Revision 4de8ebeff8ddefaceeb7fc6a9b1a514fc9624509 authored by Linus Torvalds on 22 February 2016, 22:09:18 UTC, committed by Linus Torvalds on 22 February 2016, 22:09:18 UTC
Pull tracing fixes from Steven Rostedt: "Two more small fixes. One is by Yang Shi who added a READ_ONCE_NOCHECK() to the scan of the stack made by the stack tracer. As the stack tracer scans the entire kernel stack, KASAN triggers seeing it as a "stack out of bounds" error. As the scan is looking at the contents of the stack from parent functions. The NOCHECK() tells KASAN that this is done on purpose, and is not some kind of stack overflow. The second fix is to the ftrace selftests, to retrieve the PID of executed commands from the shell with '$!' and not by parsing 'jobs'" * tag 'trace-fixes-v4.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing, kasan: Silence Kasan warning in check_stack of stack_tracer ftracetest: Fix instance test to use proper shell command for pids
nf_conntrack_extend.c
/* Structure dynamic extension infrastructure
* Copyright (C) 2004 Rusty Russell IBM Corporation
* Copyright (C) 2007 Netfilter Core Team <coreteam@netfilter.org>
* Copyright (C) 2007 USAGI/WIDE Project <http://www.linux-ipv6.org>
*
* 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/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/rcupdate.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <net/netfilter/nf_conntrack_extend.h>
static struct nf_ct_ext_type __rcu *nf_ct_ext_types[NF_CT_EXT_NUM];
static DEFINE_MUTEX(nf_ct_ext_type_mutex);
void __nf_ct_ext_destroy(struct nf_conn *ct)
{
unsigned int i;
struct nf_ct_ext_type *t;
struct nf_ct_ext *ext = ct->ext;
for (i = 0; i < NF_CT_EXT_NUM; i++) {
if (!__nf_ct_ext_exist(ext, i))
continue;
rcu_read_lock();
t = rcu_dereference(nf_ct_ext_types[i]);
/* Here the nf_ct_ext_type might have been unregisterd.
* I.e., it has responsible to cleanup private
* area in all conntracks when it is unregisterd.
*/
if (t && t->destroy)
t->destroy(ct);
rcu_read_unlock();
}
}
EXPORT_SYMBOL(__nf_ct_ext_destroy);
static void *
nf_ct_ext_create(struct nf_ct_ext **ext, enum nf_ct_ext_id id,
size_t var_alloc_len, gfp_t gfp)
{
unsigned int off, len;
struct nf_ct_ext_type *t;
size_t alloc_size;
rcu_read_lock();
t = rcu_dereference(nf_ct_ext_types[id]);
BUG_ON(t == NULL);
off = ALIGN(sizeof(struct nf_ct_ext), t->align);
len = off + t->len + var_alloc_len;
alloc_size = t->alloc_size + var_alloc_len;
rcu_read_unlock();
*ext = kzalloc(alloc_size, gfp);
if (!*ext)
return NULL;
(*ext)->offset[id] = off;
(*ext)->len = len;
return (void *)(*ext) + off;
}
void *__nf_ct_ext_add_length(struct nf_conn *ct, enum nf_ct_ext_id id,
size_t var_alloc_len, gfp_t gfp)
{
struct nf_ct_ext *old, *new;
int i, newlen, newoff;
struct nf_ct_ext_type *t;
/* Conntrack must not be confirmed to avoid races on reallocation. */
NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
old = ct->ext;
if (!old)
return nf_ct_ext_create(&ct->ext, id, var_alloc_len, gfp);
if (__nf_ct_ext_exist(old, id))
return NULL;
rcu_read_lock();
t = rcu_dereference(nf_ct_ext_types[id]);
BUG_ON(t == NULL);
newoff = ALIGN(old->len, t->align);
newlen = newoff + t->len + var_alloc_len;
rcu_read_unlock();
new = __krealloc(old, newlen, gfp);
if (!new)
return NULL;
if (new != old) {
for (i = 0; i < NF_CT_EXT_NUM; i++) {
if (!__nf_ct_ext_exist(old, i))
continue;
rcu_read_lock();
t = rcu_dereference(nf_ct_ext_types[i]);
if (t && t->move)
t->move((void *)new + new->offset[i],
(void *)old + old->offset[i]);
rcu_read_unlock();
}
kfree_rcu(old, rcu);
ct->ext = new;
}
new->offset[id] = newoff;
new->len = newlen;
memset((void *)new + newoff, 0, newlen - newoff);
return (void *)new + newoff;
}
EXPORT_SYMBOL(__nf_ct_ext_add_length);
static void update_alloc_size(struct nf_ct_ext_type *type)
{
int i, j;
struct nf_ct_ext_type *t1, *t2;
enum nf_ct_ext_id min = 0, max = NF_CT_EXT_NUM - 1;
/* unnecessary to update all types */
if ((type->flags & NF_CT_EXT_F_PREALLOC) == 0) {
min = type->id;
max = type->id;
}
/* This assumes that extended areas in conntrack for the types
whose NF_CT_EXT_F_PREALLOC bit set are allocated in order */
for (i = min; i <= max; i++) {
t1 = rcu_dereference_protected(nf_ct_ext_types[i],
lockdep_is_held(&nf_ct_ext_type_mutex));
if (!t1)
continue;
t1->alloc_size = ALIGN(sizeof(struct nf_ct_ext), t1->align) +
t1->len;
for (j = 0; j < NF_CT_EXT_NUM; j++) {
t2 = rcu_dereference_protected(nf_ct_ext_types[j],
lockdep_is_held(&nf_ct_ext_type_mutex));
if (t2 == NULL || t2 == t1 ||
(t2->flags & NF_CT_EXT_F_PREALLOC) == 0)
continue;
t1->alloc_size = ALIGN(t1->alloc_size, t2->align)
+ t2->len;
}
}
}
/* This MUST be called in process context. */
int nf_ct_extend_register(struct nf_ct_ext_type *type)
{
int ret = 0;
mutex_lock(&nf_ct_ext_type_mutex);
if (nf_ct_ext_types[type->id]) {
ret = -EBUSY;
goto out;
}
/* This ensures that nf_ct_ext_create() can allocate enough area
before updating alloc_size */
type->alloc_size = ALIGN(sizeof(struct nf_ct_ext), type->align)
+ type->len;
rcu_assign_pointer(nf_ct_ext_types[type->id], type);
update_alloc_size(type);
out:
mutex_unlock(&nf_ct_ext_type_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(nf_ct_extend_register);
/* This MUST be called in process context. */
void nf_ct_extend_unregister(struct nf_ct_ext_type *type)
{
mutex_lock(&nf_ct_ext_type_mutex);
RCU_INIT_POINTER(nf_ct_ext_types[type->id], NULL);
update_alloc_size(type);
mutex_unlock(&nf_ct_ext_type_mutex);
rcu_barrier(); /* Wait for completion of call_rcu()'s */
}
EXPORT_SYMBOL_GPL(nf_ct_extend_unregister);
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