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-rw-r--r--kernel/bpf/Makefile5
-rw-r--r--kernel/bpf/arraymap.c168
-rw-r--r--kernel/bpf/hashtab.c458
-rw-r--r--kernel/bpf/helpers.c2
-rw-r--r--kernel/bpf/percpu_freelist.c100
-rw-r--r--kernel/bpf/percpu_freelist.h31
-rw-r--r--kernel/bpf/stackmap.c290
-rw-r--r--kernel/bpf/syscall.c90
-rw-r--r--kernel/bpf/verifier.c48
-rw-r--r--kernel/events/callchain.c32
-rw-r--r--kernel/events/internal.h2
-rw-r--r--kernel/trace/bpf_trace.c4
12 files changed, 1116 insertions, 114 deletions
diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile
index 13272582eee0..eed911d091da 100644
--- a/kernel/bpf/Makefile
+++ b/kernel/bpf/Makefile
@@ -1,4 +1,7 @@
obj-y := core.o
obj-$(CONFIG_BPF_SYSCALL) += syscall.o verifier.o inode.o helpers.o
-obj-$(CONFIG_BPF_SYSCALL) += hashtab.o arraymap.o
+obj-$(CONFIG_BPF_SYSCALL) += hashtab.o arraymap.o percpu_freelist.o
+ifeq ($(CONFIG_PERF_EVENTS),y)
+obj-$(CONFIG_BPF_SYSCALL) += stackmap.o
+endif
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index 89ebbc4d1164..76d5a794e426 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -17,15 +17,43 @@
#include <linux/filter.h>
#include <linux/perf_event.h>
+static void bpf_array_free_percpu(struct bpf_array *array)
+{
+ int i;
+
+ for (i = 0; i < array->map.max_entries; i++)
+ free_percpu(array->pptrs[i]);
+}
+
+static int bpf_array_alloc_percpu(struct bpf_array *array)
+{
+ void __percpu *ptr;
+ int i;
+
+ for (i = 0; i < array->map.max_entries; i++) {
+ ptr = __alloc_percpu_gfp(array->elem_size, 8,
+ GFP_USER | __GFP_NOWARN);
+ if (!ptr) {
+ bpf_array_free_percpu(array);
+ return -ENOMEM;
+ }
+ array->pptrs[i] = ptr;
+ }
+
+ return 0;
+}
+
/* Called from syscall */
static struct bpf_map *array_map_alloc(union bpf_attr *attr)
{
+ bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
struct bpf_array *array;
- u32 elem_size, array_size;
+ u64 array_size;
+ u32 elem_size;
/* check sanity of attributes */
if (attr->max_entries == 0 || attr->key_size != 4 ||
- attr->value_size == 0)
+ attr->value_size == 0 || attr->map_flags)
return ERR_PTR(-EINVAL);
if (attr->value_size >= 1 << (KMALLOC_SHIFT_MAX - 1))
@@ -36,12 +64,16 @@ static struct bpf_map *array_map_alloc(union bpf_attr *attr)
elem_size = round_up(attr->value_size, 8);
- /* check round_up into zero and u32 overflow */
- if (elem_size == 0 ||
- attr->max_entries > (U32_MAX - PAGE_SIZE - sizeof(*array)) / elem_size)
+ array_size = sizeof(*array);
+ if (percpu)
+ array_size += (u64) attr->max_entries * sizeof(void *);
+ else
+ array_size += (u64) attr->max_entries * elem_size;
+
+ /* make sure there is no u32 overflow later in round_up() */
+ if (array_size >= U32_MAX - PAGE_SIZE)
return ERR_PTR(-ENOMEM);
- array_size = sizeof(*array) + attr->max_entries * elem_size;
/* allocate all map elements and zero-initialize them */
array = kzalloc(array_size, GFP_USER | __GFP_NOWARN);
@@ -52,12 +84,25 @@ static struct bpf_map *array_map_alloc(union bpf_attr *attr)
}
/* copy mandatory map attributes */
+ array->map.map_type = attr->map_type;
array->map.key_size = attr->key_size;
array->map.value_size = attr->value_size;
array->map.max_entries = attr->max_entries;
- array->map.pages = round_up(array_size, PAGE_SIZE) >> PAGE_SHIFT;
array->elem_size = elem_size;
+ if (!percpu)
+ goto out;
+
+ array_size += (u64) attr->max_entries * elem_size * num_possible_cpus();
+
+ if (array_size >= U32_MAX - PAGE_SIZE ||
+ elem_size > PCPU_MIN_UNIT_SIZE || bpf_array_alloc_percpu(array)) {
+ kvfree(array);
+ return ERR_PTR(-ENOMEM);
+ }
+out:
+ array->map.pages = round_up(array_size, PAGE_SIZE) >> PAGE_SHIFT;
+
return &array->map;
}
@@ -67,12 +112,50 @@ static void *array_map_lookup_elem(struct bpf_map *map, void *key)
struct bpf_array *array = container_of(map, struct bpf_array, map);
u32 index = *(u32 *)key;
- if (index >= array->map.max_entries)
+ if (unlikely(index >= array->map.max_entries))
return NULL;
return array->value + array->elem_size * index;
}
+/* Called from eBPF program */
+static void *percpu_array_map_lookup_elem(struct bpf_map *map, void *key)
+{
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+ u32 index = *(u32 *)key;
+
+ if (unlikely(index >= array->map.max_entries))
+ return NULL;
+
+ return this_cpu_ptr(array->pptrs[index]);
+}
+
+int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value)
+{
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+ u32 index = *(u32 *)key;
+ void __percpu *pptr;
+ int cpu, off = 0;
+ u32 size;
+
+ if (unlikely(index >= array->map.max_entries))
+ return -ENOENT;
+
+ /* per_cpu areas are zero-filled and bpf programs can only
+ * access 'value_size' of them, so copying rounded areas
+ * will not leak any kernel data
+ */
+ size = round_up(map->value_size, 8);
+ rcu_read_lock();
+ pptr = array->pptrs[index];
+ for_each_possible_cpu(cpu) {
+ bpf_long_memcpy(value + off, per_cpu_ptr(pptr, cpu), size);
+ off += size;
+ }
+ rcu_read_unlock();
+ return 0;
+}
+
/* Called from syscall */
static int array_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
{
@@ -99,19 +182,62 @@ static int array_map_update_elem(struct bpf_map *map, void *key, void *value,
struct bpf_array *array = container_of(map, struct bpf_array, map);
u32 index = *(u32 *)key;
- if (map_flags > BPF_EXIST)
+ if (unlikely(map_flags > BPF_EXIST))
/* unknown flags */
return -EINVAL;
- if (index >= array->map.max_entries)
+ if (unlikely(index >= array->map.max_entries))
/* all elements were pre-allocated, cannot insert a new one */
return -E2BIG;
- if (map_flags == BPF_NOEXIST)
+ if (unlikely(map_flags == BPF_NOEXIST))
/* all elements already exist */
return -EEXIST;
