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authorDavid S. Miller <davem@davemloft.net>2019-11-20 18:11:23 -0800
committerDavid S. Miller <davem@davemloft.net>2019-11-20 18:11:23 -0800
commitee5a489fd9645104925e5cdf8f8e455d833730b9 (patch)
tree1e46a8c460e1d51d465fe472e42cf1c16f92f9c7 /kernel
parente2193c9334291ecdc437cdbd9fe9ac35c14fffa8 (diff)
parent196e8ca74886c433dcfc64a809707074b936aaf5 (diff)
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Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says: ==================== pull-request: bpf-next 2019-11-20 The following pull-request contains BPF updates for your *net-next* tree. We've added 81 non-merge commits during the last 17 day(s) which contain a total of 120 files changed, 4958 insertions(+), 1081 deletions(-). There are 3 trivial conflicts, resolve it by always taking the chunk from 196e8ca74886c433: <<<<<<< HEAD ======= void *bpf_map_area_mmapable_alloc(u64 size, int numa_node); >>>>>>> 196e8ca74886c433dcfc64a809707074b936aaf5 <<<<<<< HEAD void *bpf_map_area_alloc(u64 size, int numa_node) ======= static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable) >>>>>>> 196e8ca74886c433dcfc64a809707074b936aaf5 <<<<<<< HEAD if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) { ======= /* kmalloc()'ed memory can't be mmap()'ed */ if (!mmapable && size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) { >>>>>>> 196e8ca74886c433dcfc64a809707074b936aaf5 The main changes are: 1) Addition of BPF trampoline which works as a bridge between kernel functions, BPF programs and other BPF programs along with two new use cases: i) fentry/fexit BPF programs for tracing with practically zero overhead to call into BPF (as opposed to k[ret]probes) and ii) attachment of the former to networking related programs to see input/output of networking programs (covering xdpdump use case), from Alexei Starovoitov. 2) BPF array map mmap support and use in libbpf for global data maps; also a big batch of libbpf improvements, among others, support for reading bitfields in a relocatable manner (via libbpf's CO-RE helper API), from Andrii Nakryiko. 3) Extend s390x JIT with usage of relative long jumps and loads in order to lift the current 64/512k size limits on JITed BPF programs there, from Ilya Leoshkevich. 4) Add BPF audit support and emit messages upon successful prog load and unload in order to have a timeline of events, from Daniel Borkmann and Jiri Olsa. 5) Extension to libbpf and xdpsock sample programs to demo the shared umem mode (XDP_SHARED_UMEM) as well as RX-only and TX-only sockets, from Magnus Karlsson. 6) Several follow-up bug fixes for libbpf's auto-pinning code and a new API call named bpf_get_link_xdp_info() for retrieving the full set of prog IDs attached to XDP, from Toke Høiland-Jørgensen. 7) Add BTF support for array of int, array of struct and multidimensional arrays and enable it for skb->cb[] access in kfree_skb test, from Martin KaFai Lau. 8) Fix AF_XDP by using the correct number of channels from ethtool, from Luigi Rizzo. 9) Two fixes for BPF selftest to get rid of a hang in test_tc_tunnel and to avoid xdping to be run as standalone, from Jiri Benc. 10) Various BPF selftest fixes when run with latest LLVM trunk, from Yonghong Song. 11) Fix a memory leak in BPF fentry test run data, from Colin Ian King. 12) Various smaller misc cleanups and improvements mostly all over BPF selftests and samples, from Daniel T. Lee, Andre Guedes, Anders Roxell, Mao Wenan, Yue Haibing. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/auditsc.c2
-rw-r--r--kernel/bpf/Makefile1
-rw-r--r--kernel/bpf/arraymap.c58
-rw-r--r--kernel/bpf/btf.c558
-rw-r--r--kernel/bpf/core.c15
-rw-r--r--kernel/bpf/inode.c7
-rw-r--r--kernel/bpf/map_in_map.c2
-rw-r--r--kernel/bpf/syscall.c282
