Commit eb972eab authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Catalin Marinas
Browse files

lkdtm/bugs: Add cases for BUG and PANIC occurring in hardirq context 



Add lkdtm cases to trigger a BUG() or panic() from hardirq context. This
is useful for testing pstore behavior being invoked from such contexts.

Reviewed-by: default avatarKees Cook <kees@kernel.org>
Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent b7737c38

drivers/misc/lkdtm/bugs.c

+53 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#include "lkdtm.h"

#include <linux/cpu.h>

#include <linux/list.h>

#include <linux/hrtimer.h>

#include <linux/sched.h>

#include <linux/sched/signal.h>

#include <linux/sched/task_stack.h>
@@ -100,11 +101,61 @@ static void lkdtm_PANIC_STOP_IRQOFF(void) 
	stop_machine(panic_stop_irqoff_fn, &v, cpu_online_mask);

}



static bool wait_for_panic;



static enum hrtimer_restart panic_in_hardirq(struct hrtimer *timer)

{

	panic("from hard IRQ context");



	wait_for_panic = false;

	return HRTIMER_NORESTART;

}



static void lkdtm_PANIC_IN_HARDIRQ(void)

{

	struct hrtimer timer;



	wait_for_panic = true;

	hrtimer_setup_on_stack(&timer, panic_in_hardirq,

			       CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);

	hrtimer_start(&timer, us_to_ktime(100), HRTIMER_MODE_REL_HARD);



	while (wait_for_panic)

		;



	hrtimer_cancel(&timer);

}



static void lkdtm_BUG(void)

{

	BUG();

}



static bool wait_for_bug;



static enum hrtimer_restart bug_in_hardirq(struct hrtimer *timer)

{

	BUG();



	wait_for_bug = false;

	return HRTIMER_NORESTART;

}



static void lkdtm_BUG_IN_HARDIRQ(void)

{

	struct hrtimer timer;



	wait_for_bug = true;

	hrtimer_setup_on_stack(&timer, bug_in_hardirq,

			       CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);

	hrtimer_start(&timer, us_to_ktime(100), HRTIMER_MODE_REL_HARD);



	while (wait_for_bug)

		;



	hrtimer_cancel(&timer);

}



static int warn_counter;



static void lkdtm_WARNING(void)
@@ -696,7 +747,9 @@ static noinline void lkdtm_CORRUPT_PAC(void) 
static struct crashtype crashtypes[] = {

	CRASHTYPE(PANIC),

	CRASHTYPE(PANIC_STOP_IRQOFF),

	CRASHTYPE(PANIC_IN_HARDIRQ),

	CRASHTYPE(BUG),

	CRASHTYPE(BUG_IN_HARDIRQ),

	CRASHTYPE(WARNING),

	CRASHTYPE(WARNING_MESSAGE),

	CRASHTYPE(EXCEPTION),

tools/testing/selftests/lkdtm/tests.txt

+2 −0
Original line number Diff line number Diff line 
#PANIC

#PANIC_STOP_IRQOFF Crashes entire system

#PANIC_IN_HARDIRQ Crashes entire system

BUG kernel BUG at

#BUG_IN_HARDIRQ Crashes entire system

WARNING WARNING:

WARNING_MESSAGE message trigger

EXCEPTION