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sync with latest bpf-next (#6)

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The following two new files are added:
  README.rst
  bpf_prog_linfo.c

Signed-off-by: Yonghong Song <yhs@fb.com>
This commit is contained in:
yonghong-song
2019-01-03 12:44:33 -08:00
committed by GitHub
parent 556e0a0def
commit 07a48dcda2
12 changed files with 1018 additions and 314 deletions
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223
include/uapi/linux/bpf.h
View File

@@ -133,6 +133,14 @@ enum bpf_map_type {
BPF_MAP_TYPE_STACK,
};
/* Note that tracing related programs such as
* BPF_PROG_TYPE_{KPROBE,TRACEPOINT,PERF_EVENT,RAW_TRACEPOINT}
* are not subject to a stable API since kernel internal data
* structures can change from release to release and may
* therefore break existing tracing BPF programs. Tracing BPF
* programs correspond to /a/ specific kernel which is to be
* analyzed, and not /a/ specific kernel /and/ all future ones.
*/
enum bpf_prog_type {
BPF_PROG_TYPE_UNSPEC,
BPF_PROG_TYPE_SOCKET_FILTER,
@@ -232,6 +240,20 @@ enum bpf_attach_type {
*/
#define BPF_F_STRICT_ALIGNMENT (1U << 0)
/* If BPF_F_ANY_ALIGNMENT is used in BPF_PROF_LOAD command, the
* verifier will allow any alignment whatsoever. On platforms
* with strict alignment requirements for loads ands stores (such
* as sparc and mips) the verifier validates that all loads and
* stores provably follow this requirement. This flag turns that
* checking and enforcement off.
*
* It is mostly used for testing when we want to validate the
* context and memory access aspects of the verifier, but because
* of an unaligned access the alignment check would trigger before
* the one we are interested in.
*/
#define BPF_F_ANY_ALIGNMENT (1U << 1)
/* when bpf_ldimm64->src_reg == BPF_PSEUDO_MAP_FD, bpf_ldimm64->imm == fd */
#define BPF_PSEUDO_MAP_FD 1
@@ -329,7 +351,7 @@ union bpf_attr {
__u32 log_level; /* verbosity level of verifier */
__u32 log_size; /* size of user buffer */
__aligned_u64 log_buf; /* user supplied buffer */
__u32 kern_version; /* checked when prog_type=kprobe */
__u32 kern_version; /* not used */
__u32 prog_flags;
char prog_name[BPF_OBJ_NAME_LEN];
__u32 prog_ifindex; /* ifindex of netdev to prep for */
@@ -342,6 +364,9 @@ union bpf_attr {
__u32 func_info_rec_size; /* userspace bpf_func_info size */
__aligned_u64 func_info; /* func info */
__u32 func_info_cnt; /* number of bpf_func_info records */
__u32 line_info_rec_size; /* userspace bpf_line_info size */
__aligned_u64 line_info; /* line info */
__u32 line_info_cnt; /* number of bpf_line_info records */
};
struct { /* anonymous struct used by BPF_OBJ_* commands */
@@ -360,8 +385,11 @@ union bpf_attr {
struct { /* anonymous struct used by BPF_PROG_TEST_RUN command */
__u32 prog_fd;
__u32 retval;
__u32 data_size_in;
__u32 data_size_out;
__u32 data_size_in; /* input: len of data_in */
__u32 data_size_out; /* input/output: len of data_out
* returns ENOSPC if data_out
* is too small.
*/
__aligned_u64 data_in;
__aligned_u64 data_out;
__u32 repeat;
@@ -482,18 +510,6 @@ union bpf_attr {
* Return
* 0 on success, or a negative error in case of failure.
*
* int bpf_map_pop_elem(struct bpf_map *map, void *value)
* Description
* Pop an element from *map*.
* Return
* 0 on success, or a negative error in case of failure.
*
* int bpf_map_peek_elem(struct bpf_map *map, void *value)
* Description
* Get an element from *map* without removing it.
* Return
* 0 on success, or a negative error in case of failure.
*
* int bpf_probe_read(void *dst, u32 size, const void *src)
* Description
* For tracing programs, safely attempt to read *size* bytes from
@@ -1917,9 +1933,9 @@ union bpf_attr {
* is set to metric from route (IPv4/IPv6 only), and ifindex
* is set to the device index of the nexthop from the FIB lookup.
*
* *plen* argument is the size of the passed in struct.
* *flags* argument can be a combination of one or more of the
* following values:
* *plen* argument is the size of the passed in struct.
* *flags* argument can be a combination of one or more of the
* following values:
*
* **BPF_FIB_LOOKUP_DIRECT**
* Do a direct table lookup vs full lookup using FIB
@@ -1928,9 +1944,9 @@ union bpf_attr {
* Perform lookup from an egress perspective (default is
* ingress).
*
* *ctx* is either **struct xdp_md** for XDP programs or
* **struct sk_buff** tc cls_act programs.
* Return
* *ctx* is either **struct xdp_md** for XDP programs or
* **struct sk_buff** tc cls_act programs.
* Return
* * < 0 if any input argument is invalid
* * 0 on success (packet is forwarded, nexthop neighbor exists)
* * > 0 one of **BPF_FIB_LKUP_RET_** codes explaining why the
@@ -2075,8 +2091,8 @@ union bpf_attr {
* translated to a keycode using the rc keymap, and reported as
* an input key down event. After a period a key up event is
* generated. This period can be extended by calling either
* **bpf_rc_keydown** () again with the same values, or calling
* **bpf_rc_repeat** ().
* **bpf_rc_keydown**\ () again with the same values, or calling
* **bpf_rc_repeat**\ ().
*
* Some protocols include a toggle bit, in case the button was
* released and pressed again between consecutive scancodes.
@@ -2159,29 +2175,30 @@ union bpf_attr {
* 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,
* 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
* For example, by using the **BPF_STX_XADD** instruction to alter
* the shared data.
* Return
* Pointer to the local storage area.
* A pointer to the local storage area.
*
* int bpf_sk_select_reuseport(struct sk_reuseport_md *reuse, struct bpf_map *map, void *key, u64 flags)
* Description
* Select a SO_REUSEPORT sk from a BPF_MAP_TYPE_REUSEPORT_ARRAY map
* It checks the selected sk is matching the incoming
* request in the skb.
* Select a **SO_REUSEPORT** socket from a
* **BPF_MAP_TYPE_REUSEPORT_ARRAY** *map*.
* It checks the selected socket is matching the incoming
* request in the socket buffer.
* Return
* 0 on success, or a negative error in case of failure.
*
* struct bpf_sock *bpf_sk_lookup_tcp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u32 netns, u64 flags)
* struct bpf_sock *bpf_sk_lookup_tcp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags)
* Description
* Look for TCP socket matching *tuple*, optionally in a child
* network namespace *netns*. The return value must be checked,
* and if non-NULL, released via **bpf_sk_release**\ ().
* and if non-**NULL**, released via **bpf_sk_release**\ ().
*
* The *ctx* should point to the context of the program, such as
* the skb or socket (depending on the hook in use). This is used
@@ -2194,12 +2211,14 @@ union bpf_attr {
* **sizeof**\ (*tuple*\ **->ipv6**)
* Look for an IPv6 socket.
*
* If the *netns* is zero, then the socket lookup table in the
* netns associated with the *ctx* will be used. For the TC hooks,
* this in the netns of the device in the skb. For socket hooks,
* this in the netns of the socket. If *netns* is non-zero, then
* it specifies the ID of the netns relative to the netns
* associated with the *ctx*.
* If the *netns* is a negative signed 32-bit integer, then the
* socket lookup table in the netns associated with the *ctx* will
* will be used. For the TC hooks, this is the netns of the device
* in the skb. For socket hooks, this is the netns of the socket.
* If *netns* is any other signed 32-bit value greater than or
* equal to zero then it specifies the ID of the netns relative to
* the netns associated with the *ctx*. *netns* values beyond the
* range of 32-bit integers are reserved for future use.
*
* All values for *flags* are reserved for future usage, and must
* be left at zero.
@@ -2207,15 +2226,15 @@ union bpf_attr {
* This helper is available only if the kernel was compiled with
* **CONFIG_NET** configuration option.
* Return