-rw-r--r--kernel/bpf/trampoline.c253
-rw-r--r--kernel/bpf/verifier.c137
-rw-r--r--kernel/bpf/xskmap.c6
-rw-r--r--kernel/events/core.c7
12 files changed, 1187 insertions, 141 deletions
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 4effe01ebbe2..9bf1045fedfa 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2545,7 +2545,7 @@ void __audit_ntp_log(const struct audit_ntp_data *ad)
audit_log_ntp_val(ad, "adjust", AUDIT_NTP_ADJUST);
}
-static void audit_log_task(struct audit_buffer *ab)
+void audit_log_task(struct audit_buffer *ab)
{
kuid_t auid, uid;
kgid_t gid;
diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile
index e1d9adb212f9..3f671bf617e8 100644
--- a/kernel/bpf/Makefile
+++ b/kernel/bpf/Makefile
@@ -6,6 +6,7 @@ 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-$(CONFIG_BPF_SYSCALL) += local_storage.o queue_stack_maps.o
obj-$(CONFIG_BPF_SYSCALL) += disasm.o
+obj-$(CONFIG_BPF_JIT) += trampoline.o
obj-$(CONFIG_BPF_SYSCALL) += btf.o
ifeq ($(CONFIG_NET),y)
obj-$(CONFIG_BPF_SYSCALL) += devmap.o
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index 1c65ce0098a9..633c8c701ff6 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -14,7 +14,7 @@
#include "map_in_map.h"
#define ARRAY_CREATE_FLAG_MASK \
- (BPF_F_NUMA_NODE | BPF_F_ACCESS_MASK)
+ (BPF_F_NUMA_NODE | BPF_F_MMAPABLE | BPF_F_ACCESS_MASK)
static void bpf_array_free_percpu(struct bpf_array *array)
{
@@ -59,6 +59,10 @@ int array_map_alloc_check(union bpf_attr *attr)
(percpu && numa_node != NUMA_NO_NODE))
return -EINVAL;
+ if (attr->map_type != BPF_MAP_TYPE_ARRAY &&
+ attr->map_flags & BPF_F_MMAPABLE)
+ return -EINVAL;
+
if (attr->value_size > KMALLOC_MAX_SIZE)
/* if value_size is bigger, the user space won't be able to
* access the elements.
@@ -102,10 +106,19 @@ static struct bpf_map *array_map_alloc(union bpf_attr *attr)
}
array_size = sizeof(*array);
- if (percpu)
+ if (percpu) {
array_size += (u64) max_entries * sizeof(void *);
- else
- array_size += (u64) max_entries * elem_size;
+ } else {
+ /* rely on vmalloc() to return page-aligned memory and
+ * ensure array->value is exactly page-aligned
+ */
+ if (attr->map_flags & BPF_F_MMAPABLE) {
+ array_size = PAGE_ALIGN(array_size);
+ array_size += PAGE_ALIGN((u64) max_entries * elem_size);
+ } else {
+ array_size += (u64) max_entries * elem_size;
+ }
+ }
/* make sure there is no u32 overflow later in round_up() */
cost = array_size;
@@ -117,7 +130,20 @@ static struct bpf_map *array_map_alloc(union bpf_attr *attr)
return ERR_PTR(ret);
/* allocate all map elements and zero-initialize them */
- array = bpf_map_area_alloc(array_size, numa_node);
+ if (attr->map_flags & BPF_F_MMAPABLE) {
+ void *data;
+
+ /* kmalloc'ed memory can't be mmap'ed, use explicit vmalloc */
+ data = bpf_map_area_mmapable_alloc(array_size, numa_node);
+ if (!data) {
+ bpf_map_charge_finish(&mem);
+ return ERR_PTR(-ENOMEM);
+ }
+ array = data + PAGE_ALIGN(sizeof(struct bpf_array))
+ - offsetof(struct bpf_array, value);
+ } else {
+ array = bpf_map_area_alloc(array_size, numa_node);
+ }
if (!array) {
bpf_map_charge_finish(&mem);
return ERR_PTR(-ENOMEM);
@@ -350,6 +376,11 @@ static int array_map_delete_elem(struct bpf_map *map, void *key)
return -EINVAL;
}
+static void *array_map_vmalloc_addr(struct bpf_array *array)
+{
+ return (void *)round_down((unsigned long)array, PAGE_SIZE);
+}
+
/* Called when map->refcnt goes to zero, either from workqueue or from syscall */
static void array_map_free(struct bpf_map *map)
{
@@ -365,7 +396,10 @@ static void array_map_free(struct bpf_map *map)
if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
bpf_array_free_percpu(array);
- bpf_map_area_free(array);
+ if (array->map.map_flags & BPF_F_MMAPABLE)
+ bpf_map_area_free(array_map_vmalloc_addr(array));
+ else
+ bpf_map_area_free(array);