- memcpy(array->value + array->elem_size * index, value, map->value_size);
+ if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
+ memcpy(this_cpu_ptr(array->pptrs[index]),
+ value, map->value_size);
+ else
+ memcpy(array->value + array->elem_size * index,
+ value, map->value_size);
+ return 0;
+}
+
+int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value,
+ u64 map_flags)
+{
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+ u32 index = *(u32 *)key;
+ void __percpu *pptr;
+ int cpu, off = 0;
+ u32 size;
+
+ if (unlikely(map_flags > BPF_EXIST))
+ /* unknown flags */
+ return -EINVAL;
+
+ if (unlikely(index >= array->map.max_entries))
+ /* all elements were pre-allocated, cannot insert a new one */
+ return -E2BIG;
+
+ if (unlikely(map_flags == BPF_NOEXIST))
+ /* all elements already exist */
+ return -EEXIST;
+
+ /* the user space will provide round_up(value_size, 8) bytes that
+ * will be copied into per-cpu area. bpf programs can only access
+ * value_size of it. During lookup the same extra bytes will be
+ * returned or zeros which were zero-filled by percpu_alloc,
+ * so no kernel data leaks possible
+ */
+ size = round_up(map->value_size, 8);
+ rcu_read_lock();
+ pptr = array->pptrs[index];
+ for_each_possible_cpu(cpu) {
+ bpf_long_memcpy(per_cpu_ptr(pptr, cpu), value + off, size);
+ off += size;
+ }
+ rcu_read_unlock();
return 0;
}
@@ -133,6 +259,9 @@ static void array_map_free(struct bpf_map *map)
*/
synchronize_rcu();
+ if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
+ bpf_array_free_percpu(array);
+
kvfree(array);
}
@@ -150,9 +279,24 @@ static struct bpf_map_type_list array_type __read_mostly = {
.type = BPF_MAP_TYPE_ARRAY,
};
+static const struct bpf_map_ops percpu_array_ops = {
+ .map_alloc = array_map_alloc,
+ .map_free = array_map_free,
+ .map_get_next_key = array_map_get_next_key,
+ .map_lookup_elem = percpu_array_map_lookup_elem,
+ .map_update_elem = array_map_update_elem,
+ .map_delete_elem = array_map_delete_elem,
+};
+
+static struct bpf_map_type_list percpu_array_type __read_mostly = {
+ .ops = &percpu_array_ops,
+ .type = BPF_MAP_TYPE_PERCPU_ARRAY,
+};
+
static int __init register_array_map(void)
{
bpf_register_map_type(&array_type);
+ bpf_register_map_type(&percpu_array_type);
return 0;
}
late_initcall(register_array_map);
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index c5b30fd8a315..fff3650d52fc 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -1,4 +1,5 @@
/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
+ * Copyright (c) 2016 Facebook
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
@@ -13,6 +14,7 @@
#include <linux/jhash.h>
#include <linux/filter.h>
#include <linux/vmalloc.h>
+#include "percpu_freelist.h"
struct bucket {
struct hlist_head head;
@@ -22,6 +24,8 @@ struct bucket {
struct bpf_htab {
struct bpf_map map;
struct bucket *buckets;
+ void *elems;
+ struct pcpu_freelist freelist;
atomic_t count; /* number of elements in this hashtable */
u32 n_buckets; /* number of hash buckets */
u32 elem_size; /* size of each element in bytes */
@@ -29,26 +33,108 @@ struct bpf_htab {
/* each htab element is struct htab_elem + key + value */
struct htab_elem {
- struct hlist_node hash_node;
+ union {
+ struct hlist_node hash_node;
+ struct bpf_htab *htab;
+ struct pcpu_freelist_node fnode;
+ };
struct rcu_head rcu;
u32 hash;
char key[0] __aligned(8);
};
+static inline void htab_elem_set_ptr(struct htab_elem *l, u32 key_size,
+ void __percpu *pptr)
+{
+ *(void __percpu **)(l->key + key_size) = pptr;
+}
+
+static inline void __percpu *htab_elem_get_ptr(struct htab_elem *l, u32 key_size)
+{
+ return *(void __percpu **)(l->key + key_size);
+}
+
+static struct htab_elem *get_htab_elem(struct bpf_htab *htab, int i)
+{
+ return (struct htab_elem *) (htab->elems + i * htab->elem_size);
+}
+
+static void htab_free_elems(struct bpf_htab *htab)
+{
+ int i;
+
+ if (htab->map.map_type != BPF_MAP_TYPE_PERCPU_HASH)
+ goto free_elems;
+
+ for (i = 0; i < htab->map.max_entries; i++) {
+ void __percpu *pptr;
+
+ pptr = htab_elem_get_ptr(get_htab_elem(htab, i),
+ htab->map.key_size);
+ free_percpu(pptr);
+ }
+free_elems:
+ vfree(htab->elems);
+}
+
+static int prealloc_elems_and_freelist(struct bpf_htab *htab)
+{
+ int err = -ENOMEM, i;
+
+ htab->elems = vzalloc(htab->elem_size * htab->map.max_entries);
+ if (!htab->elems)
+ return -ENOMEM;
+
+ if (htab->map.map_type != BPF_MAP_TYPE_PERCPU_HASH)
+ goto skip_percpu_elems;
+
+ for (i = 0; i < htab->map.max_entries; i++) {
+ u32 size = round_up(htab->map.value_size, 8);
+ void __percpu *pptr;
+
+ pptr = __alloc_percpu_gfp(size, 8, GFP_USER | __GFP_NOWARN);
+ if (!pptr)
+ goto free_elems;
+ htab_elem_set_ptr(get_htab_elem(htab, i), htab->map.key_size,
+ pptr);
+ }
+
+skip_percpu_elems:
+ err = pcpu_freelist_init(&htab->freelist);
+ if (err)
+ goto free_elems;
+
+ pcpu_freelist_populate(&htab->freelist, htab->elems, htab->elem_size,
+ htab->map.max_entries);
+ return 0;
+
+free_elems:
+ htab_free_elems(htab);
+ return err;
+}
+
/* Called from syscall */
static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
{
+ bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_HASH;
struct bpf_htab *htab;
int err, i;
+ u64 cost;
+
+ if (attr->map_flags & ~BPF_F_NO_PREALLOC)
+ /* reserved bits should not be used */
+ return ERR_PTR(-EINVAL);
htab = kzalloc(sizeof(*htab), GFP_USER);
if (!htab)
return ERR_PTR(-ENOMEM);
/* mandatory map attributes */
+ htab->map.map_type = attr->map_type;
htab->map.key_size = attr->key_size;
htab->map.value_size = attr->value_size;
htab->map.max_entries = attr->max_entries;
+ htab->map.map_flags = attr->map_flags;
/* check sanity of attributes.
