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Merge branch 'bpf-cgroup-local-storage' 

Roman Gushchin says:

====================
This patchset implements cgroup local storage for bpf programs.
The main idea is to provide a fast accessible memory for storing
various per-cgroup data, e.g. number of transmitted packets.

Cgroup local storage looks as a special type of map for userspace,
and is accessible using generic bpf maps API for reading and
updating of the data. The (cgroup inode id, attachment type) pair
is used as a map key.

A user can't create new entries or destroy existing entries;
it happens automatically when a user attaches/detaches a bpf program
to a cgroup.

From a bpf program's point of view, cgroup storage is accessible
without lookup using the special get_local_storage() helper function.
It takes a map fd as an argument. It always returns a valid pointer
to the corresponding memory area.

To implement such a lookup-free access a pointer to the cgroup
storage is saved for an attachment of a bpf program to a cgroup,
if required by the program. Before running the program, it's saved
in a special global per-cpu variable, which is accessible from the
get_local_storage() helper.

This patchset implement only cgroup local storage, however the API
is intentionally made extensible to support other local storage types
further: e.g. thread local storage, socket local storage, etc.

v7->v6:
  - fixed a use-after-free bug, caused by not clearing
    prog->aux->cgroup_storage pointer after releasing the map

v6->v5:
  - fixed an error with returning -EINVAL instead of a pointer

v5->v4:
  - fixed an issue in verifier (test that flags == 0 properly)
  - added a corresponding test
  - added a note about synchronization, sync docs to tools/uapi/...
  - switched the cgroup test to use XADD
  - added a check for attr->max_entries to be 0, and atter->max_flags
    to be sane
  - use bpf_uncharge_memlock() in bpf_uncharge_memlock()
  - rebased to bpf-next

v4->v3:
  - fixed a leak in cgroup attachment code (discovered by Daniel)
  - cgroup storage map will be released if the corresponding
    bpf program failed to load by any reason
  - introduced bpf_uncharge_memlock() helper

v3->v2:
  - fixed more build and sparse issues
  - rebased to bpf-next

v2->v1:
  - fixed build issues
  - removed explicit rlimit calls in patch 14
  - rebased to bpf-next
====================

Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Daniel Borkmann 2018-08-03 00:47:33 +02:00
parent fbeb1603bf 28ba068760
commit 82c018d734
22 changed files with 1031 additions and 88 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
drivers/media/rc/bpf-lirc.c
View File

@ -195,14 +195,16 @@ void lirc_bpf_run(struct rc_dev *rcdev, u32 sample)
*/
void lirc_bpf_free(struct rc_dev *rcdev)
{
struct bpf_prog **progs;
struct bpf_prog_array_item *item;
if (!rcdev->raw->progs)
return;
progs = rcu_dereference(rcdev->raw->progs)->progs;
while (*progs)
bpf_prog_put(*progs++);
item = rcu_dereference(rcdev->raw->progs)->items;
while (item->prog) {
bpf_prog_put(item->prog);
item++;
}
bpf_prog_array_free(rcdev->raw->progs);
}

54
include/linux/bpf-cgroup.h
View File

@ -4,22 +4,46 @@
#include <linux/errno.h>
#include <linux/jump_label.h>
#include <linux/percpu.h>
#include <linux/rbtree.h>
#include <uapi/linux/bpf.h>
struct sock;
struct sockaddr;
struct cgroup;
struct sk_buff;
struct bpf_map;
struct bpf_prog;
struct bpf_sock_ops_kern;
struct bpf_cgroup_storage;
#ifdef CONFIG_CGROUP_BPF
extern struct static_key_false cgroup_bpf_enabled_key;
#define cgroup_bpf_enabled static_branch_unlikely(&cgroup_bpf_enabled_key)
DECLARE_PER_CPU(void*, bpf_cgroup_storage);
struct bpf_cgroup_storage_map;
struct bpf_storage_buffer {
struct rcu_head rcu;
char data[0];
};
struct bpf_cgroup_storage {
struct bpf_storage_buffer *buf;
struct bpf_cgroup_storage_map *map;
struct bpf_cgroup_storage_key key;
struct list_head list;
struct rb_node node;
struct rcu_head rcu;
};
struct bpf_prog_list {
struct list_head node;
struct bpf_prog *prog;
struct bpf_cgroup_storage *storage;
};
struct bpf_prog_array;
@ -77,6 +101,26 @@ int __cgroup_bpf_run_filter_sock_ops(struct sock *sk,
int __cgroup_bpf_check_dev_permission(short dev_type, u32 major, u32 minor,
short access, enum bpf_attach_type type);
static inline void bpf_cgroup_storage_set(struct bpf_cgroup_storage *storage)
{
struct bpf_storage_buffer *buf;
if (!storage)
return;
buf = READ_ONCE(storage->buf);
this_cpu_write(bpf_cgroup_storage, &buf->data[0]);
}
struct bpf_cgroup_storage *bpf_cgroup_storage_alloc(struct bpf_prog *prog);
void bpf_cgroup_storage_free(struct bpf_cgroup_storage *storage);
void bpf_cgroup_storage_link(struct bpf_cgroup_storage *storage,
struct cgroup *cgroup,
enum bpf_attach_type type);
void bpf_cgroup_storage_unlink(struct bpf_cgroup_storage *storage);
int bpf_cgroup_storage_assign(struct bpf_prog *prog, struct bpf_map *map);
void bpf_cgroup_storage_release(struct bpf_prog *prog, struct bpf_map *map);
/* Wrappers for __cgroup_bpf_run_filter_skb() guarded by cgroup_bpf_enabled. */
#define BPF_CGROUP_RUN_PROG_INET_INGRESS(sk, skb) \
({ \
@ -221,6 +265,16 @@ static inline int cgroup_bpf_prog_query(const union bpf_attr *attr,
return -EINVAL;
}
static inline void bpf_cgroup_storage_set(struct bpf_cgroup_storage *storage) {}
static inline int bpf_cgroup_storage_assign(struct bpf_prog *prog,
struct bpf_map *map) { return 0; }
static inline void bpf_cgroup_storage_release(struct bpf_prog *prog,
struct bpf_map *map) {}
static inline struct bpf_cgroup_storage *bpf_cgroup_storage_alloc(
struct bpf_prog *prog) { return 0; }
static inline void bpf_cgroup_storage_free(
struct bpf_cgroup_storage *storage) {}
#define cgroup_bpf_enabled (0)
#define BPF_CGROUP_PRE_CONNECT_ENABLED(sk) (0)
#define BPF_CGROUP_RUN_PROG_INET_INGRESS(sk,skb) ({ 0; })