* Pointer to *struct bpf_sock*, or NULL in case of failure.
* For sockets with reuseport option, *struct bpf_sock*
* return is from reuse->socks[] using hash of the packet.
* Pointer to **struct bpf_sock**, or **NULL** in case of failure.
* For sockets with reuseport option, the **struct bpf_sock**
* result is from **reuse->socks**\ [] using the hash of the tuple.
*
* struct bpf_sock *bpf_sk_lookup_udp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u32 netns, u64 flags)
* struct bpf_sock *bpf_sk_lookup_udp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags)
* Description
* Look for UDP socket matching *tuple*, optionally in a child
* network namespace *netns*. The return value must be checked,
* and if non-NULL, released via **bpf_sk_release**\ ().
* and if non-**NULL**, released via **bpf_sk_release**\ ().
*
* The *ctx* should point to the context of the program, such as
* the skb or socket (depending on the hook in use). This is used
@@ -2228,12 +2247,14 @@ union bpf_attr {
* **sizeof**\ (*tuple*\ **->ipv6**)
* Look for an IPv6 socket.
*
* If the *netns* is zero, then the socket lookup table in the
* netns associated with the *ctx* will be used. For the TC hooks,
* this in the netns of the device in the skb. For socket hooks,
* this in the netns of the socket. If *netns* is non-zero, then
* it specifies the ID of the netns relative to the netns
* associated with the *ctx*.
* If the *netns* is a negative signed 32-bit integer, then the
* socket lookup table in the netns associated with the *ctx* will
* will be used. For the TC hooks, this is the netns of the device
* in the skb. For socket hooks, this is the netns of the socket.
* If *netns* is any other signed 32-bit value greater than or
* equal to zero then it specifies the ID of the netns relative to
* the netns associated with the *ctx*. *netns* values beyond the
* range of 32-bit integers are reserved for future use.
*
* All values for *flags* are reserved for future usage, and must
* be left at zero.
@@ -2241,33 +2262,71 @@ union bpf_attr {
* This helper is available only if the kernel was compiled with
* **CONFIG_NET** configuration option.
* Return
* Pointer to *struct bpf_sock*, or NULL in case of failure.
* For sockets with reuseport option, *struct bpf_sock*
* return is from reuse->socks[] using hash of the packet.
* Pointer to **struct bpf_sock**, or **NULL** in case of failure.
* For sockets with reuseport option, the **struct bpf_sock**
* result is from **reuse->socks**\ [] using the hash of the tuple.
*
* int bpf_sk_release(struct bpf_sock *sk)
* int bpf_sk_release(struct bpf_sock *sock)
* Description
* Release the reference held by *sock*. *sock* must be a non-NULL
* pointer that was returned from bpf_sk_lookup_xxx\ ().
* Release the reference held by *sock*. *sock* must be a
* non-**NULL** pointer that was returned from
* **bpf_sk_lookup_xxx**\ ().
* Return
* 0 on success, or a negative error in case of failure.
*
* int bpf_map_pop_elem(struct bpf_map *map, void *value)
* Description
* Pop an element from *map*.
* Return
* 0 on success, or a negative error in case of failure.
*
* int bpf_map_peek_elem(struct bpf_map *map, void *value)
* Description
* Get an element from *map* without removing it.
* Return
* 0 on success, or a negative error in case of failure.
*
* int bpf_msg_push_data(struct sk_buff *skb, u32 start, u32 len, u64 flags)
* Description
* For socket policies, insert *len* bytes into msg at offset
* For socket policies, insert *len* bytes into *msg* at offset
* *start*.
*
* If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a
* *msg* it may want to insert metadata or options into the msg.
* *msg* it may want to insert metadata or options into the *msg*.
* This can later be read and used by any of the lower layer BPF
* hooks.
*
* This helper may fail if under memory pressure (a malloc
* fails) in these cases BPF programs will get an appropriate
* error and BPF programs will need to handle them.
*
* Return
* 0 on success, or a negative error in case of failure.
*
* int bpf_msg_pop_data(struct sk_msg_buff *msg, u32 start, u32 pop, u64 flags)
* Description
* Will remove *pop* bytes from a *msg* starting at byte *start*.
* This may result in **ENOMEM** errors under certain situations if
* an allocation and copy are required due to a full ring buffer.
* However, the helper will try to avoid doing the allocation
* if possible. Other errors can occur if input parameters are
* invalid either due to *start* byte not being valid part of *msg*
* payload and/or *pop* value being to large.
* Return
* 0 on success, or a negative error in case of failure.
*
* int bpf_rc_pointer_rel(void *ctx, s32 rel_x, s32 rel_y)
* Description
* This helper is used in programs implementing IR decoding, to
* report a successfully decoded pointer movement.
*
* The *ctx* should point to the lirc sample as passed into
* the program.
*
* This helper is only available is the kernel was compiled with
* the **CONFIG_BPF_LIRC_MODE2** configuration option set to
* "**y**".
* Return
* 0
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -2360,7 +2419,9 @@ union bpf_attr {
FN(map_push_elem), \
FN(map_pop_elem), \
FN(map_peek_elem), \
FN(msg_push_data),
FN(msg_push_data), \
FN(msg_pop_data), \
FN(rc_pointer_rel),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
@@ -2416,6 +2477,9 @@ enum bpf_func_id {
/* BPF_FUNC_perf_event_output for sk_buff input context. */
#define BPF_F_CTXLEN_MASK (0xfffffULL << 32)
/* Current network namespace */
#define BPF_F_CURRENT_NETNS (-1L)
/* Mode for BPF_FUNC_skb_adjust_room helper. */
enum bpf_adj_room_mode {
BPF_ADJ_ROOM_NET,
@@ -2433,6 +2497,12 @@ enum bpf_lwt_encap_mode {
BPF_LWT_ENCAP_SEG6_INLINE
};
#define __bpf_md_ptr(type, name) \
union { \
type name; \
__u64 :64; \
} __attribute__((aligned(8)))
/* user accessible mirror of in-kernel sk_buff.
* new fields can only be added to the end of this structure
*/
@@ -2467,8 +2537,9 @@ struct __sk_buff {
/* ... here. */
__u32 data_meta;
struct bpf_flow_keys *flow_keys;
__bpf_md_ptr(struct bpf_flow_keys *, flow_keys);
__u64 tstamp;
__u32 wire_len;
};
struct bpf_tunnel_key {
@@ -2584,8 +2655,8 @@ enum sk_action {
* be added to the end of this structure
*/
struct sk_msg_md {
void *data;
void *data_end;
__bpf_md_ptr(void *, data);
__bpf_md_ptr(void *, data_end);
__u32 family;
__u32 remote_ip4; /* Stored in network byte order */
@@ -2594,6 +2665,7 @@ struct sk_msg_md {
__u32 local_ip6[4]; /* Stored in network byte order */
__u32 remote_port; /* Stored in network byte order */
__u32 local_port; /* stored in host byte order */
__u32 size; /* Total size of sk_msg */
};
struct sk_reuseport_md {
@@ -2601,8 +2673,9 @@ struct sk_reuseport_md {
* Start of directly accessible data. It begins from
* the tcp/udp header.
*/
void *data;
void *data_end; /* End of directly accessible data */
__bpf_md_ptr(void *, data);
/* End of directly accessible data */
__bpf_md_ptr(void *, data_end);
/*
* Total length of packet (starting from the tcp/udp header).
* Note that the directly accessible bytes (data_end - data)
@@ -2646,7 +2719,15 @@ struct bpf_prog_info {
__u32 btf_id;
__u32 func_info_rec_size;
__aligned_u64 func_info;
__u32 func_info_cnt;
__u32 nr_func_info;
__u32 nr_line_info;
__aligned_u64 line_info;
__aligned_u64 jited_line_info;
__u32 nr_jited_line_info;
__u32 line_info_rec_size;
__u32 jited_line_info_rec_size;
__u32 nr_prog_tags;
__aligned_u64 prog_tags;
} __attribute__((aligned(8)));
struct bpf_map_info {
@@ -2959,8 +3040,18 @@ struct bpf_flow_keys {
};
struct bpf_func_info {
__u32 insn_offset;
__u32 insn_off;
__u32 type_id;
};
#define BPF_LINE_INFO_LINE_NUM(line_col) ((line_col) >> 10)
#define BPF_LINE_INFO_LINE_COL(line_col) ((line_col) & 0x3ff)
struct bpf_line_info {
__u32 insn_off;
__u32 file_name_off;
__u32 line_off;
__u32 line_col;
};
#endif /* _UAPI__LINUX_BPF_H__ */

