/*
 * DF-3788 -- BT848_SCAPAREA with x_size=0 -> integer division by zero in
 *           build_dma_prog() -> #DE -> kernel panic.
 *
 * Harness compiles the exact expression from bktr_core.c:3344-3346 with
 * format_params values for NTSC (format_params[1], bktr_core.c:191-192) and
 * runs it. Userspace SIGFPE == kernel integer-divide trap == panic.
 */
#include <stdio.h>
#include <stdlib.h>

/* format_params[] fields used (bktr_core.c:186-211): */
static const struct fp { int htotal, hdelay, hactive, scaled_hactive,
			       scaled_htotal, vactive, vdelay; } FP_NTSC =
	{ 910, 135, 754, 640, 780, 480, 26 };

int main(void)
{
	int cols = 640, rows = 480;
	int capture_area_x_offset = 0, capture_area_y_offset = 0;
	int capture_area_x_size = 0, capture_area_y_size = 480; /* SCAPAREA w/ x_size=0 */
	const struct fp *fp = &FP_NTSC;
	int temp;

	/* bktr_core.c:3320-3325 HSCALE (runs first, harmless with x_size=0) */
	{
		long long t = ((long long)fp->htotal *
			       (long long)capture_area_x_size * 4096 /
			       fp->scaled_htotal / cols) - 4096;
		printf("HSCALE temp = %lld (fine)\n", t);
	}

	/* bktr_core.c:3344-3346: denominator = x_size * hactive = 0 * 754 */
	printf("denominator = capture_area_x_size * hactive = %d * %d = %d\n",
	       capture_area_x_size, fp->hactive,
	       capture_area_x_size * fp->hactive);
	fflush(stdout);

	temp = ((fp->hdelay * fp->scaled_hactive +
		 capture_area_x_offset * fp->scaled_htotal) * cols) /
	       (capture_area_x_size * fp->hactive);	/* <-- divide by zero */

	printf("unreachable: temp=%d\n", temp);	/* not reached */
	return 0;
}