}
static void array_map_seq_show_elem(struct bpf_map *map, void *key,
@@ -444,6 +478,17 @@ static int array_map_check_btf(const struct bpf_map *map,
return 0;
}
+static int array_map_mmap(struct bpf_map *map, struct vm_area_struct *vma)
+{
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+ pgoff_t pgoff = PAGE_ALIGN(sizeof(*array)) >> PAGE_SHIFT;
+
+ if (!(map->map_flags & BPF_F_MMAPABLE))
+ return -EINVAL;
+
+ return remap_vmalloc_range(vma, array_map_vmalloc_addr(array), pgoff);
+}
+
const struct bpf_map_ops array_map_ops = {
.map_alloc_check = array_map_alloc_check,
.map_alloc = array_map_alloc,
@@ -455,6 +500,7 @@ const struct bpf_map_ops array_map_ops = {
.map_gen_lookup = array_map_gen_lookup,
.map_direct_value_addr = array_map_direct_value_addr,
.map_direct_value_meta = array_map_direct_value_meta,
+ .map_mmap = array_map_mmap,
.map_seq_show_elem = array_map_seq_show_elem,
.map_check_btf = array_map_check_btf,
};
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 128d89601d73..40efde5eedcb 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -2,6 +2,8 @@
/* Copyright (c) 2018 Facebook */
#include <uapi/linux/btf.h>
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/bpf_perf_event.h>
#include <uapi/linux/types.h>
#include <linux/seq_file.h>
#include <linux/compiler.h>
@@ -16,6 +18,9 @@
#include <linux/sort.h>
#include <linux/bpf_verifier.h>
#include <linux/btf.h>
+#include <linux/skmsg.h>
+#include <linux/perf_event.h>
+#include <net/sock.h>
/* BTF (BPF Type Format) is the meta data format which describes
* the data types of BPF program/map. Hence, it basically focus
@@ -1036,6 +1041,82 @@ static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env)
return env->top_stack ? &env->stack[env->top_stack - 1] : NULL;
}
+/* Resolve the size of a passed-in "type"
+ *
+ * type: is an array (e.g. u32 array[x][y])
+ * return type: type "u32[x][y]", i.e. BTF_KIND_ARRAY,
+ * *type_size: (x * y * sizeof(u32)). Hence, *type_size always
+ * corresponds to the return type.
+ * *elem_type: u32
+ * *total_nelems: (x * y). Hence, individual elem size is
+ * (*type_size / *total_nelems)
+ *
+ * type: is not an array (e.g. const struct X)
+ * return type: type "struct X"
+ * *type_size: sizeof(struct X)
+ * *elem_type: same as return type ("struct X")
+ * *total_nelems: 1
+ */
+static const struct btf_type *
+btf_resolve_size(const struct btf *btf, const struct btf_type *type,
+ u32 *type_size, const struct btf_type **elem_type,
+ u32 *total_nelems)
+{
+ const struct btf_type *array_type = NULL;
+ const struct btf_array *array;
+ u32 i, size, nelems = 1;
+
+ for (i = 0; i < MAX_RESOLVE_DEPTH; i++) {
+ switch (BTF_INFO_KIND(type->info)) {
+ /* type->size can be used */
+ case BTF_KIND_INT:
+ case BTF_KIND_STRUCT:
+ case BTF_KIND_UNION:
+ case BTF_KIND_ENUM:
+ size = type->size;
+ goto resolved;
+
+ case BTF_KIND_PTR:
+ size = sizeof(void *);
+ goto resolved;
+
+ /* Modifiers */
+ case BTF_KIND_TYPEDEF:
+ case BTF_KIND_VOLATILE:
+ case BTF_KIND_CONST:
+ case BTF_KIND_RESTRICT:
+ type = btf_type_by_id(btf, type->type);
+ break;
+
+ case BTF_KIND_ARRAY:
+ if (!array_type)
+ array_type = type;
+ array = btf_type_array(type);
+ if (nelems && array->nelems > U32_MAX / nelems)
+ return ERR_PTR(-EINVAL);
+ nelems *= array->nelems;
+ type = btf_type_by_id(btf, array->type);
+ break;
+
+ /* type without size */
+ default:
+ return ERR_PTR(-EINVAL);
+ }
+ }
+
+ return ERR_PTR(-EINVAL);
+
+resolved:
+ if (nelems && size > U32_MAX / nelems)
+ return ERR_PTR(-EINVAL);
+
+ *type_size = nelems * size;
+ *total_nelems = nelems;
+ *elem_type = type;
+
+ return array_type ? : type;
+}
+
/* The input param "type_id" must point to a needs_resolve type */
static const struct btf_type *btf_type_id_resolve(const struct btf *btf,
u32 *type_id)