20
include/uapi/linux/btf.h
View File

@@ -34,7 +34,9 @@ struct btf_type {
* bits 0-15: vlen (e.g. # of struct's members)
* bits 16-23: unused
* bits 24-27: kind (e.g. int, ptr, array...etc)
* bits 28-31: unused
* bits 28-30: unused
* bit 31: kind_flag, currently used by
* struct, union and fwd
*/
__u32 info;
/* "size" is used by INT, ENUM, STRUCT and UNION.
@@ -52,6 +54,7 @@ struct btf_type {
#define BTF_INFO_KIND(info) (((info) >> 24) & 0x0f)
#define BTF_INFO_VLEN(info) ((info) & 0xffff)
#define BTF_INFO_KFLAG(info) ((info) >> 31)
#define BTF_KIND_UNKN 0 /* Unknown */
#define BTF_KIND_INT 1 /* Integer */
@@ -110,9 +113,22 @@ struct btf_array {
struct btf_member {
__u32 name_off;
__u32 type;
__u32 offset; /* offset in bits */
/* If the type info kind_flag is set, the btf_member offset
* contains both member bitfield size and bit offset. The
* bitfield size is set for bitfield members. If the type
* info kind_flag is not set, the offset contains only bit
* offset.
*/
__u32 offset;
};
/* If the struct/union type info kind_flag is set, the
* following two macros are used to access bitfield_size
* and bit_offset from btf_member.offset.
*/
#define BTF_MEMBER_BITFIELD_SIZE(val) ((val) >> 24)
#define BTF_MEMBER_BIT_OFFSET(val) ((val) & 0xffffff)
/* BTF_KIND_FUNC_PROTO is followed by multiple "struct btf_param".
* The exact number of btf_param is stored in the vlen (of the
* info in "struct btf_type").

2
include/uapi/linux/netlink.h
View File

@@ -155,7 +155,7 @@ enum nlmsgerr_attrs {
#define NETLINK_LIST_MEMBERSHIPS 9
#define NETLINK_CAP_ACK 10
#define NETLINK_EXT_ACK 11
#define NETLINK_DUMP_STRICT_CHK 12
#define NETLINK_GET_STRICT_CHK 12
struct nl_pktinfo {
__u32 group;

139
src/README.rst Normal file
View File

@@ -0,0 +1,139 @@
.. SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
libbpf API naming convention
============================
libbpf API provides access to a few logically separated groups of
functions and types. Every group has its own naming convention
described here. It's recommended to follow these conventions whenever a
new function or type is added to keep libbpf API clean and consistent.
All types and functions provided by libbpf API should have one of the
following prefixes: ``bpf_``, ``btf_``, ``libbpf_``.
System call wrappers
--------------------
System call wrappers are simple wrappers for commands supported by
sys_bpf system call. These wrappers should go to ``bpf.h`` header file
and map one-on-one to corresponding commands.
For example ``bpf_map_lookup_elem`` wraps ``BPF_MAP_LOOKUP_ELEM``
command of sys_bpf, ``bpf_prog_attach`` wraps ``BPF_PROG_ATTACH``, etc.
Objects
-------
Another class of types and functions provided by libbpf API is "objects"
and functions to work with them. Objects are high-level abstractions
such as BPF program or BPF map. They're represented by corresponding
structures such as ``struct bpf_object``, ``struct bpf_program``,
``struct bpf_map``, etc.
Structures are forward declared and access to their fields should be
provided via corresponding getters and setters rather than directly.
These objects are associated with corresponding parts of ELF object that
contains compiled BPF programs.
For example ``struct bpf_object`` represents ELF object itself created
from an ELF file or from a buffer, ``struct bpf_program`` represents a
program in ELF object and ``struct bpf_map`` is a map.
Functions that work with an object have names built from object name,
double underscore and part that describes function purpose.
For example ``bpf_object__open`` consists of the name of corresponding
object, ``bpf_object``, double underscore and ``open`` that defines the
purpose of the function to open ELF file and create ``bpf_object`` from
it.
Another example: ``bpf_program__load`` is named for corresponding
object, ``bpf_program``, that is separated from other part of the name
by double underscore.
All objects and corresponding functions other than BTF related should go
to ``libbpf.h``. BTF types and functions should go to ``btf.h``.
Auxiliary functions
-------------------
Auxiliary functions and types that don't fit well in any of categories
described above should have ``libbpf_`` prefix, e.g.
``libbpf_get_error`` or ``libbpf_prog_type_by_name``.
libbpf ABI
==========
libbpf can be both linked statically or used as DSO. To avoid possible
conflicts with other libraries an application is linked with, all
non-static libbpf symbols should have one of the prefixes mentioned in
API documentation above. See API naming convention to choose the right
name for a new symbol.
Symbol visibility
-----------------
libbpf follow the model when all global symbols have visibility "hidden"
by default and to make a symbol visible it has to be explicitly
attributed with ``LIBBPF_API`` macro. For example:
.. code-block:: c
LIBBPF_API int bpf_prog_get_fd_by_id(__u32 id);
This prevents from accidentally exporting a symbol, that is not supposed
to be a part of ABI what, in turn, improves both libbpf developer- and
user-experiences.
ABI versionning
---------------
To make future ABI extensions possible libbpf ABI is versioned.
Versioning is implemented by ``libbpf.map`` version script that is
passed to linker.
Version name is ``LIBBPF_`` prefix + three-component numeric version,
starting from ``0.0.1``.
Every time ABI is being changed, e.g. because a new symbol is added or
semantic of existing symbol is changed, ABI version should be bumped.
For example, if current state of ``libbpf.map`` is:
.. code-block::
LIBBPF_0.0.1 {
global:
bpf_func_a;
bpf_func_b;
local:
\*;
};
, and a new symbol ``bpf_func_c`` is being introduced, then
``libbpf.map`` should be changed like this:
.. code-block::
LIBBPF_0.0.1 {
global:
bpf_func_a;
bpf_func_b;
local:
\*;
};
LIBBPF_0.0.2 {
global:
bpf_func_c;
} LIBBPF_0.0.1;
, where new version ``LIBBPF_0.0.2`` depends on the previous
``LIBBPF_0.0.1``.
Format of version script and ways to handle ABI changes, including
incompatible ones, described in details in [1].
Links
=====
[1] https://www.akkadia.org/drepper/dsohowto.pdf
(Chapter 3. Maintaining APIs and ABIs).

