Libbpf does sanitization of BTF before loading it into kernel, if kernel
doesn't support some of newer BTF features. This removes some of the
important information from BTF (e.g., DATASEC and VAR description),
which will be used for map construction. This patch splits BTF
processing into initialization step, in which BTF is initialized from
ELF and all the original data is still preserved; and
sanitization/loading step, which ensures that BTF is safe to load into
kernel. This allows to use full BTF information to construct maps, while
still loading valid BTF into older kernels.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
To support maps to be defined in multiple sections, it's important to
identify map not just by offset within its section, but section index as
well. This patch adds tracking of section index.
For global data, we record section index of corresponding
.data/.bss/.rodata ELF section for uniformity, and thus don't need
a special value of offset for those maps.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
User and global data maps initialization has gotten pretty complicated
and unnecessarily convoluted. This patch splits out the logic for global
data map and user-defined map initialization. It also removes the
restriction of pre-calculating how many maps will be initialized,
instead allowing to keep adding new maps as they are discovered, which
will be used later for BTF-defined map definitions.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Simplify ELF parsing logic by exiting early, as there is no common clean
up path to execute. That makes it unnecessary to track when err was set
and when it was cleared. It also reduces nesting in some places.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
As a preparation for adding BTF-based BPF map loading, extract .BTF and
.BTF.ext loading logic.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Kernel internally checks that either key or value type ID is specified,
before using btf_fd. Do the same in libbpf's map creation code for
determining when to retry map creation w/o BTF.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: fba01a0689 ("libbpf: use negative fd to specify missing BTF")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Adding a new API libbpf_num_possible_cpus() that helps user with
per-CPU map operations.
Signed-off-by: Hechao Li <hechaol@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Another trivial patch to libbpf in order to enable identifying and
attaching programs to BPF_CGROUP_UDP{4,6}_RECVMSG by section name.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Before this change, function load_sk_storage_btf expected that
libbpf__probe_raw_btf was returning a BTF descriptor, but in fact it was
returning an information about whether the probe was successful (0 or
1). load_sk_storage_btf was using that value as an argument of the close
function, which was resulting in closing stdout and thus terminating the
process which called that function.
That bug was visible in bpftool. `bpftool feature` subcommand was always
exiting too early (because of closed stdout) and it didn't display all
requested probes. `bpftool -j feature` or `bpftool -p feature` were not
returning a valid json object.
This change renames the libbpf__probe_raw_btf function to
libbpf__load_raw_btf, which now returns a BTF descriptor, as expected in
load_sk_storage_btf.
v2:
- Fix typo in the commit message.
v3:
- Simplify BTF descriptor handling in bpf_object__probe_btf_* functions.
- Rename libbpf__probe_raw_btf function to libbpf__load_raw_btf and
return a BTF descriptor.
v4:
- Fix typo in the commit message.
Fixes: d7c4b3980c ("libbpf: detect supported kernel BTF features and sanitize BTF")
Signed-off-by: Michal Rostecki <mrostecki@opensuse.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
There are a bunch of lines of code or comments that are unnecessary
wrapped into multi-lines. Fix that without violating any code
guidelines.
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
A bunch of typo and formatting fixes.
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Extra check for type is unnecessary in first case.
Extra zeroing is unnecessary, as snprintf guarantees that it will
zero-terminate string.
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
0 is a valid FD, so it's better to initialize it to -1, as is done in
other places. Also, technically, BTF type ID 0 is valid (it's a VOID
type), so it's more reliable to check btf_fd, instead of
btf_key_type_id, to determine if there is any BTF associated with a map.
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
All of libbpf errors are negative, except this one. Fix it.
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Validate there was no error retrieving symbol name corresponding to
a BPF map.
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Rewrite endianness check to use "more canonical" way, using
compiler-defined macros, similar to few other places in libbpf. It also
is more obvious and shorter.
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
pr_warning ultimately may call into user-provided callback function,
which can clobber errno value, so we need to save it before that.
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Ensure that size of a section w/ BPF instruction is exactly a multiple
of BPF instruction size.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
There are two functions in libbpf that support passing a log_level
parameter for the verifier for loading programs:
bpf_object__load_xattr() and bpf_prog_load_xattr(). Both accept an
attribute object containing the log_level, and apply it to the programs
to load.
It turns out that to effectively load the programs, the latter function
eventually relies on the former. This was not taken into account when
adding support for log_level in bpf_object__load_xattr(), and the
log_level passed to bpf_prog_load_xattr() later gets overwritten with a
zero value, thus disabling verifier logs for the program in all cases:
bpf_prog_load_xattr() // prog->log_level = attr1->log_level;
-> bpf_object__load() // attr2->log_level = 0;
-> bpf_object__load_xattr() // <pass prog and attr2>
-> bpf_object__load_progs() // prog->log_level = attr2->log_level;
Fix this by OR-ing the log_level in bpf_object__load_progs(), instead of
overwriting it.
v2: Fix commit log description (confusion on function names in v1).
Fixes: 60276f9849 ("libbpf: add bpf_object__load_xattr() API function to pass log_level")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
libbpf was recently made aware of the log_level attribute for programs,
used to specify the level of information expected to be dumped by the
verifier. Function bpf_prog_load_xattr() got support for this log_level
parameter.
But some applications using libbpf rely on another function to load
programs, bpf_object__load(), which does accept any parameter for log
level. Create an API function based on bpf_object__load(), but accepting
an "attr" object as a parameter. Then add a log_level field to that
object, so that applications calling the new bpf_object__load_xattr()
can pick the desired log level.
v3:
- Rewrite commit log.
v2:
- We are in a new cycle, bump libbpf extraversion number.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Fix below warning reported by coccicheck:
/tools/lib/bpf/libbpf.c:3461:1-3: WARNING: PTR_ERR_OR_ZERO can be used
Signed-off-by: Hariprasad Kelam <hariprasad.kelam@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
libbpf doesn't allow passing "prog_flags" during bpf program load in a
couple of load related APIs, "bpf_load_program_xattr", "load_program" and
"bpf_prog_load_xattr".
It makes sense to allow passing "prog_flags" which is useful for
customizing program loading.
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
libbpf_util.h header was recently exposed as public as a dependency of
xsk.h. In addition to memory barriers, it contained logging helpers,
which are not supposed to be exposed. This patch moves those into
libbpf_internal.h, which is kept as an internal header.
Cc: Stanislav Fomichev <sdf@google.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Fixes: 7080da8909 ("libbpf: add libbpf_util.h to header install.")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Otherwise libbpf is unusable from unprivileged process with
kernel.kernel.unprivileged_bpf_disabled=1.
All I get is EPERM from the probes, even if I just want to
open an ELF object and look at what progs/maps it has.
Instead of dying on probes, let's just pr_debug the error and
try to continue.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Depending on used versions of libbpf, Clang, and kernel, it's possible to
have valid BPF object files with valid BTF information, that still won't
load successfully due to Clang emitting newer BTF features (e.g.,
BTF_KIND_FUNC, .BTF.ext's line_info/func_info, BTF_KIND_DATASEC, etc), that
are not yet supported by older kernel.
This patch adds detection of BTF features and sanitizes BPF object's BTF
by substituting various supported BTF kinds, which have compatible layout:
- BTF_KIND_FUNC -> BTF_KIND_TYPEDEF
- BTF_KIND_FUNC_PROTO -> BTF_KIND_ENUM
- BTF_KIND_VAR -> BTF_KIND_INT
- BTF_KIND_DATASEC -> BTF_KIND_STRUCT
Replacement is done in such a way as to preserve as much information as
possible (names, sizes, etc) where possible without violating kernel's
validation rules.
v2->v3:
- remove duplicate #defines from libbpf_util.h
v1->v2:
- add internal libbpf_internal.h w/ common stuff
- switch SK storage BTF to use new libbpf__probe_raw_btf()
Reported-by: Alexei Starovoitov <ast@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This adds BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE, and fixes up the
error: enumeration value ‘BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE’ not handled in switch [-Werror=switch-enum]
build errors it would otherwise cause in libbpf.
Signed-off-by: Matt Mullins <mmullins@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Ran into it while testing; in bpf_object__init_maps() data can be NULL
in the case where no map section is present. Therefore we simply cannot
access data->d_size before NULL test. Move the pr_debug() where it's
safe to access.
Fixes: d859900c4c ("bpf, libbpf: support global data/bss/rodata sections")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Andrii reported a corner case where e.g. global static data is present
in the BPF ELF file in form of .data/.bss/.rodata section, but without
any relocations to it. Such programs could be loaded before commit
d859900c4c ("bpf, libbpf: support global data/bss/rodata sections"),
whereas afterwards if kernel lacks support then loading would fail.
Add a probing mechanism which skips setting up libbpf internal maps
in case of missing kernel support. In presence of relocation entries,
we abort the load attempt.
