mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 19:29:37 +00:00
![Linus Torvalds](/assets/img/avatar_default.png)
The poll() changes were not well thought out, and completely unexplained. They also caused a huge performance regression, because "->poll()" was no longer a trivial file operation that just called down to the underlying file operations, but instead did at least two indirect calls. Indirect calls are sadly slow now with the Spectre mitigation, but the performance problem could at least be largely mitigated by changing the "->get_poll_head()" operation to just have a per-file-descriptor pointer to the poll head instead. That gets rid of one of the new indirections. But that doesn't fix the new complexity that is completely unwarranted for the regular case. The (undocumented) reason for the poll() changes was some alleged AIO poll race fixing, but we don't make the common case slower and more complex for some uncommon special case, so this all really needs way more explanations and most likely a fundamental redesign. [ This revert is a revert of about 30 different commits, not reverted individually because that would just be unnecessarily messy - Linus ] Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
408 lines
10 KiB
C
408 lines
10 KiB
C
/*
|
|
* algif_skcipher: User-space interface for skcipher algorithms
|
|
*
|
|
* This file provides the user-space API for symmetric key ciphers.
|
|
*
|
|
* Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License as published by the Free
|
|
* Software Foundation; either version 2 of the License, or (at your option)
|
|
* any later version.
|
|
*
|
|
* The following concept of the memory management is used:
|
|
*
|
|
* The kernel maintains two SGLs, the TX SGL and the RX SGL. The TX SGL is
|
|
* filled by user space with the data submitted via sendpage/sendmsg. Filling
|
|
* up the TX SGL does not cause a crypto operation -- the data will only be
|
|
* tracked by the kernel. Upon receipt of one recvmsg call, the caller must
|
|
* provide a buffer which is tracked with the RX SGL.
|
|
*
|
|
* During the processing of the recvmsg operation, the cipher request is
|
|
* allocated and prepared. As part of the recvmsg operation, the processed
|
|
* TX buffers are extracted from the TX SGL into a separate SGL.
|
|
*
|
|
* After the completion of the crypto operation, the RX SGL and the cipher
|
|
* request is released. The extracted TX SGL parts are released together with
|
|
* the RX SGL release.
|
|
*/
|
|
|
|
#include <crypto/scatterwalk.h>
|
|
#include <crypto/skcipher.h>
|
|
#include <crypto/if_alg.h>
|
|
#include <linux/init.h>
|
|
#include <linux/list.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/module.h>
|
|
#include <linux/net.h>
|
|
#include <net/sock.h>
|
|
|
|
static int skcipher_sendmsg(struct socket *sock, struct msghdr *msg,
|
|
size_t size)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct alg_sock *ask = alg_sk(sk);
|
|
struct sock *psk = ask->parent;
|
|
struct alg_sock *pask = alg_sk(psk);
|
|
struct crypto_skcipher *tfm = pask->private;
|
|
unsigned ivsize = crypto_skcipher_ivsize(tfm);
|
|
|
|
return af_alg_sendmsg(sock, msg, size, ivsize);
|
|
}
|
|
|
|
static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
|
|
size_t ignored, int flags)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct alg_sock *ask = alg_sk(sk);
|
|
struct sock *psk = ask->parent;
|
|
struct alg_sock *pask = alg_sk(psk);
|
|
struct af_alg_ctx *ctx = ask->private;
|
|
struct crypto_skcipher *tfm = pask->private;
|
|
unsigned int bs = crypto_skcipher_blocksize(tfm);
|
|
struct af_alg_async_req *areq;
|
|
int err = 0;
|
|
size_t len = 0;
|
|
|
|
if (!ctx->used) {
|
|
err = af_alg_wait_for_data(sk, flags);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
/* Allocate cipher request for current operation. */
|
|
areq = af_alg_alloc_areq(sk, sizeof(struct af_alg_async_req) +
|
|
crypto_skcipher_reqsize(tfm));
|
|
if (IS_ERR(areq))
|
|
return PTR_ERR(areq);
|
|
|
|
/* convert iovecs of output buffers into RX SGL */
|
|
err = af_alg_get_rsgl(sk, msg, flags, areq, -1, &len);
|
|
if (err)
|
|
goto free;
|
|
|
|
/* Process only as much RX buffers for which we have TX data */
|
|
if (len > ctx->used)
|
|
len = ctx->used;
|
|
|
|
/*
|
|
* If more buffers are to be expected to be processed, process only
|
|
* full block size buffers.
