Default size of dedup table (16k) is good enough for most binaries, even
typical vmlinux images. But there are cases of binaries with huge amount
of BTF types (e.g., allyesconfig variants of kernel), which benefit from
having bigger dedup table size to lower amount of unnecessary hash
collisions. Tools like pahole, thus, can tune this parameter to reach
optimal performance.
This change also serves double purpose of allowing tests to force hash
collisions to test some corner cases, used in follow up patch.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Fix invalid formatting of pointer arg.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
The "ref_type_id" variable needs to be signed for the error handling
to work.
Fixes: d5caef5b56 ("btf: add BTF types deduplication algorithm")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
readelf truncates its output by default to attempt to make it more
readable. This can lead to function names getting aliased if they
differ late in the string. Use --wide parameter to avoid
truncation.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
For historical reasons the helper to loop over maps in an object
is called bpf_map__for_each while it really should be called
bpf_object__for_each_map. Rename and add a correctly named
define for backward compatibility.
Switch all in-tree users to the correct name (Quentin).
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit adds AF_XDP support to libbpf. The main reason for this is
to facilitate writing applications that use AF_XDP by offering
higher-level APIs that hide many of the details of the AF_XDP
uapi. This is in the same vein as libbpf facilitates XDP adoption by
offering easy-to-use higher level interfaces of XDP
functionality. Hopefully this will facilitate adoption of AF_XDP, make
applications using it simpler and smaller, and finally also make it
possible for applications to benefit from optimizations in the AF_XDP
user space access code. Previously, people just copied and pasted the
code from the sample application into their application, which is not
desirable.
The interface is composed of two parts:
* Low-level access interface to the four rings and the packet
* High-level control plane interface for creating and setting
up umems and af_xdp sockets as well as a simple XDP program.
Tested-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
While it's understandable why kernel limits number of BTF types to 65535
and size of string section to 64KB, in libbpf as user-space library it's
too restrictive. E.g., pahole converting DWARF to BTF type information
for Linux kernel generates more than 3 million BTF types and more than
3MB of strings, before deduplication. So to allow btf__dedup() to do its
work, we need to be able to load bigger BTF sections using btf__new().
Singed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add new accessor for bpf_object to get opaque struct btf * from it.
struct btf * is needed for all operations with BTF and it's present in
bpf_object. The only thing missing is a way to get it.
Example use-case is to get BTF key_type_id and value_type_id for a map in
bpf_object. It can be done with btf__get_map_kv_tids() but that function
requires struct btf *.
Similar API can be added for struct btf_ext but no use-case for it yet.
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Add bpf_map__resize() to change max_entries for a map.
Quite often necessary map size is unknown at compile time and can be
calculated only at run time.
Currently the following approach is used to do so:
* bpf_object__open_buffer() to open Elf file from a buffer;
* bpf_object__find_map_by_name() to find relevant map;
* bpf_map__def() to get map attributes and create struct
bpf_create_map_attr from them;
* update max_entries in bpf_create_map_attr;
* bpf_create_map_xattr() to create new map with updated max_entries;
* bpf_map__reuse_fd() to replace the map in bpf_object with newly
created one.
And after all this bpf_object can finally be loaded. The map will have
new size.
It 1) is quite a lot of steps; 2) doesn't take BTF into account.
For "2)" even more steps should be made and some of them require changes
to libbpf (e.g. to get struct btf * from bpf_object).
Instead the whole problem can be solved by introducing simple
bpf_map__resize() API that checks the map and sets new max_entries if
the map is not loaded yet.
So the new steps are:
* bpf_object__open_buffer() to open Elf file from a buffer;
* bpf_object__find_map_by_name() to find relevant map;
* bpf_map__resize() to update max_entries.
That's much simpler and works with BTF.
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
bzero() call is deprecated and superseded by memset().
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Reported-by: David Laight <david.laight@aculab.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Now that we have btf__get_raw_data() it's trivial for tests to iterate
over all strings for testing purposes, which eliminates the need for
btf__get_strings() API.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch changes struct btf_ext to retain original data in sequential
block of memory, which makes it possible to expose
btf_ext__get_raw_data() interface similar to btf__get_raw_data(), allowing
users of libbpf to get access to raw representation of .BTF.ext section.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch exposes new API btf__get_raw_data() that allows to get a copy
of raw BTF data out of struct btf. This is useful for external programs
that need to manipulate raw data, e.g., pahole using btf__dedup() to
deduplicate BTF type info and then writing it back to file.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This change splits out previous btf__new functionality of constructing
struct btf and loading it into kernel into two:
- btf__new() just creates and initializes struct btf
- btf__load() attempts to load existing struct btf into kernel
btf__free will still close BTF fd, if it was ever loaded successfully
into kernel.