Fixes: d859900c4c ("bpf, libbpf: support global data/bss/rodata sections")
Reported-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Using %ld for printing out value of ptrdiff_t type is not portable
between 32-bit and 64-bit archs. This is causing compilation errors for
libbpf on 32-bit platform (discovered as part of an effort to integrate
libbpf into systemd ([0])). Proper formatter is %td, which is used in
this patch.
v2->v1:
- add Reported-by
- provide more context on how this issue was discovered
[0] https://github.com/systemd/systemd/pull/12151
Reported-by: Evgeny Vereshchagin <evvers@ya.ru>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Support BPF_PROG_TYPE_CGROUP_SYSCTL program in libbpf: identifying
program and attach types by section name, probe.
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reported in [1].
With gcc 8.3.0 the following error is issued:
cc -Ibpf@sta -I. -I.. -I.././include -I.././include/uapi
-fdiagnostics-color=always -fsanitize=address,undefined -fno-omit-frame-pointer
-pipe -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -Werror -g -fPIC -g -O2
-Werror -Wall -Wno-pointer-arith -Wno-sign-compare -MD -MQ
'bpf@sta/src_libbpf.c.o' -MF 'bpf@sta/src_libbpf.c.o.d' -o
'bpf@sta/src_libbpf.c.o' -c ../src/libbpf.c
../src/libbpf.c: In function 'bpf_object__elf_collect':
../src/libbpf.c:947:18: error: 'map_def_sz' may be used uninitialized in this
function [-Werror=maybe-uninitialized]
if (map_def_sz <= sizeof(struct bpf_map_def)) {
~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../src/libbpf.c:827:18: note: 'map_def_sz' was declared here
int i, map_idx, map_def_sz, nr_syms, nr_maps = 0, nr_maps_glob = 0;
^~~~~~~~~~
According to [2] -Wmaybe-uninitialized is enabled by -Wall.
Same error is generated by clang's -Wconditional-uninitialized.
[1] https://github.com/libbpf/libbpf/pull/29#issuecomment-481902601
[2] https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html
Fixes: d859900c4c ("bpf, libbpf: support global data/bss/rodata sections")
Reported-by: Evgeny Vereshchagin <evvers@ya.ru>
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This adds libbpf support for BTF Var and DataSec kinds. Main point
here is that libbpf needs to do some preparatory work before the
whole BTF object can be loaded into the kernel, that is, fixing up
of DataSec size taken from the ELF section size and non-static
variable offset which needs to be taken from the ELF's string section.
Upstream LLVM doesn't fix these up since at time of BTF emission
it is too early in the compilation process thus this information
isn't available yet, hence loader needs to take care of it.
Note, deduplication handling has not been in the scope of this work
and needs to be addressed in a future commit.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://reviews.llvm.org/D59441
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This work adds BPF loader support for global data sections
to libbpf. This allows to write BPF programs in more natural
C-like way by being able to define global variables and const
data.
Back at LPC 2018 [0] we presented a first prototype which
implemented support for global data sections by extending BPF
syscall where union bpf_attr would get additional memory/size
pair for each section passed during prog load in order to later
add this base address into the ldimm64 instruction along with
the user provided offset when accessing a variable. Consensus
from LPC was that for proper upstream support, it would be
more desirable to use maps instead of bpf_attr extension as
this would allow for introspection of these sections as well
as potential live updates of their content. This work follows
this path by taking the following steps from loader side:
1) In bpf_object__elf_collect() step we pick up ".data",
".rodata", and ".bss" section information.
2) If present, in bpf_object__init_internal_map() we add
maps to the obj's map array that corresponds to each
of the present sections. Given section size and access
properties can differ, a single entry array map is
created with value size that is corresponding to the
ELF section size of .data, .bss or .rodata. These
internal maps are integrated into the normal map
handling of libbpf such that when user traverses all
obj maps, they can be differentiated from user-created
ones via bpf_map__is_internal(). In later steps when
we actually create these maps in the kernel via
bpf_object__create_maps(), then for .data and .rodata
sections their content is copied into the map through
bpf_map_update_elem(). For .bss this is not necessary
since array map is already zero-initialized by default.
Additionally, for .rodata the map is frozen as read-only
after setup, such that neither from program nor syscall
side writes would be possible.
3) In bpf_program__collect_reloc() step, we record the
corresponding map, insn index, and relocation type for
the global data.
4) And last but not least in the actual relocation step in
bpf_program__relocate(), we mark the ldimm64 instruction
with src_reg = BPF_PSEUDO_MAP_VALUE where in the first
imm field the map's file descriptor is stored as similarly
done as in BPF_PSEUDO_MAP_FD, and in the second imm field
(as ldimm64 is 2-insn wide) we store the access offset
into the section. Given these maps have only single element
ldimm64's off remains zero in both parts.
5) On kernel side, this special marked BPF_PSEUDO_MAP_VALUE
load will then store the actual target address in order
to have a 'map-lookup'-free access. That is, the actual
map value base address + offset. The destination register
in the verifier will then be marked as PTR_TO_MAP_VALUE,
containing the fixed offset as reg->off and backing BPF
map as reg->map_ptr. Meaning, it's treated as any other
normal map value from verification side, only with
efficient, direct value access instead of actual call to
map lookup helper as in the typical case.
Currently, only support for static global variables has been
added, and libbpf rejects non-static global variables from
loading. This can be lifted until we have proper semantics
for how BPF will treat multi-object BPF loads. From BTF side,
libbpf will set the value type id of the types corresponding
to the ".bss", ".data" and ".rodata" names which LLVM will
emit without the object name prefix. The key type will be
left as zero, thus making use of the key-less BTF option in
array maps.
Simple example dump of program using globals vars in each
section:
# bpftool prog
[...]
6784: sched_cls name load_static_dat tag a7e1291567277844 gpl
loaded_at 2019-03-11T15:39:34+0000 uid 0
xlated 1776B jited 993B memlock 4096B map_ids 2238,2237,2235,2236,2239,2240
# bpftool map show id 2237
2237: array name test_glo.bss flags 0x0
key 4B value 64B max_entries 1 memlock 4096B
# bpftool map show id 2235
2235: array name test_glo.data flags 0x0
key 4B value 64B max_entries 1 memlock 4096B
# bpftool map show id 2236
2236: array name test_glo.rodata flags 0x80
key 4B value 96B max_entries 1 memlock 4096B
# bpftool prog dump xlated id 6784
int load_static_data(struct __sk_buff * skb):
; int load_static_data(struct __sk_buff *skb)
0: (b7) r6 = 0
; test_reloc(number, 0, &num0);
1: (63) *(u32 *)(r10 -4) = r6
2: (bf) r2 = r10
; int load_static_data(struct __sk_buff *skb)
3: (07) r2 += -4
; test_reloc(number, 0, &num0);
4: (18) r1 = map[id:2238]
6: (18) r3 = map[id:2237][0]+0 <-- direct addr in .bss area
8: (b7) r4 = 0
9: (85) call array_map_update_elem#100464
10: (b7) r1 = 1
; test_reloc(number, 1, &num1);
[...]
; test_reloc(string, 2, str2);
120: (18) r8 = map[id:2237][0]+16 <-- same here at offset +16
122: (18) r1 = map[id:2239]
124: (18) r3 = map[id:2237][0]+16
126: (b7) r4 = 0
127: (85) call array_map_update_elem#100464
128: (b7) r1 = 120
; str1[5] = 'x';
129: (73) *(u8 *)(r9 +5) = r1
; test_reloc(string, 3, str1);
130: (b7) r1 = 3
131: (63) *(u32 *)(r10 -4) = r1
132: (b7) r9 = 3
133: (bf) r2 = r10
; int load_static_data(struct __sk_buff *skb)
134: (07) r2 += -4
; test_reloc(string, 3, str1);
135: (18) r1 = map[id:2239]
137: (18) r3 = map[id:2235][0]+16 <-- direct addr in .data area
139: (b7) r4 = 0
140: (85) call array_map_update_elem#100464
141: (b7) r1 = 111
; __builtin_memcpy(&str2[2], "hello", sizeof("hello"));
142: (73) *(u8 *)(r8 +6) = r1 <-- further access based on .bss data
143: (b7) r1 = 108
144: (73) *(u8 *)(r8 +5) = r1
[...]
For Cilium use-case in particular, this enables migrating configuration
constants from Cilium daemon's generated header defines into global
data sections such that expensive runtime recompilations with LLVM can
be avoided altogether. Instead, the ELF file becomes effectively a
"template", meaning, it is compiled only once (!) and the Cilium daemon
will then rewrite relevant configuration data from the ELF's .data or
.rodata sections directly instead of recompiling the program. The
updated ELF is then loaded into the kernel and atomically replaces
the existing program in the networking datapath. More info in [0].
Based upon recent fix in LLVM, commit c0db6b6bd444 ("[BPF] Don't fail
for static variables").
[0] LPC 2018, BPF track, "ELF relocation for static data in BPF",
http://vger.kernel.org/lpc-bpf2018.html#session-3
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Adjust the code for relocations slightly with no functional changes,
so that upcoming patches that will introduce support for relocations
into the .data, .rodata and .bss sections can be added independent
of these changes.