120
src/bpf.c
View File

@@ -173,11 +173,36 @@ int bpf_create_map_in_map(enum bpf_map_type map_type, const char *name,
-1);
}
static void *
alloc_zero_tailing_info(const void *orecord, __u32 cnt,
__u32 actual_rec_size, __u32 expected_rec_size)
{
__u64 info_len = actual_rec_size * cnt;
void *info, *nrecord;
int i;
info = malloc(info_len);
if (!info)
return NULL;
/* zero out bytes kernel does not understand */
nrecord = info;
for (i = 0; i < cnt; i++) {
memcpy(nrecord, orecord, expected_rec_size);
memset(nrecord + expected_rec_size, 0,
actual_rec_size - expected_rec_size);
orecord += actual_rec_size;
nrecord += actual_rec_size;
}
return info;
}
int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
char *log_buf, size_t log_buf_sz)
{
void *finfo = NULL, *linfo = NULL;
union bpf_attr attr;
void *finfo = NULL;
__u32 name_len;
int fd;
@@ -201,53 +226,58 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
attr.func_info_rec_size = load_attr->func_info_rec_size;
attr.func_info_cnt = load_attr->func_info_cnt;
attr.func_info = ptr_to_u64(load_attr->func_info);
attr.line_info_rec_size = load_attr->line_info_rec_size;
attr.line_info_cnt = load_attr->line_info_cnt;
attr.line_info = ptr_to_u64(load_attr->line_info);
memcpy(attr.prog_name, load_attr->name,
min(name_len, BPF_OBJ_NAME_LEN - 1));
fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
if (fd >= 0 || !log_buf || !log_buf_sz)
if (fd >= 0)
return fd;
/* After bpf_prog_load, the kernel may modify certain attributes
* to give user space a hint how to deal with loading failure.
* Check to see whether we can make some changes and load again.
*/
if (errno == E2BIG && attr.func_info_cnt &&
attr.func_info_rec_size < load_attr->func_info_rec_size) {
__u32 actual_rec_size = load_attr->func_info_rec_size;
__u32 expected_rec_size = attr.func_info_rec_size;
__u32 finfo_cnt = load_attr->func_info_cnt;
__u64 finfo_len = actual_rec_size * finfo_cnt;
const void *orecord;
void *nrecord;
int i;
while (errno == E2BIG && (!finfo || !linfo)) {
if (!finfo && attr.func_info_cnt &&
attr.func_info_rec_size < load_attr->func_info_rec_size) {
/* try with corrected func info records */
finfo = alloc_zero_tailing_info(load_attr->func_info,
load_attr->func_info_cnt,
load_attr->func_info_rec_size,
attr.func_info_rec_size);
if (!finfo)
goto done;
finfo = malloc(finfo_len);
if (!finfo)
/* further try with log buffer won't help */
return fd;
attr.func_info = ptr_to_u64(finfo);
attr.func_info_rec_size = load_attr->func_info_rec_size;
} else if (!linfo && attr.line_info_cnt &&
attr.line_info_rec_size <
load_attr->line_info_rec_size) {
linfo = alloc_zero_tailing_info(load_attr->line_info,
load_attr->line_info_cnt,
load_attr->line_info_rec_size,
attr.line_info_rec_size);
if (!linfo)
goto done;
/* zero out bytes kernel does not understand */
orecord = load_attr->func_info;
nrecord = finfo;
for (i = 0; i < load_attr->func_info_cnt; i++) {
memcpy(nrecord, orecord, expected_rec_size);
memset(nrecord + expected_rec_size, 0,
actual_rec_size - expected_rec_size);
orecord += actual_rec_size;
nrecord += actual_rec_size;
attr.line_info = ptr_to_u64(linfo);
attr.line_info_rec_size = load_attr->line_info_rec_size;
} else {
break;
}
/* try with corrected func info records */
attr.func_info = ptr_to_u64(finfo);
attr.func_info_rec_size = load_attr->func_info_rec_size;
fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
if (fd >= 0 || !log_buf || !log_buf_sz)
if (fd >= 0)
goto done;
}
if (!log_buf || !log_buf_sz)
goto done;
/* Try again with log */
attr.log_buf = ptr_to_u64(log_buf);
attr.log_size = log_buf_sz;
@@ -256,6 +286,7 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
done:
free(finfo);
free(linfo);
return fd;
}
@@ -279,9 +310,9 @@ int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
}
int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns,
size_t insns_cnt, int strict_alignment,
const char *license, __u32 kern_version,
char *log_buf, size_t log_buf_sz, int log_level)
size_t insns_cnt, __u32 prog_flags, const char *license,
__u32 kern_version, char *log_buf, size_t log_buf_sz,
int log_level)
{
union bpf_attr attr;
@@ -295,7 +326,7 @@ int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns,
attr.log_level = log_level;
log_buf[0] = 0;
attr.kern_version = kern_version;
attr.prog_flags = strict_alignment ? BPF_F_STRICT_ALIGNMENT : 0;
attr.prog_flags = prog_flags;
return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
}
@@ -463,6 +494,29 @@ int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size,
return ret;
}
int bpf_prog_test_run_xattr(struct bpf_prog_test_run_attr *test_attr)
{
union bpf_attr attr;
int ret;
if (!test_attr->data_out && test_attr->data_size_out > 0)
return -EINVAL;
bzero(&attr, sizeof(attr));
attr.test.prog_fd = test_attr->prog_fd;
attr.test.data_in = ptr_to_u64(test_attr->data_in);
attr.test.data_out = ptr_to_u64(test_attr->data_out);
attr.test.data_size_in = test_attr->data_size_in;
attr.test.data_size_out = test_attr->data_size_out;
attr.test.repeat = test_attr->repeat;
ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr));
test_attr->data_size_out = attr.test.data_size_out;
test_attr->retval = attr.test.retval;
test_attr->duration = attr.test.duration;
return ret;
}
int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id)
{
union bpf_attr attr;

24
src/bpf.h
View File

@@ -82,6 +82,9 @@ struct bpf_load_program_attr {
__u32 func_info_rec_size;
const void *func_info;
__u32 func_info_cnt;
__u32 line_info_rec_size;
const void *line_info;
__u32 line_info_cnt;
};
/* Flags to direct loading requirements */
@@ -98,7 +101,7 @@ LIBBPF_API int bpf_load_program(enum bpf_prog_type type,
char *log_buf, size_t log_buf_sz);
LIBBPF_API int bpf_verify_program(enum bpf_prog_type type,
const struct bpf_insn *insns,
size_t insns_cnt, int strict_alignment,
size_t insns_cnt, __u32 prog_flags,
const char *license, __u32 kern_version,
char *log_buf, size_t log_buf_sz,
int log_level);
@@ -118,6 +121,25 @@ LIBBPF_API int bpf_prog_attach(int prog_fd, int attachable_fd,
LIBBPF_API int bpf_prog_detach(int attachable_fd, enum bpf_attach_type type);
LIBBPF_API int bpf_prog_detach2(int prog_fd, int attachable_fd,
enum bpf_attach_type type);
struct bpf_prog_test_run_attr {
int prog_fd;
int repeat;
const void *data_in;
__u32 data_size_in;
void *data_out; /* optional */
__u32 data_size_out; /* in: max length of data_out
* out: length of data_out */
__u32 retval; /* out: return code of the BPF program */
__u32 duration; /* out: average per repetition in ns */
};
LIBBPF_API int bpf_prog_test_run_xattr(struct bpf_prog_test_run_attr *test_attr);
/*
* bpf_prog_test_run does not check that data_out is large enough. Consider
* using bpf_prog_test_run_xattr instead.
*/
LIBBPF_API int bpf_prog_test_run(int prog_fd, int repeat, void *data,
__u32 size, void *data_out, __u32 *size_out,
__u32 *retval, __u32 *duration);