25
include/linux/bpf.h
View File

@ -155,6 +155,7 @@ enum bpf_arg_type {
enum bpf_return_type {
RET_INTEGER, /* function returns integer */
RET_VOID, /* function doesn't return anything */
RET_PTR_TO_MAP_VALUE, /* returns a pointer to map elem value */
RET_PTR_TO_MAP_VALUE_OR_NULL, /* returns a pointer to map elem value or NULL */
};
@ -282,6 +283,7 @@ struct bpf_prog_aux {
struct bpf_prog *prog;
struct user_struct *user;
u64 load_time; /* ns since boottime */
struct bpf_map *cgroup_storage;
char name[BPF_OBJ_NAME_LEN];
#ifdef CONFIG_SECURITY
void *security;
@ -348,9 +350,14 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
* The 'struct bpf_prog_array *' should only be replaced with xchg()
* since other cpus are walking the array of pointers in parallel.
*/
struct bpf_prog_array_item {
struct bpf_prog *prog;
struct bpf_cgroup_storage *cgroup_storage;
};
struct bpf_prog_array {
struct rcu_head rcu;
struct bpf_prog *progs[0];
struct bpf_prog_array_item items[0];
};
struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags);
@ -371,7 +378,8 @@ int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array,
#define __BPF_PROG_RUN_ARRAY(array, ctx, func, check_non_null) \
({ \
struct bpf_prog **_prog, *__prog; \
struct bpf_prog_array_item *_item; \
struct bpf_prog *_prog; \
struct bpf_prog_array *_array; \
u32 _ret = 1; \
preempt_disable(); \
@ -379,10 +387,11 @@ int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array,
_array = rcu_dereference(array); \
if (unlikely(check_non_null && !_array))\
goto _out; \
_prog = _array->progs; \
while ((__prog = READ_ONCE(*_prog))) { \
_ret &= func(__prog, ctx); \
_prog++; \
_item = &_array->items[0]; \
while ((_prog = READ_ONCE(_item->prog))) { \
bpf_cgroup_storage_set(_item->cgroup_storage); \
_ret &= func(_prog, ctx); \
_item++; \
} \
_out: \
rcu_read_unlock(); \
@ -435,6 +444,8 @@ struct bpf_map * __must_check bpf_map_inc(struct bpf_map *map, bool uref);
void bpf_map_put_with_uref(struct bpf_map *map);
void bpf_map_put(struct bpf_map *map);
int bpf_map_precharge_memlock(u32 pages);
int bpf_map_charge_memlock(struct bpf_map *map, u32 pages);
void bpf_map_uncharge_memlock(struct bpf_map *map, u32 pages);
void *bpf_map_area_alloc(size_t size, int numa_node);
void bpf_map_area_free(void *base);
void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr);
@ -777,6 +788,8 @@ extern const struct bpf_func_proto bpf_sock_map_update_proto;
extern const struct bpf_func_proto bpf_sock_hash_update_proto;
extern const struct bpf_func_proto bpf_get_current_cgroup_id_proto;
extern const struct bpf_func_proto bpf_get_local_storage_proto;
/* Shared helpers among cBPF and eBPF. */
void bpf_user_rnd_init_once(void);
u64 bpf_user_rnd_u32(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);

3
include/linux/bpf_types.h
View File

@ -37,6 +37,9 @@ BPF_MAP_TYPE(BPF_MAP_TYPE_PERF_EVENT_ARRAY, perf_event_array_map_ops)
#ifdef CONFIG_CGROUPS
BPF_MAP_TYPE(BPF_MAP_TYPE_CGROUP_ARRAY, cgroup_array_map_ops)
#endif
#ifdef CONFIG_CGROUP_BPF
BPF_MAP_TYPE(BPF_MAP_TYPE_CGROUP_STORAGE, cgroup_storage_map_ops)
#endif
BPF_MAP_TYPE(BPF_MAP_TYPE_HASH, htab_map_ops)
BPF_MAP_TYPE(BPF_MAP_TYPE_PERCPU_HASH, htab_percpu_map_ops)
BPF_MAP_TYPE(BPF_MAP_TYPE_LRU_HASH, htab_lru_map_ops)

27
include/uapi/linux/bpf.h
View File

@ -75,6 +75,11 @@ struct bpf_lpm_trie_key {
__u8 data[0]; /* Arbitrary size */
};
struct bpf_cgroup_storage_key {
__u64 cgroup_inode_id; /* cgroup inode id */
__u32 attach_type; /* program attach type */
};
/* BPF syscall commands, see bpf(2) man-page for details. */
enum bpf_cmd {
BPF_MAP_CREATE,
@ -120,6 +125,7 @@ enum bpf_map_type {
BPF_MAP_TYPE_CPUMAP,
BPF_MAP_TYPE_XSKMAP,
BPF_MAP_TYPE_SOCKHASH,
BPF_MAP_TYPE_CGROUP_STORAGE,
};
enum bpf_prog_type {
@ -2089,6 +2095,24 @@ union bpf_attr {
* Return
* A 64-bit integer containing the current cgroup id based
* on the cgroup within which the current task is running.
*
* void* get_local_storage(void *map, u64 flags)
* Description
* Get the pointer to the local storage area.
* The type and the size of the local storage is defined
* by the *map* argument.
* The *flags* meaning is specific for each map type,
* and has to be 0 for cgroup local storage.
*
* Depending on the bpf program type, a local storage area
* can be shared between multiple instances of the bpf program,
* running simultaneously.
*
* A user should care about the synchronization by himself.
* For example, by using the BPF_STX_XADD instruction to alter
* the shared data.
* Return
* Pointer to the local storage area.
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@ -2171,7 +2195,8 @@ union bpf_attr {
FN(rc_repeat), \
FN(rc_keydown), \
FN(skb_cgroup_id), \
FN(get_current_cgroup_id),
FN(get_current_cgroup_id), \
FN(get_local_storage),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call

1
kernel/bpf/Makefile
View File

@ -3,6 +3,7 @@ obj-y := core.o
obj-$(CONFIG_BPF_SYSCALL) += syscall.o verifier.o inode.o helpers.o tnum.o
obj-$(CONFIG_BPF_SYSCALL) += hashtab.o arraymap.o percpu_freelist.o bpf_lru_list.o lpm_trie.o map_in_map.o
obj-$(CONFIG_BPF_SYSCALL) += local_storage.o
obj-$(CONFIG_BPF_SYSCALL) += disasm.o
obj-$(CONFIG_BPF_SYSCALL) += btf.o
ifeq ($(CONFIG_NET),y)