@@ -3363,13 +3444,112 @@ errout:
extern char __weak _binary__btf_vmlinux_bin_start[];
extern char __weak _binary__btf_vmlinux_bin_end[];
+extern struct btf *btf_vmlinux;
+
+#define BPF_MAP_TYPE(_id, _ops)
+static union {
+ struct bpf_ctx_convert {
+#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
+ prog_ctx_type _id##_prog; \
+ kern_ctx_type _id##_kern;
+#include <linux/bpf_types.h>
+#undef BPF_PROG_TYPE
+ } *__t;
+ /* 't' is written once under lock. Read many times. */
+ const struct btf_type *t;
+} bpf_ctx_convert;
+enum {
+#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
+ __ctx_convert##_id,
+#include <linux/bpf_types.h>
+#undef BPF_PROG_TYPE
+};
+static u8 bpf_ctx_convert_map[] = {
+#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
+ [_id] = __ctx_convert##_id,
+#include <linux/bpf_types.h>
+#undef BPF_PROG_TYPE
+};
+#undef BPF_MAP_TYPE
+
+static const struct btf_member *
+btf_get_prog_ctx_type(struct bpf_verifier_log *log, struct btf *btf,
+ const struct btf_type *t, enum bpf_prog_type prog_type)
+{
+ const struct btf_type *conv_struct;
+ const struct btf_type *ctx_struct;
+ const struct btf_member *ctx_type;
+ const char *tname, *ctx_tname;
+
+ conv_struct = bpf_ctx_convert.t;
+ if (!conv_struct) {
+ bpf_log(log, "btf_vmlinux is malformed\n");
+ return NULL;
+ }
+ t = btf_type_by_id(btf, t->type);
+ while (btf_type_is_modifier(t))
+ t = btf_type_by_id(btf, t->type);
+ if (!btf_type_is_struct(t)) {
+ /* Only pointer to struct is supported for now.
+ * That means that BPF_PROG_TYPE_TRACEPOINT with BTF
+ * is not supported yet.
+ * BPF_PROG_TYPE_RAW_TRACEPOINT is fine.
+ */
+ bpf_log(log, "BPF program ctx type is not a struct\n");
+ return NULL;
+ }
+ tname = btf_name_by_offset(btf, t->name_off);
+ if (!tname) {
+ bpf_log(log, "BPF program ctx struct doesn't have a name\n");
+ return NULL;
+ }
+ /* prog_type is valid bpf program type. No need for bounds check. */
+ ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2;
+ /* ctx_struct is a pointer to prog_ctx_type in vmlinux.
+ * Like 'struct __sk_buff'
+ */
+ ctx_struct = btf_type_by_id(btf_vmlinux, ctx_type->type);
+ if (!ctx_struct)
+ /* should not happen */
+ return NULL;
+ ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_struct->name_off);
+ if (!ctx_tname) {
+ /* should not happen */
+ bpf_log(log, "Please fix kernel include/linux/bpf_types.h\n");
+ return NULL;
+ }
+ /* only compare that prog's ctx type name is the same as
+ * kernel expects. No need to compare field by field.
+ * It's ok for bpf prog to do:
+ * struct __sk_buff {};
+ * int socket_filter_bpf_prog(struct __sk_buff *skb)
+ * { // no fields of skb are ever used }
+ */
+ if (strcmp(ctx_tname, tname))
+ return NULL;
+ return ctx_type;
+}
+
+static int btf_translate_to_vmlinux(struct bpf_verifier_log *log,
+ struct btf *btf,
+ const struct btf_type *t,
+ enum bpf_prog_type prog_type)
+{
+ const struct btf_member *prog_ctx_type, *kern_ctx_type;
+
+ prog_ctx_type = btf_get_prog_ctx_type(log, btf, t, prog_type);
+ if (!prog_ctx_type)
+ return -ENOENT;
+ kern_ctx_type = prog_ctx_type + 1;
+ return kern_ctx_type->type;
+}
struct btf *btf_parse_vmlinux(void)
{
struct btf_verifier_env *env = NULL;
struct bpf_verifier_log *log;
struct btf *btf = NULL;
- int err;
+ int err, i;
env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN);
if (!env)
@@ -3403,6 +3583,26 @@ struct btf *btf_parse_vmlinux(void)
if (err)
goto errout;
+ /* find struct bpf_ctx_convert for type checking later */
+ for (i = 1; i <= btf->nr_types; i++) {
+ const struct btf_type *t;
+ const char *tname;
+
+ t = btf_type_by_id(btf, i);
+ if (!__btf_type_is_struct(t))
+ continue;
+ tname = __btf_name_by_offset(btf, t->name_off);
+ if (!strcmp(tname, "bpf_ctx_convert")) {
+ /* btf_parse_vmlinux() runs under bpf_verifier_lock */
