fix command completion races in the 3ware drivers

The 3w-sas driver needs to tear down the dma mappings before returning the command to the midlayer, as there is no guarantee the sglist and count are valid after that point. Also remove the dma mapping helpers which have another inherent race due to the request_id index.

Signed-off-by Christoph Hellwig <[email protected]>

Reported-by Torsten Luettgert <[email protected]>

Tested-by Bernd Kardatzki <[email protected]>

Cc [email protected]

---
 drivers/scsi/3w-sas.c | 50 ++++++++++----------------------------------------
 drivers/scsi/3w-sas.h |  4 ----
 2 files changed, 10 insertions(+), 44 deletions(-)

drivers/scsi/3w-sas.c +10 -40

index 2361772..3d4c5f9 100644
@@ -290,26 +290,6 @@ static int twl_post_command_packet(TW_Device_Extension *tw_dev, int request_id)
        return 0;
 } /* End twl_post_command_packet() */
 
-/* This function will perform a pci-dma mapping for a scatter gather list */
-static int twl_map_scsi_sg_data(TW_Device_Extension *tw_dev, int request_id)
-{
-       int use_sg;
-       struct scsi_cmnd *cmd = tw_dev->srb[request_id];
-
-       use_sg = scsi_dma_map(cmd);
-       if (!use_sg)
-               return 0;
-       else if (use_sg < 0) {
-               TW_PRINTK(tw_dev->host, TW_DRIVER, 0x1, "Failed to map scatter gather list");
-               return 0;
-       }
-
-       cmd->SCp.phase = TW_PHASE_SGLIST;
-       cmd->SCp.have_data_in = use_sg;
-
-       return use_sg;
-} /* End twl_map_scsi_sg_data() */
-
 /* This function hands scsi cdb's to the firmware */
 static int twl_scsiop_execute_scsi(TW_Device_Extension *tw_dev, int request_id, char *cdb, int use_sg, TW_SG_Entry_ISO *sglistarg)
 {

@@ -357,8 +337,8 @@ static int twl_scsiop_execute_scsi(TW_Device_Extension *tw_dev, int request_id,
        if (!sglistarg) {
                /* Map sglist from scsi layer to cmd packet */
                if (scsi_sg_count(srb)) {
-                       sg_count = twl_map_scsi_sg_data(tw_dev, request_id);
-                       if (sg_count == 0)
+                       sg_count = scsi_dma_map(srb);
+                       if (sg_count <= 0)
                                goto out;
 
                        scsi_for_each_sg(srb, sg, sg_count, i) {

@@ -1102,15 +1082,6 @@ out:
        return retval;
 } /* End twl_initialize_device_extension() */
 
-/* This function will perform a pci-dma unmap */
-static void twl_unmap_scsi_data(TW_Device_Extension *tw_dev, int request_id)
-{
-       struct scsi_cmnd *cmd = tw_dev->srb[request_id];
-
-       if (cmd->SCp.phase == TW_PHASE_SGLIST)
-               scsi_dma_unmap(cmd);
-} /* End twl_unmap_scsi_data() */
-
 /* This function will handle attention interrupts */
 static int twl_handle_attention_interrupt(TW_Device_Extension *tw_dev)
 {

@@ -1251,11 +1222,11 @@ static irqreturn_t twl_interrupt(int irq, void *dev_instance)
                        }
 
                        /* Now complete the io */
+                       scsi_dma_unmap(cmd);
+                       cmd->scsi_done(cmd);
                        tw_dev->state[request_id] = TW_S_COMPLETED;
                        twl_free_request_id(tw_dev, request_id);
                        tw_dev->posted_request_count--;
-                       tw_dev->srb[request_id]->scsi_done(tw_dev->srb[request_id]);
-                       twl_unmap_scsi_data(tw_dev, request_id);
                }
 
                /* Check for another response interrupt */

@@ -1400,10 +1371,12 @@ static int twl_reset_device_extension(TW_Device_Extension *tw_dev, int ioctl_res
                if ((tw_dev->state[i] != TW_S_FINISHED) &&
                    (tw_dev->state[i] != TW_S_INITIAL) &&
                    (tw_dev->state[i] != TW_S_COMPLETED)) {
-                       if (tw_dev->srb[i]) {
-                               tw_dev->srb[i]->result = (DID_RESET << 16);
-                               tw_dev->srb[i]->scsi_done(tw_dev->srb[i]);
-                               twl_unmap_scsi_data(tw_dev, i);
+                       struct scsi_cmnd * cmd = tw_dev->srb[i];
+
+                       if (cmd) {
+                               cmd->result = (DID_RESET << 16);
+                               scsi_dma_unmap(cmd);
+                               cmd->scsi_done(cmd);
                        }
                }
        }