|
|
*/
|
|
if (ctx->more || len < ctx->used)
|
|
len -= len % bs;
|
|
|
|
/*
|
|
* Create a per request TX SGL for this request which tracks the
|
|
* SG entries from the global TX SGL.
|
|
*/
|
|
areq->tsgl_entries = af_alg_count_tsgl(sk, len, 0);
|
|
if (!areq->tsgl_entries)
|
|
areq->tsgl_entries = 1;
|
|
areq->tsgl = sock_kmalloc(sk, array_size(sizeof(*areq->tsgl),
|
|
areq->tsgl_entries),
|
|
GFP_KERNEL);
|
|
if (!areq->tsgl) {
|
|
err = -ENOMEM;
|
|
goto free;
|
|
}
|
|
sg_init_table(areq->tsgl, areq->tsgl_entries);
|
|
af_alg_pull_tsgl(sk, len, areq->tsgl, 0);
|
|
|
|
/* Initialize the crypto operation */
|
|
skcipher_request_set_tfm(&areq->cra_u.skcipher_req, tfm);
|
|
skcipher_request_set_crypt(&areq->cra_u.skcipher_req, areq->tsgl,
|
|
areq->first_rsgl.sgl.sg, len, ctx->iv);
|
|
|
|
if (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) {
|
|
/* AIO operation */
|
|
sock_hold(sk);
|
|
areq->iocb = msg->msg_iocb;
|
|
|
|
/* Remember output size that will be generated. */
|
|
areq->outlen = len;
|
|
|
|
skcipher_request_set_callback(&areq->cra_u.skcipher_req,
|
|
CRYPTO_TFM_REQ_MAY_SLEEP,
|
|
af_alg_async_cb, areq);
|
|
err = ctx->enc ?
|
|
crypto_skcipher_encrypt(&areq->cra_u.skcipher_req) :
|
|
crypto_skcipher_decrypt(&areq->cra_u.skcipher_req);
|
|
|
|
/* AIO operation in progress */
|
|
if (err == -EINPROGRESS || err == -EBUSY)
|
|
return -EIOCBQUEUED;
|
|
|
|
sock_put(sk);
|
|
} else {
|
|
/* Synchronous operation */
|
|
skcipher_request_set_callback(&areq->cra_u.skcipher_req,
|
|
CRYPTO_TFM_REQ_MAY_SLEEP |
|
|
CRYPTO_TFM_REQ_MAY_BACKLOG,
|
|
crypto_req_done, &ctx->wait);
|
|
err = crypto_wait_req(ctx->enc ?
|
|
crypto_skcipher_encrypt(&areq->cra_u.skcipher_req) :
|
|
crypto_skcipher_decrypt(&areq->cra_u.skcipher_req),
|
|
&ctx->wait);
|
|
}
|
|
|
|
|
|
free:
|
|
af_alg_free_resources(areq);
|
|
|
|
return err ? err : len;
|
|
}
|
|
|
|
static int skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
|
|
size_t ignored, int flags)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
int ret = 0;
|
|
|
|
lock_sock(sk);
|
|
while (msg_data_left(msg)) {
|
|
int err = _skcipher_recvmsg(sock, msg, ignored, flags);
|
|
|
|
/*
|
|
* This error covers -EIOCBQUEUED which implies that we can
|
|
* only handle one AIO request. If the caller wants to have
|
|
* multiple AIO requests in parallel, he must make multiple
|
|
* separate AIO calls.
|
|
*
|
|
* Also return the error if no data has been processed so far.