* value_size == 0 may be allowed in the future to use map as a set
@@ -77,24 +163,39 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
*/
goto free_htab;
+ if (percpu && round_up(htab->map.value_size, 8) > PCPU_MIN_UNIT_SIZE)
+ /* make sure the size for pcpu_alloc() is reasonable */
+ goto free_htab;
+
htab->elem_size = sizeof(struct htab_elem) +
- round_up(htab->map.key_size, 8) +
- htab->map.value_size;
+ round_up(htab->map.key_size, 8);
+ if (percpu)
+ htab->elem_size += sizeof(void *);
+ else
+ htab->elem_size += round_up(htab->map.value_size, 8);
/* prevent zero size kmalloc and check for u32 overflow */
if (htab->n_buckets == 0 ||
htab->n_buckets > U32_MAX / sizeof(struct bucket))
goto free_htab;
- if ((u64) htab->n_buckets * sizeof(struct bucket) +
- (u64) htab->elem_size * htab->map.max_entries >=
- U32_MAX - PAGE_SIZE)
+ cost = (u64) htab->n_buckets * sizeof(struct bucket) +
+ (u64) htab->elem_size * htab->map.max_entries;
+
+ if (percpu)
+ cost += (u64) round_up(htab->map.value_size, 8) *
+ num_possible_cpus() * htab->map.max_entries;
+
+ if (cost >= U32_MAX - PAGE_SIZE)
/* make sure page count doesn't overflow */
goto free_htab;
- htab->map.pages = round_up(htab->n_buckets * sizeof(struct bucket) +
- htab->elem_size * htab->map.max_entries,
- PAGE_SIZE) >> PAGE_SHIFT;
+ htab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
+
+ /* if map size is larger than memlock limit, reject it early */
+ err = bpf_map_precharge_memlock(htab->map.pages);
+ if (err)
+ goto free_htab;
err = -ENOMEM;
htab->buckets = kmalloc_array(htab->n_buckets, sizeof(struct bucket),
@@ -111,10 +212,16 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
raw_spin_lock_init(&htab->buckets[i].lock);
}
- atomic_set(&htab->count, 0);
+ if (!(attr->map_flags & BPF_F_NO_PREALLOC)) {
+ err = prealloc_elems_and_freelist(htab);
+ if (err)
+ goto free_buckets;
+ }
return &htab->map;
+free_buckets:
+ kvfree(htab->buckets);
free_htab:
kfree(htab);
return ERR_PTR(err);
@@ -148,7 +255,7 @@ static struct htab_elem *lookup_elem_raw(struct hlist_head *head, u32 hash,
}
/* Called from syscall or from eBPF program */
-static void *htab_map_lookup_elem(struct bpf_map *map, void *key)
+static void *__htab_map_lookup_elem(struct bpf_map *map, void *key)
{
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
struct hlist_head *head;
@@ -166,6 +273,13 @@ static void *htab_map_lookup_elem(struct bpf_map *map, void *key)
l = lookup_elem_raw(head, hash, key, key_size);
+ return l;
+}
+
+static void *htab_map_lookup_elem(struct bpf_map *map, void *key)
+{
+ struct htab_elem *l = __htab_map_lookup_elem(map, key);
+
if (l)
return l->key + round_up(map->key_size, 8);
@@ -226,86 +340,248 @@ find_first_elem:
}
}
- /* itereated over all buckets and all elements */
+ /* iterated over all buckets and all elements */
return -ENOENT;
}
+static void htab_elem_free(struct bpf_htab *htab, struct htab_elem *l)
+{
+ if (htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH)
+ free_percpu(htab_elem_get_ptr(l, htab->map.key_size));
+ kfree(l);
+
+}
+
+static void htab_elem_free_rcu(struct rcu_head *head)
+{
+ struct htab_elem *l = container_of(head, struct htab_elem, rcu);
+ struct bpf_htab *htab = l->htab;
+
+ /* must increment bpf_prog_active to avoid kprobe+bpf triggering while
+ * we're calling kfree, otherwise deadlock is possible if kprobes
+ * are placed somewhere inside of slub
+ */
+ preempt_disable();
+ __this_cpu_inc(bpf_prog_active);
+ htab_elem_free(htab, l);
+ __this_cpu_dec(bpf_prog_active);
+ preempt_enable();
+}
+
+static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l)
+{
+ if (!(htab->map.map_flags & BPF_F_NO_PREALLOC)) {
+ pcpu_freelist_push(&htab->freelist, &l->fnode);
+ } else {
+ atomic_dec(&htab->count);
+ l->htab = htab;
+ call_rcu(&l->rcu, htab_elem_free_rcu);
+ }
+}
+
+static struct htab_elem *alloc_htab_elem(struct bpf_htab *htab, void *key,
+ void *value, u32 key_size, u32 hash,
+ bool percpu, bool onallcpus)
+{
+ u32 size = htab->map.value_size;
+ bool prealloc = !(htab->map.map_flags & BPF_F_NO_PREALLOC);
+ struct htab_elem *l_new;
+ void __percpu *pptr;
+
+ if (prealloc) {
+ l_new = (struct htab_elem *)pcpu_freelist_pop(&htab->freelist);
+ if (!l_new)
+ return ERR_PTR(-E2BIG);
+ } else {
+ if (atomic_inc_return(&htab->count) > htab->map.max_entries) {
+ atomic_dec(&htab->count);
+ return ERR_PTR(-E2BIG);
+ }
+ l_new = kmalloc(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN);
+ if (!l_new)
+ return ERR_PTR(-ENOMEM);
+ }
+
+ memcpy(l_new->key, key, key_size);
+ if (percpu) {
+ /* round up value_size to 8 bytes */
+ size = round_up(size, 8);
+
+ if (prealloc) {
+ pptr = htab_elem_get_ptr(l_new, key_size);
+ } else {
+ /* alloc_percpu zero-fills */
+ pptr = __alloc_percpu_gfp(size, 8,
+ GFP_ATOMIC | __GFP_NOWARN);
+ if (!pptr) {
+ kfree(l_new);
+ return ERR_PTR(-ENOMEM);
+ }
+ }
+
+ if (!onallcpus) {
+ /* copy true value_size bytes */
+ memcpy(this_cpu_ptr(pptr), value, htab->map.value_size);
+ } else {
+ int off = 0, cpu;
+
+ for_each_possible_cpu(cpu) {
+ bpf_long_memcpy(per_cpu_ptr(pptr, cpu),
+ value + off, size);
+ off += size;
+ }
+ }
+ if (!prealloc)
+ htab_elem_set_ptr(l_new, key_size, pptr);
+ } else {
+ memcpy(l_new->key + round_up(key_size, 8), value, size);
+ }
+
+ l_new->hash = hash;
+ return l_new;
+}
+
+static int check_flags(struct bpf_htab *htab, struct htab_elem *l_old,
+ u64 map_flags)
+{
+ if (l_old && map_flags == BPF_NOEXIST)
+ /* elem already exists */
+ return -EEXIST;
+
+ if (!l_old && map_flags == BPF_EXIST)
+ /* elem doesn't exist, cannot update it */
+ return -ENOENT;
+
+ return 0;
+}
+
/* Called from syscall or from eBPF program */
static int htab_map_update_elem(struct bpf_map *map, void *key, void *value,
u64 map_flags)
{
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
- struct htab_elem *l_new, *l_old;
+ struct htab_elem *l_new = NULL, *l_old;
struct hlist_head *head;
- struct bucket *b;
unsigned long flags;
- u32 key_size;
+ struct bucket *b;
+ u32 key_size, hash;
int ret;
- if (map_flags > BPF_EXIST)
+ if (unlikely(map_flags > BPF_EXIST))
/* unknown flags */
return -EINVAL;
WARN_ON_ONCE(!rcu_read_lock_held());
- /* allocate new element outside of lock */
- l_new = kmalloc(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN);
- if (!l_new)
- return -ENOMEM;