Signed-off-by: Joe Stringer <joe@wand.net.nz>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
vsprintf() in __base_pr() uses nonliteral format string and it breaks
compilation for those who provide corresponding extra CFLAGS, e.g.:
https://github.com/libbpf/libbpf/issues/27
If libbpf is built with the flags from PR:
libbpf.c:68:26: error: format string is not a string literal
[-Werror,-Wformat-nonliteral]
return vfprintf(stderr, format, args);
^~~~~~
1 error generated.
Ignore this warning since the use case in libbpf.c is legit.
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Allow bpf_prog_load_xattr() to specify log_level for program loading.
Teach libbpf to accept log_level with bit 2 set.
Increase default BPF_LOG_BUF_SIZE from 256k to 16M.
There is no downside to increase it to a maximum allowed by old kernels.
Existing 256k limit caused ENOSPC errors and users were not able to see
verifier error which is printed at the end of the verifier log.
If ENOSPC is hit, double the verifier log and try again to capture
the verifier error.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Pull networking fixes from David Miller:
"Fixes here and there, a couple new device IDs, as usual:
1) Fix BQL race in dpaa2-eth driver, from Ioana Ciornei.
2) Fix 64-bit division in iwlwifi, from Arnd Bergmann.
3) Fix documentation for some eBPF helpers, from Quentin Monnet.
4) Some UAPI bpf header sync with tools, also from Quentin Monnet.
5) Set descriptor ownership bit at the right time for jumbo frames in
stmmac driver, from Aaro Koskinen.
6) Set IFF_UP properly in tun driver, from Eric Dumazet.
7) Fix load/store doubleword instruction generation in powerpc eBPF
JIT, from Naveen N. Rao.
8) nla_nest_start() return value checks all over, from Kangjie Lu.
9) Fix asoc_id handling in SCTP after the SCTP_*_ASSOC changes this
merge window. From Marcelo Ricardo Leitner and Xin Long.
10) Fix memory corruption with large MTUs in stmmac, from Aaro
Koskinen.
11) Do not use ipv4 header for ipv6 flows in TCP and DCCP, from Eric
Dumazet.
12) Fix topology subscription cancellation in tipc, from Erik Hugne.
13) Memory leak in genetlink error path, from Yue Haibing.
14) Valid control actions properly in packet scheduler, from Davide
Caratti.
15) Even if we get EEXIST, we still need to rehash if a shrink was
delayed. From Herbert Xu.
16) Fix interrupt mask handling in interrupt handler of r8169, from
Heiner Kallweit.
17) Fix leak in ehea driver, from Wen Yang"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (168 commits)
dpaa2-eth: fix race condition with bql frame accounting
chelsio: use BUG() instead of BUG_ON(1)
net: devlink: skip info_get op call if it is not defined in dumpit
net: phy: bcm54xx: Encode link speed and activity into LEDs
tipc: change to check tipc_own_id to return in tipc_net_stop
net: usb: aqc111: Extend HWID table by QNAP device
net: sched: Kconfig: update reference link for PIE
net: dsa: qca8k: extend slave-bus implementations
net: dsa: qca8k: remove leftover phy accessors
dt-bindings: net: dsa: qca8k: support internal mdio-bus
dt-bindings: net: dsa: qca8k: fix example
net: phy: don't clear BMCR in genphy_soft_reset
bpf, libbpf: clarify bump in libbpf version info
bpf, libbpf: fix version info and add it to shared object
rxrpc: avoid clang -Wuninitialized warning
tipc: tipc clang warning
net: sched: fix cleanup NULL pointer exception in act_mirr
r8169: fix cable re-plugging issue
net: ethernet: ti: fix possible object reference leak
net: ibm: fix possible object reference leak
...
BPF:
Song Liu:
- Add support for annotating BPF programs, using the PERF_RECORD_BPF_EVENT
and PERF_RECORD_KSYMBOL recently added to the kernel and plugging
binutils's libopcodes disassembly of BPF programs with the existing
annotation interfaces in 'perf annotate', 'perf report' and 'perf top'
various output formats (--stdio, --stdio2, --tui).
perf list:
Andi Kleen:
- Filter metrics when using substring search.
perf record:
Andi Kleen:
- Allow to limit number of reported perf.data files
- Clarify help for --switch-output.
perf report:
Andi Kleen
- Indicate JITed code better.
- Show all sort keys in help output.
perf script:
Andi Kleen:
- Support relative time.
perf stat:
Andi Kleen:
- Improve scaling.
General:
Changbin Du:
- Fix some mostly error path memory and reference count leaks found
using gcc's ASan and UBSan.
Vendor events:
Mamatha Inamdar:
- Remove P8 HW events which are not supported.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Merge tag 'perf-core-for-mingo-5.1-20190321' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent
Pull perf/core improvements and fixes from Arnaldo:
BPF:
Song Liu:
- Add support for annotating BPF programs, using the PERF_RECORD_BPF_EVENT
and PERF_RECORD_KSYMBOL recently added to the kernel and plugging
binutils's libopcodes disassembly of BPF programs with the existing
annotation interfaces in 'perf annotate', 'perf report' and 'perf top'
various output formats (--stdio, --stdio2, --tui).
perf list:
Andi Kleen:
- Filter metrics when using substring search.
perf record:
Andi Kleen:
- Allow to limit number of reported perf.data files
- Clarify help for --switch-output.
perf report:
Andi Kleen
- Indicate JITed code better.
- Show all sort keys in help output.
perf script:
Andi Kleen:
- Support relative time.
perf stat:
Andi Kleen:
- Improve scaling.
General:
Changbin Du:
- Fix some mostly error path memory and reference count leaks found
using gcc's ASan and UBSan.
Vendor events:
Mamatha Inamdar:
- Remove P8 HW events which are not supported.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Currently, bpf_prog_info includes 9 arrays. The user has the option to
fetch any combination of these arrays. However, this requires a lot of
handling.
This work becomes more tricky when we need to store bpf_prog_info to a
file, because these arrays are allocated independently.
This patch introduces 'struct bpf_prog_info_linear', which stores arrays
of bpf_prog_info in continuous memory.
Helper functions are introduced to unify the work to get different sets
of bpf_prog_info. Specifically, bpf_program__get_prog_info_linear()
allows the user to select which arrays to fetch, and handles details for
the user.
Please see the comments right before 'enum bpf_prog_info_array' for more
details and examples.
Signed-off-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lkml.kernel.org/r/ce92c091-e80d-a0c1-4aa0-987706c42b20@iogearbox.net
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: kernel-team@fb.com
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stanislav Fomichev <sdf@google.com>
Link: http://lkml.kernel.org/r/20190312053051.2690567-3-songliubraving@fb.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Optimization level '-Og' offers a reasonable level of optimization while
maintaining fast compilation and a good debugging experience. This patch
tries to make it work.
$ make DEBUG=1 EXTRA_CFLAGS='-Og'
bench/epoll-ctl.c: In function ‘do_threads’:
bench/epoll-ctl.c:274:9: error: ‘ret’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
return ret;
^~~
...
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20190316080556.3075-4-changbin.du@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch splits and cleans up error handling logic for loading BTF data.
Previously, if BTF data was parsed successfully, but failed to load into
kernel, we'd report nonsensical error code, instead of error returned from
btf__load(). Now btf__new() and btf__load() are handled separately with proper
cleanup and warning reporting.
Fixes: d29d87f7e6 ("btf: separate btf creation and loading")
Reported-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
We could end up in situation when we have object file w/ all btf
info, but kernel does not support btf yet. In this situation
currently libbpf just set obj->btf to NULL w/o freeing it first.
This patch is fixing it by making sure to run btf__free first.
Fixes: d29d87f7e6 ("btf: separate btf creation and loading")
Signed-off-by: Nikita V. Shirokov <tehnerd@tehnerd.com>
Acked-by: Yonghong Song <yhs@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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
currently by default libbpf's bpf_object__open requires
bpf's program to specify version in a code because of two things:
1) default prog type is set to KPROBE
2) KPROBE requires (in kernel/bpf/syscall.c) version to be specified
in this patch i'm changing default prog type to UNSPEC and also changing
requirments for version's section to be present in object file.
now it would reflect what we have today in kernel
(only KPROBE prog type requires for version to be explicitly set).
v1 -> v2:
- RFC tag has been dropped
Signed-off-by: Nikita V. Shirokov <tehnerd@tehnerd.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
idea is pretty simple. for specified map (pointed by struct bpf_map)
we would provide descriptor of already loaded map, which is going to be
used as a prototype for inner map. proposed workflow:
1) open bpf's object (bpf_object__open)
2) create bpf's map which is going to be used as a prototype
3) find (by name) map-in-map which you want to load and update w/
descriptor of inner map w/ a new helper from this patch
4) load bpf program w/ bpf_object__load
Signed-off-by: Nikita V. Shirokov <tehnerd@tehnerd.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Use recently added capability check.
See commit 23499442c3 ("bpf: libbpf: retry map creation without
the name") for rationale.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Instead, check for a newly created caps.name bpf_object capability.
If kernel doesn't support names, don't specify the attribute.