@@ -1507,9 +1480,6 @@ static int twl_scsi_queue_lck(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_
        /* Save the scsi command for use by the ISR */
        tw_dev->srb[request_id] = SCpnt;
 
-       /* Initialize phase to zero */
-       SCpnt->SCp.phase = TW_PHASE_INITIAL;
-
        retval = twl_scsiop_execute_scsi(tw_dev, request_id, NULL, 0, NULL);
        if (retval) {
                tw_dev->state[request_id] = TW_S_COMPLETED;

drivers/scsi/3w-sas.h +0 -5

index d474892..fec6449 100644
@@ -103,10 +103,6 @@ static char *twl_aen_severity_table[] =
 #define TW_CURRENT_DRIVER_BUILD 0
 #define TW_CURRENT_DRIVER_BRANCH 0
 
-/* Phase defines */
-#define TW_PHASE_INITIAL 0
-#define TW_PHASE_SGLIST  2
-
 /* Misc defines */
 #define TW_SECTOR_SIZE                        512
 #define TW_MAX_UNITS                         32
--

1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html

The 3w-xxxx driver needs to tear down the dma mappings before returning the command to the midlayer, as there is no guarantee the sglist and count are valid after that point. Also remove the dma mapping helpers which have another inherent race due to the request_id index.

Signed-off-by Christoph Hellwig <[email protected]>

Cc [email protected]

---
 drivers/scsi/3w-xxxx.c | 42 ++++++------------------------------------
 drivers/scsi/3w-xxxx.h |  5 -----
 2 files changed, 6 insertions(+), 41 deletions(-)

drivers/scsi/3w-xxxx.c +6 -36

index c75f204..2940bd7 100644
@@ -1271,32 +1271,6 @@ static int tw_initialize_device_extension(TW_Device_Extension *tw_dev)
        return 0;
 } /* End tw_initialize_device_extension() */
 
-static int tw_map_scsi_sg_data(struct pci_dev *pdev, struct scsi_cmnd *cmd)
-{
-       int use_sg;
-
-       dprintk(KERN_WARNING "3w-xxxx: tw_map_scsi_sg_data()\n");
-
-       use_sg = scsi_dma_map(cmd);
-       if (use_sg < 0) {
-               printk(KERN_WARNING "3w-xxxx: tw_map_scsi_sg_data(): pci_map_sg() failed.\n");
-               return 0;
-       }
-
-       cmd->SCp.phase = TW_PHASE_SGLIST;
-       cmd->SCp.have_data_in = use_sg;
-
-       return use_sg;
-} /* End tw_map_scsi_sg_data() */
-
-static void tw_unmap_scsi_data(struct pci_dev *pdev, struct scsi_cmnd *cmd)
-{
-       dprintk(KERN_WARNING "3w-xxxx: tw_unmap_scsi_data()\n");
-
-       if (cmd->SCp.phase == TW_PHASE_SGLIST)
-               scsi_dma_unmap(cmd);
-} /* End tw_unmap_scsi_data() */
-
 /* This function will reset a device extension */
 static int tw_reset_device_extension(TW_Device_Extension *tw_dev)
 {

@@ -1319,8 +1293,8 @@ static int tw_reset_device_extension(TW_Device_Extension *tw_dev)
                        srb = tw_dev->srb[i];
                        if (srb != NULL) {
                                srb->result = (DID_RESET << 16);
-                               tw_dev->srb[i]->scsi_done(tw_dev->srb[i]);
-                               tw_unmap_scsi_data(tw_dev->tw_pci_dev, tw_dev->srb[i]);
+                               scsi_dma_unmap(srb);
+                               srb->scsi_done(srb);
                        }
                }
        }

@@ -1767,8 +1741,8 @@ static int tw_scsiop_read_write(TW_Device_Extension *tw_dev, int request_id)
        command_packet->byte8.io.lba = lba;
        command_packet->byte6.block_count = num_sectors;
 
-       use_sg = tw_map_scsi_sg_data(tw_dev->tw_pci_dev, tw_dev->srb[request_id]);
-       if (!use_sg)
+       use_sg = scsi_dma_map(srb);
+       if (use_sg <= 0)
                return 1;
 
        scsi_for_each_sg(tw_dev->srb[request_id], sg, use_sg, i) {

@@ -1955,9 +1929,6 @@ static int tw_scsi_queue_lck(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_c
        /* Save the scsi command for use by the ISR */
        tw_dev->srb[request_id] = SCpnt;
 