-
key_size = map->key_size;
- memcpy(l_new->key, key, key_size);
- memcpy(l_new->key + round_up(key_size, 8), value, map->value_size);
+ hash = htab_map_hash(key, key_size);
- l_new->hash = htab_map_hash(l_new->key, key_size);
- b = __select_bucket(htab, l_new->hash);
+ b = __select_bucket(htab, hash);
head = &b->head;
/* bpf_map_update_elem() can be called in_irq() */
raw_spin_lock_irqsave(&b->lock, flags);
- l_old = lookup_elem_raw(head, l_new->hash, key, key_size);
+ l_old = lookup_elem_raw(head, hash, key, key_size);
- if (!l_old && unlikely(atomic_read(&htab->count) >= map->max_entries)) {
- /* if elem with this 'key' doesn't exist and we've reached
- * max_entries limit, fail insertion of new elem
- */
- ret = -E2BIG;
+ ret = check_flags(htab, l_old, map_flags);
+ if (ret)
goto err;
- }
- if (l_old && map_flags == BPF_NOEXIST) {
- /* elem already exists */
- ret = -EEXIST;
+ l_new = alloc_htab_elem(htab, key, value, key_size, hash, false, false);
+ if (IS_ERR(l_new)) {
+ /* all pre-allocated elements are in use or memory exhausted */
+ ret = PTR_ERR(l_new);
goto err;
}
- if (!l_old && map_flags == BPF_EXIST) {
- /* elem doesn't exist, cannot update it */
- ret = -ENOENT;
- goto err;
- }
-
- /* add new element to the head of the list, so that concurrent
- * search will find it before old elem
+ /* add new element to the head of the list, so that
+ * concurrent search will find it before old elem
*/
hlist_add_head_rcu(&l_new->hash_node, head);
if (l_old) {
hlist_del_rcu(&l_old->hash_node);
- kfree_rcu(l_old, rcu);
- } else {
- atomic_inc(&htab->count);
+ free_htab_elem(htab, l_old);
}
+ ret = 0;
+err:
raw_spin_unlock_irqrestore(&b->lock, flags);
+ return ret;
+}
- return 0;
+static int __htab_percpu_map_update_elem(struct bpf_map *map, void *key,
+ void *value, u64 map_flags,
+ bool onallcpus)
+{
+ struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+ struct htab_elem *l_new = NULL, *l_old;
+ struct hlist_head *head;
+ unsigned long flags;
+ struct bucket *b;
+ u32 key_size, hash;
+ int ret;
+
+ if (unlikely(map_flags > BPF_EXIST))
+ /* unknown flags */
+ return -EINVAL;
+
+ WARN_ON_ONCE(!rcu_read_lock_held());
+
+ key_size = map->key_size;
+
+ hash = htab_map_hash(key, key_size);
+
+ b = __select_bucket(htab, hash);
+ head = &b->head;
+
+ /* bpf_map_update_elem() can be called in_irq() */
+ raw_spin_lock_irqsave(&b->lock, flags);
+
+ l_old = lookup_elem_raw(head, hash, key, key_size);
+
+ ret = check_flags(htab, l_old, map_flags);
+ if (ret)
+ goto err;
+
+ if (l_old) {
+ void __percpu *pptr = htab_elem_get_ptr(l_old, key_size);
+ u32 size = htab->map.value_size;
+
+ /* per-cpu hash map can update value in-place */
+ if (!onallcpus) {
+ memcpy(this_cpu_ptr(pptr), value, size);
+ } else {
+ int off = 0, cpu;
+
+ size = round_up(size, 8);
+ for_each_possible_cpu(cpu) {
+ bpf_long_memcpy(per_cpu_ptr(pptr, cpu),
+ value + off, size);
+ off += size;
+ }
+ }
+ } else {
+ l_new = alloc_htab_elem(htab, key, value, key_size,
+ hash, true, onallcpus);
+ if (IS_ERR(l_new)) {
+ ret = PTR_ERR(l_new);
+ goto err;
+ }
+ hlist_add_head_rcu(&l_new->hash_node, head);
+ }
+ ret = 0;
err:
raw_spin_unlock_irqrestore(&b->lock, flags);
- kfree(l_new);
return ret;
}
+static int htab_percpu_map_update_elem(struct bpf_map *map, void *key,
+ void *value, u64 map_flags)
+{
+ return __htab_percpu_map_update_elem(map, key, value, map_flags, false);
+}
+
/* Called from syscall or from eBPF program */
static int htab_map_delete_elem(struct bpf_map *map, void *key)
{
@@ -331,8 +607,7 @@ static int htab_map_delete_elem(struct bpf_map *map, void *key)
if (l) {
hlist_del_rcu(&l->hash_node);
- atomic_dec(&htab->count);
- kfree_rcu(l, rcu);
+ free_htab_elem(htab, l);
ret = 0;
}
@@ -351,12 +626,10 @@ static void delete_all_elements(struct bpf_htab *htab)
hlist_for_each_entry_safe(l, n, head, hash_node) {
hlist_del_rcu(&l->hash_node);
- atomic_dec(&htab->count);
- kfree(l);
+ htab_elem_free(htab, l);
}
}
}
-
/* Called when map->refcnt goes to zero, either from workqueue or from syscall */
static void htab_map_free(struct bpf_map *map)
{
@@ -369,10 +642,16 @@ static void htab_map_free(struct bpf_map *map)
*/
synchronize_rcu();
- /* some of kfree_rcu() callbacks for elements of this map may not have
- * executed. It's ok. Proceed to free residual elements and map itself
+ /* some of free_htab_elem() callbacks for elements of this map may
+ * not have executed. Wait for them.
*/
- delete_all_elements(htab);
+ rcu_barrier();
+ if (htab->map.map_flags & BPF_F_NO_PREALLOC) {
+ delete_all_elements(htab);
+ } else {
+ htab_free_elems(htab);
+ pcpu_freelist_destroy(&htab->freelist);
+ }
kvfree(htab->buckets);
kfree(htab);
}
@@ -391,9 +670,76 @@ static struct bpf_map_type_list htab_type __read_mostly = {
.type = BPF_MAP_TYPE_HASH,
};
+/* Called from eBPF program */
+static void *htab_percpu_map_lookup_elem(struct bpf_map *map, void *key)
+{
+ struct htab_elem *l = __htab_map_lookup_elem(map, key);
+
+ if (l)
+ return this_cpu_ptr(htab_elem_get_ptr(l, map->key_size));
+ else
+ return NULL;
+}
+
+int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value)
+{
+ struct htab_elem *l;
+ void __percpu *pptr;
+ int ret = -ENOENT;
+ int cpu, off = 0;
+ u32 size;
+
+ /* per_cpu areas are zero-filled and bpf programs can only
+ * access 'value_size' of them, so copying rounded areas
+ * will not leak any kernel data
+ */
+ size = round_up(map->value_size, 8);
+ rcu_read_lock();
+ l = __htab_map_lookup_elem(map, key);
+ if (!l)
+ goto out;
+ pptr = htab_elem_get_ptr(l, map->key_size);
+ for_each_possible_cpu(cpu) {
+ bpf_long_memcpy(value + off,
+ per_cpu_ptr(pptr, cpu), size);
+ off += size;
+ }
+ ret = 0;
+out:
+ rcu_read_unlock();
+ return ret;
+}
+
+int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value,
+ u64 map_flags)
+{
+ int ret;
+
+ rcu_read_lock();
+ ret = __htab_percpu_map_update_elem(map, key, value, map_flags, true);
+ rcu_read_unlock();
+
+ return ret;
+}
+
+static const struct bpf_map_ops htab_percpu_ops = {
+ .map_alloc = htab_map_alloc,
+ .map_free = htab_map_free,
+ .map_get_next_key = htab_map_get_next_key,
+ .map_lookup_elem = htab_percpu_map_lookup_elem,
+ .map_update_elem = htab_percpu_map_update_elem,
+ .map_delete_elem = htab_map_delete_elem,
+};
+
+static struct bpf_map_type_list htab_percpu_type __read_mostly = {
