Revision 70e6e1b971e46f5c1c2d72217ba62401a2edc22b authored by Linus Torvalds on 20 July 2019, 17:33:44 UTC, committed by Linus Torvalds on 20 July 2019, 17:33:44 UTC
Pull CONFIG_PREEMPT_RT stub config from Thomas Gleixner:
 "The real-time preemption patch set exists for almost 15 years now and
  while the vast majority of infrastructure and enhancements have found
  their way into the mainline kernel, the final integration of RT is
  still missing.

  Over the course of the last few years, we have worked on reducing the
  intrusivenness of the RT patches by refactoring kernel infrastructure
  to be more real-time friendly. Almost all of these changes were
  benefitial to the mainline kernel on their own, so there was no
  objection to integrate them.

  Though except for the still ongoing printk refactoring, the remaining
  changes which are required to make RT a first class mainline citizen
  are not longer arguable as immediately beneficial for the mainline
  kernel. Most of them are either reordering code flows or adding RT
  specific functionality.

  But this now has hit a wall and turned into a classic hen and egg
  problem:

     Maintainers are rightfully wary vs. these changes as they make only
     sense if the final integration of RT into the mainline kernel takes
     place.

  Adding CONFIG_PREEMPT_RT aims to solve this as a clear sign that RT
  will be fully integrated into the mainline kernel. The final
  integration of the missing bits and pieces will be of course done with
  the same careful approach as we have used in the past.

  While I'm aware that you are not entirely enthusiastic about that, I
  think that RT should receive the same treatment as any other widely
  used out of tree functionality, which we have accepted into mainline
  over the years.

  RT has become the de-facto standard real-time enhancement and is
  shipped by enterprise, embedded and community distros. It's in use
  throughout a wide range of industries: telecommunications, industrial
  automation, professional audio, medical devices, data acquisition,
  automotive - just to name a few major use cases.

  RT development is backed by a Linuxfoundation project which is
  supported by major stakeholders of this technology. The funding will
  continue over the actual inclusion into mainline to make sure that the
  functionality is neither introducing regressions, regressing itself,
  nor becomes subject to bitrot. There is also a lifely user community
  around RT as well, so contrary to the grim situation 5 years ago, it's
  a healthy project.

  As RT is still a good vehicle to exercise rarely used code paths and
  to detect hard to trigger issues, you could at least view it as a QA
  tool if nothing else"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/rt, Kconfig: Introduce CONFIG_PREEMPT_RT
2 parent s 07ab9d5 + a50a3f4
Raw File
crypto_user_base.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Crypto user configuration API.
 *
 * Copyright (C) 2011 secunet Security Networks AG
 * Copyright (C) 2011 Steffen Klassert <steffen.klassert@secunet.com>
 */

#include <linux/module.h>
#include <linux/crypto.h>
#include <linux/cryptouser.h>
#include <linux/sched.h>
#include <net/netlink.h>
#include <linux/security.h>
#include <net/net_namespace.h>
#include <crypto/internal/skcipher.h>
#include <crypto/internal/rng.h>
#include <crypto/akcipher.h>
#include <crypto/kpp.h>
#include <crypto/internal/cryptouser.h>

#include "internal.h"

#define null_terminated(x)	(strnlen(x, sizeof(x)) < sizeof(x))

static DEFINE_MUTEX(crypto_cfg_mutex);

/* The crypto netlink socket */
struct sock *crypto_nlsk;

struct crypto_dump_info {
	struct sk_buff *in_skb;
	struct sk_buff *out_skb;
	u32 nlmsg_seq;
	u16 nlmsg_flags;
};

struct crypto_alg *crypto_alg_match(struct crypto_user_alg *p, int exact)
{
	struct crypto_alg *q, *alg = NULL;

	down_read(&crypto_alg_sem);

	list_for_each_entry(q, &crypto_alg_list, cra_list) {
		int match = 0;

		if (crypto_is_larval(q))
			continue;

		if ((q->cra_flags ^ p->cru_type) & p->cru_mask)
			continue;

		if (strlen(p->cru_driver_name))
			match = !strcmp(q->cra_driver_name,
					p->cru_driver_name);
		else if (!exact)
			match = !strcmp(q->cra_name, p->cru_name);