See commit 23499442c3 ("bpf: libbpf: retry map creation without
the name") for rationale.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
It currently only checks whether kernel supports map/prog names.
This capability check will be used in the next two commits to
skip setting prog/map names.
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Commit 2993e0515b ("tools/bpf: add support to read .BTF.ext sections")
added support to read .BTF.ext sections from an object file, create
and pass prog_btf_fd and func_info to the kernel.
The program btf_fd (prog->btf_fd) is initialized to be -1 to please
zclose so we do not need special handling dur prog close.
Passing -1 to the kernel, however, will cause loading error.
Passing btf_fd 0 to the kernel if prog->btf_fd is invalid
fixed the problem.
Fixes: 2993e0515b ("tools/bpf: add support to read .BTF.ext sections")
Reported-by: Andrey Ignatov <rdna@fb.com>
Reported-by: Emre Cantimur <haydum@fb.com>
Tested-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
The .BTF section is already available to encode types.
These types can be used for map
pretty print. The whole .BTF will be passed to the
kernel as well for which kernel can verify and return
to the user space for pretty print etc.
The llvm patch at https://reviews.llvm.org/D53736
will generate .BTF section and one more section .BTF.ext.
The .BTF.ext section encodes function type
information and line information. Note that
this patch set only supports function type info.
The functionality is implemented in libbpf.
The .BTF section can be directly loaded into the
kernel, and the .BTF.ext section cannot. The loader
may need to do some relocation and merging,
similar to merging multiple code sections, before
loading into the kernel.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch restores the behavior in
commit eac7d84519 ("tools: libbpf: don't return '.text' as a program for multi-function programs")
such that bpf_program__next() does not return pseudo programs in ".text".
Fixes: 0c19a9fbc9 ("libbpf: cleanup after partial failure in bpf_object__pin")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
pin_name is the same as section_name where '/' is replaced
by '_'. bpf_object__pin_programs is converted to use pin_name
to avoid the situation where section_name would require creating another
subdirectory for a pin (as, for example, when calling bpf_object__pin_programs
for programs in sections like "cgroup/connect6").
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When bpf_program has only one instance, don't create a subdirectory with
per-instance pin files (<prog>/0). Instead, just create a single pin file
for that single instance. This simplifies object pinning by not creating
unnecessary subdirectories.
This can potentially break existing users that depend on the case
where '/0' is always created. However, I couldn't find any serious
usage of bpf_program__pin inside the kernel tree and I suppose there
should be none outside.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpftool will use bpf_object__pin in the next commits to pin all programs
and maps from the file; in case of a partial failure, we need to get
back to the clean state (undo previous program/map pins).
As part of a cleanup, I've added and exported separate routines to
pin all maps (bpf_object__pin_maps) and progs (bpf_object__pin_programs)
of an object.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Arnaldo Carvalho de Melo reported build error in libbpf when clang
version 3.8.1-24 (tags/RELEASE_381/final) is used:
libbpf.c:2201:36: error: comparison of constant -22 with expression of
type 'const enum bpf_attach_type' is always false
[-Werror,-Wtautological-constant-out-of-range-compare]
if (section_names[i].attach_type == -EINVAL)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~
1 error generated.
Fix the error by keeping "is_attachable" property of a program in a
separate struct field instead of trying to use attach_type itself.
Fixes: 956b620fcf ("libbpf: Introduce libbpf_attach_type_by_name")
Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Simplify bpf_perf_event_read_simple() a bit and fix up some minor
things along the way: the return code in the header is not of type
int but enum bpf_perf_event_ret instead. Once callback indicated
to break the loop walking event data, it also needs to be consumed
in data_tail since it has been processed already.
Moreover, bpf_perf_event_print_t callback should avoid void * as
we actually get a pointer to struct perf_event_header and thus
applications can make use of container_of() to have type checks.
The walk also doesn't have to use modulo op since the ring size is
required to be power of two.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Given libbpf is a generic library and not restricted to x86-64 only,
the compiler barrier in bpf_perf_event_read_simple() after fetching
the head needs to be replaced with smp_rmb() at minimum. Also, writing
out the tail we should use WRITE_ONCE() to avoid store tearing.
Now that we have the logic in place in ring_buffer_read_head() and
ring_buffer_write_tail() helper also used by perf tool which would
select the correct and best variant for a given architecture (e.g.
x86-64 can avoid CPU barriers entirely), make use of these in order
to fix bpf_perf_event_read_simple().
Fixes: d0cabbb021 ("tools: bpf: move the event reading loop to libbpf")
Fixes: 39111695b1 ("samples: bpf: add bpf_perf_event_output example")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Multiple map definition structures exist and user may have non-zero
fields in their definition that are not recognized by bpftool and
libbpf. The normal behavior is to then fail loading the map. Although
this is a good default behavior users may still want to load the map
for debugging or other reasons. This patch adds a --mapcompat flag
that can be used to override the default behavior and allow loading
the map even when it has additional non-zero fields.
For now the only user is 'bpftool prog' we can switch over other
subcommands as needed. The library exposes an API that consumes
a flags field now but I kept the original API around also in case
users of the API don't want to expose this. The flags field is an
int in case we need more control over how the API call handles
errors/features/etc in the future.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Use __u32 instead u32 in libbpf.c and also use
uapi perf_event.h instead of tools/perf/perf-sys.h.
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
libbpf is maturing as a library and gaining features that no other bpf libraries support
(BPF Type Format, bpf to bpf calls, etc)
Many Apache2 licensed projects (like bcc, bpftrace, gobpf, cilium, etc)
would like to use libbpf, but cannot do this yet, since Apache Foundation explicitly
states that LGPL is incompatible with Apache2.
Hence let's relicense libbpf as dual license LGPL-2.1 or BSD-2-Clause,
since BSD-2 is compatible with Apache2.
Dual LGPL or Apache2 is invalid combination.
Fix license mistake in Makefile as well.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: David Beckett <david.beckett@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Joe Stringer <joe@ovn.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Make bpf_program__load consistent with other interfaces: use __u32
instead of u32. That in turn fixes build of samples:
In file included from ./samples/bpf/trace_output_user.c:21:0:
./tools/lib/bpf/libbpf.h:132:9: error: unknown type name ‘u32’
u32 kern_version);
^
Fixes: commit 29cd77f416 ("libbpf: Support loading individual progs")
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
libbpf is used more and more outside kernel tree. That means the library
should follow good practices in library design and implementation to
play well with third party code that uses it.
One of such practices is to have a common prefix (or a few) for every
interface, function or data structure, library provides. I helps to
avoid name conflicts with other libraries and keeps API consistent.
Inconsistent names in libbpf already cause problems in real life. E.g.
an application can't use both libbpf and libnl due to conflicting
symbols.
Having common prefix will help to fix current and avoid future problems.
libbpf already uses the following prefixes for its interfaces:
* bpf_ for bpf system call wrappers, program/map/elf-object
abstractions and a few other things;
* btf_ for BTF related API;
* libbpf_ for everything else.
The patch renames function in str_error.h to have libbpf_ prefix since it
misses one and doesn't fit well into the first two categories.
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Allow the individual program load to be invoked. This will help with
testing, where a single ELF may contain several sections, some of which
denote subprograms that are expected to fail verification, along with
some which are expected to pass verification. By allowing programs to be
iterated and individually loaded, each program can be independently
checked against its expected verification result.
Signed-off-by: Joe Stringer <joe@wand.net.nz>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Add section names for BPF_SK_SKB_STREAM_PARSER and
BPF_SK_SKB_STREAM_VERDICT attach types to be able to identify them in
libbpf_attach_type_by_name.
"stream_parser" and "stream_verdict" are used instead of simple "parser"
and "verdict" just to avoid possible confusion in a place where attach
type is used alone (e.g. in bpftool's show sub-commands) since there is
another attach point that can be named as "verdict": BPF_SK_MSG_VERDICT.
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Add section names for BPF_CGROUP_INET_INGRESS and BPF_CGROUP_INET_EGRESS
attach types to be able to identify them in libbpf_attach_type_by_name.
"cgroup_skb" is used instead of "cgroup/skb" mostly to easy possible
unifying of how libbpf and bpftool works with section names:
* bpftool uses "cgroup_skb" to in "prog list" sub-command;
* bpftool uses "ingress" and "egress" in "cgroup list" sub-command;
* having two parts instead of three in a string like "cgroup_skb/ingress"
can be leveraged to split it to prog_type part and attach_type part,
or vise versa: use two parts to make a section name.
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
There is a common use-case when ELF object contains multiple BPF
programs and every program has its own section name. If it's cgroup-bpf
then programs have to be 1) loaded and 2) attached to a cgroup.
It's convenient to have information necessary to load BPF program
together with program itself. This is where section name works fine in
conjunction with libbpf_prog_type_by_name that identifies prog_type and
expected_attach_type and these can be used with BPF_PROG_LOAD.
But there is currently no way to identify attach_type by section name
and it leads to messy code in user space that reinvents guessing logic
every time it has to identify attach type to use with BPF_PROG_ATTACH.