249
src/bpf_prog_linfo.c Normal file
View File

@@ -0,0 +1,249 @@
// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
/* Copyright (c) 2018 Facebook */
#include <string.h>
#include <stdlib.h>
#include <linux/err.h>
#include <linux/bpf.h>
#include "libbpf.h"
#ifndef min
#define min(x, y) ((x) < (y) ? (x) : (y))
#endif
struct bpf_prog_linfo {
void *raw_linfo;
void *raw_jited_linfo;
__u32 *nr_jited_linfo_per_func;
__u32 *jited_linfo_func_idx;
__u32 nr_linfo;
__u32 nr_jited_func;
__u32 rec_size;
__u32 jited_rec_size;
};
static int dissect_jited_func(struct bpf_prog_linfo *prog_linfo,
const __u64 *ksym_func, const __u32 *ksym_len)
{
__u32 nr_jited_func, nr_linfo;
const void *raw_jited_linfo;
const __u64 *jited_linfo;
__u64 last_jited_linfo;
/*
* Index to raw_jited_linfo:
* i: Index for searching the next ksym_func
* prev_i: Index to the last found ksym_func
*/
__u32 i, prev_i;
__u32 f; /* Index to ksym_func */
raw_jited_linfo = prog_linfo->raw_jited_linfo;
jited_linfo = raw_jited_linfo;
if (ksym_func[0] != *jited_linfo)
goto errout;
prog_linfo->jited_linfo_func_idx[0] = 0;
nr_jited_func = prog_linfo->nr_jited_func;
nr_linfo = prog_linfo->nr_linfo;
for (prev_i = 0, i = 1, f = 1;
i < nr_linfo && f < nr_jited_func;
i++) {
raw_jited_linfo += prog_linfo->jited_rec_size;
last_jited_linfo = *jited_linfo;
jited_linfo = raw_jited_linfo;
if (ksym_func[f] == *jited_linfo) {
prog_linfo->jited_linfo_func_idx[f] = i;
/* Sanity check */
if (last_jited_linfo - ksym_func[f - 1] + 1 >
ksym_len[f - 1])
goto errout;
prog_linfo->nr_jited_linfo_per_func[f - 1] =
i - prev_i;
prev_i = i;
/*
* The ksym_func[f] is found in jited_linfo.
* Look for the next one.
*/
f++;
} else if (*jited_linfo <= last_jited_linfo) {
/* Ensure the addr is increasing _within_ a func */
goto errout;
}
}
if (f != nr_jited_func)
goto errout;
prog_linfo->nr_jited_linfo_per_func[nr_jited_func - 1] =
nr_linfo - prev_i;
return 0;
errout:
return -EINVAL;
}
void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo)
{
if (!prog_linfo)
return;
free(prog_linfo->raw_linfo);
free(prog_linfo->raw_jited_linfo);
free(prog_linfo->nr_jited_linfo_per_func);
free(prog_linfo->jited_linfo_func_idx);
free(prog_linfo);
}
struct bpf_prog_linfo *bpf_prog_linfo__new(const struct bpf_prog_info *info)
{
struct bpf_prog_linfo *prog_linfo;
__u32 nr_linfo, nr_jited_func;
nr_linfo = info->nr_line_info;
if (!nr_linfo)
return NULL;
/*
* The min size that bpf_prog_linfo has to access for
* searching purpose.
*/
if (info->line_info_rec_size <
offsetof(struct bpf_line_info, file_name_off))
return NULL;
prog_linfo = calloc(1, sizeof(*prog_linfo));
if (!prog_linfo)
return NULL;
/* Copy xlated line_info */
prog_linfo->nr_linfo = nr_linfo;
prog_linfo->rec_size = info->line_info_rec_size;
prog_linfo->raw_linfo = malloc(nr_linfo * prog_linfo->rec_size);
if (!prog_linfo->raw_linfo)
goto err_free;
memcpy(prog_linfo->raw_linfo, (void *)(long)info->line_info,
nr_linfo * prog_linfo->rec_size);
nr_jited_func = info->nr_jited_ksyms;
if (!nr_jited_func ||
!info->jited_line_info ||
info->nr_jited_line_info != nr_linfo ||
info->jited_line_info_rec_size < sizeof(__u64) ||
info->nr_jited_func_lens != nr_jited_func ||
!info->jited_ksyms ||
!info->jited_func_lens)
/* Not enough info to provide jited_line_info */
return prog_linfo;
/* Copy jited_line_info */
prog_linfo->nr_jited_func = nr_jited_func;
prog_linfo->jited_rec_size = info->jited_line_info_rec_size;
prog_linfo->raw_jited_linfo = malloc(nr_linfo *
prog_linfo->jited_rec_size);
if (!prog_linfo->raw_jited_linfo)
goto err_free;
memcpy(prog_linfo->raw_jited_linfo,
(void *)(long)info->jited_line_info,
nr_linfo * prog_linfo->jited_rec_size);
/* Number of jited_line_info per jited func */
prog_linfo->nr_jited_linfo_per_func = malloc(nr_jited_func *
sizeof(__u32));
if (!prog_linfo->nr_jited_linfo_per_func)
goto err_free;
/*
* For each jited func,
* the start idx to the "linfo" and "jited_linfo" array,
*/
prog_linfo->jited_linfo_func_idx = malloc(nr_jited_func *
sizeof(__u32));
if (!prog_linfo->jited_linfo_func_idx)
goto err_free;
if (dissect_jited_func(prog_linfo,
(__u64 *)(long)info->jited_ksyms,
(__u32 *)(long)info->jited_func_lens))
goto err_free;
return prog_linfo;
err_free:
bpf_prog_linfo__free(prog_linfo);
return NULL;
}
const struct bpf_line_info *
bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo,
__u64 addr, __u32 func_idx, __u32 nr_skip)
{
__u32 jited_rec_size, rec_size, nr_linfo, start, i;
const void *raw_jited_linfo, *raw_linfo;
const __u64 *jited_linfo;
if (func_idx >= prog_linfo->nr_jited_func)
return NULL;
nr_linfo = prog_linfo->nr_jited_linfo_per_func[func_idx];
if (nr_skip >= nr_linfo)
return NULL;
start = prog_linfo->jited_linfo_func_idx[func_idx] + nr_skip;
jited_rec_size = prog_linfo->jited_rec_size;
raw_jited_linfo = prog_linfo->raw_jited_linfo +
(start * jited_rec_size);
jited_linfo = raw_jited_linfo;
if (addr < *jited_linfo)
return NULL;
nr_linfo -= nr_skip;
rec_size = prog_linfo->rec_size;
raw_linfo = prog_linfo->raw_linfo + (start * rec_size);
for (i = 0; i < nr_linfo; i++) {
if (addr < *jited_linfo)
break;
raw_linfo += rec_size;
raw_jited_linfo += jited_rec_size;
jited_linfo = raw_jited_linfo;
}
return raw_linfo - rec_size;
}
const struct bpf_line_info *
bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo,
__u32 insn_off, __u32 nr_skip)
{
const struct bpf_line_info *linfo;
__u32 rec_size, nr_linfo, i;
const void *raw_linfo;
nr_linfo = prog_linfo->nr_linfo;
if (nr_skip >= nr_linfo)
return NULL;
rec_size = prog_linfo->rec_size;
raw_linfo = prog_linfo->raw_linfo + (nr_skip * rec_size);
linfo = raw_linfo;
if (insn_off < linfo->insn_off)
return NULL;
nr_linfo -= nr_skip;
for (i = 0; i < nr_linfo; i++) {
if (insn_off < linfo->insn_off)
break;
raw_linfo += rec_size;
linfo = raw_linfo;
}
return raw_linfo - rec_size;
}