		if (!match)
			continue;

		if (unlikely(!crypto_mod_get(q)))
			continue;

		alg = q;
		break;
	}

	up_read(&crypto_alg_sem);

	return alg;
}

static int crypto_report_cipher(struct sk_buff *skb, struct crypto_alg *alg)
{
	struct crypto_report_cipher rcipher;

	memset(&rcipher, 0, sizeof(rcipher));

	strscpy(rcipher.type, "cipher", sizeof(rcipher.type));

	rcipher.blocksize = alg->cra_blocksize;
	rcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
	rcipher.max_keysize = alg->cra_cipher.cia_max_keysize;

	return nla_put(skb, CRYPTOCFGA_REPORT_CIPHER,
		       sizeof(rcipher), &rcipher);
}

static int crypto_report_comp(struct sk_buff *skb, struct crypto_alg *alg)
{
	struct crypto_report_comp rcomp;

	memset(&rcomp, 0, sizeof(rcomp));

	strscpy(rcomp.type, "compression", sizeof(rcomp.type));

	return nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS, sizeof(rcomp), &rcomp);
}

static int crypto_report_one(struct crypto_alg *alg,
			     struct crypto_user_alg *ualg, struct sk_buff *skb)
{
	memset(ualg, 0, sizeof(*ualg));

	strscpy(ualg->cru_name, alg->cra_name, sizeof(ualg->cru_name));
	strscpy(ualg->cru_driver_name, alg->cra_driver_name,
		sizeof(ualg->cru_driver_name));
	strscpy(ualg->cru_module_name, module_name(alg->cra_module),
		sizeof(ualg->cru_module_name));

	ualg->cru_type = 0;
	ualg->cru_mask = 0;
	ualg->cru_flags = alg->cra_flags;
	ualg->cru_refcnt = refcount_read(&alg->cra_refcnt);

	if (nla_put_u32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority))
		goto nla_put_failure;
	if (alg->cra_flags & CRYPTO_ALG_LARVAL) {
		struct crypto_report_larval rl;

		memset(&rl, 0, sizeof(rl));
		strscpy(rl.type, "larval", sizeof(rl.type));
		if (nla_put(skb, CRYPTOCFGA_REPORT_LARVAL, sizeof(rl), &rl))
			goto nla_put_failure;
		goto out;
	}

	if (alg->cra_type && alg->cra_type->report) {
		if (alg->cra_type->report(skb, alg))
			goto nla_put_failure;

		goto out;
	}

	switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL)) {
	case CRYPTO_ALG_TYPE_CIPHER:
		if (crypto_report_cipher(skb, alg))
			goto nla_put_failure;

		break;
	case CRYPTO_ALG_TYPE_COMPRESS:
		if (crypto_report_comp(skb, alg))
			goto nla_put_failure;

		break;
	}

out:
	return 0;

nla_put_failure:
	return -EMSGSIZE;
}

static int crypto_report_alg(struct crypto_alg *alg,
			     struct crypto_dump_info *info)
{
	struct sk_buff *in_skb = info->in_skb;
	struct sk_buff *skb = info->out_skb;
	struct nlmsghdr *nlh;
	struct crypto_user_alg *ualg;
	int err = 0;

	nlh = nlmsg_put(skb, NETLINK_CB(in_skb).portid, info->nlmsg_seq,
			CRYPTO_MSG_GETALG, sizeof(*ualg), info->nlmsg_flags);
	if (!nlh) {
		err = -EMSGSIZE;
		goto out;
	}

	ualg = nlmsg_data(nlh);

	err = crypto_report_one(alg, ualg, skb);
	if (err) {
		nlmsg_cancel(skb, nlh);
		goto out;
	}

	nlmsg_end(skb, nlh);

out:
	return err;
}

static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
			 struct nlattr **attrs)
{
	struct crypto_user_alg *p = nlmsg_data(in_nlh);
	struct crypto_alg *alg;
	struct sk_buff *skb;
	struct crypto_dump_info info;
	int err;

	if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
		return -EINVAL;

	alg = crypto_alg_match(p, 0);
	if (!alg)
		return -ENOENT;

	err = -ENOMEM;
	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
	if (!skb)
		goto drop_alg;

