rcu_read_lock() implicitly disables preemption.
Link: https://lore.kernel.org/r/20211129191958.101968.87329.stgit@awfm-01.cornelisnetworks.com
Cc: stable@vger.kernel.org
Fixes: 0cb2aa690c7e ("IB/hfi1: Add sysfs interface for affinity setup")
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@cornelisnetworks.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Diffstat (limited to 'drivers/infiniband')
| -rw-r--r-- | drivers/infiniband/hw/hfi1/sdma.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/infiniband/hw/hfi1/sdma.c b/drivers/infiniband/hw/hfi1/sdma.c index 2b6c24b7b586..f07d328689d3 100644 --- a/drivers/infiniband/hw/hfi1/sdma.c +++ b/drivers/infiniband/hw/hfi1/sdma.c @@ -838,8 +838,8 @@ struct sdma_engine *sdma_select_user_engine(struct hfi1_devdata *dd, if (current->nr_cpus_allowed != 1) goto out; - cpu_id = smp_processor_id(); rcu_read_lock(); + cpu_id = smp_processor_id(); rht_node = rhashtable_lookup(dd->sdma_rht, &cpu_id, sdma_rht_params); |