352
src/btf.c
View File

@@ -37,18 +37,43 @@ struct btf {
int fd;
};
struct btf_ext_info {
/*
* info points to a deep copy of the individual info section
* (e.g. func_info and line_info) from the .BTF.ext.
* It does not include the __u32 rec_size.
*/
void *info;
__u32 rec_size;
__u32 len;
};
struct btf_ext {
void *func_info;
__u32 func_info_rec_size;
__u32 func_info_len;
struct btf_ext_info func_info;
struct btf_ext_info line_info;
};
struct btf_ext_info_sec {
__u32 sec_name_off;
__u32 num_info;
/* Followed by num_info * record_size number of bytes */
__u8 data[0];
};
/* The minimum bpf_func_info checked by the loader */
struct bpf_func_info_min {
__u32 insn_offset;
__u32 insn_off;
__u32 type_id;
};
/* The minimum bpf_line_info checked by the loader */
struct bpf_line_info_min {
__u32 insn_off;
__u32 file_name_off;
__u32 line_off;
__u32 line_col;
};
static inline __u64 ptr_to_u64(const void *ptr)
{
return (__u64) (unsigned long) ptr;
@@ -415,7 +440,7 @@ const char *btf__name_by_offset(const struct btf *btf, __u32 offset)
return NULL;
}
int btf_get_from_id(__u32 id, struct btf **btf)
int btf__get_from_id(__u32 id, struct btf **btf)
{
struct bpf_btf_info btf_info = { 0 };
__u32 len = sizeof(btf_info);
@@ -466,7 +491,7 @@ int btf_get_from_id(__u32 id, struct btf **btf)
goto exit_free;
}
*btf = btf__new((__u8 *)btf_info.btf, btf_info.btf_size, NULL);
*btf = btf__new((__u8 *)(long)btf_info.btf, btf_info.btf_size, NULL);
if (IS_ERR(*btf)) {
err = PTR_ERR(*btf);
*btf = NULL;
@@ -479,71 +504,147 @@ exit_free:
return err;
}
static int btf_ext_validate_func_info(const void *finfo, __u32 size,
btf_print_fn_t err_log)
struct btf_ext_sec_copy_param {
__u32 off;
__u32 len;
__u32 min_rec_size;
struct btf_ext_info *ext_info;
const char *desc;
};
static int btf_ext_copy_info(struct btf_ext *btf_ext,
__u8 *data, __u32 data_size,
struct btf_ext_sec_copy_param *ext_sec,
btf_print_fn_t err_log)
{
int sec_hdrlen = sizeof(struct btf_sec_func_info);
__u32 size_left, num_records, record_size;
const struct btf_sec_func_info *sinfo;
__u64 total_record_size;
const struct btf_ext_header *hdr = (struct btf_ext_header *)data;
const struct btf_ext_info_sec *sinfo;
struct btf_ext_info *ext_info;
__u32 info_left, record_size;
/* The start of the info sec (including the __u32 record_size). */
const void *info;
/* At least a func_info record size */
if (size < sizeof(__u32)) {
elog("BTF.ext func_info record size not found");
/* data and data_size do not include btf_ext_header from now on */
data = data + hdr->hdr_len;
data_size -= hdr->hdr_len;
if (ext_sec->off & 0x03) {
elog(".BTF.ext %s section is not aligned to 4 bytes\n",
ext_sec->desc);
return -EINVAL;
}
/* The record size needs to meet below minimum standard */
record_size = *(__u32 *)finfo;
if (record_size < sizeof(struct bpf_func_info_min) ||
record_size % sizeof(__u32)) {
elog("BTF.ext func_info invalid record size");
if (data_size < ext_sec->off ||
ext_sec->len > data_size - ext_sec->off) {
elog("%s section (off:%u len:%u) is beyond the end of the ELF section .BTF.ext\n",
ext_sec->desc, ext_sec->off, ext_sec->len);
return -EINVAL;
}
sinfo = finfo + sizeof(__u32);
size_left = size - sizeof(__u32);
info = data + ext_sec->off;
info_left = ext_sec->len;
/* If no func_info records, return failure now so .BTF.ext
* won't be used.
*/
if (!size_left) {
elog("BTF.ext no func info records");
/* At least a record size */
if (info_left < sizeof(__u32)) {
elog(".BTF.ext %s record size not found\n", ext_sec->desc);
return -EINVAL;
}
while (size_left) {
if (size_left < sec_hdrlen) {
elog("BTF.ext func_info header not found");
/* The record size needs to meet the minimum standard */
record_size = *(__u32 *)info;
if (record_size < ext_sec->min_rec_size ||
record_size & 0x03) {
elog("%s section in .BTF.ext has invalid record size %u\n",
ext_sec->desc, record_size);
return -EINVAL;
}
sinfo = info + sizeof(__u32);
info_left -= sizeof(__u32);
/* If no records, return failure now so .BTF.ext won't be used. */
if (!info_left) {
elog("%s section in .BTF.ext has no records", ext_sec->desc);
return -EINVAL;
}
while (info_left) {
unsigned int sec_hdrlen = sizeof(struct btf_ext_info_sec);
__u64 total_record_size;
__u32 num_records;
if (info_left < sec_hdrlen) {
elog("%s section header is not found in .BTF.ext\n",
ext_sec->desc);
return -EINVAL;
}
num_records = sinfo->num_func_info;
num_records = sinfo->num_info;
if (num_records == 0) {
elog("incorrect BTF.ext num_func_info");
elog("%s section has incorrect num_records in .BTF.ext\n",
ext_sec->desc);
return -EINVAL;
}
total_record_size = sec_hdrlen +
(__u64)num_records * record_size;
if (size_left < total_record_size) {
elog("incorrect BTF.ext num_func_info");
if (info_left < total_record_size) {
elog("%s section has incorrect num_records in .BTF.ext\n",
ext_sec->desc);
return -EINVAL;
}
size_left -= total_record_size;
info_left -= total_record_size;
sinfo = (void *)sinfo + total_record_size;
}
ext_info = ext_sec->ext_info;
ext_info->len = ext_sec->len - sizeof(__u32);
ext_info->rec_size = record_size;
ext_info->info = malloc(ext_info->len);
if (!ext_info->info)
return -ENOMEM;
memcpy(ext_info->info, info + sizeof(__u32), ext_info->len);
return 0;
}
static int btf_ext_copy_func_info(struct btf_ext *btf_ext,
__u8 *data, __u32 data_size,
btf_print_fn_t err_log)
{
const struct btf_ext_header *hdr = (struct btf_ext_header *)data;
struct btf_ext_sec_copy_param param = {
.off = hdr->func_info_off,
.len = hdr->func_info_len,
.min_rec_size = sizeof(struct bpf_func_info_min),
.ext_info = &btf_ext->func_info,
.desc = "func_info"
};
return btf_ext_copy_info(btf_ext, data, data_size, &param, err_log);
}
static int btf_ext_copy_line_info(struct btf_ext *btf_ext,
__u8 *data, __u32 data_size,
btf_print_fn_t err_log)
{
const struct btf_ext_header *hdr = (struct btf_ext_header *)data;
struct btf_ext_sec_copy_param param = {
.off = hdr->line_info_off,
.len = hdr->line_info_len,
.min_rec_size = sizeof(struct bpf_line_info_min),
.ext_info = &btf_ext->line_info,
.desc = "line_info",
};
return btf_ext_copy_info(btf_ext, data, data_size, &param, err_log);
}
static int btf_ext_parse_hdr(__u8 *data, __u32 data_size,
btf_print_fn_t err_log)
{
const struct btf_ext_header *hdr = (struct btf_ext_header *)data;
__u32 meta_left, last_func_info_pos;
void *finfo;
if (data_size < offsetof(struct btf_ext_header, func_info_off) ||
data_size < hdr->hdr_len) {
@@ -566,34 +667,12 @@ static int btf_ext_parse_hdr(__u8 *data, __u32 data_size,
return -ENOTSUP;
}
meta_left = data_size - hdr->hdr_len;
if (!meta_left) {
if (data_size == hdr->hdr_len) {
elog("BTF.ext has no data\n");
return -EINVAL;
}
if (meta_left < hdr->func_info_off) {
elog("Invalid BTF.ext func_info section offset:%u\n",
hdr->func_info_off);
return -EINVAL;
}
if (hdr->func_info_off & 0x03) {
elog("BTF.ext func_info section is not aligned to 4 bytes\n");
return -EINVAL;
}
last_func_info_pos = hdr->hdr_len + hdr->func_info_off +
hdr->func_info_len;
if (last_func_info_pos > data_size) {
elog("Invalid BTF.ext func_info section size:%u\n",
hdr->func_info_len);
return -EINVAL;
}
finfo = data + hdr->hdr_len + hdr->func_info_off;
return btf_ext_validate_func_info(finfo, hdr->func_info_len,
err_log);
return 0;
}
void btf_ext__free(struct btf_ext *btf_ext)
@@ -601,16 +680,14 @@ void btf_ext__free(struct btf_ext *btf_ext)
if (!btf_ext)
return;
free(btf_ext->func_info);
free(btf_ext->func_info.info);
free(btf_ext->line_info.info);
free(btf_ext);
}
struct btf_ext *btf_ext__new(__u8 *data, __u32 size, btf_print_fn_t err_log)
{
const struct btf_ext_header *hdr;
struct btf_ext *btf_ext;
void *org_fdata, *fdata;
__u32 hdrlen, size_u32;
int err;
err = btf_ext_parse_hdr(data, size, err_log);
@@ -621,94 +698,38 @@ struct btf_ext *btf_ext__new(__u8 *data, __u32 size, btf_print_fn_t err_log)
if (!btf_ext)
return ERR_PTR(-ENOMEM);
hdr = (const struct btf_ext_header *)data;
hdrlen = hdr->hdr_len;
size_u32 = sizeof(__u32);
fdata = malloc(hdr->func_info_len - size_u32);
if (!fdata) {
free(btf_ext);
return ERR_PTR(-ENOMEM);
err = btf_ext_copy_func_info(btf_ext, data, size, err_log);
if (err) {
btf_ext__free(btf_ext);
return ERR_PTR(err);
}
/* remember record size and copy rest of func_info data */
org_fdata = data + hdrlen + hdr->func_info_off;
btf_ext->func_info_rec_size = *(__u32 *)org_fdata;
memcpy(fdata, org_fdata + size_u32, hdr->func_info_len - size_u32);
btf_ext->func_info = fdata;
btf_ext->func_info_len = hdr->func_info_len - size_u32;
err = btf_ext_copy_line_info(btf_ext, data, size, err_log);
if (err) {
btf_ext__free(btf_ext);
return ERR_PTR(err);
}
return btf_ext;
}
int btf_ext__reloc_init(struct btf *btf, struct btf_ext *btf_ext,
const char *sec_name, void **func_info,
__u32 *func_info_rec_size, __u32 *func_info_len)
static int btf_ext_reloc_info(const struct btf *btf,
const struct btf_ext_info *ext_info,
const char *sec_name, __u32 insns_cnt,
void **info, __u32 *cnt)
{
__u32 sec_hdrlen = sizeof(struct btf_sec_func_info);
__u32 i, record_size, records_len;
struct btf_sec_func_info *sinfo;
const char *info_sec_name;
__s64 remain_len;
void *data;
record_size = btf_ext->func_info_rec_size;
sinfo = btf_ext->func_info;
remain_len = btf_ext->func_info_len;
while (remain_len > 0) {
records_len = sinfo->num_func_info * record_size;
info_sec_name = btf__name_by_offset(btf, sinfo->sec_name_off);
if (strcmp(info_sec_name, sec_name)) {
remain_len -= sec_hdrlen + records_len;
sinfo = (void *)sinfo + sec_hdrlen + records_len;
continue;
}
data = malloc(records_len);
if (!data)
return -ENOMEM;
memcpy(data, sinfo->data, records_len);
/* adjust the insn_offset, the data in .BTF.ext is
* the actual byte offset, and the kernel expects
* the offset in term of bpf_insn.
*
* adjust the insn offset only, the rest data will
* be passed to kernel.
*/
for (i = 0; i < sinfo->num_func_info; i++) {
struct bpf_func_info_min *record;
record = data + i * record_size;
record->insn_offset /= sizeof(struct bpf_insn);
}
*func_info = data;
*func_info_len = records_len;
*func_info_rec_size = record_size;
return 0;
}
return -EINVAL;
}
int btf_ext__reloc(struct btf *btf, struct btf_ext *btf_ext,
const char *sec_name, __u32 insns_cnt,
void **func_info, __u32 *func_info_len)
{
__u32 sec_hdrlen = sizeof(struct btf_sec_func_info);
__u32 i, record_size, existing_flen, records_len;
struct btf_sec_func_info *sinfo;
__u32 sec_hdrlen = sizeof(struct btf_ext_info_sec);
__u32 i, record_size, existing_len, records_len;
struct btf_ext_info_sec *sinfo;
const char *info_sec_name;
__u64 remain_len;
void *data;
record_size = btf_ext->func_info_rec_size;
sinfo = btf_ext->func_info;
remain_len = btf_ext->func_info_len;
record_size = ext_info->rec_size;
sinfo = ext_info->info;
remain_len = ext_info->len;
while (remain_len > 0) {
records_len = sinfo->num_func_info * record_size;
records_len = sinfo->num_info * record_size;
info_sec_name = btf__name_by_offset(btf, sinfo->sec_name_off);
if (strcmp(info_sec_name, sec_name)) {
remain_len -= sec_hdrlen + records_len;
@@ -716,27 +737,52 @@ int btf_ext__reloc(struct btf *btf, struct btf_ext *btf_ext,
continue;
}
existing_flen = *func_info_len;
data = realloc(*func_info, existing_flen + records_len);
existing_len = (*cnt) * record_size;
data = realloc(*info, existing_len + records_len);
if (!data)
return -ENOMEM;
memcpy(data + existing_flen, sinfo->data, records_len);
/* adjust insn_offset only, the rest data will be passed
memcpy(data + existing_len, sinfo->data, records_len);
/* adjust insn_off only, the rest data will be passed
* to the kernel.
*/
for (i = 0; i < sinfo->num_func_info; i++) {
struct bpf_func_info_min *record;
for (i = 0; i < sinfo->num_info; i++) {
__u32 *insn_off;
record = data + existing_flen + i * record_size;
record->insn_offset =
record->insn_offset / sizeof(struct bpf_insn) +
insn_off = data + existing_len + (i * record_size);
*insn_off = *insn_off / sizeof(struct bpf_insn) +
insns_cnt;
}
*func_info = data;
*func_info_len = existing_flen + records_len;
*info = data;
*cnt += sinfo->num_info;
return 0;
}
return -EINVAL;
return -ENOENT;
}
int btf_ext__reloc_func_info(const struct btf *btf, const struct btf_ext *btf_ext,
const char *sec_name, __u32 insns_cnt,
void **func_info, __u32 *cnt)
{
return btf_ext_reloc_info(btf, &btf_ext->func_info, sec_name,
insns_cnt, func_info, cnt);
}
int btf_ext__reloc_line_info(const struct btf *btf, const struct btf_ext *btf_ext,
const char *sec_name, __u32 insns_cnt,
void **line_info, __u32 *cnt)
{
return btf_ext_reloc_info(btf, &btf_ext->line_info, sec_name,
insns_cnt, line_info, cnt);
}
__u32 btf_ext__func_info_rec_size(const struct btf_ext *btf_ext)
{
return btf_ext->func_info.rec_size;
}
__u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext)
{
return btf_ext->line_info.rec_size;
}