58
kernel/bpf/cgroup.c
View File

@ -34,6 +34,8 @@ void cgroup_bpf_put(struct cgroup *cgrp)
list_for_each_entry_safe(pl, tmp, progs, node) {
list_del(&pl->node);
bpf_prog_put(pl->prog);
bpf_cgroup_storage_unlink(pl->storage);
bpf_cgroup_storage_free(pl->storage);
kfree(pl);
static_branch_dec(&cgroup_bpf_enabled_key);
}
@ -115,15 +117,18 @@ static int compute_effective_progs(struct cgroup *cgrp,
cnt = 0;
p = cgrp;
do {
if (cnt == 0 || (p->bpf.flags[type] & BPF_F_ALLOW_MULTI))
list_for_each_entry(pl,
&p->bpf.progs[type], node) {
if (!pl->prog)
continue;
progs->progs[cnt++] = pl->prog;
}
p = cgroup_parent(p);
} while (p);
if (cnt > 0 && !(p->bpf.flags[type] & BPF_F_ALLOW_MULTI))
continue;
list_for_each_entry(pl, &p->bpf.progs[type], node) {
if (!pl->prog)
continue;
progs->items[cnt].prog = pl->prog;
progs->items[cnt].cgroup_storage = pl->storage;
cnt++;
}
} while ((p = cgroup_parent(p)));
rcu_assign_pointer(*array, progs);
return 0;
@ -188,6 +193,7 @@ int __cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog,
{
struct list_head *progs = &cgrp->bpf.progs[type];
struct bpf_prog *old_prog = NULL;
struct bpf_cgroup_storage *storage, *old_storage = NULL;
struct cgroup_subsys_state *css;
struct bpf_prog_list *pl;
bool pl_was_allocated;
@ -210,31 +216,47 @@ int __cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog,
if (prog_list_length(progs) >= BPF_CGROUP_MAX_PROGS)
return -E2BIG;
storage = bpf_cgroup_storage_alloc(prog);
if (IS_ERR(storage))
return -ENOMEM;
if (flags & BPF_F_ALLOW_MULTI) {
list_for_each_entry(pl, progs, node)
if (pl->prog == prog)
list_for_each_entry(pl, progs, node) {
if (pl->prog == prog) {
/* disallow attaching the same prog twice */
bpf_cgroup_storage_free(storage);
return -EINVAL;
}
}
pl = kmalloc(sizeof(*pl), GFP_KERNEL);
if (!pl)
if (!pl) {
bpf_cgroup_storage_free(storage);
return -ENOMEM;
}
pl_was_allocated = true;
pl->prog = prog;
pl->storage = storage;
list_add_tail(&pl->node, progs);
} else {
if (list_empty(progs)) {
pl = kmalloc(sizeof(*pl), GFP_KERNEL);
if (!pl)
if (!pl) {
bpf_cgroup_storage_free(storage);
return -ENOMEM;
}
pl_was_allocated = true;
list_add_tail(&pl->node, progs);
} else {
pl = list_first_entry(progs, typeof(*pl), node);
old_prog = pl->prog;
old_storage = pl->storage;
bpf_cgroup_storage_unlink(old_storage);
pl_was_allocated = false;
}
pl->prog = prog;
pl->storage = storage;
}
cgrp->bpf.flags[type] = flags;
@ -257,10 +279,13 @@ int __cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog,
}
static_branch_inc(&cgroup_bpf_enabled_key);
if (old_storage)
bpf_cgroup_storage_free(old_storage);
if (old_prog) {
bpf_prog_put(old_prog);
static_branch_dec(&cgroup_bpf_enabled_key);
}
bpf_cgroup_storage_link(storage, cgrp, type);
return 0;
cleanup:
@ -276,6 +301,9 @@ cleanup:
/* and cleanup the prog list */
pl->prog = old_prog;
bpf_cgroup_storage_free(pl->storage);
pl->storage = old_storage;
bpf_cgroup_storage_link(old_storage, cgrp, type);
if (pl_was_allocated) {
list_del(&pl->node);
kfree(pl);
@ -356,6 +384,8 @@ int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
/* now can actually delete it from this cgroup list */
list_del(&pl->node);
bpf_cgroup_storage_unlink(pl->storage);
bpf_cgroup_storage_free(pl->storage);
kfree(pl);
if (list_empty(progs))
/* last program was detached, reset flags to zero */
@ -654,6 +684,8 @@ cgroup_dev_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_map_delete_elem_proto;
case BPF_FUNC_get_current_uid_gid:
return &bpf_get_current_uid_gid_proto;
case BPF_FUNC_get_local_storage:
return &bpf_get_local_storage_proto;
case BPF_FUNC_trace_printk:
if (capable(CAP_SYS_ADMIN))
return bpf_get_trace_printk_proto();

77
kernel/bpf/core.c
View File

@ -1542,7 +1542,8 @@ struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags)
{
if (prog_cnt)
return kzalloc(sizeof(struct bpf_prog_array) +
sizeof(struct bpf_prog *) * (prog_cnt + 1),
sizeof(struct bpf_prog_array_item) *
(prog_cnt + 1),
flags);
return &empty_prog_array.hdr;
@ -1556,43 +1557,45 @@ void bpf_prog_array_free(struct bpf_prog_array __rcu *progs)
kfree_rcu(progs, rcu);
}
int bpf_prog_array_length(struct bpf_prog_array __rcu *progs)
int bpf_prog_array_length(struct bpf_prog_array __rcu *array)
{
struct bpf_prog **prog;
struct bpf_prog_array_item *item;
u32 cnt = 0;
rcu_read_lock();
prog = rcu_dereference(progs)->progs;
for (; *prog; prog++)
if (*prog != &dummy_bpf_prog.prog)
item = rcu_dereference(array)->items;
for (; item->prog; item++)
if (item->prog != &dummy_bpf_prog.prog)
cnt++;
rcu_read_unlock();
return cnt;
}
static bool bpf_prog_array_copy_core(struct bpf_prog **prog,
static bool bpf_prog_array_copy_core(struct bpf_prog_array __rcu *array,
u32 *prog_ids,
u32 request_cnt)
{
struct bpf_prog_array_item *item;
int i = 0;
for (; *prog; prog++) {
if (*prog == &dummy_bpf_prog.prog)
item = rcu_dereference(array)->items;
for (; item->prog; item++) {
if (item->prog == &dummy_bpf_prog.prog)
continue;
prog_ids[i] = (*prog)->aux->id;
prog_ids[i] = item->prog->aux->id;
if (++i == request_cnt) {
prog++;
item++;
break;
}
}
return !!(*prog);
return !!(item->prog);
}
int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *progs,
int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *array,
__u32 __user *prog_ids, u32 cnt)
{
struct bpf_prog **prog;
unsigned long err = 0;
bool nospc;
u32 *ids;
@ -1611,8 +1614,7 @@ int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *progs,
if (!ids)
return -ENOMEM;
rcu_read_lock();
prog = rcu_dereference(progs)->progs;
nospc = bpf_prog_array_copy_core(prog, ids, cnt);
nospc = bpf_prog_array_copy_core(array, ids, cnt);
rcu_read_unlock();
err = copy_to_user(prog_ids, ids, cnt * sizeof(u32));
kfree(ids);
@ -1623,14 +1625,14 @@ int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *progs,
return 0;
}
void bpf_prog_array_delete_safe(struct bpf_prog_array __rcu *progs,
void bpf_prog_array_delete_safe(struct bpf_prog_array __rcu *array,
struct bpf_prog *old_prog)
{
struct bpf_prog **prog = progs->progs;
struct bpf_prog_array_item *item = array->items;
for (; *prog; prog++)
if (*prog == old_prog) {
WRITE_ONCE(*prog, &dummy_bpf_prog.prog);
for (; item->prog; item++)
if (item->prog == old_prog) {
WRITE_ONCE(item->prog, &dummy_bpf_prog.prog);
break;
}
}
@ -1641,7 +1643,7 @@ int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array,
struct bpf_prog_array **new_array)
{
int new_prog_cnt, carry_prog_cnt = 0;
struct bpf_prog **existing_prog;
struct bpf_prog_array_item *existing;
struct bpf_prog_array *array;
bool found_exclude = false;
int new_prog_idx = 0;
@ -1650,15 +1652,15 @@ int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array,
* the new array.
*/
if (old_array) {
existing_prog = old_array->progs;
for (; *existing_prog; existing_prog++) {
if (*existing_prog == exclude_prog) {
existing = old_array->items;
for (; existing->prog; existing++) {
if (existing->prog == exclude_prog) {
found_exclude = true;
continue;
}
if (*existing_prog != &dummy_bpf_prog.prog)
if (existing->prog != &dummy_bpf_prog.prog)
carry_prog_cnt++;
if (*existing_prog == include_prog)
if (existing->prog == include_prog)
return -EEXIST;
}
}
@ -1684,15 +1686,17 @@ int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array,
/* Fill in the new prog array */
if (carry_prog_cnt) {
existing_prog = old_array->progs;
for (; *existing_prog; existing_prog++)
if (*existing_prog != exclude_prog &&
*existing_prog != &dummy_bpf_prog.prog)
array->progs[new_prog_idx++] = *existing_prog;
existing = old_array->items;
for (; existing->prog; existing++)
if (existing->prog != exclude_prog &&
existing->prog != &dummy_bpf_prog.prog) {
array->items[new_prog_idx++].prog =
existing->prog;
}
}
if (include_prog)
array->progs[new_prog_idx++] = include_prog;
array->progs[new_prog_idx] = NULL;
array->items[new_prog_idx++].prog = include_prog;
array->items[new_prog_idx].prog = NULL;
*new_array = array;
return 0;
}
@ -1701,7 +1705,6 @@ int bpf_prog_array_copy_info(struct bpf_prog_array __rcu *array,
u32 *prog_ids, u32 request_cnt,
u32 *prog_cnt)
{
struct bpf_prog **prog;
u32 cnt = 0;
if (array)
@ -1714,8 +1717,7 @@ int bpf_prog_array_copy_info(struct bpf_prog_array __rcu *array,
return 0;
/* this function is called under trace/bpf_trace.c: bpf_event_mutex */
prog = rcu_dereference_check(array, 1)->progs;
return bpf_prog_array_copy_core(prog, prog_ids, request_cnt) ? -ENOSPC
return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC
: 0;
}
@ -1793,6 +1795,7 @@ const struct bpf_func_proto bpf_get_current_comm_proto __weak;
const struct bpf_func_proto bpf_sock_map_update_proto __weak;
const struct bpf_func_proto bpf_sock_hash_update_proto __weak;
const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
const struct bpf_func_proto bpf_get_local_storage_proto __weak;
const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
{