+ bpf_ctx_convert.t = t;
+ break;
+ }
+ }
+ if (i > btf->nr_types) {
+ err = -ENOENT;
+ goto errout;
+ }
+
btf_verifier_env_free(env);
refcount_set(&btf->refcnt, 1);
return btf;
@@ -3416,17 +3616,29 @@ errout:
return ERR_PTR(err);
}
-extern struct btf *btf_vmlinux;
+struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog)
+{
+ struct bpf_prog *tgt_prog = prog->aux->linked_prog;
+
+ if (tgt_prog) {
+ return tgt_prog->aux->btf;
+ } else {
+ return btf_vmlinux;
+ }
+}
bool btf_ctx_access(int off, int size, enum bpf_access_type type,
const struct bpf_prog *prog,
struct bpf_insn_access_aux *info)
{
const struct btf_type *t = prog->aux->attach_func_proto;
+ struct bpf_prog *tgt_prog = prog->aux->linked_prog;
+ struct btf *btf = bpf_prog_get_target_btf(prog);
const char *tname = prog->aux->attach_func_name;
struct bpf_verifier_log *log = info->log;
const struct btf_param *args;
u32 nr_args, arg;
+ int ret;
if (off % 8) {
bpf_log(log, "func '%s' offset %d is not multiple of 8\n",
@@ -3435,22 +3647,34 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type,
}
arg = off / 8;
args = (const struct btf_param *)(t + 1);
- nr_args = btf_type_vlen(t);
+ /* if (t == NULL) Fall back to default BPF prog with 5 u64 arguments */
+ nr_args = t ? btf_type_vlen(t) : 5;
if (prog->aux->attach_btf_trace) {
/* skip first 'void *__data' argument in btf_trace_##name typedef */
args++;
nr_args--;
}
- if (arg >= nr_args) {
+
+ if (prog->expected_attach_type == BPF_TRACE_FEXIT &&
+ arg == nr_args) {
+ if (!t)
+ /* Default prog with 5 args. 6th arg is retval. */
+ return true;
+ /* function return type */
+ t = btf_type_by_id(btf, t->type);
+ } else if (arg >= nr_args) {
bpf_log(log, "func '%s' doesn't have %d-th argument\n",
- tname, arg);
+ tname, arg + 1);
return false;
+ } else {
+ if (!t)
+ /* Default prog with 5 args */
+ return true;
+ t = btf_type_by_id(btf, args[arg].type);
}
-
- t = btf_type_by_id(btf_vmlinux, args[arg].type);
/* skip modifiers */
while (btf_type_is_modifier(t))
- t = btf_type_by_id(btf_vmlinux, t->type);
+ t = btf_type_by_id(btf, t->type);
if (btf_type_is_int(t))
/* accessing a scalar */
return true;
@@ -3458,7 +3682,7 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type,
bpf_log(log,
"func '%s' arg%d '%s' has type %s. Only pointer access is allowed\n",
tname, arg,
- __btf_name_by_offset(btf_vmlinux, t->name_off),
+ __btf_name_by_offset(btf, t->name_off),
btf_kind_str[BTF_INFO_KIND(t->info)]);
return false;
}
@@ -3473,10 +3697,19 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type,
info->reg_type = PTR_TO_BTF_ID;
info->btf_id = t->type;
- t = btf_type_by_id(btf_vmlinux, t->type);
+ if (tgt_prog) {
+ ret = btf_translate_to_vmlinux(log, btf, t, tgt_prog->type);
+ if (ret > 0) {
+ info->btf_id = ret;
+ return true;
+ } else {
+ return false;
+ }
+ }
+ t = btf_type_by_id(btf, t->type);
/* skip modifiers */
while (btf_type_is_modifier(t))
- t = btf_type_by_id(btf_vmlinux, t->type);
+ t = btf_type_by_id(btf, t->type);
if (!btf_type_is_struct(t)) {
bpf_log(log,
"func '%s' arg%d type %s is not a struct\n",
@@ -3485,7 +3718,7 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type,
}
bpf_log(log, "func '%s' arg%d has btf_id %d type %s '%s'\n",
tname, arg, info->btf_id, btf_kind_str[BTF_INFO_KIND(t->info)],
- __btf_name_by_offset(btf_vmlinux, t->name_off));
+ __btf_name_by_offset(btf, t->name_off));
return true;
}
@@ -3494,10 +3727,10 @@ int btf_struct_access(struct bpf_verifier_log *log,
enum bpf_access_type atype,
u32 *next_btf_id)
{
+ u32 i, moff, mtrue_end, msize = 0, total_nelems = 0;
+ const struct btf_type *mtype, *elem_type = NULL;
const struct btf_member *member;
- const struct btf_type *mtype;
const char *tname, *mname;
- int i, moff = 0, msize;
again:
tname = __btf_name_by_offset(btf_vmlinux, t->name_off);
