Revision 0fb9a1abc8c97f858997e962694eb36b4517144e authored by Mathieu Desnoyers on 09 July 2018, 19:51:52 UTC, committed by Thomas Gleixner on 10 July 2018, 20:18:52 UTC
Update rseq uapi header comments to reflect that user-space need to do thread-local loads/stores from/to the struct rseq fields. As a consequence of this added requirement, the kernel does not need to perform loads/stores with single-copy atomicity. Update the comment associated to the "flags" fields to describe more accurately that it's only useful to facilitate single-stepping through rseq critical sections with debuggers. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-api@vger.kernel.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Watson <davejwatson@fb.com> Cc: Paul Turner <pjt@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Chris Lameter <cl@linux.com> Cc: Ben Maurer <bmaurer@fb.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Joel Fernandes <joelaf@google.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Link: https://lkml.kernel.org/r/20180709195155.7654-4-mathieu.desnoyers@efficios.com
1 parent 8f28177
scompress.c
/*
* Synchronous Compression operations
*
* Copyright 2015 LG Electronics Inc.
* Copyright (c) 2016, Intel Corporation
* Author: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
*
* 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.
*
*/
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/crypto.h>
#include <linux/compiler.h>
#include <linux/vmalloc.h>
#include <crypto/algapi.h>
#include <linux/cryptouser.h>
#include <net/netlink.h>
#include <linux/scatterlist.h>
#include <crypto/scatterwalk.h>
#include <crypto/internal/acompress.h>
#include <crypto/internal/scompress.h>
#include "internal.h"
static const struct crypto_type crypto_scomp_type;
static void * __percpu *scomp_src_scratches;
static void * __percpu *scomp_dst_scratches;
static int scomp_scratch_users;
static DEFINE_MUTEX(scomp_lock);
#ifdef CONFIG_NET
static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_report_comp rscomp;
strncpy(rscomp.type, "scomp", sizeof(rscomp.type));
if (nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS,
sizeof(struct crypto_report_comp), &rscomp))
goto nla_put_failure;
return 0;
nla_put_failure:
return -EMSGSIZE;
}
#else
static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg)
{
return -ENOSYS;
}
#endif
static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
__maybe_unused;
static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
{
seq_puts(m, "type : scomp\n");
}
static void crypto_scomp_free_scratches(void * __percpu *scratches)
{
int i;
if (!scratches)
return;
for_each_possible_cpu(i)
vfree(*per_cpu_ptr(scratches, i));
free_percpu(scratches);
}
static void * __percpu *crypto_scomp_alloc_scratches(void)
{
void * __percpu *scratches;
int i;
scratches = alloc_percpu(void *);
if (!scratches)
return NULL;
for_each_possible_cpu(i) {
void *scratch;
scratch = vmalloc_node(SCOMP_SCRATCH_SIZE, cpu_to_node(i));
if (!scratch)
goto error;
*per_cpu_ptr(scratches, i) = scratch;
}
return scratches;
error:
crypto_scomp_free_scratches(scratches);
return NULL;
}
static void crypto_scomp_free_all_scratches(void)
{
if (!--scomp_scratch_users) {
crypto_scomp_free_scratches(scomp_src_scratches);
crypto_scomp_free_scratches(scomp_dst_scratches);
scomp_src_scratches = NULL;
scomp_dst_scratches = NULL;
}
}
static int crypto_scomp_alloc_all_scratches(void)
{
if (!scomp_scratch_users++) {
scomp_src_scratches = crypto_scomp_alloc_scratches();
if (!scomp_src_scratches)
return -ENOMEM;
scomp_dst_scratches = crypto_scomp_alloc_scratches();
if (!scomp_dst_scratches) {
crypto_scomp_free_scratches(scomp_src_scratches);
scomp_src_scratches = NULL;
return -ENOMEM;
}
}
return 0;
}
static int crypto_scomp_init_tfm(struct crypto_tfm *tfm)
{
int ret;
mutex_lock(&scomp_lock);
ret = crypto_scomp_alloc_all_scratches();
mutex_unlock(&scomp_lock);
return ret;
}
static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir)
{