This change allows users of libbpf to manipulate BTF using its API,
without the need to unnecessarily load it into kernel.
One of the intended use cases is pahole, which will do DWARF to BTF
conversion and then use libbpf to do type deduplication, while then
handling ELF sections overwriting and other concerns on its own.
Fixes: 2d3feca8c4 ("bpf: btf: print map dump and lookup with btf info")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The kernel verifier has three levels of logs:
0: no logs
1: logs mostly useful
> 1: verbose
Current libbpf API functions bpf_load_program_xattr() and
bpf_load_program() cannot specify log_level.
The bcc, however, provides an interface for user to
specify log_level 2 for verbose output.
This patch added log_level into structure
bpf_load_program_attr, so users, including bcc, can use
bpf_load_program_xattr() to change log_level. The
supported log_level is 0, 1, and 2.
The bpf selftest test_sock.c is modified to enable log_level = 2.
If the "verbose" in test_sock.c is changed to true,
the test will output logs like below:
$ ./test_sock
func#0 @0
0: R1=ctx(id=0,off=0,imm=0) R10=fp0,call_-1
0: (bf) r6 = r1
1: R1=ctx(id=0,off=0,imm=0) R6_w=ctx(id=0,off=0,imm=0) R10=fp0,call_-1
1: (61) r7 = *(u32 *)(r6 +28)
invalid bpf_context access off=28 size=4
Test case: bind4 load with invalid access: src_ip6 .. [PASS]
...
Test case: bind6 allow all .. [PASS]
Summary: 16 PASSED, 0 FAILED
Some test_sock tests are negative tests and verbose verifier
log will be printed out as shown in the above.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Few files in libbpf are using bzero() function (defined in strings.h header), but
don't include corresponding header. When libbpf is added as a dependency to pahole,
this undeterministically causes warnings on some machines:
bpf.c:225:2: warning: implicit declaration of function 'bzero' [-Wimplicit-function-declaration]
bzero(&attr, sizeof(attr));
^~~~~
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Commit 96408c4344 ("tools/bpf: implement libbpf
btf__get_map_kv_tids() API function") refactored
function bpf_map_find_btf_info() and moved bulk of
implementation into btf.c as btf__get_map_kv_tids().
This change introduced a bug such that test_btf will
print out the following warning although the test passed:
BTF libbpf test[2] (test_btf_nokv.o): libbpf: map:btf_map
container_name:____btf_map_btf_map cannot be found
in BTF. Missing BPF_ANNOTATE_KV_PAIR?
Previously, the error message is guarded with pr_debug().
Commit 96408c4344 changed it to pr_warning() and
hence caused the warning.
Restoring to pr_debug() for the message fixed the issue.
Fixes: 96408c4344 ("tools/bpf: implement libbpf btf__get_map_kv_tids() API function")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Commit 96408c4344 ("tools/bpf: implement libbpf btf__get_map_kv_tids() API function")
added the API function btf__get_map_kv_tids():
btf__get_map_kv_tids(const struct btf *btf, char *map_name, ...)
The parameter map_name has type "char *". This is okay inside libbpf library since
the map_name is from bpf_map->name which also has type "char *".
This will be problematic if the caller for map_name already has attribute "const",
e.g., from C++ string.c_str(). It will result in either a warning or an error.
/home/yhs/work/bcc/src/cc/btf.cc:166:51:
error: invalid conversion from ‘const char*’ to ‘char*’ [-fpermissive]
return btf__get_map_kv_tids(btf_, map_name.c_str()
This patch added "const" attributes to map_name parameter.
Fixes: 96408c4344 ("tools/bpf: implement libbpf btf__get_map_kv_tids() API function")
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch sets up a new kind of tests (BTF dedup tests) and tests few aspects of
BTF dedup algorithm. More complete set of tests will come in follow up patches.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This patch implements BTF types deduplication algorithm. It allows to
greatly compress typical output of pahole's DWARF-to-BTF conversion or
LLVM's compilation output by detecting and collapsing identical types emitted in
isolation per compilation unit. Algorithm also resolves struct/union forward
declarations into concrete BTF types representing referenced struct/union. If
undesired, this resolution can be disabled through specifying corresponding options.