-       /* Initialize phase to zero */
-       SCpnt->SCp.phase = TW_PHASE_INITIAL;
-
        switch (*command) {
                case READ_10:
                case READ_6:

@@ -2185,12 +2156,11 @@ static irqreturn_t tw_interrupt(int irq, void *dev_instance)
 
                                /* Now complete the io */
                                if ((error != TW_ISR_DONT_COMPLETE)) {
+                                       scsi_dma_unmap(tw_dev->srb[request_id]);
+                                       tw_dev->srb[request_id]->scsi_done(tw_dev->srb[request_id]);
                                        tw_dev->state[request_id] = TW_S_COMPLETED;
                                        tw_state_request_finish(tw_dev, request_id);
                                        tw_dev->posted_request_count--;
-                                       tw_dev->srb[request_id]->scsi_done(tw_dev->srb[request_id]);
-
-                                       tw_unmap_scsi_data(tw_dev->tw_pci_dev, tw_dev->srb[request_id]);
                                }
                        }
 

drivers/scsi/3w-xxxx.h +0 -6

index 29b0b84e..6f65e66 100644
@@ -195,11 +195,6 @@ static unsigned char tw_sense_table[][4] =
 #define TW_AEN_SMART_FAIL        0x000F
 #define TW_AEN_SBUF_FAIL         0x0024
 
-/* Phase defines */
-#define TW_PHASE_INITIAL 0
-#define TW_PHASE_SINGLE 1
-#define TW_PHASE_SGLIST 2
-
 /* Misc defines */
 #define TW_ALIGNMENT_6000                    64 /* 64 bytes */
 #define TW_ALIGNMENT_7000                     4  /* 4 bytes */
--

1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html

The 3w-9xxx driver needs to tear down the dma mappings before returning the command to the midlayer, as there is no guarantee the sglist and count are valid after that point. Also remove the dma mapping helpers which have another inherent race due to the request_id index.

Signed-off-by Christoph Hellwig <[email protected]>

Cc [email protected]

---
 drivers/scsi/3w-9xxx.c | 57 ++++++++++++--------------------------------------
 drivers/scsi/3w-9xxx.h |  5 -----
 2 files changed, 13 insertions(+), 49 deletions(-)

drivers/scsi/3w-9xxx.c +13 -44

index 7600639..c3224b6 100644
@@ -149,7 +149,6 @@ static int twa_reset_sequence(TW_Device_Extension *tw_dev, int soft_reset);
 static int twa_scsiop_execute_scsi(TW_Device_Extension *tw_dev, int request_id, char *cdb, int use_sg, TW_SG_Entry *sglistarg);
 static void twa_scsiop_execute_scsi_complete(TW_Device_Extension *tw_dev, int request_id);
 static char *twa_string_lookup(twa_message_type *table, unsigned int aen_code);
-static void twa_unmap_scsi_data(TW_Device_Extension *tw_dev, int request_id);
 
 /* Functions */
 

@@ -1340,11 +1339,11 @@ static irqreturn_t twa_interrupt(int irq, void *dev_instance)
                                }
 
                                /* Now complete the io */
+                               scsi_dma_unmap(cmd);
+                               cmd->scsi_done(cmd);
                                tw_dev->state[request_id] = TW_S_COMPLETED;
                                twa_free_request_id(tw_dev, request_id);
                                tw_dev->posted_request_count--;
-                               tw_dev->srb[request_id]->scsi_done(tw_dev->srb[request_id]);
-                               twa_unmap_scsi_data(tw_dev, request_id);
                        }
 
                        /* Check for valid status after each drain */

@@ -1402,26 +1401,6 @@ static void twa_load_sgl(TW_Device_Extension *tw_dev, TW_Command_Full *full_comm
        }
 } /* End twa_load_sgl() */
 
-/* This function will perform a pci-dma mapping for a scatter gather list */
-static int twa_map_scsi_sg_data(TW_Device_Extension *tw_dev, int request_id)
-{
-       int use_sg;
-       struct scsi_cmnd *cmd = tw_dev->srb[request_id];
-
-       use_sg = scsi_dma_map(cmd);
-       if (!use_sg)
-               return 0;
-       else if (use_sg < 0) {
-               TW_PRINTK(tw_dev->host, TW_DRIVER, 0x1c, "Failed to map scatter gather list");
-               return 0;
-       }
-
-       cmd->SCp.phase = TW_PHASE_SGLIST;
-       cmd->SCp.have_data_in = use_sg;
-
-       return use_sg;
-} /* End twa_map_scsi_sg_data() */
-
 /* This function will poll for a response interrupt of a request */
 static int twa_poll_response(TW_Device_Extension *tw_dev, int request_id, int seconds)
 {

