3.10-stable review patch. If anyone has any objections, please let me know.
------------------ From: Brian King <[email protected]> commit bb7c54339e6a10ecce5c4961adf5e75b3cf0af30 upstream. When ipr's internal driver trace was changed to an atomic, a signed/unsigned bug slipped in which results in us indexing backwards in our memory buffer writing on memory that does not belong to us. This patch fixes this by removing the modulo and instead just mask off the low bits. Tested-by: Wen Xiong <[email protected]> Reviewed-by: Wen Xiong <[email protected]> Reviewed-by: Gabriel Krisman Bertazi <[email protected]> Signed-off-by: Brian King <[email protected]> Reviewed-by: Martin K. Petersen <[email protected]> Signed-off-by: James Bottomley <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/scsi/ipr.c | 5 +++-- drivers/scsi/ipr.h | 1 + 2 files changed, 4 insertions(+), 2 deletions(-) --- a/drivers/scsi/ipr.c +++ b/drivers/scsi/ipr.c @@ -554,9 +554,10 @@ static void ipr_trc_hook(struct ipr_cmnd { struct ipr_trace_entry *trace_entry; struct ipr_ioa_cfg *ioa_cfg = ipr_cmd->ioa_cfg; + unsigned int trace_index; - trace_entry = &ioa_cfg->trace[atomic_add_return - (1, &ioa_cfg->trace_index)%IPR_NUM_TRACE_ENTRIES]; + trace_index = atomic_add_return(1, &ioa_cfg->trace_index) & IPR_TRACE_INDEX_MASK; + trace_entry = &ioa_cfg->trace[trace_index]; trace_entry->time = jiffies; trace_entry->op_code = ipr_cmd->ioarcb.cmd_pkt.cdb[0]; trace_entry->type = type; --- a/drivers/scsi/ipr.h +++ b/drivers/scsi/ipr.h @@ -1452,6 +1452,7 @@ struct ipr_ioa_cfg { #define IPR_NUM_TRACE_INDEX_BITS 8 #define IPR_NUM_TRACE_ENTRIES (1 << IPR_NUM_TRACE_INDEX_BITS) +#define IPR_TRACE_INDEX_MASK (IPR_NUM_TRACE_ENTRIES - 1) #define IPR_TRACE_SIZE (sizeof(struct ipr_trace_entry) * IPR_NUM_TRACE_ENTRIES) char trace_start[8]; #define IPR_TRACE_START_LABEL "trace" -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