Algorithm itself and its application to Linux kernel's BTF types is
described in details at:
https://facebookmicrosites.github.io/bpf/blog/2018/11/14/btf-enhancement.html
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This pre-patch extracts calculation of amount of space taken by BTF type descriptor
for later reuse by btf_dedup functionality.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
With the recent print rework we now have the following problem:
pr_{warning,info,debug} expand to __pr which calls libbpf_print.
libbpf_print does va_start and calls __libbpf_pr with va_list argument.
In __base_pr we again do va_start. Because the next argument is a
va_list, we don't get correct pointer to the argument (and print noting
in my case, I don't know why it doesn't crash tbh).
Fix this by changing libbpf_print_fn_t signature to accept va_list and
remove unneeded calls to va_start in the existing users.
Alternatively, this can we solved by exporting __libbpf_pr and
changing __pr macro to (and killing libbpf_print):
{
if (__libbpf_pr)
__libbpf_pr(level, "libbpf: " fmt, ##__VA_ARGS__)
}
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently, to get map key/value type id's, the macro
BPF_ANNOTATE_KV_PAIR(<map_name>, <key_type>, <value_type>)
needs to be defined in the bpf program for the
corresponding map.
During program/map loading time,
the local static function bpf_map_find_btf_info()
in libbpf.c is implemented to retrieve the key/value
type ids given the map name.
The patch refactored function bpf_map_find_btf_info()
to create an API btf__get_map_kv_tids() which includes
the bulk of implementation for the original function.
The API btf__get_map_kv_tids() can be used by bcc,
a JIT based bpf compilation system, which uses the
same BPF_ANNOTATE_KV_PAIR to record map key/value types.
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The following set of functions, which manipulates .BTF.ext
section, are exposed as API functions:
. btf_ext__new
. btf_ext__free
. btf_ext__reloc_func_info
. btf_ext__reloc_line_info
. btf_ext__func_info_rec_size
. btf_ext__line_info_rec_size
These functions are useful for JIT based bpf codegen, e.g.,
bcc, to manipulate in-memory .BTF.ext sections.
The signature of function btf_ext__reloc_func_info()
is also changed to be the same as its definition in btf.c.
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently, the libbpf API function libbpf_set_print()
takes three function pointer parameters for warning, info
and debug printout respectively.
This patch changes the API to have just one function pointer
parameter and the function pointer has one additional
parameter "debugging level". So if in the future, if
the debug level is increased, the function signature
won't change.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently, the btf log is allocated and printed out in case
of error at LIBBPF_DEBUG level.
Such logs from kernel are very important for debugging.
For example, bpf syscall BPF_PROG_LOAD command can get
verifier logs back to user space. In function load_program()
of libbpf.c, the log buffer is allocated unconditionally
and printed out at pr_warning() level.
Let us do the similar thing here for btf. Allocate buffer
unconditionally and print out error logs at pr_warning() level.
This can reduce one global function and
optimize for common situations where pr_warning()
is activated either by default or by user supplied
debug output function.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
A global function libbpf_print, which is invisible
outside the shared library, is defined to print based
on levels. The pr_warning, pr_info and pr_debug
macros are moved into the newly created header
common.h. So any .c file including common.h can
use these macros directly.
Currently btf__new and btf_ext__new API has an argument getting
__pr_debug function pointer into btf.c so the debugging information
can be printed there. This patch removed this parameter
from btf__new and btf_ext__new and directly using pr_debug in btf.c.
Another global function libbpf_print_level_available, also
invisible outside the shared library, can test
whether a particular level debug printing is
available or not. It is used in btf.c to
test whether DEBUG level debug printing is availabl or not,
based on which the log buffer will be allocated when loading
btf to the kernel.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Since we have a dedicated netlink attributes for xdp setup on a
particular interface, it is now possible to retrieve the program id that
is currently attached to the interface. The use case is targeted for
sample xdp programs, which will store the program id just after loading
bpf program onto iface. On shutdown, the sample will make sure that it
can unload the program by querying again the iface and verifying that
both program id's matches.
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
XDP samples are mostly cooperating with eBPF maps through their file
descriptors. In case of a eBPF program that contains multiple maps it
might be tiresome to iterate through them and call bpf_map__fd for each
one. Add a helper mostly based on bpf_object__find_map_by_name, but
instead of returning the struct bpf_map pointer, return map fd.