|
|
*/
|
|
if (err <= 0) {
|
|
if (err == -EIOCBQUEUED || !ret)
|
|
ret = err;
|
|
goto out;
|
|
}
|
|
|
|
ret += err;
|
|
}
|
|
|
|
out:
|
|
af_alg_wmem_wakeup(sk);
|
|
release_sock(sk);
|
|
return ret;
|
|
}
|
|
|
|
static struct proto_ops algif_skcipher_ops = {
|
|
.family = PF_ALG,
|
|
|
|
.connect = sock_no_connect,
|
|
.socketpair = sock_no_socketpair,
|
|
.getname = sock_no_getname,
|
|
.ioctl = sock_no_ioctl,
|
|
.listen = sock_no_listen,
|
|
.shutdown = sock_no_shutdown,
|
|
.getsockopt = sock_no_getsockopt,
|
|
.mmap = sock_no_mmap,
|
|
.bind = sock_no_bind,
|
|
.accept = sock_no_accept,
|
|
.setsockopt = sock_no_setsockopt,
|
|
|
|
.release = af_alg_release,
|
|
.sendmsg = skcipher_sendmsg,
|
|
.sendpage = af_alg_sendpage,
|
|
.recvmsg = skcipher_recvmsg,
|
|
.poll = af_alg_poll,
|
|
};
|
|
|
|
static int skcipher_check_key(struct socket *sock)
|
|
{
|
|
int err = 0;
|
|
struct sock *psk;
|
|
struct alg_sock *pask;
|
|
struct crypto_skcipher *tfm;
|
|
struct sock *sk = sock->sk;
|
|
struct alg_sock *ask = alg_sk(sk);
|
|
|
|
lock_sock(sk);
|
|
if (ask->refcnt)
|
|
goto unlock_child;
|
|
|
|
psk = ask->parent;
|
|
pask = alg_sk(ask->parent);
|
|
tfm = pask->private;
|
|
|
|
err = -ENOKEY;
|
|
lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
|
|
if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
|
|
goto unlock;
|
|
|
|
if (!pask->refcnt++)
|
|
sock_hold(psk);
|
|
|
|
ask->refcnt = 1;
|
|
sock_put(psk);
|
|
|
|
err = 0;
|
|
|
|
unlock:
|
|
release_sock(psk);
|
|
unlock_child:
|
|
release_sock(sk);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int skcipher_sendmsg_nokey(struct socket *sock, struct msghdr *msg,
|
|
size_t size)
|
|
{
|
|
int err;
|
|
|
|
err = skcipher_check_key(sock);
|
|
if (err)
|
|
return err;
|
|
|
|
return skcipher_sendmsg(sock, msg, size);
|
|
}
|
|
|
|
static ssize_t skcipher_sendpage_nokey(struct socket *sock, struct page *page,
|
|
int offset, size_t size, int flags)
|
|
{
|
|
int err;
|
|
|
|
err = skcipher_check_key(sock);
|
|
if (err)
|
|
return err;
|
|
|
|
return af_alg_sendpage(sock, page, offset, size, flags);
|
|
}
|
|
|
|
static int skcipher_recvmsg_nokey(struct socket *sock, struct msghdr *msg,
|
|
size_t ignored, int flags)
|
|
{
|
|
int err;
|
|
|
|
err = skcipher_check_key(sock);
|
|
if (err)
|
|
return err;
|
|
|
|
return skcipher_recvmsg(sock, msg, ignored, flags);
|
|
}
|
|
|
|
static struct proto_ops algif_skcipher_ops_nokey = {
|
|
.family = PF_ALG,
|
|
|
|
.connect = sock_no_connect,
|
|
.socketpair = sock_no_socketpair,
|
|
.getname = sock_no_getname,
|
|
.ioctl = sock_no_ioctl,
|
|
.listen = sock_no_listen,
|
|
.shutdown = sock_no_shutdown,
|
|
.getsockopt = sock_no_getsockopt,
|
|
.mmap = sock_no_mmap,
|
|
.bind = sock_no_bind,
|
|
.accept = sock_no_accept,
|
|
.setsockopt = sock_no_setsockopt,
|
|
|
|
.release = af_alg_release,
|
|