The patch introduces libbpf_attach_type_by_name that guesses attach type
by section name if a program can be attached.
The difference between expected_attach_type provided by
libbpf_prog_type_by_name and attach_type provided by
libbpf_attach_type_by_name is the former is used at BPF_PROG_LOAD time
and can be zero if a program of prog_type X has only one corresponding
attach type Y whether the latter provides specific attach type to use
with BPF_PROG_ATTACH.
No new section names were added to section_names array. Only existing
ones were reorganized and attach_type was added where appropriate.
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Daniel Borkmann says:
====================
pull-request: bpf-next 2018-09-25
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) Allow for RX stack hardening by implementing the kernel's flow
dissector in BPF. Idea was originally presented at netconf 2017 [0].
Quote from merge commit:
[...] Because of the rigorous checks of the BPF verifier, this
provides significant security guarantees. In particular, the BPF
flow dissector cannot get inside of an infinite loop, as with
CVE-2013-4348, because BPF programs are guaranteed to terminate.
It cannot read outside of packet bounds, because all memory accesses
are checked. Also, with BPF the administrator can decide which
protocols to support, reducing potential attack surface. Rarely
encountered protocols can be excluded from dissection and the
program can be updated without kernel recompile or reboot if a
bug is discovered. [...]
Also, a sample flow dissector has been implemented in BPF as part
of this work, from Petar and Willem.
[0] http://vger.kernel.org/netconf2017_files/rx_hardening_and_udp_gso.pdf
2) Add support for bpftool to list currently active attachment
points of BPF networking programs providing a quick overview
similar to bpftool's perf subcommand, from Yonghong.
3) Fix a verifier pruning instability bug where a union member
from the register state was not cleared properly leading to
branches not being pruned despite them being valid candidates,
from Alexei.
4) Various smaller fast-path optimizations in XDP's map redirect
code, from Jesper.
5) Enable to recognize BPF_MAP_TYPE_REUSEPORT_SOCKARRAY maps
in bpftool, from Roman.
6) Remove a duplicate check in libbpf that probes for function
storage, from Taeung.
7) Fix an issue in test_progs by avoid checking for errno since
on success its value should not be checked, from Mauricio.
8) Fix unused variable warning in bpf_getsockopt() helper when
CONFIG_INET is not configured, from Anders.
9) Fix a compilation failure in the BPF sample code's use of
bpf_flow_keys, from Prashant.
10) Minor cleanups in BPF code, from Yue and Zhong.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Same problem that got fixed in a similar fashion in tools/perf/ in
c8b5f2c96d ("tools: Introduce str_error_r()"), fix it in the same
way, licensing needs to be sorted out to libbpf to use libapi, so,
for this simple case, just get the same wrapper in tools/lib/bpf.
This makes libbpf and its users (bpftool, selftests, perf) to build
again in Alpine Linux 3.[45678] and edge.
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: Hendrik Brueckner <brueckner@linux.ibm.com>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Quentin Monnet <quentin.monnet@netronome.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Yonghong Song <yhs@fb.com>
Fixes: 1ce6a9fc15 ("bpf: fix build error in libbpf with EXTRA_CFLAGS="-Wp, -D_FORTIFY_SOURCE=2 -O2"")
Link: https://lkml.kernel.org/r/20180917151636.GA21790@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch extends libbpf and bpftool to work with programs of type
BPF_PROG_TYPE_FLOW_DISSECTOR.
Signed-off-by: Petar Penkov <ppenkov@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
After the commit eac7d84519 ("tools: libbpf: don't return '.text'
as a program for multi-function programs"), bpf_program__next()
in bpf_object__for_each_program skips the function storage such as .text,
so eliminate the duplicate checking.
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch adds tests for the new BPF_MAP_TYPE_REUSEPORT_SOCKARRAY.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Daniel Borkmann says:
====================
pull-request: bpf-next 2018-08-07
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) Add cgroup local storage for BPF programs, which provides a fast
accessible memory for storing various per-cgroup data like number
of transmitted packets, etc, from Roman.
2) Support bpf_get_socket_cookie() BPF helper in several more program
types that have a full socket available, from Andrey.
3) Significantly improve the performance of perf events which are
reported from BPF offload. Also convert a couple of BPF AF_XDP
samples overto use libbpf, both from Jakub.
4) seg6local LWT provides the End.DT6 action, which allows to
decapsulate an outer IPv6 header containing a Segment Routing Header.
Adds this action now to the seg6local BPF interface, from Mathieu.
5) Do not mark dst register as unbounded in MOV64 instruction when
both src and dst register are the same, from Arthur.
6) Define u_smp_rmb() and u_smp_wmb() to their respective barrier
instructions on arm64 for the AF_XDP sample code, from Brian.
7) Convert the tcp_client.py and tcp_server.py BPF selftest scripts
over from Python 2 to Python 3, from Jeremy.
8) Enable BTF build flags to the BPF sample code Makefile, from Taeung.
9) Remove an unnecessary rcu_read_lock() in run_lwt_bpf(), from Taehee.
10) Several improvements to the README.rst from the BPF documentation
to make it more consistent with RST format, from Tobin.
11) Replace all occurrences of strerror() by calls to strerror_r()
in libbpf and fix a FORTIFY_SOURCE build error along with it,
from Thomas.
12) Fix a bug in bpftool's get_btf() function to correctly propagate
an error via PTR_ERR(), from Yue.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
The BTF conflicts were simple overlapping changes.
The virtio_net conflict was an overlap of a fix of statistics counter,
happening alongisde a move over to a bonafide statistics structure
rather than counting value on the stack.
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 531b014e7a ("tools: bpf: make use of reallocarray") causes
a compiler error when building the perf tool in the linux-next tree.
Compile file tools/lib/bpf/libbpf.c on a FEDORA 28 installation with
gcc compiler version: gcc (GCC) 8.0.1 20180324 (Red Hat 8.0.1-0.20)
shows this error message:
[root@p23lp27] # make V=1 EXTRA_CFLAGS="-Wp,-D_FORTIFY_SOURCE=2 -O2"
[...]
make -f /home6/tmricht/linux-next/tools/build/Makefile.build
dir=./util/scripting-engines obj=libperf
libbpf.c: In function ‘bpf_object__elf_collect’:
libbpf.c:811:15: error: ignoring return value of ‘strerror_r’,
declared with attribute warn_unused_result [-Werror=unused-result]
strerror_r(-err, errmsg, sizeof(errmsg));
^
cc1: all warnings being treated as errors
mv: cannot stat './.libbpf.o.tmp': No such file or directory
/home6/tmricht/linux-next/tools/build/Makefile.build:96: recipe for target 'libbpf.o' failed
Replace all occurrences of strerror() by calls to strerror_r(). To
keep the compiler quiet also use the return value from strerror_r()
otherwise a 'variable set but not use' warning which is treated as
error terminates the compile.
Fixes: 531b014e7a ("tools: bpf: make use of reallocarray")
Suggested-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
In linux-next tree compiling the perf tool with additional make flags
EXTRA_CFLAGS="-Wp,-D_FORTIFY_SOURCE=2 -O2" causes a compiler error.
It is the warning 'variable may be used uninitialized' which is treated
as error: I compile it using a FEDORA 28 installation, my gcc compiler
version: gcc (GCC) 8.0.1 20180324 (Red Hat 8.0.1-0.20). The file that
causes the error is tools/lib/bpf/libbpf.c.
[root@p23lp27] # make V=1 EXTRA_CFLAGS="-Wp,-D_FORTIFY_SOURCE=2 -O2"
[...]
Makefile.config:849: No openjdk development package found, please
install JDK package, e.g. openjdk-8-jdk, java-1.8.0-openjdk-devel
Warning: Kernel ABI header at 'tools/include/uapi/linux/if_link.h'
differs from latest version at 'include/uapi/linux/if_link.h'
CC libbpf.o
libbpf.c: In function ‘bpf_perf_event_read_simple’:
libbpf.c:2342:6: error: ‘ret’ may be used uninitialized in this
function [-Werror=maybe-uninitialized]
int ret;
^
cc1: all warnings being treated as errors
mv: cannot stat './.libbpf.o.tmp': No such file or directory
/home6/tmricht/linux-next/tools/build/Makefile.build:96: recipe for target 'libbpf.o' failed
Suggested-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Allow users to find programs by section names.
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>
bpf_map__fd() handles NULL map gracefully and returns -EINVAL.
bpf_program__fd() and bpf_program__nth_fd() crash in this case.
Make the behaviour more consistent by validating prog pointer
as well.
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 patch introduces BPF_ANNOTATE_KV_PAIR to signal the
bpf loader about the btf key_type and value_type of a bpf map.
Please refer to the changes in test_btf_haskv.c for its usage.
Both iproute2 and libbpf loader will then have the same
convention to find out the map's btf_key_type_id and
btf_value_type_id from a map's name.
Fixes: 8a138aed4a ("bpf: btf: Add BTF support to libbpf")
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This patch replaces [u]int32_t and [u]int64_t usage with
__[su]32 and __[su]64. The same change goes for [u]int16_t
and [u]int8_t.