Suggested-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Daniel Borkmann says:
====================
pull-request: bpf-next 2019-01-29
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) Teach verifier dead code removal, this also allows for optimizing /
removing conditional branches around dead code and to shrink the
resulting image. Code store constrained architectures like nfp would
have hard time doing this at JIT level, from Jakub.
2) Add JMP32 instructions to BPF ISA in order to allow for optimizing
code generation for 32-bit sub-registers. Evaluation shows that this
can result in code reduction of ~5-20% compared to 64 bit-only code
generation. Also add implementation for most JITs, from Jiong.
3) Add support for __int128 types in BTF which is also needed for
vmlinux's BTF conversion to work, from Yonghong.
4) Add a new command to bpftool in order to dump a list of BPF-related
parameters from the system or for a specific network device e.g. in
terms of available prog/map types or helper functions, from Quentin.
5) Add AF_XDP sock_diag interface for querying sockets from user
space which provides information about the RX/TX/fill/completion
rings, umem, memory usage etc, from Björn.
6) Add skb context access for skb_shared_info->gso_segs field, from Eric.
7) Add support for testing flow dissector BPF programs by extending
existing BPF_PROG_TEST_RUN infrastructure, from Stanislav.
8) Split BPF kselftest's test_verifier into various subgroups of tests
in order better deal with merge conflicts in this area, from Jakub.
9) Add support for queue/stack manipulations in bpftool, from Stanislav.
10) Document BTF, from Yonghong.
11) Dump supported ELF section names in libbpf on program load
failure, from Taeung.
12) Silence a false positive compiler warning in verifier's BTF
handling, from Peter.
13) Fix help string in bpftool's feature probing, from Prashant.
14) Remove duplicate includes in BPF kselftests, from Yue.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
We need to let users check their wrong ELF section name with proper
ELF section names when they fail to get a prog/attach type from it.
Because users can't realize libbpf guess prog/attach types from given
ELF section names. For example, when a 'cgroup' section name of a
BPF program is used, show available ELF section names(types).
Before:
$ bpftool prog load bpf-prog.o /sys/fs/bpf/prog1
Error: failed to guess program type based on ELF section name cgroup
After:
libbpf: failed to guess program type based on ELF section name 'cgroup'
libbpf: supported section(type) names are: socket kprobe/ kretprobe/ classifier action tracepoint/ raw_tracepoint/ xdp perf_event lwt_in lwt_out lwt_xmit lwt_seg6local cgroup_skb/ingress cgroup_skb/egress cgroup/skb cgroup/sock cgroup/post_bind4 cgroup/post_bind6 cgroup/dev sockops sk_skb/stream_parser sk_skb/stream_verdict sk_skb sk_msg lirc_mode2 flow_dissector cgroup/bind4 cgroup/bind6 cgroup/connect4 cgroup/connect6 cgroup/sendmsg4 cgroup/sendmsg6
Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Cc: Quentin Monnet <quentin.monnet@netronome.com>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Andrey Ignatov <rdna@fb.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Similarly to what was done for program types and map types, add a set of
probes to test the availability of the different eBPF helper functions
on the current system.
For each known program type, all known helpers are tested, in order to
establish a compatibility matrix. Output is provided as a set of lists
of available helpers, one per program type.
Sample output:
# bpftool feature probe kernel
...
Scanning eBPF helper functions...
eBPF helpers supported for program type socket_filter:
- bpf_map_lookup_elem
- bpf_map_update_elem
- bpf_map_delete_elem
...
eBPF helpers supported for program type kprobe:
- bpf_map_lookup_elem
- bpf_map_update_elem
- bpf_map_delete_elem
...
# bpftool --json --pretty feature probe kernel
{
...
"helpers": {
"socket_filter_available_helpers": ["bpf_map_lookup_elem", \
"bpf_map_update_elem","bpf_map_delete_elem", ...
],
"kprobe_available_helpers": ["bpf_map_lookup_elem", \
"bpf_map_update_elem","bpf_map_delete_elem", ...
],
...
}
}
v5:
- In libbpf.map, move global symbol to the new LIBBPF_0.0.2 section.
v4:
- Use "enum bpf_func_id" instead of "__u32" in bpf_probe_helper()
declaration for the type of the argument used to pass the id of
the helper to probe.
- Undef BPF_HELPER_MAKE_ENTRY after using it.
v3:
- Do not pass kernel version from bpftool to libbpf probes (kernel
version for testing program with kprobes is retrieved directly from
libbpf).
