Revision fe45386a208277cae4648106133c08246eecd012 authored by Maxim Mikityanskiy on 11 June 2020, 10:55:19 UTC, committed by Saeed Mahameed on 22 September 2020, 00:22:21 UTC
Currently, the RQs are temporarily deactivated while hot-replacing the XDP program, and napi_synchronize is used to make sure rq->xdp_prog is not in use. However, napi_synchronize is not ideal: instead of waiting till the end of a NAPI cycle, it polls and waits until NAPI is not running, sleeping for 1ms between the periodic checks. Under heavy workloads, this loop will never end, which may even lead to a kernel panic if the kernel detects the hangup. Such workloads include XSK TX and possibly also heavy RX (XSK or normal). The fix is inspired by commit 326fe02d1ed6 ("net/mlx4_en: protect ring->xdp_prog with rcu_read_lock"). As mlx5e_xdp_handle is already protected by rcu_read_lock, and bpf_prog_put uses call_rcu to free the program, there is no need for additional synchronization if proper RCU functions are used to access the pointer. This patch converts all accesses to rq->xdp_prog to use RCU functions. Fixes: 86994156c736 ("net/mlx5e: XDP fast RX drop bpf programs support") Fixes: db05815b36cb ("net/mlx5e: Add XSK zero-copy support") Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com> Reviewed-by: Tariq Toukan <tariqt@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
1 parent cefc235
blacklist.c
// SPDX-License-Identifier: GPL-2.0-or-later
/* System hash blacklist.
*
* Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#define pr_fmt(fmt) "blacklist: "fmt
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/key.h>
#include <linux/key-type.h>
#include <linux/sched.h>
#include <linux/ctype.h>
#include <linux/err.h>
#include <linux/seq_file.h>
#include <keys/system_keyring.h>
#include "blacklist.h"
static struct key *blacklist_keyring;
/*
* The description must be a type prefix, a colon and then an even number of
* hex digits. The hash is kept in the description.
*/
static int blacklist_vet_description(const char *desc)
{
int n = 0;
if (*desc == ':')
return -EINVAL;
for (; *desc; desc++)
if (*desc == ':')
goto found_colon;
return -EINVAL;
found_colon:
desc++;
for (; *desc; desc++) {
if (!isxdigit(*desc))
return -EINVAL;
n++;
}
if (n == 0 || n & 1)
return -EINVAL;
return 0;
}
/*
* The hash to be blacklisted is expected to be in the description. There will
* be no payload.
*/
static int blacklist_preparse(struct key_preparsed_payload *prep)
{
if (prep->datalen > 0)
return -EINVAL;
return 0;
}
static void blacklist_free_preparse(struct key_preparsed_payload *prep)
{
}
static void blacklist_describe(const struct key *key, struct seq_file *m)
{
seq_puts(m, key->description);
}
static struct key_type key_type_blacklist = {
.name = "blacklist",
.vet_description = blacklist_vet_description,
.preparse = blacklist_preparse,
.free_preparse = blacklist_free_preparse,
.instantiate = generic_key_instantiate,
.describe = blacklist_describe,
};
/**
* mark_hash_blacklisted - Add a hash to the system blacklist
* @hash - The hash as a hex string with a type prefix (eg. "tbs:23aa429783")
*/
int mark_hash_blacklisted(const char *hash)
{
key_ref_t key;
key = key_create_or_update(make_key_ref(blacklist_keyring, true),
"blacklist",
hash,
NULL,
0,
((KEY_POS_ALL & ~KEY_POS_SETATTR) |
KEY_USR_VIEW),
KEY_ALLOC_NOT_IN_QUOTA |
KEY_ALLOC_BUILT_IN);
if (IS_ERR(key)) {
pr_err("Problem blacklisting hash (%ld)\n", PTR_ERR(key));
return PTR_ERR(key);
}
return 0;
}
/**
* is_hash_blacklisted - Determine if a hash is blacklisted
* @hash: The hash to be checked as a binary blob
* @hash_len: The length of the binary hash
* @type: Type of hash
*/
int is_hash_blacklisted(const u8 *hash, size_t hash_len, const char *type)
{
key_ref_t kref;
size_t type_len = strlen(type);
char *buffer, *p;
int ret = 0;
buffer = kmalloc(type_len + 1 + hash_len * 2 + 1, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
p = memcpy(buffer, type, type_len);
p += type_len;
*p++ = ':';
bin2hex(p, hash, hash_len);
p += hash_len * 2;
*p = 0;
kref = keyring_search(make_key_ref(blacklist_keyring, true),
&key_type_blacklist, buffer, false);
if (!IS_ERR(kref)) {
key_ref_put(kref);
ret = -EKEYREJECTED;
}
kfree(buffer);
return ret;
}
EXPORT_SYMBOL_GPL(is_hash_blacklisted);
int is_binary_blacklisted(const u8 *hash, size_t hash_len)
{
if (is_hash_blacklisted(hash, hash_len, "bin") == -EKEYREJECTED)
return -EPERM;
return 0;
}
EXPORT_SYMBOL_GPL(is_binary_blacklisted);
/*
* Initialise the blacklist
*/
static int __init blacklist_init(void)
{
const char *const *bl;
if (register_key_type(&key_type_blacklist) < 0)
panic("Can't allocate system blacklist key type\n");
blacklist_keyring =
keyring_alloc(".blacklist",
KUIDT_INIT(0), KGIDT_INIT(0),
current_cred(),
(KEY_POS_ALL & ~KEY_POS_SETATTR) |
KEY_USR_VIEW | KEY_USR_READ |
KEY_USR_SEARCH,
KEY_ALLOC_NOT_IN_QUOTA |
KEY_FLAG_KEEP,
NULL, NULL);
if (IS_ERR(blacklist_keyring))
panic("Can't allocate system blacklist keyring\n");
for (bl = blacklist_hashes; *bl; bl++)
if (mark_hash_blacklisted(*bl) < 0)
pr_err("- blacklisting failed\n");
return 0;
}
/*
* Must be initialised before we try and load the keys into the keyring.
*/
device_initcall(blacklist_init);
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...