Function db_md_set_watchpoint

freebsd/amd64/amd64/db_trace.c:472–519

(addr, size)

}

int
db_md_set_watchpoint(addr, size)
	db_expr_t addr;
	db_expr_t size;
{
	struct dbreg *d;
	struct pcpu *pc;
	int avail, c, cpu, i, wsize;

	d = (struct dbreg *)PCPU_PTR(dbreg);
	cpu = PCPU_GET(cpuid);
	fill_dbregs(NULL, d);

	avail = 0;
	for (i = 0; i < 4; i++) {
		if (!DBREG_DR7_ENABLED(d->dr[7], i))
			avail++;
	}

	if (avail * 8 < size)
		return (-1);

	for (i = 0; i < 4 && size > 0; i++) {
		if (!DBREG_DR7_ENABLED(d->dr[7], i)) {
			if (size >= 8 || (avail == 1 && size > 4))
				wsize = 8;
			else if (size > 2)
				wsize = 4;
			else
				wsize = size;
			amd64_set_watch(i, addr, wsize, DBREG_DR7_WRONLY, d);
			addr += wsize;
			size -= wsize;
			avail--;
		}
	}

	set_dbregs(NULL, d);
	CPU_FOREACH(c) {
		if (c == cpu)
			continue;
		pc = pcpu_find(c);
		memcpy(pc->pc_dbreg, d, sizeof(*d));
		pc->pc_dbreg_cmd = PC_DBREG_CMD_LOAD;
	}

	return (0);
}

int
db_md_clr_watchpoint(addr, size)