+ .ops = &htab_percpu_ops,
+ .type = BPF_MAP_TYPE_PERCPU_HASH,
+};
+
static int __init register_htab_map(void)
{
bpf_register_map_type(&htab_type);
+ bpf_register_map_type(&htab_percpu_type);
return 0;
}
late_initcall(register_htab_map);
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 4504ca66118d..50da680c479f 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -166,7 +166,7 @@ static u64 bpf_get_current_comm(u64 r1, u64 size, u64 r3, u64 r4, u64 r5)
if (!task)
return -EINVAL;
- memcpy(buf, task->comm, min_t(size_t, size, sizeof(task->comm)));
+ strlcpy(buf, task->comm, min_t(size_t, size, sizeof(task->comm)));
return 0;
}
diff --git a/kernel/bpf/percpu_freelist.c b/kernel/bpf/percpu_freelist.c
new file mode 100644
index 000000000000..5c51d1985b51
--- /dev/null
+++ b/kernel/bpf/percpu_freelist.c
@@ -0,0 +1,100 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include "percpu_freelist.h"
+
+int pcpu_freelist_init(struct pcpu_freelist *s)
+{
+ int cpu;
+
+ s->freelist = alloc_percpu(struct pcpu_freelist_head);
+ if (!s->freelist)
+ return -ENOMEM;
+
+ for_each_possible_cpu(cpu) {
+ struct pcpu_freelist_head *head = per_cpu_ptr(s->freelist, cpu);
+
+ raw_spin_lock_init(&head->lock);
+ head->first = NULL;
+ }
+ return 0;
+}
+
+void pcpu_freelist_destroy(struct pcpu_freelist *s)
+{
+ free_percpu(s->freelist);
+}
+
+static inline void __pcpu_freelist_push(struct pcpu_freelist_head *head,
+ struct pcpu_freelist_node *node)
+{
+ raw_spin_lock(&head->lock);
+ node->next = head->first;
+ head->first = node;
+ raw_spin_unlock(&head->lock);
+}
+
+void pcpu_freelist_push(struct pcpu_freelist *s,
+ struct pcpu_freelist_node *node)
+{
+ struct pcpu_freelist_head *head = this_cpu_ptr(s->freelist);
+
+ __pcpu_freelist_push(head, node);
+}
+
+void pcpu_freelist_populate(struct pcpu_freelist *s, void *buf, u32 elem_size,
+ u32 nr_elems)
+{
+ struct pcpu_freelist_head *head;
+ unsigned long flags;
+ int i, cpu, pcpu_entries;
+
+ pcpu_entries = nr_elems / num_possible_cpus() + 1;
+ i = 0;
+
+ /* disable irq to workaround lockdep false positive
+ * in bpf usage pcpu_freelist_populate() will never race
+ * with pcpu_freelist_push()
+ */
+ local_irq_save(flags);
+ for_each_possible_cpu(cpu) {
+again:
+ head = per_cpu_ptr(s->freelist, cpu);
+ __pcpu_freelist_push(head, buf);
+ i++;
+ buf += elem_size;
+ if (i == nr_elems)
+ break;
+ if (i % pcpu_entries)
+ goto again;
+ }
+ local_irq_restore(flags);
+}
+
+struct pcpu_freelist_node *pcpu_freelist_pop(struct pcpu_freelist *s)
+{
+ struct pcpu_freelist_head *head;
+ struct pcpu_freelist_node *node;
+ int orig_cpu, cpu;
+
+ orig_cpu = cpu = raw_smp_processor_id();
+ while (1) {
+ head = per_cpu_ptr(s->freelist, cpu);
+ raw_spin_lock(&head->lock);
+ node = head->first;
+ if (node) {
+ head->first = node->next;
+ raw_spin_unlock(&head->lock);
+ return node;
+ }
+ raw_spin_unlock(&head->lock);
+ cpu = cpumask_next(cpu, cpu_possible_mask);
+ if (cpu >= nr_cpu_ids)
+ cpu = 0;
+ if (cpu == orig_cpu)
+ return NULL;
+ }
+}
diff --git a/kernel/bpf/percpu_freelist.h b/kernel/bpf/percpu_freelist.h
new file mode 100644
index 000000000000..3049aae8ea1e
--- /dev/null
+++ b/kernel/bpf/percpu_freelist.h
@@ -0,0 +1,31 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#ifndef __PERCPU_FREELIST_H__
+#define __PERCPU_FREELIST_H__
+#include <linux/spinlock.h>
+#include <linux/percpu.h>
+
+struct pcpu_freelist_head {
+ struct pcpu_freelist_node *first;
+ raw_spinlock_t lock;
+};
+
+struct pcpu_freelist {
+ struct pcpu_freelist_head __percpu *freelist;
+};
+
+struct pcpu_freelist_node {
+ struct pcpu_freelist_node *next;
+};
+
+void pcpu_freelist_push(struct pcpu_freelist *, struct pcpu_freelist_node *);
+struct pcpu_freelist_node *pcpu_freelist_pop(struct pcpu_freelist *);
+void pcpu_freelist_populate(struct pcpu_freelist *s, void *buf, u32 elem_size,
+ u32 nr_elems);
+int pcpu_freelist_init(struct pcpu_freelist *);
+void pcpu_freelist_destroy(struct pcpu_freelist *s);
+#endif
diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c
new file mode 100644
index 000000000000..499d9e933f8e
--- /dev/null
+++ b/kernel/bpf/stackmap.c
@@ -0,0 +1,290 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/bpf.h>
+#include <linux/jhash.h>
+#include <linux/filter.h>
+#include <linux/vmalloc.h>
+#include <linux/stacktrace.h>
+#include <linux/perf_event.h>
+#include "percpu_freelist.h"
+
+struct stack_map_bucket {
+ struct pcpu_freelist_node fnode;
+ u32 hash;
+ u32 nr;
+ u64 ip[];
+};
+
+struct bpf_stack_map {
+ struct bpf_map map;
+ void *elems;
+ struct pcpu_freelist freelist;
+ u32 n_buckets;
+ struct stack_map_bucket *buckets[];
+};
+
+static int prealloc_elems_and_freelist(struct bpf_stack_map *smap)
+{
+ u32 elem_size = sizeof(struct stack_map_bucket) + smap->map.value_size;
+ int err;
+
+ smap->elems = vzalloc(elem_size * smap->map.max_entries);
+ if (!smap->elems)
+ return -ENOMEM;
+
+ err = pcpu_freelist_init(&smap->freelist);
+ if (err)
+ goto free_elems;
+
+ pcpu_freelist_populate(&smap->freelist, smap->elems, elem_size,
+ smap->map.max_entries);
+ return 0;
+
+free_elems:
+ vfree(smap->elems);
+ return err;
+}
+
+/* Called from syscall */
+static struct bpf_map *stack_map_alloc(union bpf_attr *attr)
+{
+ u32 value_size = attr->value_size;
+ struct bpf_stack_map *smap;
+ u64 cost, n_buckets;
+ int err;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return ERR_PTR(-EPERM);
+
+ if (attr->map_flags)
+ return ERR_PTR(-EINVAL);
+
+ /* check sanity of attributes */
+ if (attr->max_entries == 0 || attr->key_size != 4 ||
+ value_size < 8 || value_size % 8 ||
+ value_size / 8 > PERF_MAX_STACK_DEPTH)
+ return ERR_PTR(-EINVAL);
+
+ /* hash table size must be power of 2 */
+ n_buckets = roundup_pow_of_two(attr->max_entries);
+
+ cost = n_buckets * sizeof(struct stack_map_bucket *) + sizeof(*smap);
+ if (cost >= U32_MAX - PAGE_SIZE)
+ return ERR_PTR(-E2BIG);
+
+ smap = kzalloc(cost, GFP_USER | __GFP_NOWARN);
+ if (!smap) {
+ smap = vzalloc(cost);
+ if (!smap)
+ return ERR_PTR(-ENOMEM);
+ }
+
+ err = -E2BIG;
+ cost += n_buckets * (value_size + sizeof(struct stack_map_bucket));
+ if (cost >= U32_MAX - PAGE_SIZE)
+ goto free_smap;
+
+ smap->map.map_type = attr->map_type;
+ smap->map.key_size = attr->key_size;
+ smap->map.value_size = value_size;
+ smap->map.max_entries = attr->max_entries;
