lkdtm: replace ll_rw_block with submit_bh

Function ll_rw_block was removed in commit 79f59784 ("fs/buffer:
remove ll_rw_block() helper"). There is no unified function to sumbit
read or write buffer in block layer for now. Consider similar sematics,
we can choose submit_bh() to replace ll_rw_block() as predefined crash
point. In submit_bh(), it also takes read or write flag as the first
argument and invoke submit_bio() to submit I/O request to block layer.

Fixes: 79f59784 ("fs/buffer: remove ll_rw_block() helper")
Signed-off-by: Yue Zhao <findns94@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230503162944.3969-1-findns94@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/fault-injection/provoke-crashes.rst

@@ -29,7 +29,7 @@ recur_count
 cpoint_name
 	Where in the kernel to trigger the action. It can be
 	one of INT_HARDWARE_ENTRY, INT_HW_IRQ_EN, INT_TASKLET_ENTRY,
-	FS_DEVRW, MEM_SWAPOUT, TIMERADD, SCSI_QUEUE_RQ, or DIRECT.
+	FS_SUBMIT_BH, MEM_SWAPOUT, TIMERADD, SCSI_QUEUE_RQ, or DIRECT.
 
 cpoint_type
 	Indicates the action to be taken on hitting the crash point.

drivers/misc/lkdtm/core.c

@@ -79,7 +79,7 @@ static struct crashpoint crashpoints[] = {
 	CRASHPOINT("INT_HARDWARE_ENTRY", "do_IRQ"),
 	CRASHPOINT("INT_HW_IRQ_EN",	 "handle_irq_event"),
 	CRASHPOINT("INT_TASKLET_ENTRY",	 "tasklet_action"),
-	CRASHPOINT("FS_DEVRW",		 "ll_rw_block"),
+	CRASHPOINT("FS_SUBMIT_BH",		 "submit_bh"),
 	CRASHPOINT("MEM_SWAPOUT",	 "shrink_inactive_list"),
 	CRASHPOINT("TIMERADD",		 "hrtimer_start"),
 	CRASHPOINT("SCSI_QUEUE_RQ",	 "scsi_queue_rq"),