Fixes: 8a138aed4a ("bpf: btf: Add BTF support to libbpf")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
More advanced applications may want to only replace programs without
destroying associated maps. Allow libbpf users to achieve that.
Instead of always creating all of the maps at load time, expose to
users an API to reconstruct the map object from already existing
map.
The map parameters are read from the kernel and replace the parameters
of the ELF map. libbpf does not restrict the map replacement, i.e.
the reused map does not have to be compatible with the ELF map
definition. We relay on the verifier for checking the compatibility
between maps and programs. The ELF map definition is completely
overwritten by the information read from the kernel, to make sure
libbpf's view of map object corresponds to the actual map.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
reallocarray() is a safer variant of realloc which checks for
multiplication overflow in case of array allocation. Since it's
not available in Glibc < 2.26 import kernel's overflow.h and
add a static inline implementation when needed. Use feature
detection to probe for existence of reallocarray.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
libbpf_strerror() depends on XSI-compliant (POSIX) version of
strerror_r(), which prevents us from using GNU-extensions in
libbpf.c, like reallocarray() or dup3(). Move error printing
code into a separate file to allow it to continue using POSIX
strerror_r().
No functional changes.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Similarly to bpf_prog_load() users of bpf_object__open() may need
to specify the expected program type. Program type is needed at
open to avoid the kernel version check for program types which don't
require it.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Add helper to libbpf for recognizing maps which should not have
ifindex set when program is loaded. These maps only contain
host metadata and therefore are not marked for offload, e.g.
the perf event map.
Use this helper in bpf_prog_load_xattr().
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>
libbpf can guess program type based on ELF section names. As libbpf
becomes more popular its association between section name strings and
types becomes more of a standard. Allow libbpf users to use the same
logic for matching strings to types, e.g. when the string originates
from command line.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Make bpf_program__next() skip over '.text' section if object file
has pseudo calls. The '.text' section is hardly a program in that
case, it's more of a storage for code of functions other than main.
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>
libbpf used to be able to load programs from the default section
called '.text'. It's not very common to leave sections unnamed,
but if it happens libbpf will fail to load the programs reporting
-EINVAL from the kernel. The -EINVAL comes from bpf_obj_name_cpy()
because since 48cca7e44f ("libbpf: add support for bpf_call")
libbpf does not resolve program names for programs in '.text',
defaulting to '.text'. '.text', however, does not pass the
(isalnum(*src) || *src == '_') check in bpf_obj_name_cpy().
With few extra lines of code we can limit the pseudo call
assumptions only to objects which actually contain code relocations.
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>
Users of bpf_object__open()/bpf_object__load() APIs may want to
load the programs and maps onto a device for offload. Allow
setting ifindex on those sub-objects.
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>
Specify default section names for BPF_PROG_TYPE_LIRC_MODE2
and BPF_PROG_TYPE_LWT_SEG6LOCAL, these are the only two
missing right now.
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 is simple test over rc-loopback.
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
libbpf can guess prog type and expected attach type based on section
name. Add hints for "cgroup/sendmsg4" and "cgroup/sendmsg6" section
names.
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Alexei Starovoitov says:
====================
pull-request: bpf-next 2018-05-24
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) Björn Töpel cleans up AF_XDP (removes rebind, explicit cache alignment from uapi, etc).
2) David Ahern adds mtu checks to bpf_ipv{4,6}_fib_lookup() helpers.
3) Jesper Dangaard Brouer adds bulking support to ndo_xdp_xmit.
4) Jiong Wang adds support for indirect and arithmetic shifts to NFP
5) Martin KaFai Lau cleans up BTF uapi and makes the btf_header extensible.
6) Mathieu Xhonneux adds an End.BPF action to seg6local with BPF helpers allowing
to edit/grow/shrink a SRH and apply on a packet generic SRv6 actions.
7) Sandipan Das adds support for bpf2bpf function calls in ppc64 JIT.
8) Yonghong Song adds BPF_TASK_FD_QUERY command for introspection of tracing events.
9) other misc fixes from Gustavo A. R. Silva, Sirio Balmelli, John Fastabend, and Magnus Karlsson
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds the End.BPF action to the LWT seg6local infrastructure.
This action works like any other seg6local End action, meaning that an IPv6
header with SRH is needed, whose DA has to be equal to the SID of the
action. It will also advance the SRH to the next segment, the BPF program
does not have to take care of this.
Since the BPF program may not be a source of instability in the kernel, it
is important to ensure that the integrity of the packet is maintained
before yielding it back to the IPv6 layer. The hook hence keeps track if
the SRH has been altered through the helpers, and re-validates its
content if needed with seg6_validate_srh. The state kept for validation is
stored in a per-CPU buffer. The BPF program is not allowed to directly
write into the packet, and only some fields of the SRH can be altered
through the helper bpf_lwt_seg6_store_bytes.
Performances profiling has shown that the SRH re-validation does not induce
a significant overhead. If the altered SRH is deemed as invalid, the packet
is dropped.
This validation is also done before executing any action through
bpf_lwt_seg6_action, and will not be performed again if the SRH is not
modified after calling the action.
The BPF program may return 3 types of return codes:
- BPF_OK: the End.BPF action will look up the next destination through
seg6_lookup_nexthop.
- BPF_REDIRECT: if an action has been executed through the
bpf_lwt_seg6_action helper, the BPF program should return this
value, as the skb's destination is already set and the default
lookup should not be performed.
- BPF_DROP : the packet will be dropped.
Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com>
Acked-by: David Lebrun <dlebrun@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
On arm32, 'cd tools/testing/selftests/bpf && make' fails with:
libbpf.c:80:10: error: format ‘%ld’ expects argument of type ‘long int’, but argument 4 has type ‘int64_t {aka long long int}’ [-Werror=format=]
(func)("libbpf: " fmt, ##__VA_ARGS__); \
^
libbpf.c:83:30: note: in expansion of macro ‘__pr’
#define pr_warning(fmt, ...) __pr(__pr_warning, fmt, ##__VA_ARGS__)
^~~~
libbpf.c:1072:3: note: in expansion of macro ‘pr_warning’
pr_warning("map:%s value_type:%s has BTF type_size:%ld != value_size:%u\n",
To fix, typecast 'key_size' and amend format string.
Signed-off-by: Sirio Balmelli <sirio@b-ad.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This patch does the followings:
1. Modify libbpf and test_btf to reflect the uapi changes in btf
2. Add test for the btf_header changes
3. Add tests for array->index_type
4. Add err_str check to the tests
5. Fix a 4 bytes hole in "struct test #1" by swapping "m" and "n"
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
S390 bpf_jit.S is removed in net-next and had changes in 'net',
since that code isn't used any more take the removal.
TLS data structures split the TX and RX components in 'net-next',
put the new struct members from the bug fix in 'net' into the RX
part.
The 'net-next' tree had some reworking of how the ERSPAN code works in
the GRE tunneling code, overlapping with a one-line headroom
calculation fix in 'net'.
Overlapping changes in __sock_map_ctx_update_elem(), keep the bits
that read the prog members via READ_ONCE() into local variables
before using them.
Signed-off-by: David S. Miller <davem@davemloft.net>
BPF programs currently can only be offloaded using iproute2. This
patch will allow programs to be offloaded using libbpf calls.
Signed-off-by: David Beckett <david.beckett@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
BPF programs only have to specify the target kernel version for
tracing related hooks, in networking world that requirement does
not really apply. Loosen the checks in libbpf to reflect that.
bpf_object__open() users will continue to see the error for backward
compatibility (and because prog_type is not available there).
Error code for NULL file name is changed from ENOENT to EINVAL,
as it seems more appropriate, hopefully, that's an OK change.
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>
There are two copies of event reading loop - in bpftool and
trace_helpers "library". Consolidate them and move the code
to libbpf. Return codes from trace_helpers are kept, but
renamed to include LIBBPF prefix.
Suggested-by: Alexei Starovoitov <ast@kernel.org>
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 adds a new test program test_sockmap which is the old sample
sockmap program. By moving the sample program here we can now run it
as part of the self tests suite. To support this a populate_progs()
routine is added to load programs and maps which was previously done
with load_bpf_file(). This is needed because self test libs do not
provide a similar routine. Also we now use the cgroup_helpers
routines to manage cgroup use instead of manually creating one and
supplying it to the CLI.
Notice we keep the CLI around though because it is useful for dbg
and specialized testing.
To run use ./test_sockmap and the result should be,
Summary 660 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
If the ".BTF" elf section exists, libbpf will try to create
a btf_fd (through BPF_BTF_LOAD). If that fails, it will still
continue loading the bpf prog/map without the BTF.
If the bpf_object has a BTF loaded, it will create a map with the btf_fd.
libbpf will try to figure out the btf_key_id and btf_value_id of a map by
finding the BTF type with name "<map_name>_key" and "<map_name>_value".
If they cannot be found, it will continue without using the BTF.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Add missing pieces for BPF_PROG_TYPE_RAW_TRACEPOINT in libbpf:
* is- and set- functions;
* support guessing prog type.
