scsi: scsi_debug: Fix a recently introduced regression

A recent commit removed an element from opcode_info_arr[] but did not
modify opcode_ind_arr[] nor was SDEB_I_XDWRITEREAD removed. Remove
SDEB_I_XDWRITEREAD and bring the two arrays again in sync. This patch
avoids that the following is reported:

BUG: KASAN: null-ptr-deref in scsi_debug_queuecommand+0x60f/0xc90 [scsi_debug]
Read of size 1 at addr 0000000000000001 by task iscsi-test-cu/683
CPU: 3 PID: 683 Comm: iscsi-test-cu Not tainted 5.0.0-rc5-dbg+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
Call Trace:
 dump_stack+0x86/0xca
 kasan_report.cold.3+0x5/0x3e
 __asan_load1+0x47/0x50
 scsi_debug_queuecommand+0x60f/0xc90 [scsi_debug]
 scsi_queue_rq+0xc17/0x12e0
 blk_mq_dispatch_rq_list+0x5fc/0xb10
 blk_mq_sched_dispatch_requests+0x2f7/0x300
 __blk_mq_run_hw_queue+0xd6/0x180
 __blk_mq_delay_run_hw_queue+0x25c/0x290
 blk_mq_run_hw_queue+0x119/0x1b0
 blk_mq_sched_insert_request+0x274/0x350
 blk_execute_rq_nowait+0x78/0x90
 blk_execute_rq+0xcc/0x140
 sg_io+0x30f/0x700
 scsi_cmd_ioctl+0x4d4/0x540
 scsi_cmd_blk_ioctl+0x7b/0x8b
 sd_ioctl+0xba/0x150
 blkdev_ioctl+0x6e1/0xea0
 block_ioctl+0x79/0x90
 do_vfs_ioctl+0x12b/0x9b0
 ksys_ioctl+0x41/0x80
 __x64_sys_ioctl+0x43/0x50
 do_syscall_64+0x71/0x210
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Cc: Christoph Hellwig <hch@lst.de>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Fixes: ae3d56d8 ("scsi: remove bidirectional command support")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/scsi_debug.c

@@ -351,12 +351,11 @@ enum sdeb_opcode_index {
 	SDEB_I_ATA_PT = 22,		/* 12, 16 */
 	SDEB_I_SEND_DIAG = 23,
 	SDEB_I_UNMAP = 24,
-	SDEB_I_XDWRITEREAD = 25,	/* 10 only */
-	SDEB_I_WRITE_BUFFER = 26,
-	SDEB_I_WRITE_SAME = 27,		/* 10, 16 */
-	SDEB_I_SYNC_CACHE = 28,		/* 10, 16 */
-	SDEB_I_COMP_WRITE = 29,
-	SDEB_I_LAST_ELEMENT = 30,	/* keep this last (previous + 1) */
+	SDEB_I_WRITE_BUFFER = 25,
+	SDEB_I_WRITE_SAME = 26,		/* 10, 16 */
+	SDEB_I_SYNC_CACHE = 27,		/* 10, 16 */
+	SDEB_I_COMP_WRITE = 28,
+	SDEB_I_LAST_ELEMENT = 29,	/* keep this last (previous + 1) */
 };
 
 
@@ -377,7 +376,7 @@ static const unsigned char opcode_ind_arr[256] = {
 /* 0x40; 0x40->0x5f: 10 byte cdbs */
 	0, SDEB_I_WRITE_SAME, SDEB_I_UNMAP, 0, 0, 0, 0, 0,
 	0, 0, 0, 0, 0, SDEB_I_LOG_SENSE, 0, 0,
-	0, 0, 0, SDEB_I_XDWRITEREAD, 0, SDEB_I_MODE_SELECT, SDEB_I_RESERVE,
+	0, 0, 0, 0, 0, SDEB_I_MODE_SELECT, SDEB_I_RESERVE,
 	    SDEB_I_RELEASE,
 	0, 0, SDEB_I_MODE_SENSE, 0, 0, 0, 0, 0,
 /* 0x60; 0x60->0x7d are reserved, 0x7e is "extended cdb" */
@@ -614,7 +613,7 @@ static const struct opcode_info_t opcode_info_arr[SDEB_I_LAST_ELEMENT + 1] = {
 	    {16,  0xf8, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0, 0,
 	     0, 0xff, 0x3f, 0xc7} },		/* COMPARE AND WRITE */
 
-/* 30 */
+/* 29 */
 	{0xff, 0, 0, 0, NULL, NULL,		/* terminating element */
 	    {0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
 };