20
kernel/bpf/helpers.c
View File

@ -193,4 +193,24 @@ const struct bpf_func_proto bpf_get_current_cgroup_id_proto = {
.gpl_only = false,
.ret_type = RET_INTEGER,
};
DECLARE_PER_CPU(void*, bpf_cgroup_storage);
BPF_CALL_2(bpf_get_local_storage, struct bpf_map *, map, u64, flags)
{
/* map and flags arguments are not used now,
* but provide an ability to extend the API
* for other types of local storages.
* verifier checks that their values are correct.
*/
return (unsigned long) this_cpu_read(bpf_cgroup_storage);
}
const struct bpf_func_proto bpf_get_local_storage_proto = {
.func = bpf_get_local_storage,
.gpl_only = false,
.ret_type = RET_PTR_TO_MAP_VALUE,
.arg1_type = ARG_CONST_MAP_PTR,
.arg2_type = ARG_ANYTHING,
};
#endif

378
kernel/bpf/local_storage.c Normal file
View File

@ -0,0 +1,378 @@
//SPDX-License-Identifier: GPL-2.0
#include <linux/bpf-cgroup.h>
#include <linux/bpf.h>
#include <linux/bug.h>
#include <linux/filter.h>
#include <linux/mm.h>
#include <linux/rbtree.h>
#include <linux/slab.h>
DEFINE_PER_CPU(void*, bpf_cgroup_storage);
#ifdef CONFIG_CGROUP_BPF
#define LOCAL_STORAGE_CREATE_FLAG_MASK \
(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
struct bpf_cgroup_storage_map {
struct bpf_map map;
spinlock_t lock;
struct bpf_prog *prog;
struct rb_root root;
struct list_head list;
};
static struct bpf_cgroup_storage_map *map_to_storage(struct bpf_map *map)
{
return container_of(map, struct bpf_cgroup_storage_map, map);
}
static int bpf_cgroup_storage_key_cmp(
const struct bpf_cgroup_storage_key *key1,
const struct bpf_cgroup_storage_key *key2)
{
if (key1->cgroup_inode_id < key2->cgroup_inode_id)
return -1;
else if (key1->cgroup_inode_id > key2->cgroup_inode_id)
return 1;
else if (key1->attach_type < key2->attach_type)
return -1;
else if (key1->attach_type > key2->attach_type)
return 1;
return 0;
}
static struct bpf_cgroup_storage *cgroup_storage_lookup(
struct bpf_cgroup_storage_map *map, struct bpf_cgroup_storage_key *key,
bool locked)
{
struct rb_root *root = &map->root;
struct rb_node *node;
if (!locked)
spin_lock_bh(&map->lock);
node = root->rb_node;
while (node) {
struct bpf_cgroup_storage *storage;
storage = container_of(node, struct bpf_cgroup_storage, node);
switch (bpf_cgroup_storage_key_cmp(key, &storage->key)) {
case -1:
node = node->rb_left;
break;
case 1:
node = node->rb_right;
break;
default:
if (!locked)
spin_unlock_bh(&map->lock);
return storage;
}
}
if (!locked)
spin_unlock_bh(&map->lock);
return NULL;
}
static int cgroup_storage_insert(struct bpf_cgroup_storage_map *map,
struct bpf_cgroup_storage *storage)
{
struct rb_root *root = &map->root;
struct rb_node **new = &(root->rb_node), *parent = NULL;
while (*new) {
struct bpf_cgroup_storage *this;
this = container_of(*new, struct bpf_cgroup_storage, node);
parent = *new;
switch (bpf_cgroup_storage_key_cmp(&storage->key, &this->key)) {
case -1:
new = &((*new)->rb_left);
break;
case 1:
new = &((*new)->rb_right);
break;
default:
return -EEXIST;
}
}
rb_link_node(&storage->node, parent, new);
rb_insert_color(&storage->node, root);
return 0;
}
static void *cgroup_storage_lookup_elem(struct bpf_map *_map, void *_key)
{
struct bpf_cgroup_storage_map *map = map_to_storage(_map);
struct bpf_cgroup_storage_key *key = _key;
struct bpf_cgroup_storage *storage;
storage = cgroup_storage_lookup(map, key, false);
if (!storage)
return NULL;
return &READ_ONCE(storage->buf)->data[0];
}
static int cgroup_storage_update_elem(struct bpf_map *map, void *_key,
void *value, u64 flags)
{
struct bpf_cgroup_storage_key *key = _key;
struct bpf_cgroup_storage *storage;
struct bpf_storage_buffer *new;
if (flags & BPF_NOEXIST)
return -EINVAL;
storage = cgroup_storage_lookup((struct bpf_cgroup_storage_map *)map,
key, false);
if (!storage)
return -ENOENT;
new = kmalloc_node(sizeof(struct bpf_storage_buffer) +
map->value_size, __GFP_ZERO | GFP_USER,
map->numa_node);
if (!new)
return -ENOMEM;
memcpy(&new->data[0], value, map->value_size);
new = xchg(&storage->buf, new);
kfree_rcu(new, rcu);
return 0;
}
static int cgroup_storage_get_next_key(struct bpf_map *_map, void *_key,
void *_next_key)
{
struct bpf_cgroup_storage_map *map = map_to_storage(_map);
struct bpf_cgroup_storage_key *key = _key;
struct bpf_cgroup_storage_key *next = _next_key;
struct bpf_cgroup_storage *storage;
spin_lock_bh(&map->lock);
if (list_empty(&map->list))
goto enoent;
if (key) {
storage = cgroup_storage_lookup(map, key, true);
if (!storage)
goto enoent;
storage = list_next_entry(storage, list);
if (!storage)
goto enoent;
} else {
storage = list_first_entry(&map->list,
struct bpf_cgroup_storage, list);
}
spin_unlock_bh(&map->lock);
next->attach_type = storage->key.attach_type;
next->cgroup_inode_id = storage->key.cgroup_inode_id;
return 0;
enoent:
spin_unlock_bh(&map->lock);
return -ENOENT;
}
static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr)
{
int numa_node = bpf_map_attr_numa_node(attr);
struct bpf_cgroup_storage_map *map;
if (attr->key_size != sizeof(struct bpf_cgroup_storage_key))
return ERR_PTR(-EINVAL);
if (attr->value_size > PAGE_SIZE)
return ERR_PTR(-E2BIG);
if (attr->map_flags & ~LOCAL_STORAGE_CREATE_FLAG_MASK)
/* reserved bits should not be used */
return ERR_PTR(-EINVAL);
if (attr->max_entries)
/* max_entries is not used and enforced to be 0 */
return ERR_PTR(-EINVAL);
map = kmalloc_node(sizeof(struct bpf_cgroup_storage_map),
__GFP_ZERO | GFP_USER, numa_node);
if (!map)
return ERR_PTR(-ENOMEM);
map->map.pages = round_up(sizeof(struct bpf_cgroup_storage_map),
PAGE_SIZE) >> PAGE_SHIFT;
/* copy mandatory map attributes */
bpf_map_init_from_attr(&map->map, attr);
spin_lock_init(&map->lock);
map->root = RB_ROOT;
INIT_LIST_HEAD(&map->list);
return &map->map;
}
static void cgroup_storage_map_free(struct bpf_map *_map)
{
struct bpf_cgroup_storage_map *map = map_to_storage(_map);
WARN_ON(!RB_EMPTY_ROOT(&map->root));
WARN_ON(!list_empty(&map->list));
kfree(map);
}
static int cgroup_storage_delete_elem(struct bpf_map *map, void *key)
{
return -EINVAL;
}
const struct bpf_map_ops cgroup_storage_map_ops = {
.map_alloc = cgroup_storage_map_alloc,
.map_free = cgroup_storage_map_free,
.map_get_next_key = cgroup_storage_get_next_key,
.map_lookup_elem = cgroup_storage_lookup_elem,
.map_update_elem = cgroup_storage_update_elem,
.map_delete_elem = cgroup_storage_delete_elem,
};
int bpf_cgroup_storage_assign(struct bpf_prog *prog, struct bpf_map *_map)
{
struct bpf_cgroup_storage_map *map = map_to_storage(_map);
int ret = -EBUSY;
spin_lock_bh(&map->lock);
if (map->prog && map->prog != prog)
goto unlock;
if (prog->aux->cgroup_storage && prog->aux->cgroup_storage != _map)
goto unlock;
map->prog = prog;
prog->aux->cgroup_storage = _map;
ret = 0;
unlock:
spin_unlock_bh(&map->lock);
return ret;
}
void bpf_cgroup_storage_release(struct bpf_prog *prog, struct bpf_map *_map)
{
struct bpf_cgroup_storage_map *map = map_to_storage(_map);
spin_lock_bh(&map->lock);
if (map->prog == prog) {
WARN_ON(prog->aux->cgroup_storage != _map);
map->prog = NULL;
prog->aux->cgroup_storage = NULL;
}
spin_unlock_bh(&map->lock);
}
struct bpf_cgroup_storage *bpf_cgroup_storage_alloc(struct bpf_prog *prog)
{
struct bpf_cgroup_storage *storage;
struct bpf_map *map;
u32 pages;
map = prog->aux->cgroup_storage;
if (!map)
return NULL;
pages = round_up(sizeof(struct bpf_cgroup_storage) +
sizeof(struct bpf_storage_buffer) +
map->value_size, PAGE_SIZE) >> PAGE_SHIFT;
if (bpf_map_charge_memlock(map, pages))
return ERR_PTR(-EPERM);
storage = kmalloc_node(sizeof(struct bpf_cgroup_storage),
__GFP_ZERO | GFP_USER, map->numa_node);
if (!storage) {
bpf_map_uncharge_memlock(map, pages);
return ERR_PTR(-ENOMEM);
}
storage->buf = kmalloc_node(sizeof(struct bpf_storage_buffer) +
map->value_size, __GFP_ZERO | GFP_USER,
map->numa_node);
if (!storage->buf) {
bpf_map_uncharge_memlock(map, pages);
kfree(storage);
return ERR_PTR(-ENOMEM);
}
storage->map = (struct bpf_cgroup_storage_map *)map;
return storage;
}
void bpf_cgroup_storage_free(struct bpf_cgroup_storage *storage)
{
u32 pages;
struct bpf_map *map;
if (!storage)
return;
map = &storage->map->map;
pages = round_up(sizeof(struct bpf_cgroup_storage) +
sizeof(struct bpf_storage_buffer) +
map->value_size, PAGE_SIZE) >> PAGE_SHIFT;
bpf_map_uncharge_memlock(map, pages);
kfree_rcu(storage->buf, rcu);
kfree_rcu(storage, rcu);
}
void bpf_cgroup_storage_link(struct bpf_cgroup_storage *storage,
struct cgroup *cgroup,
enum bpf_attach_type type)
{
struct bpf_cgroup_storage_map *map;
if (!storage)
return;
storage->key.attach_type = type;
storage->key.cgroup_inode_id = cgroup->kn->id.id;
map = storage->map;
spin_lock_bh(&map->lock);
WARN_ON(cgroup_storage_insert(map, storage));
list_add(&storage->list, &map->list);
spin_unlock_bh(&map->lock);
}
void bpf_cgroup_storage_unlink(struct bpf_cgroup_storage *storage)
{
struct bpf_cgroup_storage_map *map;
struct rb_root *root;
if (!storage)
return;
map = storage->map;
spin_lock_bh(&map->lock);
root = &map->root;
rb_erase(&storage->node, root);
list_del(&storage->list);
spin_unlock_bh(&map->lock);
}
#endif