@@ -3507,40 +3740,88 @@ again:
}
for_each_member(i, t, member) {
- /* offset of the field in bits */
- moff = btf_member_bit_offset(t, member);
-
if (btf_member_bitfield_size(t, member))
/* bitfields are not supported yet */
continue;
- if (off + size <= moff / 8)
+ /* offset of the field in bytes */
+ moff = btf_member_bit_offset(t, member) / 8;
+ if (off + size <= moff)
/* won't find anything, field is already too far */
break;
+ /* In case of "off" is pointing to holes of a struct */
+ if (off < moff)
+ continue;
/* type of the field */
mtype = btf_type_by_id(btf_vmlinux, member->type);
mname = __btf_name_by_offset(btf_vmlinux, member->name_off);
- /* skip modifiers */
- while (btf_type_is_modifier(mtype))
- mtype = btf_type_by_id(btf_vmlinux, mtype->type);
-
- if (btf_type_is_array(mtype))
- /* array deref is not supported yet */
- continue;
-
- if (!btf_type_has_size(mtype) && !btf_type_is_ptr(mtype)) {
+ mtype = btf_resolve_size(btf_vmlinux, mtype, &msize,
+ &elem_type, &total_nelems);
+ if (IS_ERR(mtype)) {
bpf_log(log, "field %s doesn't have size\n", mname);
return -EFAULT;
}
- if (btf_type_is_ptr(mtype))
- msize = 8;
- else
- msize = mtype->size;
- if (off >= moff / 8 + msize)
+
+ mtrue_end = moff + msize;
+ if (off >= mtrue_end)
/* no overlap with member, keep iterating */
continue;
+
+ if (btf_type_is_array(mtype)) {
+ u32 elem_idx;
+
+ /* btf_resolve_size() above helps to
+ * linearize a multi-dimensional array.
+ *
+ * The logic here is treating an array
+ * in a struct as the following way:
+ *
+ * struct outer {
+ * struct inner array[2][2];
+ * };
+ *
+ * looks like:
+ *
+ * struct outer {
+ * struct inner array_elem0;
+ * struct inner array_elem1;
+ * struct inner array_elem2;
+ * struct inner array_elem3;
+ * };
+ *
+ * When accessing outer->array[1][0], it moves
+ * moff to "array_elem2", set mtype to
+ * "struct inner", and msize also becomes
+ * sizeof(struct inner). Then most of the
+ * remaining logic will fall through without
+ * caring the current member is an array or
+ * not.
+ *
+ * Unlike mtype/msize/moff, mtrue_end does not
+ * change. The naming difference ("_true") tells
+ * that it is not always corresponding to
+ * the current mtype/msize/moff.
+ * It is the true end of the current
+ * member (i.e. array in this case). That
+ * will allow an int array to be accessed like
+ * a scratch space,
+ * i.e. allow access beyond the size of
+ * the array's element as long as it is
+ * within the mtrue_end boundary.
+ */
+
+ /* skip empty array */
+ if (moff == mtrue_end)
+ continue;
+
+ msize /= total_nelems;
+ elem_idx = (off - moff) / msize;
+ moff += elem_idx * msize;
+ mtype = elem_type;
+ }
+
/* the 'off' we're looking for is either equal to start
* of this field or inside of this struct
*/
@@ -3549,20 +3830,20 @@ again:
t = mtype;
/* adjust offset we're looking for */
- off -= moff / 8;
+ off -= moff;
goto again;
}
- if (msize != size) {
- /* field access size doesn't match */
- bpf_log(log,
- "cannot access %d bytes in struct %s field %s that has size %d\n",
- size, tname, mname, msize);
- return -EACCES;
- }
if (btf_type_is_ptr(mtype)) {
const struct btf_type *stype;
+ if (msize != size || off != moff) {
+ bpf_log(log,
+ "cannot access ptr member %s with moff %u in struct %s with off %u size %u\n",
+ mname, moff, tname, off, size);
+ return -EACCES;
+ }
+
stype = btf_type_by_id(btf_vmlinux, mtype->type);
/* skip modifiers */
while (btf_type_is_modifier(stype))
@@ -3572,14 +3853,28 @@ again:
return PTR_TO_BTF_ID;
}
}
- /* all other fields are treated as scalars */
+
+ /* Allow more flexible access within an int as long as
+ * it is within mtrue_end.
+ * Since mtrue_end could be the end of an array,
+ * that also allows using an array of int as a scratch
+ * space. e.g. skb->cb[].