struct crypto_acomp *tfm = crypto_acomp_reqtfm(req);
void **tfm_ctx = acomp_tfm_ctx(tfm);
struct crypto_scomp *scomp = *tfm_ctx;
void **ctx = acomp_request_ctx(req);
const int cpu = get_cpu();
u8 *scratch_src = *per_cpu_ptr(scomp_src_scratches, cpu);
u8 *scratch_dst = *per_cpu_ptr(scomp_dst_scratches, cpu);
int ret;
if (!req->src || !req->slen || req->slen > SCOMP_SCRATCH_SIZE) {
ret = -EINVAL;
goto out;
}
if (req->dst && !req->dlen) {
ret = -EINVAL;
goto out;
}
if (!req->dlen || req->dlen > SCOMP_SCRATCH_SIZE)
req->dlen = SCOMP_SCRATCH_SIZE;
scatterwalk_map_and_copy(scratch_src, req->src, 0, req->slen, 0);
if (dir)
ret = crypto_scomp_compress(scomp, scratch_src, req->slen,
scratch_dst, &req->dlen, *ctx);
else
ret = crypto_scomp_decompress(scomp, scratch_src, req->slen,
scratch_dst, &req->dlen, *ctx);
if (!ret) {
if (!req->dst) {
req->dst = sgl_alloc(req->dlen, GFP_ATOMIC, NULL);
if (!req->dst)
goto out;
}
scatterwalk_map_and_copy(scratch_dst, req->dst, 0, req->dlen,
1);
}
out:
put_cpu();
return ret;
}
static int scomp_acomp_compress(struct acomp_req *req)
{
return scomp_acomp_comp_decomp(req, 1);
}
static int scomp_acomp_decompress(struct acomp_req *req)
{
return scomp_acomp_comp_decomp(req, 0);
}
static void crypto_exit_scomp_ops_async(struct crypto_tfm *tfm)
{
struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
crypto_free_scomp(*ctx);
mutex_lock(&scomp_lock);
crypto_scomp_free_all_scratches();
mutex_unlock(&scomp_lock);
}
int crypto_init_scomp_ops_async(struct crypto_tfm *tfm)
{
struct crypto_alg *calg = tfm->__crt_alg;
struct crypto_acomp *crt = __crypto_acomp_tfm(tfm);
struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
struct crypto_scomp *scomp;
if (!crypto_mod_get(calg))
return -EAGAIN;
scomp = crypto_create_tfm(calg, &crypto_scomp_type);
if (IS_ERR(scomp)) {
crypto_mod_put(calg);
return PTR_ERR(scomp);
}
*ctx = scomp;
tfm->exit = crypto_exit_scomp_ops_async;
crt->compress = scomp_acomp_compress;
crt->decompress = scomp_acomp_decompress;
crt->dst_free = sgl_free;
crt->reqsize = sizeof(void *);
return 0;
}
struct acomp_req *crypto_acomp_scomp_alloc_ctx(struct acomp_req *req)
{
struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
struct crypto_scomp *scomp = *tfm_ctx;
void *ctx;
ctx = crypto_scomp_alloc_ctx(scomp);
if (IS_ERR(ctx)) {
kfree(req);
return NULL;
}
*req->__ctx = ctx;
return req;
}
void crypto_acomp_scomp_free_ctx(struct acomp_req *req)
{
struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
struct crypto_scomp *scomp = *tfm_ctx;
void *ctx = *req->__ctx;
if (ctx)
crypto_scomp_free_ctx(scomp, ctx);
}
static const struct crypto_type crypto_scomp_type = {
.extsize = crypto_alg_extsize,
.init_tfm = crypto_scomp_init_tfm,
#ifdef CONFIG_PROC_FS
.show = crypto_scomp_show,
#endif
.report = crypto_scomp_report,
.maskclear = ~CRYPTO_ALG_TYPE_MASK,
.maskset = CRYPTO_ALG_TYPE_MASK,
.type = CRYPTO_ALG_TYPE_SCOMPRESS,
.tfmsize = offsetof(struct crypto_scomp, base),
};
int crypto_register_scomp(struct scomp_alg *alg)
{
struct crypto_alg *base = &alg->base;
base->cra_type = &crypto_scomp_type;
base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
base->cra_flags |= CRYPTO_ALG_TYPE_SCOMPRESS;
return crypto_register_alg(base);
}
EXPORT_SYMBOL_GPL(crypto_register_scomp);
int crypto_unregister_scomp(struct scomp_alg *alg)
{
return crypto_unregister_alg(&alg->base);
}
EXPORT_SYMBOL_GPL(crypto_unregister_scomp);
int crypto_register_scomps(struct scomp_alg *algs, int count)
{
int i, ret;
for (i = 0; i < count; i++) {
ret = crypto_register_scomp(&algs[i]);
if (ret)
goto err;
}
return 0;
err:
for (--i; i >= 0; --i)
crypto_unregister_scomp(&algs[i]);
return ret;
}
EXPORT_SYMBOL_GPL(crypto_register_scomps);
void crypto_unregister_scomps(struct scomp_alg *algs, int count)
{
int i;
for (i = count - 1; i >= 0; --i)
crypto_unregister_scomp(&algs[i]);
}
EXPORT_SYMBOL_GPL(crypto_unregister_scomps);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Synchronous compression type");
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...