Re: [Bug 7994] New: sleeping function called from invalid context at mm/slab.c:3034

[Douglas Gilbert <dougg@torque.net>]

Andrew Morton wrote:
> On Fri, 16 Feb 2007 22:59:31 -0500 Douglas Gilbert <dougg@torque.net> wrote:
> 
>> The patch that I sent, shown at the end of this post,
>> is incomplete as it doesn't check the return value
>> from kzalloc(..., GFP_ATOMIC).
> 
> The diff which is in mainline now looks to be OK?

Yes.

Doug Gilbert


> --- linux-2.6.20/drivers/scsi/scsi_debug.c	2006-11-29 19:14:18.000000000 -0800
> +++ devel/drivers/scsi/scsi_debug.c	2007-02-16 21:21:08.000000000 -0800
> @@ -28,7 +28,6 @@
>  #include <linux/module.h>
>  
>  #include <linux/kernel.h>
> -#include <linux/sched.h>
>  #include <linux/errno.h>
>  #include <linux/timer.h>
>  #include <linux/types.h>
> @@ -51,10 +50,10 @@
>  #include "scsi_logging.h"
>  #include "scsi_debug.h"
>  
> -#define SCSI_DEBUG_VERSION "1.80"
> -static const char * scsi_debug_version_date = "20061018";
> +#define SCSI_DEBUG_VERSION "1.81"
> +static const char * scsi_debug_version_date = "20070104";
>  
> -/* Additional Sense Code (ASC) used */
> +/* Additional Sense Code (ASC) */
>  #define NO_ADDITIONAL_SENSE 0x0
>  #define LOGICAL_UNIT_NOT_READY 0x4
>  #define UNRECOVERED_READ_ERR 0x11
> @@ -65,9 +64,13 @@ static const char * scsi_debug_version_d
>  #define INVALID_FIELD_IN_PARAM_LIST 0x26
>  #define POWERON_RESET 0x29
>  #define SAVING_PARAMS_UNSUP 0x39
> +#define TRANSPORT_PROBLEM 0x4b
>  #define THRESHOLD_EXCEEDED 0x5d
>  #define LOW_POWER_COND_ON 0x5e
>  
> +/* Additional Sense Code Qualifier (ASCQ) */
> +#define ACK_NAK_TO 0x3
> +
>  #define SDEBUG_TAGGED_QUEUING 0 /* 0 | MSG_SIMPLE_TAG | MSG_ORDERED_TAG */
>  
>  /* Default values for driver parameters */
> @@ -95,15 +98,20 @@ static const char * scsi_debug_version_d
>  #define SCSI_DEBUG_OPT_MEDIUM_ERR   2
>  #define SCSI_DEBUG_OPT_TIMEOUT   4
>  #define SCSI_DEBUG_OPT_RECOVERED_ERR   8
> +#define SCSI_DEBUG_OPT_TRANSPORT_ERR   16
>  /* When "every_nth" > 0 then modulo "every_nth" commands:
>   *   - a no response is simulated if SCSI_DEBUG_OPT_TIMEOUT is set
>   *   - a RECOVERED_ERROR is simulated on successful read and write
>   *     commands if SCSI_DEBUG_OPT_RECOVERED_ERR is set.
> + *   - a TRANSPORT_ERROR is simulated on successful read and write
> + *     commands if SCSI_DEBUG_OPT_TRANSPORT_ERR is set.
>   *
>   * When "every_nth" < 0 then after "- every_nth" commands:
>   *   - a no response is simulated if SCSI_DEBUG_OPT_TIMEOUT is set
>   *   - a RECOVERED_ERROR is simulated on successful read and write
>   *     commands if SCSI_DEBUG_OPT_RECOVERED_ERR is set.
> + *   - a TRANSPORT_ERROR is simulated on successful read and write
> + *     commands if SCSI_DEBUG_OPT_TRANSPORT_ERR is set.
>   * This will continue until some other action occurs (e.g. the user
>   * writing a new value (other than -1 or 1) to every_nth via sysfs).
>   */
> @@ -315,6 +323,7 @@ int scsi_debug_queuecommand(struct scsi_
>  	int target = SCpnt->device->id;
>  	struct sdebug_dev_info * devip = NULL;
>  	int inj_recovered = 0;
> +	int inj_transport = 0;
>  	int delay_override = 0;
>  
>  	if (done == NULL)
> @@ -352,6 +361,8 @@ int scsi_debug_queuecommand(struct scsi_
>  			return 0; /* ignore command causing timeout */
>  		else if (SCSI_DEBUG_OPT_RECOVERED_ERR & scsi_debug_opts)
>  			inj_recovered = 1; /* to reads and writes below */
> +		else if (SCSI_DEBUG_OPT_TRANSPORT_ERR & scsi_debug_opts)
> +			inj_transport = 1; /* to reads and writes below */
>          }
>  