+ */
+ if (off + size > mtrue_end) {
+ bpf_log(log,
+ "access beyond the end of member %s (mend:%u) in struct %s with off %u size %u\n",
+ mname, mtrue_end, tname, off, size);
+ return -EACCES;
+ }
+
return SCALAR_VALUE;
}
bpf_log(log, "struct %s doesn't have field at offset %d\n", tname, off);
return -EINVAL;
}
-u32 btf_resolve_helper_id(struct bpf_verifier_log *log, void *fn, int arg)
+static int __btf_resolve_helper_id(struct bpf_verifier_log *log, void *fn,
+ int arg)
{
char fnname[KSYM_SYMBOL_LEN + 4] = "btf_";
const struct btf_param *args;
@@ -3647,6 +3942,185 @@ u32 btf_resolve_helper_id(struct bpf_verifier_log *log, void *fn, int arg)
return btf_id;
}
+int btf_resolve_helper_id(struct bpf_verifier_log *log,
+ const struct bpf_func_proto *fn, int arg)
+{
+ int *btf_id = &fn->btf_id[arg];
+ int ret;
+
+ if (fn->arg_type[arg] != ARG_PTR_TO_BTF_ID)
+ return -EINVAL;
+
+ ret = READ_ONCE(*btf_id);
+ if (ret)
+ return ret;
+ /* ok to race the search. The result is the same */
+ ret = __btf_resolve_helper_id(log, fn->func, arg);
+ if (!ret) {
+ /* Function argument cannot be type 'void' */
+ bpf_log(log, "BTF resolution bug\n");
+ return -EFAULT;
+ }
+ WRITE_ONCE(*btf_id, ret);
+ return ret;
+}
+
+static int __get_type_size(struct btf *btf, u32 btf_id,
+ const struct btf_type **bad_type)
+{
+ const struct btf_type *t;
+
+ if (!btf_id)
+ /* void */
+ return 0;
+ t = btf_type_by_id(btf, btf_id);
+ while (t && btf_type_is_modifier(t))
+ t = btf_type_by_id(btf, t->type);
+ if (!t)
+ return -EINVAL;
+ if (btf_type_is_ptr(t))
+ /* kernel size of pointer. Not BPF's size of pointer*/
+ return sizeof(void *);
+ if (btf_type_is_int(t) || btf_type_is_enum(t))
+ return t->size;
+ *bad_type = t;
+ return -EINVAL;
+}
+
+int btf_distill_func_proto(struct bpf_verifier_log *log,
+ struct btf *btf,
+ const struct btf_type *func,
+ const char *tname,
+ struct btf_func_model *m)
+{
+ const struct btf_param *args;
+ const struct btf_type *t;
+ u32 i, nargs;
+ int ret;
+
+ if (!func) {
+ /* BTF function prototype doesn't match the verifier types.
+ * Fall back to 5 u64 args.
+ */
+ for (i = 0; i < 5; i++)
+ m->arg_size[i] = 8;
+ m->ret_size = 8;
+ m->nr_args = 5;
+ return 0;
+ }
+ args = (const struct btf_param *)(func + 1);
+ nargs = btf_type_vlen(func);
+ if (nargs >= MAX_BPF_FUNC_ARGS) {
+ bpf_log(log,
+ "The function %s has %d arguments. Too many.\n",
+ tname, nargs);
+ return -EINVAL;
+ }
+ ret = __get_type_size(btf, func->type, &t);
+ if (ret < 0) {
+ bpf_log(log,
+ "The function %s return type %s is unsupported.\n",
+ tname, btf_kind_str[BTF_INFO_KIND(t->info)]);
+ return -EINVAL;
+ }
+ m->ret_size = ret;
+
+ for (i = 0; i < nargs; i++) {
+ ret = __get_type_size(btf, args[i].type, &t);
+ if (ret < 0) {
+ bpf_log(log,
+ "The function %s arg%d type %s is unsupported.\n",
+ tname, i, btf_kind_str[BTF_INFO_KIND(t->info)]);
+ return -EINVAL;
+ }
+ m->arg_size[i] = ret;
+ }
+ m->nr_args = nargs;
+ return 0;
+}
+
+int btf_check_func_arg_match(struct bpf_verifier_env *env, int subprog)
+{
+ struct bpf_verifier_state *st = env->cur_state;
+ struct bpf_func_state *func = st->frame[st->curframe];
+ struct bpf_reg_state *reg = func->regs;
+ struct bpf_verifier_log *log = &env->log;
+ struct bpf_prog *prog = env->prog;
+ struct btf *btf = prog->aux->btf;
+ const struct btf_param *args;
+ const struct btf_type *t;
+ u32 i, nargs, btf_id;
+ const char *tname;
+
+ if (!prog->aux->func_info)
+ return 0;
+
+ btf_id = prog->aux->func_info[subprog].type_id;
+ if (!btf_id)
+ return 0;
+
+ if (prog->aux->func_info_aux[subprog].unreliable)
+ return 0;
+
+ t = btf_type_by_id(btf, btf_id);
+ if (!t || !btf_type_is_func(t)) {
+ bpf_log(log, "BTF of subprog %d doesn't point to KIND_FUNC\n",
+ subprog);
+ return -EINVAL;
+ }
+ tname = btf_name_by_offset(btf, t->name_off);
+
+ t = btf_type_by_id(btf, t->type);
+ if (!t || !btf_type_is_func_proto(t)) {
+ bpf_log(log, "Invalid type of func %s\n", tname);
+ return -EINVAL;
+ }
+ args = (const struct btf_param *)(t + 1);
+ nargs = btf_type_vlen(t);
+ if (nargs > 5) {
+ bpf_log(log, "Function %s has %d > 5 args\n", tname, nargs);
+ goto out;
+ }
+ /* check that BTF function arguments match actual types that the
+ * verifier sees.