+ smap->n_buckets = n_buckets;
+ smap->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
+
+ err = bpf_map_precharge_memlock(smap->map.pages);
+ if (err)
+ goto free_smap;
+
+ err = get_callchain_buffers();
+ if (err)
+ goto free_smap;
+
+ err = prealloc_elems_and_freelist(smap);
+ if (err)
+ goto put_buffers;
+
+ return &smap->map;
+
+put_buffers:
+ put_callchain_buffers();
+free_smap:
+ kvfree(smap);
+ return ERR_PTR(err);
+}
+
+static u64 bpf_get_stackid(u64 r1, u64 r2, u64 flags, u64 r4, u64 r5)
+{
+ struct pt_regs *regs = (struct pt_regs *) (long) r1;
+ struct bpf_map *map = (struct bpf_map *) (long) r2;
+ struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map);
+ struct perf_callchain_entry *trace;
+ struct stack_map_bucket *bucket, *new_bucket, *old_bucket;
+ u32 max_depth = map->value_size / 8;
+ /* stack_map_alloc() checks that max_depth <= PERF_MAX_STACK_DEPTH */
+ u32 init_nr = PERF_MAX_STACK_DEPTH - max_depth;
+ u32 skip = flags & BPF_F_SKIP_FIELD_MASK;
+ u32 hash, id, trace_nr, trace_len;
+ bool user = flags & BPF_F_USER_STACK;
+ bool kernel = !user;
+ u64 *ips;
+
+ if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK |
+ BPF_F_FAST_STACK_CMP | BPF_F_REUSE_STACKID)))
+ return -EINVAL;
+
+ trace = get_perf_callchain(regs, init_nr, kernel, user, false, false);
+
+ if (unlikely(!trace))
+ /* couldn't fetch the stack trace */
+ return -EFAULT;
+
+ /* get_perf_callchain() guarantees that trace->nr >= init_nr
+ * and trace-nr <= PERF_MAX_STACK_DEPTH, so trace_nr <= max_depth
+ */
+ trace_nr = trace->nr - init_nr;
+
+ if (trace_nr <= skip)
+ /* skipping more than usable stack trace */
+ return -EFAULT;
+
+ trace_nr -= skip;
+ trace_len = trace_nr * sizeof(u64);
+ ips = trace->ip + skip + init_nr;
+ hash = jhash2((u32 *)ips, trace_len / sizeof(u32), 0);
+ id = hash & (smap->n_buckets - 1);
+ bucket = READ_ONCE(smap->buckets[id]);
+
+ if (bucket && bucket->hash == hash) {
+ if (flags & BPF_F_FAST_STACK_CMP)
+ return id;
+ if (bucket->nr == trace_nr &&
+ memcmp(bucket->ip, ips, trace_len) == 0)
+ return id;
+ }
+
+ /* this call stack is not in the map, try to add it */
+ if (bucket && !(flags & BPF_F_REUSE_STACKID))
+ return -EEXIST;
+
+ new_bucket = (struct stack_map_bucket *)
+ pcpu_freelist_pop(&smap->freelist);
+ if (unlikely(!new_bucket))
+ return -ENOMEM;
+
+ memcpy(new_bucket->ip, ips, trace_len);
+ new_bucket->hash = hash;
+ new_bucket->nr = trace_nr;
+
+ old_bucket = xchg(&smap->buckets[id], new_bucket);
+ if (old_bucket)
+ pcpu_freelist_push(&smap->freelist, &old_bucket->fnode);
+ return id;
+}
+
+const struct bpf_func_proto bpf_get_stackid_proto = {
+ .func = bpf_get_stackid,
+ .gpl_only = true,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_CTX,
+ .arg2_type = ARG_CONST_MAP_PTR,
+ .arg3_type = ARG_ANYTHING,
+};
+
+/* Called from eBPF program */
+static void *stack_map_lookup_elem(struct bpf_map *map, void *key)
+{
+ return NULL;
+}
+
+/* Called from syscall */
+int bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
+{
+ struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map);
+ struct stack_map_bucket *bucket, *old_bucket;
+ u32 id = *(u32 *)key, trace_len;
+
+ if (unlikely(id >= smap->n_buckets))
+ return -ENOENT;
+
+ bucket = xchg(&smap->buckets[id], NULL);
+ if (!bucket)
+ return -ENOENT;
+
+ trace_len = bucket->nr * sizeof(u64);
+ memcpy(value, bucket->ip, trace_len);
+ memset(value + trace_len, 0, map->value_size - trace_len);
+
+ old_bucket = xchg(&smap->buckets[id], bucket);
+ if (old_bucket)
+ pcpu_freelist_push(&smap->freelist, &old_bucket->fnode);
+ return 0;
+}
+
+static int stack_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
+{
+ return -EINVAL;
+}
+
+static int stack_map_update_elem(struct bpf_map *map, void *key, void *value,
+ u64 map_flags)
+{
+ return -EINVAL;
+}
+
+/* Called from syscall or from eBPF program */
+static int stack_map_delete_elem(struct bpf_map *map, void *key)
+{
+ struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map);
+ struct stack_map_bucket *old_bucket;
+ u32 id = *(u32 *)key;
+
+ if (unlikely(id >= smap->n_buckets))
+ return -E2BIG;
+
+ old_bucket = xchg(&smap->buckets[id], NULL);
+ if (old_bucket) {
+ pcpu_freelist_push(&smap->freelist, &old_bucket->fnode);
+ return 0;
+ } else {
+ return -ENOENT;
+ }
+}
+
+/* Called when map->refcnt goes to zero, either from workqueue or from syscall */
+static void stack_map_free(struct bpf_map *map)
+{
+ struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map);
+
+ /* wait for bpf programs to complete before freeing stack map */
+ synchronize_rcu();
+
+ vfree(smap->elems);
+ pcpu_freelist_destroy(&smap->freelist);
+ kvfree(smap);
+ put_callchain_buffers();
+}
+
+static const struct bpf_map_ops stack_map_ops = {
+ .map_alloc = stack_map_alloc,
+ .map_free = stack_map_free,
+ .map_get_next_key = stack_map_get_next_key,
+ .map_lookup_elem = stack_map_lookup_elem,
+ .map_update_elem = stack_map_update_elem,
+ .map_delete_elem = stack_map_delete_elem,
+};
+
+static struct bpf_map_type_list stack_map_type __read_mostly = {
+ .ops = &stack_map_ops,
+ .type = BPF_MAP_TYPE_STACK_TRACE,
+};
+
+static int __init register_stack_map(void)
+{
+ bpf_register_map_type(&stack_map_type);
+ return 0;
+}
+late_initcall(register_stack_map);
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 637397059f76..2a2efe1bc76c 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -18,6 +18,8 @@
#include <linux/filter.h>
#include <linux/version.h>
+DEFINE_PER_CPU(int, bpf_prog_active);
+
int sysctl_unprivileged_bpf_disabled __read_mostly;
static LIST_HEAD(bpf_map_types);
@@ -46,6 +48,19 @@ void bpf_register_map_type(struct bpf_map_type_list *tl)
list_add(&tl->list_node, &bpf_map_types);
}
+int bpf_map_precharge_memlock(u32 pages)
+{
+ struct user_struct *user = get_current_user();
+ unsigned long memlock_limit, cur;
+
+ memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
+ cur = atomic_long_read(&user->locked_vm);
+ free_uid(user);
+ if (cur + pages > memlock_limit)
+ return -EPERM;
+ return 0;
+}
+
static int bpf_map_charge_memlock(struct bpf_map *map)
{
struct user_struct *user = get_current_user();
@@ -151,7 +166,7 @@ int bpf_map_new_fd(struct bpf_map *map)
offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
sizeof(attr->CMD##_LAST_FIELD)) != NULL