3
kernel/bpf/map_in_map.c
View File

@ -23,7 +23,8 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd)
* is a runtime binding. Doing static check alone
* in the verifier is not enough.
*/
if (inner_map->map_type == BPF_MAP_TYPE_PROG_ARRAY) {
if (inner_map->map_type == BPF_MAP_TYPE_PROG_ARRAY ||
inner_map->map_type == BPF_MAP_TYPE_CGROUP_STORAGE) {
fdput(f);
return ERR_PTR(-ENOTSUPP);
}

65
kernel/bpf/syscall.c
View File

@ -181,32 +181,60 @@ int bpf_map_precharge_memlock(u32 pages)
return 0;
}
static int bpf_map_charge_memlock(struct bpf_map *map)
static int bpf_charge_memlock(struct user_struct *user, u32 pages)
{
struct user_struct *user = get_current_user();
unsigned long memlock_limit;
unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
atomic_long_add(map->pages, &user->locked_vm);
if (atomic_long_read(&user->locked_vm) > memlock_limit) {
atomic_long_sub(map->pages, &user->locked_vm);
free_uid(user);
if (atomic_long_add_return(pages, &user->locked_vm) > memlock_limit) {
atomic_long_sub(pages, &user->locked_vm);
return -EPERM;
}
map->user = user;
return 0;
}
static void bpf_map_uncharge_memlock(struct bpf_map *map)
static void bpf_uncharge_memlock(struct user_struct *user, u32 pages)
{
atomic_long_sub(pages, &user->locked_vm);
}
static int bpf_map_init_memlock(struct bpf_map *map)
{
struct user_struct *user = get_current_user();
int ret;
ret = bpf_charge_memlock(user, map->pages);
if (ret) {
free_uid(user);
return ret;
}
map->user = user;
return ret;
}
static void bpf_map_release_memlock(struct bpf_map *map)
{
struct user_struct *user = map->user;
atomic_long_sub(map->pages, &user->locked_vm);
bpf_uncharge_memlock(user, map->pages);
free_uid(user);
}
int bpf_map_charge_memlock(struct bpf_map *map, u32 pages)
{
int ret;
ret = bpf_charge_memlock(map->user, pages);
if (ret)
return ret;
map->pages += pages;
return ret;
}
void bpf_map_uncharge_memlock(struct bpf_map *map, u32 pages)
{
bpf_uncharge_memlock(map->user, pages);
map->pages -= pages;
}
static int bpf_map_alloc_id(struct bpf_map *map)
{
int id;
@ -256,7 +284,7 @@ static void bpf_map_free_deferred(struct work_struct *work)
{
struct bpf_map *map = container_of(work, struct bpf_map, work);
bpf_map_uncharge_memlock(map);
bpf_map_release_memlock(map);
security_bpf_map_free(map);
/* implementation dependent freeing */
map->ops->map_free(map);
@ -492,7 +520,7 @@ static int map_create(union bpf_attr *attr)
if (err)
goto free_map_nouncharge;
err = bpf_map_charge_memlock(map);
err = bpf_map_init_memlock(map);
if (err)
goto free_map_sec;
@ -515,7 +543,7 @@ static int map_create(union bpf_attr *attr)
return err;
free_map:
bpf_map_uncharge_memlock(map);
bpf_map_release_memlock(map);
free_map_sec:
security_bpf_map_free(map);
free_map_nouncharge:
@ -929,6 +957,9 @@ static void free_used_maps(struct bpf_prog_aux *aux)
{
int i;
if (aux->cgroup_storage)
bpf_cgroup_storage_release(aux->prog, aux->cgroup_storage);
for (i = 0; i < aux->used_map_cnt; i++)
bpf_map_put(aux->used_maps[i]);

