On Mon, Dec 04, 2017 at 04:38:08PM -0800, Bart Van Assche wrote: > Since the next patch will make it possible that scsi_show_rq() gets > called before the CDB pointer is changed into a non-NULL value, > only show the CDB if the CDB pointer is not NULL. Additionally, > show the request timeout and SCSI command flags. This patch also > fixes a bug that was reported by Ming Lei. See also Ming Lei, > scsi_debugfs: fix crash in scsi_show_rq(), linux-scsi, 7 November > 2017 (https://marc.info/?l=linux-block&m=151006655317188). Please cook a patch for fixing the crash issue only, since we need to backport the fix to stable kernel. > > Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxx> > Cc: James E.J. Bottomley <jejb@xxxxxxxxxxxxxxxxxx> > Cc: Martin K. Petersen <martin.petersen@xxxxxxxxxx> > Cc: Ming Lei <ming.lei@xxxxxxxxxx> > Cc: Christoph Hellwig <hch@xxxxxx> > Cc: Hannes Reinecke <hare@xxxxxxxx> > Cc: Johannes Thumshirn <jthumshirn@xxxxxxx> Please Cc: <stable@xxxxxxxxxxxxxxx> > --- > drivers/scsi/scsi_debugfs.c | 47 ++++++++++++++++++++++++++++++++++++++++----- > 1 file changed, 42 insertions(+), 5 deletions(-) > > diff --git a/drivers/scsi/scsi_debugfs.c b/drivers/scsi/scsi_debugfs.c > index 01f08c03f2c1..37ed6bb8e6ec 100644 > --- a/drivers/scsi/scsi_debugfs.c > +++ b/drivers/scsi/scsi_debugfs.c > @@ -4,13 +4,50 @@ > #include <scsi/scsi_dbg.h> > #include "scsi_debugfs.h" > > +#define SCSI_CMD_FLAG_NAME(name) [ilog2(SCMD_##name)] = #name > +static const char *const scsi_cmd_flags[] = { > + SCSI_CMD_FLAG_NAME(TAGGED), > + SCSI_CMD_FLAG_NAME(UNCHECKED_ISA_DMA), > + SCSI_CMD_FLAG_NAME(ZONE_WRITE_LOCK), > + SCSI_CMD_FLAG_NAME(INITIALIZED), > +}; > +#undef SCSI_CMD_FLAG_NAME > + > +static int scsi_flags_show(struct seq_file *m, const unsigned long flags, > + const char *const *flag_name, int flag_name_count) > +{ > + bool sep = false; > + int i; > + > + for (i = 0; i < sizeof(flags) * BITS_PER_BYTE; i++) { > + if (!(flags & BIT(i))) > + continue; > + if (sep) > + seq_puts(m, "|"); > + sep = true; > + if (i < flag_name_count && flag_name[i]) > + seq_puts(m, flag_name[i]); > + else > + seq_printf(m, "%d", i); > + } > + return 0; > +} > + > void scsi_show_rq(struct seq_file *m, struct request *rq) > { > struct scsi_cmnd *cmd = container_of(scsi_req(rq), typeof(*cmd), req); > - int msecs = jiffies_to_msecs(jiffies - cmd->jiffies_at_alloc); > - char buf[80]; > + int alloc_ms = jiffies_to_msecs(jiffies - cmd->jiffies_at_alloc); > + int timeout_ms = jiffies_to_msecs(rq->timeout); > + const u8 *const cdb = READ_ONCE(cmd->cmnd); > + char buf[80] = "(?)"; > > - __scsi_format_command(buf, sizeof(buf), cmd->cmnd, cmd->cmd_len); > - seq_printf(m, ", .cmd=%s, .retries=%d, allocated %d.%03d s ago", buf, > - cmd->retries, msecs / 1000, msecs % 1000); > + if (cdb) > + __scsi_format_command(buf, sizeof(buf), cdb, cmd->cmd_len); > + seq_printf(m, ", .cmd=%s, .retries=%d, .result = %#x, .flags=", buf, > + cmd->retries, cmd->result); > + scsi_flags_show(m, cmd->flags, scsi_cmd_flags, > + ARRAY_SIZE(scsi_cmd_flags)); > + seq_printf(m, ", .timeout=%d.%03d, allocated %d.%03d s ago", > + timeout_ms / 1000, timeout_ms % 1000, > + alloc_ms / 1000, alloc_ms % 1000); > } > -- > 2.15.0 > -- Ming