	info.in_skb = in_skb;
	info.out_skb = skb;
	info.nlmsg_seq = in_nlh->nlmsg_seq;
	info.nlmsg_flags = 0;

	err = crypto_report_alg(alg, &info);

drop_alg:
	crypto_mod_put(alg);

	if (err)
		return err;

	return nlmsg_unicast(crypto_nlsk, skb, NETLINK_CB(in_skb).portid);
}

static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb)
{
	const size_t start_pos = cb->args[0];
	size_t pos = 0;
	struct crypto_dump_info info;
	struct crypto_alg *alg;
	int res;

	info.in_skb = cb->skb;
	info.out_skb = skb;
	info.nlmsg_seq = cb->nlh->nlmsg_seq;
	info.nlmsg_flags = NLM_F_MULTI;

	down_read(&crypto_alg_sem);
	list_for_each_entry(alg, &crypto_alg_list, cra_list) {
		if (pos >= start_pos) {
			res = crypto_report_alg(alg, &info);
			if (res == -EMSGSIZE)
				break;
			if (res)
				goto out;
		}
		pos++;
	}
	cb->args[0] = pos;
	res = skb->len;
out:
	up_read(&crypto_alg_sem);
	return res;
}

static int crypto_dump_report_done(struct netlink_callback *cb)
{
	return 0;
}

static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
			     struct nlattr **attrs)
{
	struct crypto_alg *alg;
	struct crypto_user_alg *p = nlmsg_data(nlh);
	struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
	LIST_HEAD(list);

	if (!netlink_capable(skb, CAP_NET_ADMIN))
		return -EPERM;

	if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
		return -EINVAL;

	if (priority && !strlen(p->cru_driver_name))
		return -EINVAL;

	alg = crypto_alg_match(p, 1);
	if (!alg)
		return -ENOENT;

	down_write(&crypto_alg_sem);

	crypto_remove_spawns(alg, &list, NULL);

	if (priority)
		alg->cra_priority = nla_get_u32(priority);

	up_write(&crypto_alg_sem);

	crypto_mod_put(alg);
	crypto_remove_final(&list);

	return 0;
}

static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
			  struct nlattr **attrs)
{
	struct crypto_alg *alg;
	struct crypto_user_alg *p = nlmsg_data(nlh);
	int err;

	if (!netlink_capable(skb, CAP_NET_ADMIN))
		return -EPERM;

	if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
		return -EINVAL;

	alg = crypto_alg_match(p, 1);
	if (!alg)
		return -ENOENT;

	/* We can not unregister core algorithms such as aes-generic.
	 * We would loose the reference in the crypto_alg_list to this algorithm
	 * if we try to unregister. Unregistering such an algorithm without
	 * removing the module is not possible, so we restrict to crypto
	 * instances that are build from templates. */
	err = -EINVAL;
	if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))
		goto drop_alg;

	err = -EBUSY;
	if (refcount_read(&alg->cra_refcnt) > 2)
		goto drop_alg;

	err = crypto_unregister_instance((struct crypto_instance *)alg);

drop_alg:
	crypto_mod_put(alg);
	return err;
}

static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
			  struct nlattr **attrs)
{
	int exact = 0;
	const char *name;
	struct crypto_alg *alg;
	struct crypto_user_alg *p = nlmsg_data(nlh);
	struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];

	if (!netlink_capable(skb, CAP_NET_ADMIN))
		return -EPERM;

	if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
		return -EINVAL;

	if (strlen(p->cru_driver_name))
		exact = 1;

	if (priority && !exact)
		return -EINVAL;

	alg = crypto_alg_match(p, exact);
	if (alg) {
		crypto_mod_put(alg);
		return -EEXIST;
	}

	if (strlen(p->cru_driver_name))
		name = p->cru_driver_name;
	else
		name = p->cru_name;

	alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask);
	if (IS_ERR(alg))
		return PTR_ERR(alg);

	down_write(&crypto_alg_sem);

	if (priority)
		alg->cra_priority = nla_get_u32(priority);

	up_write(&crypto_alg_sem);

	crypto_mod_put(alg);

	return 0;
}

static int crypto_del_rng(struct sk_buff *skb, struct nlmsghdr *nlh,
			  struct nlattr **attrs)
{
	if (!netlink_capable(skb, CAP_NET_ADMIN))
		return -EPERM;
	return crypto_del_default_rng();
}