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
libbpf can guess prog type and expected attach type based on section
name. Add hints for "cgroup/post_bind4" and "cgroup/post_bind6" section
names.
Existing "cgroup/sock" is not changed, i.e. expected_attach_type for it
is not set to `BPF_CGROUP_INET_SOCK_CREATE`, for backward compatibility.
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Add selftest to work with bpf_sock_addr context from
`BPF_PROG_TYPE_CGROUP_SOCK_ADDR` programs.
Try to bind(2) on IP:port and apply:
* loads to make sure context can be read correctly, including narrow
loads (byte, half) for IP and full-size loads (word) for all fields;
* stores to those fields allowed by verifier.
All combination from IPv4/IPv6 and TCP/UDP are tested.
Both scenarios are tested:
* valid programs can be loaded and attached;
* invalid programs can be neither loaded nor attached.
Test passes when expected data can be read from context in the
BPF-program, and after the call to bind(2) socket is bound to IP:port
pair that was written by BPF-program to the context.
Example:
# ./test_sock_addr
Attached bind4 program.
Test case #1 (IPv4/TCP):
Requested: bind(192.168.1.254, 4040) ..
Actual: bind(127.0.0.1, 4444)
Test case #2 (IPv4/UDP):
Requested: bind(192.168.1.254, 4040) ..
Actual: bind(127.0.0.1, 4444)
Attached bind6 program.
Test case #3 (IPv6/TCP):
Requested: bind(face:b00c:1234:5678::abcd, 6060) ..
Actual: bind(::1, 6666)
Test case #4 (IPv6/UDP):
Requested: bind(face:b00c:1234:5678::abcd, 6060) ..
Actual: bind(::1, 6666)
### SUCCESS
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Support setting `expected_attach_type` at prog load time in both
`bpf/bpf.h` and `bpf/libbpf.h`.
Since both headers already have API to load programs, new functions are
added not to break backward compatibility for existing ones:
* `bpf_load_program_xattr()` is added to `bpf/bpf.h`;
* `bpf_prog_load_xattr()` is added to `bpf/libbpf.h`.
Both new functions accept structures, `struct bpf_load_program_attr` and
`struct bpf_prog_load_attr` correspondingly, where new fields can be
added in the future w/o changing the API.
Standard `_xattr` suffix is used to name the new API functions.
Since `bpf_load_program_name()` is not used as heavily as
`bpf_load_program()`, it was removed in favor of more generic
`bpf_load_program_xattr()`.
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Add sockmap option to use SK_MSG program types.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Fixes a GCC maybe-uninitialized warning introduced by 48cca7e44f.
"text" is only initialized inside the if statement so only print debug
info there.
Fixes: 48cca7e44f ("libbpf: add support for bpf_call")
Signed-off-by: Jeremy Cline <jeremy@jcline.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
V3: More generic skipping of relo-section (suggested by Daniel)
If clang >= 4.0.1 is missing the option '-target bpf', it will cause
llc/llvm to create two ELF sections for "Exception Frames", with
section names '.eh_frame' and '.rel.eh_frame'.
The BPF ELF loader library libbpf fails when loading files with these
sections. The other in-kernel BPF ELF loader in samples/bpf/bpf_load.c,
handle this gracefully. And iproute2 loader also seems to work with these
"eh" sections.
The issue in libbpf is caused by bpf_object__elf_collect() skipping
some sections, and later when performing relocation it will be
pointing to a skipped section, as these sections cannot be found by
bpf_object__find_prog_by_idx() in bpf_object__collect_reloc().
This is a general issue that also occurs for other sections, like
debug sections which are also skipped and can have relo section.
As suggested by Daniel. To avoid keeping state about all skipped
sections, instead perform a direct qlookup in the ELF object. Lookup
the section that the relo-section points to and check if it contains
executable machine instructions (denoted by the sh_flags
SHF_EXECINSTR). Use this check to also skip irrelevant relo-sections.
Note, for samples/bpf/ the '-target bpf' parameter to clang cannot be used
due to incompatibility with asm embedded headers, that some of the samples
include. This is explained in more details by Yonghong Song in bpf_devel_QA.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
While debugging a bpf ELF loading issue, I needed to correlate the
ELF section number with the failed relocation section reference.
Thus, add section numbers/index to the pr_debug.
In debug mode, also print section that were skipped. This helped
me identify that a section (.eh_frame) was skipped, and this was
the reason the relocation section (.rel.eh_frame) could not find
that section number.
The section numbers corresponds to the readelf tools Section Headers [Nr].
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
It seems that the type guessing feature for libbpf, based on the name of
the ELF section the program is located in, was inspired from
samples/bpf/prog_load.c, which was not used by any sample for loading
programs of certain types such as TC actions and classifiers, or
LWT-related types. As a consequence, libbpf is not able to guess the
type of such programs and to load them automatically if type is not
provided to the `bpf_load_prog()` function.
Add ELF section names associated to those eBPF program types so that
they can be loaded with e.g. bpftool as well.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Most of the code is taken from set_link_xdp_fd() in bpf_load.c and
slightly modified to be library compliant.
Signed-off-by: Eric Leblond <eric@regit.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
libbpf is able to deduce the type of a program from the name of the ELF
section in which it is located. However, the comparison is made on the
first n characters, n being determined with sizeof() applied to the
reference string (e.g. "xdp"). When such section names are supposed to
receive a suffix separated with a slash (e.g. "kprobe/"), using sizeof()
takes the final NUL character of the reference string into account,
which implies that both strings must be equal. Instead, the desired
behaviour would consist in taking the length of the string, *without*
accounting for the ending NUL character, and to make sure the reference
string is a prefix to the ELF section name.
Subtract 1 to the total size of the string for obtaining the length for
the comparison.
Fixes: 583c90097f ("libbpf: add ability to guess program type based on section name")
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
These elf object pieces are of type Elf64_Xword and therefore could be
"long long" on some builds.
Cast to "long long" and use printf format %lld to deal with this since
we are building with -Werror=format.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
- recognize relocation emitted by llvm
- since all regular function will be kept in .text section and llvm
takes care of pc-relative offsets in bpf_call instruction
simply copy all of .text to relevant program section while adjusting
bpf_call instructions in program section to point to newly copied
body of instructions from .text
- do so for all programs in the elf file
- set all programs types to the one passed to bpf_prog_load()
Note for elf files with multiple programs that use different
functions in .text section we need to do 'linker' style logic.
This work is still TBD
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Libbpf picks the name of the first symbol in the corresponding
elf section to use as a program name. But without taking symbol's
scope into account it may end's up with some local label
as a program name. E.g.:
$ bpftool prog
1: type 15 name LBB0_10 tag 0390a5136ba23f5c
loaded_at Dec 07/17:22 uid 0
xlated 456B not jited memlock 4096B
Fix this by preferring global symbols as program name.
For instance:
$ bpftool prog
1: type 15 name bpf_prog1 tag 0390a5136ba23f5c
loaded_at Dec 07/17:26 uid 0
xlated 456B not jited memlock 4096B
Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Quentin Monnet <quentin.monnet@netronome.com>
Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
The bpf_prog_load() function will guess program type if it's not
specified explicitly. This functionality will be used to implement
loading of different programs without asking a user to specify
the program type. In first order it will be used by bpftool.
Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Quentin Monnet <quentin.monnet@netronome.com>
Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This is required to use BPF_MAP_TYPE_LPM_TRIE or any other map type
which requires flags.
Signed-off-by: Craig Gallek <kraig@google.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This library previously assumed a fixed-size map options structure.
Any new options were ignored. In order to allow the options structure
to grow and to support parsing older programs, this patch updates
the maps section parsing to handle varying sizes.
Object files with maps sections smaller than expected will have the new
fields initialized to zero. Object files which have larger than expected
maps sections will be rejected unless all of the unrecognized data is zero.
This change still assumes that each map definition in the maps section
is the same size.
Signed-off-by: Craig Gallek <kraig@google.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch extends the libbpf to provide API support to
allow specifying BPF object name.
In tools/lib/bpf/libbpf, the C symbol of the function
and the map is used. Regarding section name, all maps are
under the same section named "maps". Hence, section name
is not a good choice for map's name. To be consistent with
map, bpf_prog also follows and uses its function symbol as
the prog's name.
This patch adds logic to collect function's symbols in libbpf.
There is existing codes to collect the map's symbols and no change
is needed.
The bpf_load_program_name() and bpf_map_create_name() are
added to take the name argument. For the other bpf_map_create_xxx()
variants, a name argument is directly added to them.
In samples/bpf, bpf_load.c in particular, the symbol is also
used as the map's name and the map symbols has already been
collected in the existing code. For bpf_prog, bpf_load.c does
not collect the function symbol name. We can consider to collect
them later if there is a need to continue supporting the bpf_load.c.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Eric Leblond <eric@regit.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This generates a set of sockets, attaches BPF programs, and sends some
simple traffic using basic send/recv pattern. Additionally, we do a bunch
of negative tests to ensure adding/removing socks out of the sockmap fail
correctly.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
expose bpf_program__set_type() to set program type
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a new API to pin a BPF object to the filesystem. The user can
specify the path within a BPF filesystem to pin the object.