38
kernel/bpf/verifier.c
View File

@ -2127,6 +2127,10 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env,
func_id != BPF_FUNC_current_task_under_cgroup)
goto error;
break;
case BPF_MAP_TYPE_CGROUP_STORAGE:
if (func_id != BPF_FUNC_get_local_storage)
goto error;
break;
/* devmap returns a pointer to a live net_device ifindex that we cannot
* allow to be modified from bpf side. So do not allow lookup elements
* for now.
@ -2209,6 +2213,10 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env,
if (map->map_type != BPF_MAP_TYPE_SOCKHASH)
goto error;
break;
case BPF_FUNC_get_local_storage:
if (map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE)
goto error;
break;
default:
break;
}
@ -2533,6 +2541,16 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
}
regs = cur_regs(env);
/* check that flags argument in get_local_storage(map, flags) is 0,
* this is required because get_local_storage() can't return an error.
*/
if (func_id == BPF_FUNC_get_local_storage &&
!register_is_null(&regs[BPF_REG_2])) {
verbose(env, "get_local_storage() doesn't support non-zero flags\n");
return -EINVAL;
}
/* reset caller saved regs */
for (i = 0; i < CALLER_SAVED_REGS; i++) {
mark_reg_not_init(env, regs, caller_saved[i]);
@ -2545,8 +2563,12 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
mark_reg_unknown(env, regs, BPF_REG_0);
} else if (fn->ret_type == RET_VOID) {
regs[BPF_REG_0].type = NOT_INIT;
} else if (fn->ret_type == RET_PTR_TO_MAP_VALUE_OR_NULL) {
regs[BPF_REG_0].type = PTR_TO_MAP_VALUE_OR_NULL;
} else if (fn->ret_type == RET_PTR_TO_MAP_VALUE_OR_NULL ||
fn->ret_type == RET_PTR_TO_MAP_VALUE) {
if (fn->ret_type == RET_PTR_TO_MAP_VALUE)
regs[BPF_REG_0].type = PTR_TO_MAP_VALUE;
else
regs[BPF_REG_0].type = PTR_TO_MAP_VALUE_OR_NULL;
/* There is no offset yet applied, variable or fixed */
mark_reg_known_zero(env, regs, BPF_REG_0);
regs[BPF_REG_0].off = 0;
@ -5154,6 +5176,14 @@ static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env)
}
env->used_maps[env->used_map_cnt++] = map;
if (map->map_type == BPF_MAP_TYPE_CGROUP_STORAGE &&
bpf_cgroup_storage_assign(env->prog, map)) {
verbose(env,
"only one cgroup storage is allowed\n");
fdput(f);
return -EBUSY;
}
fdput(f);
next_insn:
insn++;
@ -5180,6 +5210,10 @@ static void release_maps(struct bpf_verifier_env *env)
{
int i;
if (env->prog->aux->cgroup_storage)
bpf_cgroup_storage_release(env->prog,
env->prog->aux->cgroup_storage);
for (i = 0; i < env->used_map_cnt; i++)
bpf_map_put(env->used_maps[i]);
}

13
net/bpf/test_run.c
View File

@ -11,12 +11,14 @@
#include <linux/filter.h>
#include <linux/sched/signal.h>
static __always_inline u32 bpf_test_run_one(struct bpf_prog *prog, void *ctx)
static __always_inline u32 bpf_test_run_one(struct bpf_prog *prog, void *ctx,
struct bpf_cgroup_storage *storage)
{
u32 ret;
preempt_disable();
rcu_read_lock();
bpf_cgroup_storage_set(storage);
ret = BPF_PROG_RUN(prog, ctx);
rcu_read_unlock();
preempt_enable();
@ -26,14 +28,19 @@ static __always_inline u32 bpf_test_run_one(struct bpf_prog *prog, void *ctx)
static u32 bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat, u32 *time)
{
struct bpf_cgroup_storage *storage = NULL;
u64 time_start, time_spent = 0;
u32 ret = 0, i;
storage = bpf_cgroup_storage_alloc(prog);
if (IS_ERR(storage))
return PTR_ERR(storage);
if (!repeat)
repeat = 1;
time_start = ktime_get_ns();
for (i = 0; i < repeat; i++) {
ret = bpf_test_run_one(prog, ctx);
ret = bpf_test_run_one(prog, ctx, storage);
if (need_resched()) {
if (signal_pending(current))
break;
@ -46,6 +53,8 @@ static u32 bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat, u32 *time)
do_div(time_spent, repeat);
*time = time_spent > U32_MAX ? U32_MAX : (u32)time_spent;
bpf_cgroup_storage_free(storage);
return ret;
}

23
net/core/filter.c
View File

@ -4820,6 +4820,8 @@ sock_filter_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
*/
case BPF_FUNC_get_current_uid_gid:
return &bpf_get_current_uid_gid_proto;
case BPF_FUNC_get_local_storage:
return &bpf_get_local_storage_proto;
default:
return bpf_base_func_proto(func_id);
}
@ -4844,6 +4846,8 @@ sock_addr_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
}
case BPF_FUNC_get_socket_cookie:
return &bpf_get_socket_cookie_sock_addr_proto;
case BPF_FUNC_get_local_storage:
return &bpf_get_local_storage_proto;
default:
return bpf_base_func_proto(func_id);
}
@ -4866,6 +4870,17 @@ sk_filter_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
}
}
static const struct bpf_func_proto *
cg_skb_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
switch (func_id) {
case BPF_FUNC_get_local_storage:
return &bpf_get_local_storage_proto;
default:
return sk_filter_func_proto(func_id, prog);
}
}
static const struct bpf_func_proto *
tc_cls_act_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
@ -4988,6 +5003,8 @@ sock_ops_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_sock_hash_update_proto;
case BPF_FUNC_get_socket_cookie:
return &bpf_get_socket_cookie_sock_ops_proto;
case BPF_FUNC_get_local_storage:
return &bpf_get_local_storage_proto;
default:
return bpf_base_func_proto(func_id);
}
@ -5007,6 +5024,8 @@ sk_msg_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_msg_cork_bytes_proto;
case BPF_FUNC_msg_pull_data:
return &bpf_msg_pull_data_proto;
case BPF_FUNC_get_local_storage:
return &bpf_get_local_storage_proto;
default:
return bpf_base_func_proto(func_id);
}
@ -5034,6 +5053,8 @@ sk_skb_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_sk_redirect_map_proto;
case BPF_FUNC_sk_redirect_hash:
return &bpf_sk_redirect_hash_proto;
case BPF_FUNC_get_local_storage:
return &bpf_get_local_storage_proto;
default:
return bpf_base_func_proto(func_id);
}
@ -6838,7 +6859,7 @@ const struct bpf_prog_ops xdp_prog_ops = {
};
const struct bpf_verifier_ops cg_skb_verifier_ops = {
.get_func_proto = sk_filter_func_proto,
.get_func_proto = cg_skb_func_proto,
.is_valid_access = sk_filter_is_valid_access,
.convert_ctx_access = bpf_convert_ctx_access,
};

