diff options
| author | Bart Van Assche <bvanassche@acm.org> | 2021-03-16 20:26:48 -0700 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2021-03-18 22:39:30 -0400 |
| commit | 035e9f471691a16c32b389c8b2f236043a2a50d7 (patch) | |
| tree | b805f7c2fb51aad0c3e280c082f054732a69bda2 /include/linux/sbitmap.h | |
| parent | b1ebd3b0e4664c4aa8362bd8abb61861dff61849 (diff) | |
scsi: sbitmap: Silence a debug kernel warning triggered by sbitmap_put()
All sbitmap code uses implied preemption protection to update
sb->alloc_hint except sbitmap_put(). Using implied preemption protection is
safe since the value of sb->alloc_hint only affects performance of sbitmap
allocations but not their correctness. Change this_cpu_ptr() in
sbitmap_put() into raw_cpu_ptr() to suppress the following kernel warning
that appears with preemption debugging enabled (CONFIG_DEBUG_PREEMPT):
BUG: using smp_processor_id() in preemptible [00000000] code: scsi_eh_0/152
caller is debug_smp_processor_id+0x17/0x20
CPU: 1 PID: 152 Comm: scsi_eh_0 Tainted: G W 5.12.0-rc1-dbg+ #6
Call Trace:
show_stack+0x52/0x58
dump_stack+0xaf/0xf3
check_preemption_disabled+0xce/0xd0
debug_smp_processor_id+0x17/0x20
scsi_device_unbusy+0x13a/0x1c0 [scsi_mod]
scsi_finish_command+0x4d/0x290 [scsi_mod]
scsi_eh_flush_done_q+0x1e7/0x280 [scsi_mod]
ata_scsi_port_error_handler+0x592/0x750 [libata]
ata_scsi_error+0x1a0/0x1f0 [libata]
scsi_error_handler+0x19e/0x330 [scsi_mod]
kthread+0x222/0x250
ret_from_fork+0x1f/0x30
Link: https://lore.kernel.org/r/20210317032648.9080-1-bvanassche@acm.org
Fixes: c548e62bcf6a ("scsi: sbitmap: Move allocation hint into sbitmap")
Cc: Hannes Reinecke <hare@suse.de>
Cc: Omar Sandoval <osandov@fb.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'include/linux/sbitmap.h')
| -rw-r--r-- | include/linux/sbitmap.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/sbitmap.h b/include/linux/sbitmap.h index 3087e1f15fdd..2713e689ad66 100644 --- a/include/linux/sbitmap.h +++ b/include/linux/sbitmap.h @@ -324,7 +324,7 @@ static inline void sbitmap_put(struct sbitmap *sb, unsigned int bitnr) sbitmap_deferred_clear_bit(sb, bitnr); if (likely(sb->alloc_hint && !sb->round_robin && bitnr < sb->depth)) - *this_cpu_ptr(sb->alloc_hint) = bitnr; + *raw_cpu_ptr(sb->alloc_hint) = bitnr; } static inline int sbitmap_test_bit(struct sbitmap *sb, unsigned int bitnr) |