27
src/btf.h
View File

@@ -51,13 +51,8 @@ struct btf_ext_header {
/* All offsets are in bytes relative to the end of this header */
__u32 func_info_off;
__u32 func_info_len;
};
struct btf_sec_func_info {
__u32 sec_name_off;
__u32 num_func_info;
/* Followed by num_func_info number of bpf func_info records */
__u8 data[0];
__u32 line_info_off;
__u32 line_info_len;
};
typedef int (*btf_print_fn_t)(const char *, ...)
@@ -73,16 +68,20 @@ LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id);
LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id);
LIBBPF_API int btf__fd(const struct btf *btf);
LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset);
LIBBPF_API int btf_get_from_id(__u32 id, struct btf **btf);
LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf);
struct btf_ext *btf_ext__new(__u8 *data, __u32 size, btf_print_fn_t err_log);
void btf_ext__free(struct btf_ext *btf_ext);
int btf_ext__reloc_init(struct btf *btf, struct btf_ext *btf_ext,
const char *sec_name, void **func_info,
__u32 *func_info_rec_size, __u32 *func_info_len);
int btf_ext__reloc(struct btf *btf, struct btf_ext *btf_ext,
const char *sec_name, __u32 insns_cnt, void **func_info,
__u32 *func_info_len);
int btf_ext__reloc_func_info(const struct btf *btf,
const struct btf_ext *btf_ext,
const char *sec_name, __u32 insns_cnt,
void **func_info, __u32 *func_info_len);
int btf_ext__reloc_line_info(const struct btf *btf,
const struct btf_ext *btf_ext,
const char *sec_name, __u32 insns_cnt,
void **line_info, __u32 *cnt);
__u32 btf_ext__func_info_rec_size(const struct btf_ext *btf_ext);
__u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext);
#ifdef __cplusplus
} /* extern "C" */