.sendmsg = skcipher_sendmsg_nokey,
|
|
.sendpage = skcipher_sendpage_nokey,
|
|
.recvmsg = skcipher_recvmsg_nokey,
|
|
.poll = af_alg_poll,
|
|
};
|
|
|
|
static void *skcipher_bind(const char *name, u32 type, u32 mask)
|
|
{
|
|
return crypto_alloc_skcipher(name, type, mask);
|
|
}
|
|
|
|
static void skcipher_release(void *private)
|
|
{
|
|
crypto_free_skcipher(private);
|
|
}
|
|
|
|
static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen)
|
|
{
|
|
return crypto_skcipher_setkey(private, key, keylen);
|
|
}
|
|
|
|
static void skcipher_sock_destruct(struct sock *sk)
|
|
{
|
|
struct alg_sock *ask = alg_sk(sk);
|
|
struct af_alg_ctx *ctx = ask->private;
|
|
struct sock *psk = ask->parent;
|
|
struct alg_sock *pask = alg_sk(psk);
|
|
struct crypto_skcipher *tfm = pask->private;
|
|
|
|
af_alg_pull_tsgl(sk, ctx->used, NULL, 0);
|
|
sock_kzfree_s(sk, ctx->iv, crypto_skcipher_ivsize(tfm));
|
|
sock_kfree_s(sk, ctx, ctx->len);
|
|
af_alg_release_parent(sk);
|
|
}
|
|
|
|
static int skcipher_accept_parent_nokey(void *private, struct sock *sk)
|
|
{
|
|
struct af_alg_ctx *ctx;
|
|
struct alg_sock *ask = alg_sk(sk);
|
|
struct crypto_skcipher *tfm = private;
|
|
unsigned int len = sizeof(*ctx);
|
|
|
|
ctx = sock_kmalloc(sk, len, GFP_KERNEL);
|
|
if (!ctx)
|
|
return -ENOMEM;
|
|
|
|
ctx->iv = sock_kmalloc(sk, crypto_skcipher_ivsize(tfm),
|
|
GFP_KERNEL);
|
|
if (!ctx->iv) {
|
|
sock_kfree_s(sk, ctx, len);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
memset(ctx->iv, 0, crypto_skcipher_ivsize(tfm));
|
|
|
|
INIT_LIST_HEAD(&ctx->tsgl_list);
|
|
ctx->len = len;
|
|
ctx->used = 0;
|
|
atomic_set(&ctx->rcvused, 0);
|
|
ctx->more = 0;
|
|
ctx->merge = 0;
|
|
ctx->enc = 0;
|
|
crypto_init_wait(&ctx->wait);
|
|
|
|
ask->private = ctx;
|
|
|
|
sk->sk_destruct = skcipher_sock_destruct;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int skcipher_accept_parent(void *private, struct sock *sk)
|
|
{
|
|
struct crypto_skcipher *tfm = private;
|
|
|
|
if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
|
|
return -ENOKEY;
|
|
|
|
return skcipher_accept_parent_nokey(private, sk);
|
|
}
|
|
|
|
static const struct af_alg_type algif_type_skcipher = {
|
|
.bind = skcipher_bind,
|
|
.release = skcipher_release,
|
|
.setkey = skcipher_setkey,
|
|
.accept = skcipher_accept_parent,
|
|
.accept_nokey = skcipher_accept_parent_nokey,
|
|
.ops = &algif_skcipher_ops,
|
|
.ops_nokey = &algif_skcipher_ops_nokey,
|
|
.name = "skcipher",
|
|
.owner = THIS_MODULE
|
|
};
|
|
|
|
static int __init algif_skcipher_init(void)
|
|
{
|
|
return af_alg_register_type(&algif_type_skcipher);
|
|
}
|
|
|
|
static void __exit algif_skcipher_exit(void)
|
|
{
|
|
int err = af_alg_unregister_type(&algif_type_skcipher);
|
|
BUG_ON(err);
|
|
}
|
|
|
|
module_init(algif_skcipher_init);
|
|
module_exit(algif_skcipher_exit);
|
|
MODULE_LICENSE("GPL");
|