AcoSail/kernel_optimize_test
8
0
Fork 0
forked from luck/tmp_suning_uos_patched
Code Pull Requests Activity

drivers, net, mlx5: convert fs_node.refcount from atomic_t to refcount_t

Browse Source 
atomic_t variables are currently used to implement reference
counters with the following properties:
 - counter is initialized to 1 using atomic_set()
 - a resource is freed upon counter reaching zero
 - once counter reaches zero, its further
   increments aren't allowed
 - counter schema uses basic atomic operations
   (set, inc, inc_not_zero, dec_and_test, etc.)

Such atomic variables should be converted to a newly provided
refcount_t type and API that prevents accidental counter overflows
and underflows. This is important since overflows and underflows
can lead to use-after-free situation and be exploitable.

The variable fs_node.refcount is used as pure reference counter.
Convert it to refcount_t and fix up the operations.

Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Windsor <dwindsor@gmail.com>
Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Elena Reshetova 2017-10-20 10:23:41 +03:00 committed by David S. Miller
parent a4b51a9f83
commit dd8e19456d
2 changed files with 16 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
View File

@ -188,7 +188,7 @@ static void tree_init_node(struct fs_node *node,
void (*del_hw_func)(struct fs_node *),
void (*del_sw_func)(struct fs_node *))
{
atomic_set(&node->refcount, 1);
refcount_set(&node->refcount, 1);
INIT_LIST_HEAD(&node->list);
INIT_LIST_HEAD(&node->children);
init_rwsem(&node->lock);
@ -200,7 +200,7 @@ static void tree_init_node(struct fs_node *node,
static void tree_add_node(struct fs_node *node, struct fs_node *parent)
{
if (parent)
atomic_inc(&parent->refcount);
refcount_inc(&parent->refcount);
node->parent = parent;
/* Parent is the root */
@ -212,7 +212,7 @@ static void tree_add_node(struct fs_node *node, struct fs_node *parent)
static int tree_get_node(struct fs_node *node)
{
return atomic_add_unless(&node->refcount, 1, 0);
return refcount_inc_not_zero(&node->refcount);
}
static void nested_down_read_ref_node(struct fs_node *node,
@ -220,7 +220,7 @@ static void nested_down_read_ref_node(struct fs_node *node,
{
if (node) {
down_read_nested(&node->lock, class);
atomic_inc(&node->refcount);
refcount_inc(&node->refcount);
}
}
@ -229,7 +229,7 @@ static void nested_down_write_ref_node(struct fs_node *node,
{
if (node) {
down_write_nested(&node->lock, class);
atomic_inc(&node->refcount);
refcount_inc(&node->refcount);
}
}
@ -237,19 +237,19 @@ static void down_write_ref_node(struct fs_node *node)
{
if (node) {
down_write(&node->lock);
atomic_inc(&node->refcount);
refcount_inc(&node->refcount);
}
}
static void up_read_ref_node(struct fs_node *node)
{
atomic_dec(&node->refcount);
refcount_dec(&node->refcount);
up_read(&node->lock);
}
static void up_write_ref_node(struct fs_node *node)
{
atomic_dec(&node->refcount);
refcount_dec(&node->refcount);
up_write(&node->lock);
}
@ -257,7 +257,7 @@ static void tree_put_node(struct fs_node *node)
{
struct fs_node *parent_node = node->parent;
if (atomic_dec_and_test(&node->refcount)) {
if (refcount_dec_and_test(&node->refcount)) {
if (node->del_hw_func)
node->del_hw_func(node);
if (parent_node) {
@ -280,8 +280,8 @@ static void tree_put_node(struct fs_node *node)
static int tree_remove_node(struct fs_node *node)
{
if (atomic_read(&node->refcount) > 1) {
atomic_dec(&node->refcount);
if (refcount_read(&node->refcount) > 1) {
refcount_dec(&node->refcount);
return -EEXIST;
}
tree_put_node(node);
@ -1184,7 +1184,7 @@ static void destroy_flow_handle(struct fs_fte *fte,
int i)
{
for (; --i >= 0;) {
if (atomic_dec_and_test(&handle->rule[i]->node.refcount)) {
if (refcount_dec_and_test(&handle->rule[i]->node.refcount)) {
fte->dests_size--;
list_del(&handle->rule[i]->node.list);
kfree(handle->rule[i]);
@ -1215,7 +1215,7 @@ create_flow_handle(struct fs_fte *fte,
if (dest) {
rule = find_flow_rule(fte, dest + i);
if (rule) {
atomic_inc(&rule->node.refcount);
refcount_inc(&rule->node.refcount);
goto rule_found;
}
}
@ -1466,7 +1466,7 @@ static struct mlx5_flow_handle *add_rule_fg(struct mlx5_flow_group *fg,
trace_mlx5_fs_set_fte(fte, false);
for (i = 0; i < handle->num_rules; i++) {
if (atomic_read(&handle->rule[i]->node.refcount) == 1) {
if (refcount_read(&handle->rule[i]->node.refcount) == 1) {
tree_add_node(&handle->rule[i]->node, &fte->node);
trace_mlx5_fs_add_rule(handle->rule[i]);
}

3
drivers/net/ethernet/mellanox/mlx5/core/fs_core.h
View File

@ -33,6 +33,7 @@
#ifndef _MLX5_FS_CORE_
#define _MLX5_FS_CORE_
#include <linux/refcount.h>
#include <linux/mlx5/fs.h>
#include <linux/rhashtable.h>
@ -84,7 +85,7 @@ struct fs_node {
struct fs_node *root;
/* lock the node for writing and traversing */
struct rw_semaphore lock;
atomic_t refcount;
refcount_t refcount;
bool active;
void (*del_hw_func)(struct fs_node *);
void (*del_sw_func)(struct fs_node *);