21
samples/bpf/test_cgrp2_attach2.c
View File

@ -8,7 +8,8 @@
* information. The number of invocations of the program, which maps
* to the number of packets received, is stored to key 0. Key 1 is
* incremented on each iteration by the number of bytes stored in
* the skb.
* the skb. The program also stores the number of received bytes
* in the cgroup storage.
*
* - Attaches the new program to a cgroup using BPF_PROG_ATTACH
*
@ -21,12 +22,15 @@
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <sys/resource.h>
#include <sys/time.h>
#include <unistd.h>
#include <linux/bpf.h>
#include <bpf/bpf.h>
#include "bpf_insn.h"
#include "bpf_rlimit.h"
#include "cgroup_helpers.h"
#define FOO "/foo"
@ -205,6 +209,8 @@ static int map_fd = -1;
static int prog_load_cnt(int verdict, int val)
{
int cgroup_storage_fd;
if (map_fd < 0)
map_fd = bpf_create_map(BPF_MAP_TYPE_ARRAY, 4, 8, 1, 0);
if (map_fd < 0) {
@ -212,6 +218,13 @@ static int prog_load_cnt(int verdict, int val)
return -1;
}
cgroup_storage_fd = bpf_create_map(BPF_MAP_TYPE_CGROUP_STORAGE,
sizeof(struct bpf_cgroup_storage_key), 8, 0, 0);
if (cgroup_storage_fd < 0) {
printf("failed to create map '%s'\n", strerror(errno));
return -1;
}
struct bpf_insn prog[] = {
BPF_MOV32_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -4), /* *(u32 *)(fp - 4) = r0 */
@ -222,6 +235,11 @@ static int prog_load_cnt(int verdict, int val)
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
BPF_MOV64_IMM(BPF_REG_1, val), /* r1 = 1 */
BPF_RAW_INSN(BPF_STX | BPF_XADD | BPF_DW, BPF_REG_0, BPF_REG_1, 0, 0), /* xadd r0 += r1 */
BPF_LD_MAP_FD(BPF_REG_1, cgroup_storage_fd),
BPF_MOV64_IMM(BPF_REG_2, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_get_local_storage),
BPF_MOV64_IMM(BPF_REG_1, val),
BPF_RAW_INSN(BPF_STX | BPF_XADD | BPF_W, BPF_REG_0, BPF_REG_1, 0, 0),
BPF_MOV64_IMM(BPF_REG_0, verdict), /* r0 = verdict */
BPF_EXIT_INSN(),
};
@ -237,6 +255,7 @@ static int prog_load_cnt(int verdict, int val)
printf("Output from verifier:\n%s\n-------\n", bpf_log_buf);
return 0;
}
close(cgroup_storage_fd);
return ret;
}

1
tools/bpf/bpftool/map.c
View File

@ -68,6 +68,7 @@ static const char * const map_type_name[] = {
[BPF_MAP_TYPE_SOCKMAP] = "sockmap",
[BPF_MAP_TYPE_CPUMAP] = "cpumap",
[BPF_MAP_TYPE_SOCKHASH] = "sockhash",
[BPF_MAP_TYPE_CGROUP_STORAGE] = "cgroup_storage",
};
static bool map_is_per_cpu(__u32 type)

27
tools/include/uapi/linux/bpf.h
View File

@ -75,6 +75,11 @@ struct bpf_lpm_trie_key {
__u8 data[0]; /* Arbitrary size */
};
struct bpf_cgroup_storage_key {
__u64 cgroup_inode_id; /* cgroup inode id */
__u32 attach_type; /* program attach type */
};
/* BPF syscall commands, see bpf(2) man-page for details. */
enum bpf_cmd {
BPF_MAP_CREATE,
@ -120,6 +125,7 @@ enum bpf_map_type {
BPF_MAP_TYPE_CPUMAP,
BPF_MAP_TYPE_XSKMAP,
BPF_MAP_TYPE_SOCKHASH,
BPF_MAP_TYPE_CGROUP_STORAGE,
};
enum bpf_prog_type {
@ -2089,6 +2095,24 @@ union bpf_attr {
* Return
* A 64-bit integer containing the current cgroup id based
* on the cgroup within which the current task is running.
*
* void* get_local_storage(void *map, u64 flags)
* Description
* Get the pointer to the local storage area.
* The type and the size of the local storage is defined
* by the *map* argument.
* The *flags* meaning is specific for each map type,
* and has to be 0 for cgroup local storage.
*
* Depending on the bpf program type, a local storage area
* can be shared between multiple instances of the bpf program,
* running simultaneously.
*
* A user should care about the synchronization by himself.
* For example, by using the BPF_STX_XADD instruction to alter
* the shared data.
* Return
* Pointer to the local storage area.
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@ -2171,7 +2195,8 @@ union bpf_attr {
FN(rc_repeat), \
FN(rc_keydown), \
FN(skb_cgroup_id), \
FN(get_current_cgroup_id),
FN(get_current_cgroup_id), \
FN(get_local_storage),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call

3
tools/testing/selftests/bpf/Makefile
View File

@ -23,7 +23,7 @@ $(TEST_CUSTOM_PROGS): $(OUTPUT)/%: %.c
TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test_progs \
test_align test_verifier_log test_dev_cgroup test_tcpbpf_user \
test_sock test_btf test_sockmap test_lirc_mode2_user get_cgroup_id_user \
test_socket_cookie
test_socket_cookie test_cgroup_storage
TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test_obj_id.o \
test_pkt_md_access.o test_xdp_redirect.o test_xdp_meta.o sockmap_parse_prog.o \
@ -66,6 +66,7 @@ $(OUTPUT)/test_sockmap: cgroup_helpers.c
$(OUTPUT)/test_tcpbpf_user: cgroup_helpers.c
$(OUTPUT)/test_progs: trace_helpers.c
$(OUTPUT)/get_cgroup_id_user: cgroup_helpers.c
$(OUTPUT)/test_cgroup_storage: cgroup_helpers.c
.PHONY: force

2
tools/testing/selftests/bpf/bpf_helpers.h
View File

@ -135,6 +135,8 @@ static int (*bpf_rc_keydown)(void *ctx, unsigned int protocol,
(void *) BPF_FUNC_rc_keydown;
static unsigned long long (*bpf_get_current_cgroup_id)(void) =
(void *) BPF_FUNC_get_current_cgroup_id;
static void *(*bpf_get_local_storage)(void *map, unsigned long long flags) =
(void *) BPF_FUNC_get_local_storage;
/* llvm builtin functions that eBPF C program may use to
* emit BPF_LD_ABS and BPF_LD_IND instructions