#define MSGSIZE(type) sizeof(struct type)

static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = {
	[CRYPTO_MSG_NEWALG	- CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
	[CRYPTO_MSG_DELALG	- CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
	[CRYPTO_MSG_UPDATEALG	- CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
	[CRYPTO_MSG_GETALG	- CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
	[CRYPTO_MSG_DELRNG	- CRYPTO_MSG_BASE] = 0,
	[CRYPTO_MSG_GETSTAT	- CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
};

static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = {
	[CRYPTOCFGA_PRIORITY_VAL]   = { .type = NLA_U32},
};

#undef MSGSIZE

static const struct crypto_link {
	int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **);
	int (*dump)(struct sk_buff *, struct netlink_callback *);
	int (*done)(struct netlink_callback *);
} crypto_dispatch[CRYPTO_NR_MSGTYPES] = {
	[CRYPTO_MSG_NEWALG	- CRYPTO_MSG_BASE] = { .doit = crypto_add_alg},
	[CRYPTO_MSG_DELALG	- CRYPTO_MSG_BASE] = { .doit = crypto_del_alg},
	[CRYPTO_MSG_UPDATEALG	- CRYPTO_MSG_BASE] = { .doit = crypto_update_alg},
	[CRYPTO_MSG_GETALG	- CRYPTO_MSG_BASE] = { .doit = crypto_report,
						       .dump = crypto_dump_report,
						       .done = crypto_dump_report_done},
	[CRYPTO_MSG_DELRNG	- CRYPTO_MSG_BASE] = { .doit = crypto_del_rng },
	[CRYPTO_MSG_GETSTAT	- CRYPTO_MSG_BASE] = { .doit = crypto_reportstat},
};

static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
			       struct netlink_ext_ack *extack)
{
	struct nlattr *attrs[CRYPTOCFGA_MAX+1];
	const struct crypto_link *link;
	int type, err;

	type = nlh->nlmsg_type;
	if (type > CRYPTO_MSG_MAX)
		return -EINVAL;

	type -= CRYPTO_MSG_BASE;
	link = &crypto_dispatch[type];

	if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) &&
	    (nlh->nlmsg_flags & NLM_F_DUMP))) {
		struct crypto_alg *alg;
		unsigned long dump_alloc = 0;

		if (link->dump == NULL)
			return -EINVAL;

		down_read(&crypto_alg_sem);
		list_for_each_entry(alg, &crypto_alg_list, cra_list)
			dump_alloc += CRYPTO_REPORT_MAXSIZE;
		up_read(&crypto_alg_sem);

		{
			struct netlink_dump_control c = {
				.dump = link->dump,
				.done = link->done,
				.min_dump_alloc = min(dump_alloc, 65535UL),
			};
			err = netlink_dump_start(crypto_nlsk, skb, nlh, &c);
		}

		return err;
	}

	err = nlmsg_parse_deprecated(nlh, crypto_msg_min[type], attrs,
				     CRYPTOCFGA_MAX, crypto_policy, extack);
	if (err < 0)
		return err;

	if (link->doit == NULL)
		return -EINVAL;

	return link->doit(skb, nlh, attrs);
}

static void crypto_netlink_rcv(struct sk_buff *skb)
{
	mutex_lock(&crypto_cfg_mutex);
	netlink_rcv_skb(skb, &crypto_user_rcv_msg);
	mutex_unlock(&crypto_cfg_mutex);
}

static int __init crypto_user_init(void)
{
	struct netlink_kernel_cfg cfg = {
		.input	= crypto_netlink_rcv,
	};

	crypto_nlsk = netlink_kernel_create(&init_net, NETLINK_CRYPTO, &cfg);
	if (!crypto_nlsk)
		return -ENOMEM;

	return 0;
}

static void __exit crypto_user_exit(void)
{
	netlink_kernel_release(crypto_nlsk);
}

module_init(crypto_user_init);
module_exit(crypto_user_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
MODULE_DESCRIPTION("Crypto userspace configuration API");
MODULE_ALIAS("net-pf-16-proto-21");
back to top