@@ -592,9 +592,10 @@ static void ipr_trc_hook(struct ipr_cmnd *ipr_cmd,
{
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;
@@ -1479,6 +1479,7 @@ 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"
This is a note to let you know that I have just added a patch titled ipr: Fix incorrect trace indexing to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue This patch is scheduled to be released in version 3.19.8-ckt6. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.19.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From 8c2052285e6bdc596da7ece45cf803a6db81ae9c Mon Sep 17 00:00:00 2001 From: Brian King <brking@linux.vnet.ibm.com> Date: Tue, 14 Jul 2015 11:41:31 -0500 Subject: ipr: Fix incorrect trace indexing 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 <wenxiong@linux.vnet.ibm.com> Reviewed-by: Wen Xiong <wenxiong@linux.vnet.ibm.com> Reviewed-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com> Signed-off-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: James Bottomley <JBottomley@Odin.com> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- drivers/scsi/ipr.c | 5 +++-- drivers/scsi/ipr.h | 1 + 2 files changed, 4 insertions(+), 2 deletions(-) -- 1.9.1