- Dump one list of available helpers per program type (instead of one
list of compatible program types per helper).
v2:
- Move probes from bpftool to libbpf.
- Test all program types for each helper, print a list of working prog
types for each helper.
- Fall back on include/uapi/linux/bpf.h for names and ids of helpers.
- Remove C-style macros output from this patch.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add new probes for eBPF map types, to detect what are the ones available
on the system. Try creating one map of each type, and see if the kernel
complains.
Sample output:
# bpftool feature probe kernel
...
Scanning eBPF map types...
eBPF map_type hash is available
eBPF map_type array is available
eBPF map_type prog_array is available
...
# bpftool --json --pretty feature probe kernel
{
...
"map_types": {
"have_hash_map_type": true,
"have_array_map_type": true,
"have_prog_array_map_type": true,
...
}
}
v5:
- In libbpf.map, move global symbol to the new LIBBPF_0.0.2 section.
v3:
- Use a switch with all enum values for setting specific map parameters,
so that gcc complains at compile time (-Wswitch-enum) if new map types
were added to the kernel but libbpf was not updated.
v2:
- Move probes from bpftool to libbpf.
- Remove C-style macros output from this patch.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Introduce probes for supported BPF program types in libbpf, and call it
from bpftool to test what types are available on the system. The probe
simply consists in loading a very basic program of that type and see if
the verifier complains or not.
Sample output:
# bpftool feature probe kernel
...
Scanning eBPF program types...
eBPF program_type socket_filter is available
eBPF program_type kprobe is available
eBPF program_type sched_cls is available
...
# bpftool --json --pretty feature probe kernel
{
...
"program_types": {
"have_socket_filter_prog_type": true,
"have_kprobe_prog_type": true,
"have_sched_cls_prog_type": true,
...
}
}
v5:
- In libbpf.map, move global symbol to a new LIBBPF_0.0.2 section.
- Rename (non-API function) prog_load() as probe_load().
v3:
- Get kernel version for checking kprobes availability from libbpf
instead of from bpftool. Do not pass kernel_version as an argument
when calling libbpf probes.
- Use a switch with all enum values for setting specific program
parameters just before probing, so that gcc complains at compile time
(-Wswitch-enum) if new prog types were added to the kernel but libbpf
was not updated.
- Add a comment in libbpf.h about setrlimit() usage to allow many
consecutive probe attempts.
v2:
- Move probes from bpftool to libbpf.
- Remove C-style macros output from this patch.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
We are already including tools/scripts/Makefile.include which correctly
handles CROSS_COMPILE, no need to define our own vars.
See related commit 7ed1c1901f ("tools: fix cross-compile var clobbering")
for more details.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Commit c3494801cd ("bpf: check pending signals while
verifying programs") makes it possible for the BPF_PROG_LOAD
to fail with EAGAIN. Retry unconditionally in this case.
Fixes: c3494801cd ("bpf: check pending signals while verifying programs")
Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
We build test_libbpf with CXX to make sure linking against C++ works.
$ make -s -C tools/lib/bpf
$ git status -sb
? tools/lib/bpf/test_libbpf
$ make -s -C tools/testing/selftests/bpf
$ git status -sb
? tools/lib/bpf/test_libbpf
? tools/testing/selftests/bpf/test_libbpf
Fixes: 8c4905b995 ("libbpf: make sure bpf headers are c++ include-able")
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Given this came up couple of times, add a note to libbpf's readme
about the semi-automated mirror for a stand-alone build which is
officially managed by BPF folks. While at it, also explicitly state
the libbpf license in the readme file.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch fixes a memory leak in libbpf by freeing up line_info
member of struct bpf_program while unloading a program.
Fixes: 3d65014146 ("bpf: libbpf: Add btf_line_info support to libbpf")
Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
kernel can provide the func_info and line_info even
it fails the btf_dump_raw_ok() test because they don't contain
kernel address. This patch removes the corresponding '== 0'
test.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Rename all occurances of *_info_cnt field access
to nr_*_info in tools directory.
The local variables finfo_cnt, linfo_cnt and jited_linfo_cnt
in function do_dump() of tools/bpf/bpftool/prog.c are also
changed to nr_finfo, nr_linfo and nr_jited_linfo to
keep naming convention consistent.
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch adds bpf_line_info support to libbpf:
1) Parsing the line_info sec from ".BTF.ext"
2) Relocating the line_info. If the main prog *_info relocation
fails, it will ignore the remaining subprog line_info and continue.