-#define BPF_MAP_CREATE_LAST_FIELD max_entries
+#define BPF_MAP_CREATE_LAST_FIELD map_flags
/* called via syscall */
static int map_create(union bpf_attr *attr)
{
@@ -229,6 +244,11 @@ static void __user *u64_to_ptr(__u64 val)
return (void __user *) (unsigned long) val;
}
+int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
+{
+ return -ENOTSUPP;
+}
+
/* last field in 'union bpf_attr' used by this command */
#define BPF_MAP_LOOKUP_ELEM_LAST_FIELD value
@@ -239,6 +259,7 @@ static int map_lookup_elem(union bpf_attr *attr)
int ufd = attr->map_fd;
struct bpf_map *map;
void *key, *value, *ptr;
+ u32 value_size;
struct fd f;
int err;
@@ -259,23 +280,37 @@ static int map_lookup_elem(union bpf_attr *attr)
if (copy_from_user(key, ukey, map->key_size) != 0)
goto free_key;
+ if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+ map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
+ value_size = round_up(map->value_size, 8) * num_possible_cpus();
+ else
+ value_size = map->value_size;
+
err = -ENOMEM;
- value = kmalloc(map->value_size, GFP_USER | __GFP_NOWARN);
+ value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
if (!value)
goto free_key;
- rcu_read_lock();
- ptr = map->ops->map_lookup_elem(map, key);
- if (ptr)
- memcpy(value, ptr, map->value_size);
- rcu_read_unlock();
+ if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH) {
+ err = bpf_percpu_hash_copy(map, key, value);
+ } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
+ err = bpf_percpu_array_copy(map, key, value);
+ } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
+ err = bpf_stackmap_copy(map, key, value);
+ } else {
+ rcu_read_lock();
+ ptr = map->ops->map_lookup_elem(map, key);
+ if (ptr)
+ memcpy(value, ptr, value_size);
+ rcu_read_unlock();
+ err = ptr ? 0 : -ENOENT;
+ }
- err = -ENOENT;
- if (!ptr)
+ if (err)
goto free_value;
err = -EFAULT;
- if (copy_to_user(uvalue, value, map->value_size) != 0)
+ if (copy_to_user(uvalue, value, value_size) != 0)
goto free_value;
err = 0;
@@ -298,6 +333,7 @@ static int map_update_elem(union bpf_attr *attr)
int ufd = attr->map_fd;
struct bpf_map *map;
void *key, *value;
+ u32 value_size;
struct fd f;
int err;
@@ -318,21 +354,37 @@ static int map_update_elem(union bpf_attr *attr)
if (copy_from_user(key, ukey, map->key_size) != 0)
goto free_key;
+ if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+ map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
+ value_size = round_up(map->value_size, 8) * num_possible_cpus();
+ else
+ value_size = map->value_size;
+
err = -ENOMEM;
- value = kmalloc(map->value_size, GFP_USER | __GFP_NOWARN);
+ value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
if (!value)
goto free_key;
err = -EFAULT;
- if (copy_from_user(value, uvalue, map->value_size) != 0)
+ if (copy_from_user(value, uvalue, value_size) != 0)
goto free_value;
- /* eBPF program that use maps are running under rcu_read_lock(),
- * therefore all map accessors rely on this fact, so do the same here
+ /* must increment bpf_prog_active to avoid kprobe+bpf triggering from
+ * inside bpf map update or delete otherwise deadlocks are possible
*/
- rcu_read_lock();
- err = map->ops->map_update_elem(map, key, value, attr->flags);
- rcu_read_unlock();
+ preempt_disable();
+ __this_cpu_inc(bpf_prog_active);
+ if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH) {
+ err = bpf_percpu_hash_update(map, key, value, attr->flags);
+ } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
+ err = bpf_percpu_array_update(map, key, value, attr->flags);
+ } else {
+ rcu_read_lock();
+ err = map->ops->map_update_elem(map, key, value, attr->flags);
+ rcu_read_unlock();
+ }
+ __this_cpu_dec(bpf_prog_active);
+ preempt_enable();
free_value:
kfree(value);
@@ -371,9 +423,13 @@ static int map_delete_elem(union bpf_attr *attr)
if (copy_from_user(key, ukey, map->key_size) != 0)
goto free_key;
+ preempt_disable();
+ __this_cpu_inc(bpf_prog_active);
rcu_read_lock();
err = map->ops->map_delete_elem(map, key);
rcu_read_unlock();
+ __this_cpu_dec(bpf_prog_active);
+ preempt_enable();
free_key:
kfree(key);
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 2e7f7ab739e4..2e08f8e9b771 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -246,6 +246,7 @@ static const struct {
{BPF_MAP_TYPE_PROG_ARRAY, BPF_FUNC_tail_call},
{BPF_MAP_TYPE_PERF_EVENT_ARRAY, BPF_FUNC_perf_event_read},
{BPF_MAP_TYPE_PERF_EVENT_ARRAY, BPF_FUNC_perf_event_output},
+ {BPF_MAP_TYPE_STACK_TRACE, BPF_FUNC_get_stackid},
};
static void print_verifier_state(struct verifier_env *env)
@@ -778,15 +779,24 @@ static int check_xadd(struct verifier_env *env, struct bpf_insn *insn)
* bytes from that pointer, make sure that it's within stack boundary
* and all elements of stack are initialized
*/
-static int check_stack_boundary(struct verifier_env *env,
- int regno, int access_size)
+static int check_stack_boundary(struct verifier_env *env, int regno,
+ int access_size, bool zero_size_allowed)
{
struct verifier_state *state = &env->cur_state;
struct reg_state *regs = state->regs;
int off, i;
- if (regs[regno].type != PTR_TO_STACK)
+ if (regs[regno].type != PTR_TO_STACK) {
+ if (zero_size_allowed && access_size == 0 &&
+ regs[regno].type == CONST_IMM &&
+ regs[regno].imm == 0)
+ return 0;
+
+ verbose("R%d type=%s expected=%s\n", regno,
+ reg_type_str[regs[regno].type],
+ reg_type_str[PTR_TO_STACK]);
return -EACCES;
+ }
off = regs[regno].imm;
if (off >= 0 || off < -MAX_BPF_STACK || off + access_size > 0 ||
@@ -829,15 +839,24 @@ static int check_func_arg(struct verifier_env *env, u32 regno,
return 0;
}
- if (arg_type == ARG_PTR_TO_STACK || arg_type == ARG_PTR_TO_MAP_KEY ||
+ if (arg_type == ARG_PTR_TO_MAP_KEY ||
arg_type == ARG_PTR_TO_MAP_VALUE) {
expected_type = PTR_TO_STACK;
- } else if (arg_type == ARG_CONST_STACK_SIZE) {
+ } else if (arg_type == ARG_CONST_STACK_SIZE ||
+ arg_type == ARG_CONST_STACK_SIZE_OR_ZERO) {
expected_type = CONST_IMM;
} else if (arg_type == ARG_CONST_MAP_PTR) {
expected_type = CONST_PTR_TO_MAP;
} else if (arg_type == ARG_PTR_TO_CTX) {
expected_type = PTR_TO_CTX;
+ } else if (arg_type == ARG_PTR_TO_STACK) {
+ expected_type = PTR_TO_STACK;
+ /* One exception here. In case function allows for NULL to be
+ * passed in as argument, it's a CONST_IMM type. Final test
+ * happens during stack boundary checking.