@@ -1600,9 +1579,11 @@ static int twa_reset_device_extension(TW_Device_Extension *tw_dev)
                    (tw_dev->state[i] != TW_S_INITIAL) &&
                    (tw_dev->state[i] != TW_S_COMPLETED)) {
                        if (tw_dev->srb[i]) {
-                               tw_dev->srb[i]->result = (DID_RESET << 16);
-                               tw_dev->srb[i]->scsi_done(tw_dev->srb[i]);
-                               twa_unmap_scsi_data(tw_dev, i);
+                               struct scsi_cmnd * cmd = tw_dev->srb[i];
+
+                               cmd->result = (DID_RESET << 16);
+                               scsi_dma_unmap(cmd);
+                               cmd->scsi_done(cmd);
                        }
                }
        }

@@ -1781,21 +1762,18 @@ static int twa_scsi_queue_lck(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_
        /* Save the scsi command for use by the ISR */
        tw_dev->srb[request_id] = SCpnt;
 
-       /* Initialize phase to zero */
-       SCpnt->SCp.phase = TW_PHASE_INITIAL;
-
        retval = twa_scsiop_execute_scsi(tw_dev, request_id, NULL, 0, NULL);
        switch (retval) {
        case SCSI_MLQUEUE_HOST_BUSY:
+               scsi_dma_unmap(SCpnt);
                twa_free_request_id(tw_dev, request_id);
-               twa_unmap_scsi_data(tw_dev, request_id);
                break;
        case 1:
-               tw_dev->state[request_id] = TW_S_COMPLETED;
-               twa_free_request_id(tw_dev, request_id);
-               twa_unmap_scsi_data(tw_dev, request_id);
                SCpnt->result = (DID_ERROR << 16);
+               scsi_dma_unmap(SCpnt);
                done(SCpnt);
+               tw_dev->state[request_id] = TW_S_COMPLETED;
+               twa_free_request_id(tw_dev, request_id);
                retval = 0;
        }
 out:

@@ -1863,8 +1841,8 @@ static int twa_scsiop_execute_scsi(TW_Device_Extension *tw_dev, int request_id,
                                command_packet->sg_list[0].address = TW_CPU_TO_SGL(tw_dev->generic_buffer_phys[request_id]);
                                command_packet->sg_list[0].length = cpu_to_le32(TW_MIN_SGL_LENGTH);
                        } else {
-                               sg_count = twa_map_scsi_sg_data(tw_dev, request_id);
-                               if (sg_count == 0)
+                               sg_count = scsi_dma_map(srb);
+                               if (sg_count < 0)
                                        goto out;
 
                                scsi_for_each_sg(srb, sg, sg_count, i) {

@@ -1979,15 +1957,6 @@ static char *twa_string_lookup(twa_message_type *table, unsigned int code)
        return(table[index].text);
 } /* End twa_string_lookup() */
 
-/* This function will perform a pci-dma unmap */
-static void twa_unmap_scsi_data(TW_Device_Extension *tw_dev, int request_id)
-{
-       struct scsi_cmnd *cmd = tw_dev->srb[request_id];
-
-       if (cmd->SCp.phase == TW_PHASE_SGLIST)
-               scsi_dma_unmap(cmd);
-} /* End twa_unmap_scsi_data() */
-
 /* This function gets called when a disk is coming on-line */
 static int twa_slave_configure(struct scsi_device *sdev)
 {

drivers/scsi/3w-9xxx.h +0 -6

index 040f721..0fdc83c 100644
@@ -324,11 +324,6 @@ static twa_message_type twa_error_table[] = {
 #define TW_CURRENT_DRIVER_BUILD 0
 #define TW_CURRENT_DRIVER_BRANCH 0
 
-/* Phase defines */
-#define TW_PHASE_INITIAL 0
-#define TW_PHASE_SINGLE  1
-#define TW_PHASE_SGLIST  2
-
 /* Misc defines */
 #define TW_9550SX_DRAIN_COMPLETED            0xFFFF
 #define TW_SECTOR_SIZE                        512
--

1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html