+ */
+ for (i = 0; i < nargs; i++) {
+ t = btf_type_by_id(btf, args[i].type);
+ while (btf_type_is_modifier(t))
+ t = btf_type_by_id(btf, t->type);
+ if (btf_type_is_int(t) || btf_type_is_enum(t)) {
+ if (reg[i + 1].type == SCALAR_VALUE)
+ continue;
+ bpf_log(log, "R%d is not a scalar\n", i + 1);
+ goto out;
+ }
+ if (btf_type_is_ptr(t)) {
+ if (reg[i + 1].type == SCALAR_VALUE) {
+ bpf_log(log, "R%d is not a pointer\n", i + 1);
+ goto out;
+ }
+ /* If program is passing PTR_TO_CTX into subprogram
+ * check that BTF type matches.
+ */
+ if (reg[i + 1].type == PTR_TO_CTX &&
+ !btf_get_prog_ctx_type(log, btf, t, prog->type))
+ goto out;
+ /* All other pointers are ok */
+ continue;
+ }
+ bpf_log(log, "Unrecognized argument type %s\n",
+ btf_kind_str[BTF_INFO_KIND(t->info)]);
+ goto out;
+ }
+ return 0;
+out:
+ /* LLVM optimizations can remove arguments from static functions. */
+ bpf_log(log,
+ "Type info disagrees with actual arguments due to compiler optimizations\n");
+ prog->aux->func_info_aux[subprog].unreliable = true;
+ return 0;
+}
+
void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj,
struct seq_file *m)
{
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 97e37d82a1cc..b5945c3aaa8e 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -31,6 +31,7 @@
#include <linux/rcupdate.h>
#include <linux/perf_event.h>
#include <linux/extable.h>
+#include <linux/log2.h>
#include <asm/unaligned.h>
/* Registers */
@@ -815,6 +816,9 @@ bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
struct bpf_binary_header *hdr;
u32 size, hole, start, pages;
+ WARN_ON_ONCE(!is_power_of_2(alignment) ||
+ alignment > BPF_IMAGE_ALIGNMENT);
+
/* Most of BPF filters are really small, but if some of them
* fill a page, allow at least 128 extra bytes to insert a
* random section of illegal instructions.
@@ -1569,7 +1573,7 @@ out:
#undef LDST
#define LDX_PROBE(SIZEOP, SIZE) \
LDX_PROBE_MEM_##SIZEOP: \
- bpf_probe_read_kernel(&DST, SIZE, (const void *)(long) SRC); \
+ bpf_probe_read_kernel(&DST, SIZE, (const void *)(long) (SRC + insn->off)); \
CONT;
LDX_PROBE(B, 1)
LDX_PROBE(H, 2)
@@ -2011,6 +2015,7 @@ static void bpf_prog_free_deferred(struct work_struct *work)
if (aux->prog->has_callchain_buf)
put_callchain_buffers();
#endif
+ bpf_trampoline_put(aux->trampoline);
for (i = 0; i < aux->func_cnt; i++)
bpf_jit_free(aux->func[i]);
if (aux->func_cnt) {
@@ -2026,6 +2031,8 @@ void bpf_prog_free(struct bpf_prog *fp)
{
struct bpf_prog_aux *aux = fp->aux;
+ if (aux->linked_prog)
+ bpf_prog_put(aux->linked_prog);
INIT_WORK(&aux->work, bpf_prog_free_deferred);
schedule_work(&aux->work);
}
@@ -2140,6 +2147,12 @@ int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
return -EFAULT;
}
+int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
+ void *addr1, void *addr2)
+{
+ return -ENOTSUPP;
+}
+
DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
EXPORT_SYMBOL(bpf_stats_enabled_key);
diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
index a70f7209cda3..ecf42bec38c0 100644
--- a/kernel/bpf/inode.c
+++ b/kernel