5.15-stable review patch. If anyone has any objections, please let me know.
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From: Francisco Gutierrez frankramirez@google.com
[ Upstream commit d6477ee38ccfbeaed885733c13f41d9076e2f94a ]
Eliminate the use of static variables within the log pull implementation to resolve a race condition and prevent data gaps when pulling logs from multiple controllers in parallel, ensuring each operation is properly isolated.
Signed-off-by: Francisco Gutierrez frankramirez@google.com Link: https://lore.kernel.org/r/20250723183543.1443301-1-frankramirez@google.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/pm8001/pm8001_ctl.c | 22 ++++++++++++---------- drivers/scsi/pm8001/pm8001_init.c | 1 + drivers/scsi/pm8001/pm8001_sas.h | 4 ++++ 3 files changed, 17 insertions(+), 10 deletions(-)
diff --git a/drivers/scsi/pm8001/pm8001_ctl.c b/drivers/scsi/pm8001/pm8001_ctl.c index ec05c42e8ee6c..e2ff42e16f94b 100644 --- a/drivers/scsi/pm8001/pm8001_ctl.c +++ b/drivers/scsi/pm8001/pm8001_ctl.c @@ -536,23 +536,25 @@ static ssize_t pm8001_ctl_iop_log_show(struct device *cdev, char *str = buf; u32 read_size = pm8001_ha->main_cfg_tbl.pm80xx_tbl.event_log_size / 1024; - static u32 start, end, count; u32 max_read_times = 32; u32 max_count = (read_size * 1024) / (max_read_times * 4); u32 *temp = (u32 *)pm8001_ha->memoryMap.region[IOP].virt_ptr;
- if ((count % max_count) == 0) { - start = 0; - end = max_read_times; - count = 0; + mutex_lock(&pm8001_ha->iop_log_lock); + + if ((pm8001_ha->iop_log_count % max_count) == 0) { + pm8001_ha->iop_log_start = 0; + pm8001_ha->iop_log_end = max_read_times; + pm8001_ha->iop_log_count = 0; } else { - start = end; - end = end + max_read_times; + pm8001_ha->iop_log_start = pm8001_ha->iop_log_end; + pm8001_ha->iop_log_end = pm8001_ha->iop_log_end + max_read_times; }
- for (; start < end; start++) - str += sprintf(str, "%08x ", *(temp+start)); - count++; + for (; pm8001_ha->iop_log_start < pm8001_ha->iop_log_end; pm8001_ha->iop_log_start++) + str += sprintf(str, "%08x ", *(temp+pm8001_ha->iop_log_start)); + pm8001_ha->iop_log_count++; + mutex_unlock(&pm8001_ha->iop_log_lock); return str - buf; } static DEVICE_ATTR(iop_log, S_IRUGO, pm8001_ctl_iop_log_show, NULL); diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c index 0659ee9aafce7..f1a6922bed5d5 100644 --- a/drivers/scsi/pm8001/pm8001_init.c +++ b/drivers/scsi/pm8001/pm8001_init.c @@ -510,6 +510,7 @@ static struct pm8001_hba_info *pm8001_pci_alloc(struct pci_dev *pdev, pm8001_ha->id = pm8001_id++; pm8001_ha->logging_level = logging_level; pm8001_ha->non_fatal_count = 0; + mutex_init(&pm8001_ha->iop_log_lock); if (link_rate >= 1 && link_rate <= 15) pm8001_ha->link_rate = (link_rate << 8); else { diff --git a/drivers/scsi/pm8001/pm8001_sas.h b/drivers/scsi/pm8001/pm8001_sas.h index 75864b47921aa..afa81a362a11c 100644 --- a/drivers/scsi/pm8001/pm8001_sas.h +++ b/drivers/scsi/pm8001/pm8001_sas.h @@ -538,6 +538,10 @@ struct pm8001_hba_info { u32 ci_offset; u32 pi_offset; u32 max_memcnt; + u32 iop_log_start; + u32 iop_log_end; + u32 iop_log_count; + struct mutex iop_log_lock; };
struct pm8001_work {