+ */
+ if (reg->type == CONST_IMM && reg->imm == 0)
+ expected_type = CONST_IMM;
} else {
verbose("unsupported arg_type %d\n", arg_type);
return -EFAULT;
@@ -867,8 +886,8 @@ static int check_func_arg(struct verifier_env *env, u32 regno,
verbose("invalid map_ptr to access map->key\n");
return -EACCES;
}
- err = check_stack_boundary(env, regno, (*mapp)->key_size);
-
+ err = check_stack_boundary(env, regno, (*mapp)->key_size,
+ false);
} else if (arg_type == ARG_PTR_TO_MAP_VALUE) {
/* bpf_map_xxx(..., map_ptr, ..., value) call:
* check [value, value + map->value_size) validity
@@ -878,9 +897,12 @@ static int check_func_arg(struct verifier_env *env, u32 regno,
verbose("invalid map_ptr to access map->value\n");
return -EACCES;
}
- err = check_stack_boundary(env, regno, (*mapp)->value_size);
+ err = check_stack_boundary(env, regno, (*mapp)->value_size,
+ false);
+ } else if (arg_type == ARG_CONST_STACK_SIZE ||
+ arg_type == ARG_CONST_STACK_SIZE_OR_ZERO) {
+ bool zero_size_allowed = (arg_type == ARG_CONST_STACK_SIZE_OR_ZERO);
- } else if (arg_type == ARG_CONST_STACK_SIZE) {
/* bpf_xxx(..., buf, len) call will access 'len' bytes
* from stack pointer 'buf'. Check it
* note: regno == len, regno - 1 == buf
@@ -890,7 +912,8 @@ static int check_func_arg(struct verifier_env *env, u32 regno,
verbose("ARG_CONST_STACK_SIZE cannot be first argument\n");
return -EACCES;
}
- err = check_stack_boundary(env, regno - 1, reg->imm);
+ err = check_stack_boundary(env, regno - 1, reg->imm,
+ zero_size_allowed);
}
return err;
@@ -911,8 +934,11 @@ static int check_map_func_compatibility(struct bpf_map *map, int func_id)
* don't allow any other map type to be passed into
* the special func;
*/
- if (bool_func && bool_map != bool_func)
+ if (bool_func && bool_map != bool_func) {
+ verbose("cannot pass map_type %d into func %d\n",
+ map->map_type, func_id);
return -EINVAL;
+ }
}
return 0;
diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c
index 9c418002b8c1..343c22f5e867 100644
--- a/kernel/events/callchain.c
+++ b/kernel/events/callchain.c
@@ -159,15 +159,24 @@ put_callchain_entry(int rctx)
struct perf_callchain_entry *
perf_callchain(struct perf_event *event, struct pt_regs *regs)
{
- int rctx;
- struct perf_callchain_entry *entry;
-
- int kernel = !event->attr.exclude_callchain_kernel;
- int user = !event->attr.exclude_callchain_user;
+ bool kernel = !event->attr.exclude_callchain_kernel;
+ bool user = !event->attr.exclude_callchain_user;
+ /* Disallow cross-task user callchains. */
+ bool crosstask = event->ctx->task && event->ctx->task != current;
if (!kernel && !user)
return NULL;
+ return get_perf_callchain(regs, 0, kernel, user, crosstask, true);
+}
+
+struct perf_callchain_entry *
+get_perf_callchain(struct pt_regs *regs, u32 init_nr, bool kernel, bool user,
+ bool crosstask, bool add_mark)
+{
+ struct perf_callchain_entry *entry;
+ int rctx;
+
entry = get_callchain_entry(&rctx);
if (rctx == -1)
return NULL;
@@ -175,10 +184,11 @@ perf_callchain(struct perf_event *event, struct pt_regs *regs)
if (!entry)
goto exit_put;
- entry->nr = 0;
+ entry->nr = init_nr;
if (kernel && !user_mode(regs)) {
- perf_callchain_store(entry, PERF_CONTEXT_KERNEL);
+ if (add_mark)
+ perf_callchain_store(entry, PERF_CONTEXT_KERNEL);
perf_callchain_kernel(entry, regs);
}
@@ -191,13 +201,11 @@ perf_callchain(struct perf_event *event, struct pt_regs *regs)
}
if (regs) {
- /*
- * Disallow cross-task user callchains.
- */
- if (event->ctx->task && event->ctx->task != current)
+ if (crosstask)
goto exit_put;
- perf_callchain_store(entry, PERF_CONTEXT_USER);
+ if (add_mark)
+ perf_callchain_store(entry, PERF_CONTEXT_USER);
perf_callchain_user(entry, regs);
}
}
diff --git a/kernel/events/internal.h b/kernel/events/internal.h
index 2bbad9c1274c..4199b6d193f5 100644
--- a/kernel/events/internal.h
+++ b/kernel/events/internal.h
@@ -182,8 +182,6 @@ DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user)
/* Callchain handling */
extern struct perf_callchain_entry *
perf_callchain(struct perf_event *event, struct pt_regs *regs);
-extern int get_callchain_buffers(void);
-extern void put_callchain_buffers(void);
static inline int get_recursion_context(int *recursion)
{
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 326a75e884db..3e4ffb3ace5f 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -13,8 +13,6 @@
#include <linux/ctype.h>
#include "trace.h"
-static DEFINE_PER_CPU(int, bpf_prog_active);
-
/**
* trace_call_bpf - invoke BPF program
* @prog: BPF program
@@ -299,6 +297,8 @@ static const struct bpf_func_proto *kprobe_prog_func_proto(enum bpf_func_id func
return &bpf_perf_event_read_proto;
case BPF_FUNC_perf_event_output:
return &bpf_perf_event_output_proto;
+ case BPF_FUNC_get_stackid:
+ return &bpf_get_stackid_proto;
default:
return NULL;
}
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-23 08:09:04 +0300