s390/topology: correct topology mode proc handler (196851be) · Commits · 戴 / test

Reuse proc_douintvec_minmax to simplify topology mode proc handler. This also enforces correct range of 0-1 on proc writes and correctly handles numbers starting with 0 or spaces. Before: $ echo 01 > /proc/sys/s390/topology $ cat /proc/sys/s390/topology 0 $ echo ' 1' > /proc/sys/s390/topology -bash: echo: write error: Invalid argument $ echo 2 > /proc/sys/s390/topology -bash: echo: write error: Invalid argument $ echo 12 > /proc/sys/s390/topology $ cat /proc/sys/s390/topology 1 After: $ echo 01 > /proc/sys/s390/topology $ cat /proc/sys/s390/topology 1 $ echo ' 1' > /proc/sys/s390/topology $ cat /proc/sys/s390/topology 1 $ echo 2 > /proc/sys/s390/topology -bash: echo: write error: Invalid argument $ echo 12 > /proc/sys/s390/topology -bash: echo: write error: Invalid argument $ echo ' 0' > /proc/sys/s390/topology $ cat /proc/sys/s390/topology 0 Reviewed-by:

Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by:

Vasily Gorbik <gor@linux.ibm.com> Signed-off-by:

Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/topology.c

+18 −25

Original line number	Diff line number	Diff line
		@@ -579,40 +579,33 @@ early_param("topology", topology_setup);
		static int topology_ctl_handler(struct ctl_table *ctl, int write,
		void __user buffer, size_t lenp, loff_t *ppos)
		{
		unsigned int len;
		int enabled = topology_is_enabled();
		int new_mode;
		char buf[2];
		int zero = 0;
		int one = 1;
		int rc;
		struct ctl_table ctl_entry = {
		.procname = ctl->procname,
		.data = &enabled,
		.maxlen = sizeof(int),
		.extra1 = &zero,
		.extra2 = &one,
		};

		rc = proc_douintvec_minmax(&ctl_entry, write, buffer, lenp, ppos);
		if (rc < 0 \|\| !write)
		return rc;

		if (!lenp \|\| ppos) {
		*lenp = 0;
		return 0;
		}
		if (!write) {
		memcpy(buf, topology_is_enabled() ? "1\n" : "0\n", ARRAY_SIZE(buf));
		len = strnlen(buf, ARRAY_SIZE(buf));
		if (len > *lenp)
		len = *lenp;
		if (copy_to_user(buffer, buf, len))
		return -EFAULT;
		goto out;
		}
		len = *lenp;
		if (copy_from_user(buf, buffer, len > sizeof(buf) ? sizeof(buf) : len))
		return -EFAULT;
		if (buf[0] != '0' && buf[0] != '1')
		return -EINVAL;
		mutex_lock(&smp_cpu_state_mutex);
		new_mode = topology_get_mode(buf[0] == '1');
		new_mode = topology_get_mode(enabled);
		if (topology_mode != new_mode) {
		topology_mode = new_mode;
		topology_schedule_update();
		}
		mutex_unlock(&smp_cpu_state_mutex);
		topology_flush_work();
		out:
		*lenp = len;
		*ppos += len;
		return 0;

		return rc;
		}

		static struct ctl_table topology_ctl_table[] = {

Admin message