If the subprog *_info relocation fails, it will bail out.
3) BPF_PROG_LOAD a prog with line_info
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch refactor and fix a bug in the libbpf's bpf_func_info loading
logic. The bug fix and refactoring are targeting the same
commit 2993e0515b ("tools/bpf: add support to read .BTF.ext sections")
which is in the bpf-next branch.
1) In bpf_load_program_xattr(), it should retry when errno == E2BIG
regardless of log_buf and log_buf_sz. This patch fixes it.
2) btf_ext__reloc_init() and btf_ext__reloc() are essentially
the same except btf_ext__reloc_init() always has insns_cnt == 0.
Hence, btf_ext__reloc_init() is removed.
btf_ext__reloc() is also renamed to btf_ext__reloc_func_info()
to get ready for the line_info support in the next patch.
3) Consolidate func_info section logic from "btf_ext_parse_hdr()",
"btf_ext_validate_func_info()" and "btf_ext__new()" to
a new function "btf_ext_copy_func_info()" such that similar
logic can be reused by the later libbpf's line_info patch.
4) The next line_info patch will store line_info_cnt instead of
line_info_len in the bpf_program because the kernel is taking
line_info_cnt also. It will save a few "len" to "cnt" conversions
and will also save some function args.
Hence, this patch also makes bpf_program to store func_info_cnt
instead of func_info_len.
5) btf_ext depends on btf. e.g. the func_info's type_id
in ".BTF.ext" is not useful when ".BTF" is absent.
This patch only init the obj->btf_ext pointer after
it has successfully init the obj->btf pointer.
This can avoid always checking "obj->btf && obj->btf_ext"
together for accessing ".BTF.ext". Checking "obj->btf_ext"
alone will do.
6) Move "struct btf_sec_func_info" from btf.h to btf.c.
There is no external usage outside btf.c.
Fixes: 2993e0515b ("tools/bpf: add support to read .BTF.ext sections")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Similar to info.jited_*, info.func_info could be 0 if
bpf_dump_raw_ok() == false.
This patch makes changes to test_btf and bpftool to expect info.func_info
could be 0.
This patch also makes the needed changes for s/insn_offset/insn_off/.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add a new function, which encourages safe usage of the test interface.
bpf_prog_test_run continues to work as before, but should be considered
unsafe.
Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The whole libbpf is licensed as (LGPL-2.1 OR BSD-2-Clause). I missed it
while adding README.rst. Fix it and use same license as all other files
in libbpf do. Since I'm the only author of README.rst so far, no others'
permissions should be needed.
Fixes: 76d1b894c5 ("libbpf: Document API and ABI conventions")
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Often we want to write tests cases that check things like bad context
offset accesses. And one way to do this is to use an odd offset on,
for example, a 32-bit load.
This unfortunately triggers the alignment checks first on platforms
that do not set CONFIG_EFFICIENT_UNALIGNED_ACCESS. So the test
case see the alignment failure rather than what it was testing for.
It is often not completely possible to respect the original intention
of the test, or even test the same exact thing, while solving the
alignment issue.
Another option could have been to check the alignment after the
context and other validations are performed by the verifier, but
that is a non-trivial change to the verifier.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
During porting libbpf to bcc, I got some warnings like below:
...
[ 2%] Building C object src/cc/CMakeFiles/bpf-shared.dir/libbpf/src/libbpf.c.o
/home/yhs/work/bcc2/src/cc/libbpf/src/libbpf.c:12:0:
warning: "_GNU_SOURCE" redefined [enabled by default]
#define _GNU_SOURCE
...
[ 3%] Building C object src/cc/CMakeFiles/bpf-shared.dir/libbpf/src/libbpf_errno.c.o
/home/yhs/work/bcc2/src/cc/libbpf/src/libbpf_errno.c: In function ‘libbpf_strerror’:
/home/yhs/work/bcc2/src/cc/libbpf/src/libbpf_errno.c:45:7:
warning: assignment makes integer from pointer without a cast [enabled by default]
ret = strerror_r(err, buf, size);
...
bcc is built with _GNU_SOURCE defined and this caused the above warning.
This patch intends to make libpf _GNU_SOURCE friendly by
. define _GNU_SOURCE in libbpf.c unless it is not defined
. undefine _GNU_SOURCE as non-gnu version of strerror_r is expected.
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