162
src/libbpf.c
View File

@@ -9,7 +9,9 @@
* Copyright (C) 2017 Nicira, Inc.
*/
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
@@ -165,9 +167,13 @@ struct bpf_program {
int btf_fd;
void *func_info;
__u32 func_info_rec_size;
__u32 func_info_len;
__u32 func_info_cnt;
struct bpf_capabilities *caps;
void *line_info;
__u32 line_info_rec_size;
__u32 line_info_cnt;
};
struct bpf_map {
@@ -260,6 +266,7 @@ void bpf_program__unload(struct bpf_program *prog)
zclose(prog->btf_fd);
zfree(&prog->func_info);
zfree(&prog->line_info);
}
static void bpf_program__exit(struct bpf_program *prog)
@@ -777,6 +784,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
{
Elf *elf = obj->efile.elf;
GElf_Ehdr *ep = &obj->efile.ehdr;
Elf_Data *btf_ext_data = NULL;
Elf_Scn *scn = NULL;
int idx = 0, err = 0;
@@ -839,14 +847,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
obj->btf = NULL;
}
} else if (strcmp(name, BTF_EXT_ELF_SEC) == 0) {
obj->btf_ext = btf_ext__new(data->d_buf, data->d_size,
__pr_debug);
if (IS_ERR(obj->btf_ext)) {
pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",
BTF_EXT_ELF_SEC,
PTR_ERR(obj->btf_ext));
obj->btf_ext = NULL;
}
btf_ext_data = data;
} else if (sh.sh_type == SHT_SYMTAB) {
if (obj->efile.symbols) {
pr_warning("bpf: multiple SYMTAB in %s\n",
@@ -908,6 +909,22 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
pr_warning("Corrupted ELF file: index of strtab invalid\n");
return LIBBPF_ERRNO__FORMAT;
}
if (btf_ext_data) {
if (!obj->btf) {
pr_debug("Ignore ELF section %s because its depending ELF section %s is not found.\n",
BTF_EXT_ELF_SEC, BTF_ELF_SEC);
} else {
obj->btf_ext = btf_ext__new(btf_ext_data->d_buf,
btf_ext_data->d_size,
__pr_debug);
if (IS_ERR(obj->btf_ext)) {
pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",
BTF_EXT_ELF_SEC,
PTR_ERR(obj->btf_ext));
obj->btf_ext = NULL;
}
}
}
if (obj->efile.maps_shndx >= 0) {
err = bpf_object__init_maps(obj, flags);
if (err)
@@ -1273,6 +1290,82 @@ bpf_object__create_maps(struct bpf_object *obj)
return 0;
}
static int
check_btf_ext_reloc_err(struct bpf_program *prog, int err,
void *btf_prog_info, const char *info_name)
{
if (err != -ENOENT) {
pr_warning("Error in loading %s for sec %s.\n",
info_name, prog->section_name);
return err;
}
/* err == -ENOENT (i.e. prog->section_name not found in btf_ext) */
if (btf_prog_info) {
/*
* Some info has already been found but has problem
* in the last btf_ext reloc. Must have to error
* out.
*/
pr_warning("Error in relocating %s for sec %s.\n",
info_name, prog->section_name);
return err;
}
/*
* Have problem loading the very first info. Ignore
* the rest.
*/
pr_warning("Cannot find %s for main program sec %s. Ignore all %s.\n",
info_name, prog->section_name, info_name);
return 0;
}
static int
bpf_program_reloc_btf_ext(struct bpf_program *prog, struct bpf_object *obj,
const char *section_name, __u32 insn_offset)
{
int err;
if (!insn_offset || prog->func_info) {
/*
* !insn_offset => main program
*
* For sub prog, the main program's func_info has to
* be loaded first (i.e. prog->func_info != NULL)
*/
err = btf_ext__reloc_func_info(obj->btf, obj->btf_ext,
section_name, insn_offset,
&prog->func_info,
&prog->func_info_cnt);
if (err)
return check_btf_ext_reloc_err(prog, err,
prog->func_info,
"bpf_func_info");
prog->func_info_rec_size = btf_ext__func_info_rec_size(obj->btf_ext);
}
if (!insn_offset || prog->line_info) {
err = btf_ext__reloc_line_info(obj->btf, obj->btf_ext,
section_name, insn_offset,
&prog->line_info,
&prog->line_info_cnt);
if (err)
return check_btf_ext_reloc_err(prog, err,
prog->line_info,
"bpf_line_info");
prog->line_info_rec_size = btf_ext__line_info_rec_size(obj->btf_ext);
}
if (!insn_offset)
prog->btf_fd = btf__fd(obj->btf);
return 0;
}
static int
bpf_program__reloc_text(struct bpf_program *prog, struct bpf_object *obj,
struct reloc_desc *relo)
@@ -1304,17 +1397,12 @@ bpf_program__reloc_text(struct bpf_program *prog, struct bpf_object *obj,
return -ENOMEM;
}
if (obj->btf && obj->btf_ext) {
err = btf_ext__reloc(obj->btf, obj->btf_ext,
text->section_name,
prog->insns_cnt,
&prog->func_info,
&prog->func_info_len);
if (err) {
pr_warning("error in btf_ext__reloc for sec %s\n",
text->section_name);
if (obj->btf_ext) {
err = bpf_program_reloc_btf_ext(prog, obj,
text->section_name,
prog->insns_cnt);
if (err)
return err;
}
}
memcpy(new_insn + prog->insns_cnt, text->insns,
@@ -1339,18 +1427,11 @@ bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj)
if (!prog)
return 0;
if (obj->btf && obj->btf_ext) {
err = btf_ext__reloc_init(obj->btf, obj->btf_ext,
prog->section_name,
&prog->func_info,
&prog->func_info_rec_size,
&prog->func_info_len);
if (err) {
pr_warning("err in btf_ext__reloc_init for sec %s\n",
prog->section_name);
if (obj->btf_ext) {
err = bpf_program_reloc_btf_ext(prog, obj,
prog->section_name, 0);
if (err)
return err;
}
prog->btf_fd = btf__fd(obj->btf);
}
if (!prog->reloc_desc)
@@ -1442,8 +1523,7 @@ static int bpf_object__collect_reloc(struct bpf_object *obj)
static int
load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
char *license, __u32 kern_version, int *pfd,
__u32 func_info_cnt)
char *license, __u32 kern_version, int *pfd)
{
struct bpf_load_program_attr load_attr;
char *cp, errmsg[STRERR_BUFSIZE];
@@ -1463,8 +1543,10 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
load_attr.prog_btf_fd = prog->btf_fd >= 0 ? prog->btf_fd : 0;
load_attr.func_info = prog->func_info;
load_attr.func_info_rec_size = prog->func_info_rec_size;
load_attr.func_info_cnt = func_info_cnt;
load_attr.func_info_cnt = prog->func_info_cnt;
load_attr.line_info = prog->line_info;
load_attr.line_info_rec_size = prog->line_info_rec_size;
load_attr.line_info_cnt = prog->line_info_cnt;
if (!load_attr.insns || !load_attr.insns_cnt)
return -EINVAL;
@@ -1521,14 +1603,8 @@ int
bpf_program__load(struct bpf_program *prog,
char *license, __u32 kern_version)
{
__u32 func_info_cnt;
int err = 0, fd, i;
if (prog->func_info_len == 0)
func_info_cnt = 0;
else
func_info_cnt = prog->func_info_len / prog->func_info_rec_size;
if (prog->instances.nr < 0 || !prog->instances.fds) {
if (prog->preprocessor) {
pr_warning("Internal error: can't load program '%s'\n",
@@ -1551,8 +1627,7 @@ bpf_program__load(struct bpf_program *prog,
prog->section_name, prog->instances.nr);
}
err = load_program(prog, prog->insns, prog->insns_cnt,
license, kern_version, &fd,
func_info_cnt);
license, kern_version, &fd);
if (!err)
prog->instances.fds[0] = fd;
goto out;
@@ -1582,8 +1657,7 @@ bpf_program__load(struct bpf_program *prog,
err = load_program(prog, result.new_insn_ptr,
result.new_insn_cnt,
license, kern_version, &fd,
func_info_cnt);
license, kern_version, &fd);
if (err) {
pr_warning("Loading the %dth instance of program '%s' failed\n",

13
src/libbpf.h
View File

@@ -342,6 +342,19 @@ int libbpf_nl_get_qdisc(int sock, unsigned int nl_pid, int ifindex,
int libbpf_nl_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle,
libbpf_dump_nlmsg_t dump_filter_nlmsg, void *cookie);
struct bpf_prog_linfo;
struct bpf_prog_info;
LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo);
LIBBPF_API struct bpf_prog_linfo *
bpf_prog_linfo__new(const struct bpf_prog_info *info);
LIBBPF_API const struct bpf_line_info *
bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo,
__u64 addr, __u32 func_idx, __u32 nr_skip);
LIBBPF_API const struct bpf_line_info *
bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo,
__u32 insn_off, __u32 nr_skip);
#ifdef __cplusplus
} /* extern "C" */
#endif

1
src/libbpf_errno.c
View File

@@ -7,6 +7,7 @@
* Copyright (C) 2017 Nicira, Inc.
*/
#undef _GNU_SOURCE
#include <stdio.h>
#include <string.h>