>  	if (devip->wlun) {
> @@ -468,7 +479,11 @@ int scsi_debug_queuecommand(struct scsi_
>  			mk_sense_buffer(devip, RECOVERED_ERROR,
>  					THRESHOLD_EXCEEDED, 0);
>  			errsts = check_condition_result;
> -		}
> +		} else if (inj_transport && (0 == errsts)) {
> +                        mk_sense_buffer(devip, ABORTED_COMMAND,
> +                                        TRANSPORT_PROBLEM, ACK_NAK_TO);
> +                        errsts = check_condition_result;
> +                }
>  		break;
>  	case REPORT_LUNS:	/* mandatory, ignore unit attention */
>  		delay_override = 1;
> @@ -531,6 +546,9 @@ int scsi_debug_queuecommand(struct scsi_
>  		delay_override = 1;
>  		errsts = check_readiness(SCpnt, 0, devip);
>  		break;
> +	case WRITE_BUFFER:
> +		errsts = check_readiness(SCpnt, 1, devip);
> +		break;
>  	default:
>  		if (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts)
>  			printk(KERN_INFO "scsi_debug: Opcode: 0x%x not "
> @@ -954,7 +972,9 @@ static int resp_inquiry(struct scsi_cmnd
>  	int alloc_len, n, ret;
>  
>  	alloc_len = (cmd[3] << 8) + cmd[4];
> -	arr = kzalloc(SDEBUG_MAX_INQ_ARR_SZ, GFP_KERNEL);
> +	arr = kzalloc(SDEBUG_MAX_INQ_ARR_SZ, GFP_ATOMIC);
> +	if (! arr)
> +		return DID_REQUEUE << 16;
>  	if (devip->wlun)
>  		pq_pdt = 0x1e;	/* present, wlun */
>  	else if (scsi_debug_no_lun_0 && (0 == devip->lun))
> @@ -1217,7 +1237,9 @@ static int resp_report_tgtpgs(struct scs
>  	alen = ((cmd[6] << 24) + (cmd[7] << 16) + (cmd[8] << 8)
>  		+ cmd[9]);
>  
> -	arr = kzalloc(SDEBUG_MAX_TGTPGS_ARR_SZ, GFP_KERNEL);
> +	arr = kzalloc(SDEBUG_MAX_TGTPGS_ARR_SZ, GFP_ATOMIC);
> +	if (! arr)
> +		return DID_REQUEUE << 16;
>  	/*
>  	 * EVPD page 0x88 states we have two ports, one
>  	 * real and a fake port with no device connected.
> @@ -1996,6 +2018,8 @@ static int scsi_debug_slave_configure(st
>  	if (sdp->host->max_cmd_len != SCSI_DEBUG_MAX_CMD_LEN)
>  		sdp->host->max_cmd_len = SCSI_DEBUG_MAX_CMD_LEN;
>  	devip = devInfoReg(sdp);
> +	if (NULL == devip)
> +		return 1;	/* no resources, will be marked offline */
>  	sdp->hostdata = devip;
>  	if (sdp->host->cmd_per_lun)
>  		scsi_adjust_queue_depth(sdp, SDEBUG_TAGGED_QUEUING,
> @@ -2044,7 +2068,7 @@ static struct sdebug_dev_info * devInfoR
>  		}
>  	}
>  	if (NULL == open_devip) { /* try and make a new one */
> -		open_devip = kzalloc(sizeof(*open_devip),GFP_KERNEL);
> +		open_devip = kzalloc(sizeof(*open_devip),GFP_ATOMIC);
>  		if (NULL == open_devip) {
>  			printk(KERN_ERR "%s: out of memory at line %d\n",
>  				__FUNCTION__, __LINE__);
> @@ -2388,7 +2412,7 @@ MODULE_PARM_DESC(max_luns, "number of LU
>  MODULE_PARM_DESC(no_lun_0, "no LU number 0 (def=0 -> have lun 0)");
>  MODULE_PARM_DESC(num_parts, "number of partitions(def=0)");
>  MODULE_PARM_DESC(num_tgts, "number of targets per host to simulate(def=1)");
> -MODULE_PARM_DESC(opts, "1->noise, 2->medium_error, 4->... (def=0)");
> +MODULE_PARM_DESC(opts, "1->noise, 2->medium_err, 4->timeout, 8->recovered_err... (def=0)");
>  MODULE_PARM_DESC(ptype, "SCSI peripheral type(def=0[disk])");
>  MODULE_PARM_DESC(scsi_level, "SCSI level to simulate(def=5[SPC-3])");
>  MODULE_PARM_DESC(virtual_gb, "virtual gigabyte size (def=0 -> use dev_size_mb)");
> @@ -2943,7 +2967,6 @@ static int sdebug_add_adapter(void)
>          struct list_head *lh, *lh_sf;
>  
>          sdbg_host = kzalloc(sizeof(*sdbg_host),GFP_KERNEL);
> -
>          if (NULL == sdbg_host) {
>                  printk(KERN_ERR "%s: out of memory at line %d\n",
>                         __FUNCTION__, __LINE__);
>