static int __nd_ioctl()

in bus.c [1019:1201]

• 157 lines of code
• 41 McCabe index (conditional complexity)

static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
		int read_only, unsigned int ioctl_cmd, unsigned long arg)
{
	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
	const struct nd_cmd_desc *desc = NULL;
	unsigned int cmd = _IOC_NR(ioctl_cmd);
	struct device *dev = &nvdimm_bus->dev;
	void __user *p = (void __user *) arg;
	char *out_env = NULL, *in_env = NULL;
	const char *cmd_name, *dimm_name;
	u32 in_len = 0, out_len = 0;
	unsigned int func = cmd;
	unsigned long cmd_mask;
	struct nd_cmd_pkg pkg;
	int rc, i, cmd_rc;
	void *buf = NULL;
	u64 buf_len = 0;

	if (nvdimm) {
		desc = nd_cmd_dimm_desc(cmd);
		cmd_name = nvdimm_cmd_name(cmd);
		cmd_mask = nvdimm->cmd_mask;
		dimm_name = dev_name(&nvdimm->dev);
	} else {
		desc = nd_cmd_bus_desc(cmd);
		cmd_name = nvdimm_bus_cmd_name(cmd);
		cmd_mask = nd_desc->cmd_mask;
		dimm_name = "bus";
	}

	/* Validate command family support against bus declared support */
	if (cmd == ND_CMD_CALL) {
		unsigned long *mask;

		if (copy_from_user(&pkg, p, sizeof(pkg)))
			return -EFAULT;

		if (nvdimm) {
			if (pkg.nd_family > NVDIMM_FAMILY_MAX)
				return -EINVAL;
			mask = &nd_desc->dimm_family_mask;
		} else {
			if (pkg.nd_family > NVDIMM_BUS_FAMILY_MAX)
				return -EINVAL;
			mask = &nd_desc->bus_family_mask;
		}

		if (!test_bit(pkg.nd_family, mask))
			return -EINVAL;
	}

	if (!desc ||
	    (desc->out_num + desc->in_num == 0) ||
	    cmd > ND_CMD_CALL ||
	    !test_bit(cmd, &cmd_mask))
		return -ENOTTY;

	/* fail write commands (when read-only) */
	if (read_only)
		switch (cmd) {
		case ND_CMD_VENDOR:
		case ND_CMD_SET_CONFIG_DATA:
		case ND_CMD_ARS_START:
		case ND_CMD_CLEAR_ERROR:
		case ND_CMD_CALL:
			dev_dbg(dev, "'%s' command while read-only.\n",
					nvdimm ? nvdimm_cmd_name(cmd)
					: nvdimm_bus_cmd_name(cmd));
			return -EPERM;
		default:
			break;
		}

	/* process an input envelope */
	in_env = kzalloc(ND_CMD_MAX_ENVELOPE, GFP_KERNEL);
	if (!in_env)
		return -ENOMEM;
	for (i = 0; i < desc->in_num; i++) {
		u32 in_size, copy;

		in_size = nd_cmd_in_size(nvdimm, cmd, desc, i, in_env);
		if (in_size == UINT_MAX) {
			dev_err(dev, "%s:%s unknown input size cmd: %s field: %d\n",
					__func__, dimm_name, cmd_name, i);
			rc = -ENXIO;
			goto out;
		}
		if (in_len < ND_CMD_MAX_ENVELOPE)
			copy = min_t(u32, ND_CMD_MAX_ENVELOPE - in_len, in_size);
		else
			copy = 0;
		if (copy && copy_from_user(&in_env[in_len], p + in_len, copy)) {
			rc = -EFAULT;
			goto out;
		}
		in_len += in_size;
	}

	if (cmd == ND_CMD_CALL) {
		func = pkg.nd_command;
		dev_dbg(dev, "%s, idx: %llu, in: %u, out: %u, len %llu\n",
				dimm_name, pkg.nd_command,
				in_len, out_len, buf_len);
	}

	/* process an output envelope */
	out_env = kzalloc(ND_CMD_MAX_ENVELOPE, GFP_KERNEL);
	if (!out_env) {
		rc = -ENOMEM;
		goto out;
	}

	for (i = 0; i < desc->out_num; i++) {
		u32 out_size = nd_cmd_out_size(nvdimm, cmd, desc, i,
				(u32 *) in_env, (u32 *) out_env, 0);
		u32 copy;

		if (out_size == UINT_MAX) {
			dev_dbg(dev, "%s unknown output size cmd: %s field: %d\n",
					dimm_name, cmd_name, i);
			rc = -EFAULT;
			goto out;
		}
		if (out_len < ND_CMD_MAX_ENVELOPE)
			copy = min_t(u32, ND_CMD_MAX_ENVELOPE - out_len, out_size);
		else
			copy = 0;
		if (copy && copy_from_user(&out_env[out_len],
					p + in_len + out_len, copy)) {
			rc = -EFAULT;
			goto out;
		}
		out_len += out_size;
	}

	buf_len = (u64) out_len + (u64) in_len;
	if (buf_len > ND_IOCTL_MAX_BUFLEN) {
		dev_dbg(dev, "%s cmd: %s buf_len: %llu > %d\n", dimm_name,
				cmd_name, buf_len, ND_IOCTL_MAX_BUFLEN);
		rc = -EINVAL;
		goto out;
	}

	buf = vmalloc(buf_len);
	if (!buf) {
		rc = -ENOMEM;
		goto out;
	}

	if (copy_from_user(buf, p, buf_len)) {
		rc = -EFAULT;
		goto out;
	}

	nd_device_lock(dev);
	nvdimm_bus_lock(dev);
	rc = nd_cmd_clear_to_send(nvdimm_bus, nvdimm, func, buf);
	if (rc)
		goto out_unlock;

	rc = nd_desc->ndctl(nd_desc, nvdimm, cmd, buf, buf_len, &cmd_rc);
	if (rc < 0)
		goto out_unlock;

	if (!nvdimm && cmd == ND_CMD_CLEAR_ERROR && cmd_rc >= 0) {
		struct nd_cmd_clear_error *clear_err = buf;

		nvdimm_account_cleared_poison(nvdimm_bus, clear_err->address,
				clear_err->cleared);
	}

	if (copy_to_user(p, buf, buf_len))
		rc = -EFAULT;

out_unlock:
	nvdimm_bus_unlock(dev);
	nd_device_unlock(dev);
out:
	kfree(in_env);
	kfree(out_env);
	vfree(buf);
	return rc;
}