130
tools/testing/selftests/bpf/test_cgroup_storage.c Normal file
View File

@ -0,0 +1,130 @@
// SPDX-License-Identifier: GPL-2.0
#include <assert.h>
#include <bpf/bpf.h>
#include <linux/filter.h>
#include <stdio.h>
#include <stdlib.h>
#include "cgroup_helpers.h"
char bpf_log_buf[BPF_LOG_BUF_SIZE];
#define TEST_CGROUP "/test-bpf-cgroup-storage-buf/"
int main(int argc, char **argv)
{
struct bpf_insn prog[] = {
BPF_LD_MAP_FD(BPF_REG_1, 0), /* map fd */
BPF_MOV64_IMM(BPF_REG_2, 0), /* flags, not used */
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_get_local_storage),
BPF_MOV64_IMM(BPF_REG_1, 1),
BPF_STX_XADD(BPF_DW, BPF_REG_0, BPF_REG_1, 0),
BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 0),
BPF_ALU64_IMM(BPF_AND, BPF_REG_1, 0x1),
BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
BPF_EXIT_INSN(),
};
size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn);
int error = EXIT_FAILURE;
int map_fd, prog_fd, cgroup_fd;
struct bpf_cgroup_storage_key key;
unsigned long long value;
map_fd = bpf_create_map(BPF_MAP_TYPE_CGROUP_STORAGE, sizeof(key),
sizeof(value), 0, 0);
if (map_fd < 0) {
printf("Failed to create map: %s\n", strerror(errno));
goto out;
}
prog[0].imm = map_fd;
prog_fd = bpf_load_program(BPF_PROG_TYPE_CGROUP_SKB,
prog, insns_cnt, "GPL", 0,
bpf_log_buf, BPF_LOG_BUF_SIZE);
if (prog_fd < 0) {
printf("Failed to load bpf program: %s\n", bpf_log_buf);
goto out;
}
if (setup_cgroup_environment()) {
printf("Failed to setup cgroup environment\n");
goto err;
}
/* Create a cgroup, get fd, and join it */
cgroup_fd = create_and_get_cgroup(TEST_CGROUP);
if (!cgroup_fd) {
printf("Failed to create test cgroup\n");
goto err;
}
if (join_cgroup(TEST_CGROUP)) {
printf("Failed to join cgroup\n");
goto err;
}
/* Attach the bpf program */
if (bpf_prog_attach(prog_fd, cgroup_fd, BPF_CGROUP_INET_EGRESS, 0)) {
printf("Failed to attach bpf program\n");
goto err;
}
if (bpf_map_get_next_key(map_fd, NULL, &key)) {
printf("Failed to get the first key in cgroup storage\n");
goto err;
}
if (bpf_map_lookup_elem(map_fd, &key, &value)) {
printf("Failed to lookup cgroup storage\n");
goto err;
}
/* Every second packet should be dropped */
assert(system("ping localhost -c 1 -W 1 -q > /dev/null") == 0);
assert(system("ping localhost -c 1 -W 1 -q > /dev/null"));
assert(system("ping localhost -c 1 -W 1 -q > /dev/null") == 0);
/* Check the counter in the cgroup local storage */
if (bpf_map_lookup_elem(map_fd, &key, &value)) {
printf("Failed to lookup cgroup storage\n");
goto err;
}
if (value != 3) {
printf("Unexpected data in the cgroup storage: %llu\n", value);
goto err;
}
/* Bump the counter in the cgroup local storage */
value++;
if (bpf_map_update_elem(map_fd, &key, &value, 0)) {
printf("Failed to update the data in the cgroup storage\n");
goto err;
}
/* Every second packet should be dropped */
assert(system("ping localhost -c 1 -W 1 -q > /dev/null") == 0);
assert(system("ping localhost -c 1 -W 1 -q > /dev/null"));
assert(system("ping localhost -c 1 -W 1 -q > /dev/null") == 0);
/* Check the final value of the counter in the cgroup local storage */
if (bpf_map_lookup_elem(map_fd, &key, &value)) {
printf("Failed to lookup the cgroup storage\n");
goto err;
}
if (value != 7) {
printf("Unexpected data in the cgroup storage: %llu\n", value);
goto err;
}
error = 0;
printf("test_cgroup_storage:PASS\n");
err:
cleanup_cgroup_environment();
out:
return error;
}

140
tools/testing/selftests/bpf/test_verifier.c
View File

@ -50,7 +50,7 @@
#define MAX_INSNS BPF_MAXINSNS
#define MAX_FIXUPS 8
#define MAX_NR_MAPS 7
#define MAX_NR_MAPS 8
#define POINTER_VALUE 0xcafe4all
#define TEST_DATA_LEN 64
@ -70,6 +70,7 @@ struct bpf_test {
int fixup_prog1[MAX_FIXUPS];
int fixup_prog2[MAX_FIXUPS];
int fixup_map_in_map[MAX_FIXUPS];
int fixup_cgroup_storage[MAX_FIXUPS];
const char *errstr;
const char *errstr_unpriv;
uint32_t retval;
@ -4630,6 +4631,121 @@ static struct bpf_test tests[] = {
.result = REJECT,
.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
},
{
"valid cgroup storage access",
.insns = {
BPF_MOV64_IMM(BPF_REG_2, 0),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_get_local_storage),
BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 0),
BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.fixup_cgroup_storage = { 1 },
.result = ACCEPT,
.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
},
{
"invalid cgroup storage access 1",
.insns = {
BPF_MOV64_IMM(BPF_REG_2, 0),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_get_local_storage),
BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 0),
BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.fixup_map1 = { 1 },
.result = REJECT,
.errstr = "cannot pass map_type 1 into func bpf_get_local_storage",
.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
},
{
"invalid cgroup storage access 2",
.insns = {
BPF_MOV64_IMM(BPF_REG_2, 0),
BPF_LD_MAP_FD(BPF_REG_1, 1),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_get_local_storage),
BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.result = REJECT,
.errstr = "fd 1 is not pointing to valid bpf_map",
.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
},
{
"invalid per-cgroup storage access 3",
.insns = {
BPF_MOV64_IMM(BPF_REG_2, 0),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_get_local_storage),
BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 256),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.fixup_cgroup_storage = { 1 },
.result = REJECT,
.errstr = "invalid access to map value, value_size=64 off=256 size=4",
.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
},
{
"invalid cgroup storage access 4",
.insns = {
BPF_MOV64_IMM(BPF_REG_2, 0),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_get_local_storage),
BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, -2),
BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
BPF_EXIT_INSN(),
},
.fixup_cgroup_storage = { 1 },
.result = REJECT,
.errstr = "invalid access to map value, value_size=64 off=-2 size=4",
.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
},
{
"invalid cgroup storage access 5",
.insns = {
BPF_MOV64_IMM(BPF_REG_2, 7),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_get_local_storage),
BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 0),
BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.fixup_cgroup_storage = { 1 },
.result = REJECT,
.errstr = "get_local_storage() doesn't support non-zero flags",
.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
},
{
"invalid cgroup storage access 6",
.insns = {
BPF_MOV64_REG(BPF_REG_2, BPF_REG_1),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_get_local_storage),
BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 0),
BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.fixup_cgroup_storage = { 1 },
.result = REJECT,
.errstr = "get_local_storage() doesn't support non-zero flags",
.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
},
{
"multiple registers share map_lookup_elem result",
.insns = {
@ -12462,6 +12578,19 @@ static int create_map_in_map(void)
return outer_map_fd;
}
static int create_cgroup_storage(void)
{
int fd;
fd = bpf_create_map(BPF_MAP_TYPE_CGROUP_STORAGE,
sizeof(struct bpf_cgroup_storage_key),
TEST_DATA_LEN, 0, 0);
if (fd < 0)
printf("Failed to create array '%s'!\n", strerror(errno));
return fd;
}
static char bpf_vlog[UINT_MAX >> 8];
static void do_test_fixup(struct bpf_test *test, struct bpf_insn *prog,
@ -12474,6 +12603,7 @@ static void do_test_fixup(struct bpf_test *test, struct bpf_insn *prog,
int *fixup_prog1 = test->fixup_prog1;
int *fixup_prog2 = test->fixup_prog2;
int *fixup_map_in_map = test->fixup_map_in_map;
int *fixup_cgroup_storage = test->fixup_cgroup_storage;
if (test->fill_helper)
test->fill_helper(test);
@ -12541,6 +12671,14 @@ static void do_test_fixup(struct bpf_test *test, struct bpf_insn *prog,
fixup_map_in_map++;
} while (*fixup_map_in_map);
}
if (*fixup_cgroup_storage) {
map_fds[7] = create_cgroup_storage();
do {
prog[*fixup_cgroup_storage].imm = map_fds[7];
fixup_cgroup_storage++;
} while (*fixup_cgroup_storage);
}
}
static void do_test_single(struct bpf_test *test, bool unpriv,