Programs will be pinned under a subdirectory named the same as the
program, with each instance appearing as a numbered file under that
directory, and maps will be pinned under the path using the name of
the map as the file basename.
For example, with the directory '/sys/fs/bpf/foo' and a BPF object which
contains two instances of a program named 'bar', and a map named 'baz':
/sys/fs/bpf/foo/bar/0
/sys/fs/bpf/foo/bar/1
/sys/fs/bpf/foo/baz
Signed-off-by: Joe Stringer <joe@ovn.org>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/20170126212001.14103-4-joe@ovn.org
[ Check snprintf >= for truncation, as snprintf(bf, size, ...) == size also means truncation ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add a new API to pin a BPF map to the filesystem. The user can specify
the path full path within a BPF filesystem to pin the map.
Signed-off-by: Joe Stringer <joe@ovn.org>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/20170126212001.14103-3-joe@ovn.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add new APIs to pin a BPF program (or specific instances) to the
filesystem. The user can specify the path full path within a BPF
filesystem to pin the program.
bpf_program__pin_instance(prog, path, n) will pin the nth instance of
'prog' to the specified path.
bpf_program__pin(prog, path) will create the directory 'path' (if it
does not exist) and pin each instance within that directory. For
instance, path/0, path/1, path/2.
Committer notes:
- Add missing headers for mkdir()
- Check strdup() for failure
- Check snprintf >= size, not >, as == also means truncated, see 'man
snprintf', return value.
- Conditionally define BPF_FS_MAGIC, as it isn't in magic.h in older
systems and we're not yet having a tools/include/uapi/linux/magic.h
copy.
- Do not include linux/magic.h, not present in older distros.
Signed-off-by: Joe Stringer <joe@ovn.org>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/20170126212001.14103-2-joe@ovn.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This function will turn a libbpf pointer into a standard error code (or
0 if the pointer is valid).
This also allows removal of the dependency on linux/err.h in the public
header file, which causes problems in userspace programs built against
libbpf.
Signed-off-by: Joe Stringer <joe@ovn.org>
Acked-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/20170123011128.26534-5-joe@ovn.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
These bpf_prog_types were exposed in the uapi but there were no
corresponding functions to set these types for programs in libbpf.
Signed-off-by: Joe Stringer <joe@ovn.org>
Acked-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/20170123011128.26534-4-joe@ovn.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Turning this into a macro allows future prog types to be added with a
single line per type.
Signed-off-by: Joe Stringer <joe@ovn.org>
Acked-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/20170123011128.26534-3-joe@ovn.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Commit 4708bbda5c ("tools lib bpf: Fix maps resolution") attempted to
fix map resolution by identifying the number of symbols that point to
maps, and using this number to resolve each of the maps.
However, during relocation the original definition of the map size was
still in use. For up to two maps, the calculation was correct if there
was a small difference in size between the map definition in libbpf and
the one that the client library uses. However if the difference was
large, particularly if more than two maps were used in the BPF program,
the relocation would fail.
For example, when using a map definition with size 28, with three maps,
map relocation would count:
(sym_offset / sizeof(struct bpf_map_def) => map_idx)
(0 / 16 => 0), ie map_idx = 0
(28 / 16 => 1), ie map_idx = 1
(56 / 16 => 3), ie map_idx = 3
So, libbpf reports:
libbpf: bpf relocation: map_idx 3 large than 2
Fix map relocation by checking the exact offset of maps when doing
relocation.
Signed-off-by: Joe Stringer <joe@ovn.org>
[Allow different map size in an object]
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: netdev@vger.kernel.org
Fixes: 4708bbda5c ("tools lib bpf: Fix maps resolution")
Link: http://lkml.kernel.org/r/20170123011128.26534-2-joe@ovn.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Commit 6c90598174 ("bpf: pre-allocate hash map elements") introduces
map_flags to bpf_attr for BPF_MAP_CREATE command. Expose this new
parameter in libbpf.
By exposing it, users can access flags such as whether or not to
preallocate the map.
Signed-off-by: Joe Stringer <joe@ovn.org>
Acked-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Link: http://lkml.kernel.org/r/20161209024620.31660-4-joe@ovn.org
[ Added clarifying comment made by Wang Nan ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add a new API to libbpf, caller is able to get bpf_map through the
offset of bpf_map_def to 'maps' section.
The API will be used to help jitted perf hook code find fd of a map.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Joe Stringer <joe@ovn.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/20161126070354.141764-4-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Similar to other classes defined in libbpf.h (map and program), allow
'object' class has its own private data.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: He Kuang <hekuang@huawei.com>
Cc: Joe Stringer <joe@ovn.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/20161126070354.141764-3-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
It is not correct to assimilate the elf data of the maps section to an
array of map definition. In fact the sizes differ. The offset provided
in the symbol section has to be used instead.
This patch fixes a bug causing a elf with two maps not to load
correctly.
Wang Nan added:
This patch requires a name for each BPF map, so array of BPF maps is not
allowed. This restriction is reasonable, because kernel verifier forbid
indexing BPF map from such array unless the index is a fixed value, but
if the index is fixed why not merging it into name?
For example:
Program like this:
...
unsigned long cpu = get_smp_processor_id();
int *pval = map_lookup_elem(&map_array[cpu], &key);
...
Generates bytecode like this:
0: (b7) r1 = 0
1: (63) *(u32 *)(r10 -4) = r1
2: (b7) r1 = 680997
3: (63) *(u32 *)(r10 -8) = r1
4: (85) call 8
5: (67) r0 <<= 4
6: (18) r1 = 0x112dd000
8: (0f) r0 += r1
9: (bf) r2 = r10
10: (07) r2 += -4
11: (bf) r1 = r0
12: (85) call 1
Where instruction 8 is the computation, 8 and 11 render r1 to an invalid
value for function map_lookup_elem, causes verifier report error.
Signed-off-by: Eric Leblond <eric@regit.org>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Wang Nan <wangnan0@huawei.com>
[ Merge bpf_object__init_maps_name into bpf_object__init_maps.
Fix segfault for buggy BPF script Validate obj->maps ]
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/20161115040617.69788-5-wangnan0@huawei.com
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
New LLVM will issue newly assigned EM_BPF machine code. The new code
will be propagated to glibc and libelf.
This patch introduces the new machine code to libbpf.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1468821668-60088-1-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Now libbpf support tracepoint program type. Report meaningful error when kernel
version is less than 4.7.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1468406646-21642-3-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add 4 new APIs to adjust and query the type of a BPF program.
Load program according to type set by caller. Default is set to
BPF_PROG_TYPE_KPROBE.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1468406646-21642-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Adding a missing license descriptopn header to files in libbpf, make it
LGPL-2.1.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Eric Leblond <eleblond@stamus-networks.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1467630162-193121-1-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Trivial fix to spelling mistake
Signed-off-by: Colin King <colin.king@canonical.com>
Acked-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: He Kuang <hekuang@huawei.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1467116617-8318-1-git-send-email-colin.king@canonical.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
For consistency with class__priv() elsewhere, and with the callback
typedef for clearing those areas (e.g. bpf_map_clear_priv_t).
Acked-by: Wang Nan <wangnan0@huawei.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/n/tip-rnbiyv27ohw8xppsgx0el3xb@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
For consistency with bpf_map__priv() and elsewhere.
Acked-by: Wang Nan <wangnan0@huawei.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/n/tip-x17nk5mrazkf45z0l0ahlmo8@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The use of this term is not warranted here, we use it in the kernel
sources and in tools/ for refcounting, so, for consistency, rename them.
Acked-bu: Wang Nan <wangnan0@huawei.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/n/tip-4ya1ot2e2fkrz48ws9ebiofs@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
For consistency, leaving "get" for reference counting.
Acked-by: Wang Nan <wangnan0@huawei.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/n/tip-msy8sxfz9th6gl2xjeci2btm@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
And for consistency, rename it to bpf_map__def(), leaving "get" for
reference counting.
Also make it return a const pointer, as suggested by Wang.
Acked-by: Wang Nan <wangnan0@huawei.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/n/tip-mer00xqkiho0ymg66b5i9luw@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
For consistency, leaving "get" for reference counting.
Acked-by: Wang Nan <wangnan0@huawei.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/n/tip-crnflv84ejyhpba933ec71gs@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To try to, over time, consistently use the IS_ERR() interface instead of
using two return values, i.e. the integer return value for an error and
the pointer address to return the bpf_map->priv pointer.
Also rename it to bpf__priv(), to leave the "get" term for reference
counting.
Noticed while working on using BPF for collecting non-integer syscall
argument payloads (struct sockaddr in calls such as connect(), for
instance), where we need to use BPF maps and thus generalise
bpf__setup_stdout() to connect bpf_output events with maps in a bpf
proggie.
Acked-by: Wang Nan <wangnan0@huawei.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/n/tip-saypxyd6ptrct379jqgxx4bl@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Libbpf should check the target section before doing relocation to ensure
the relocation is correct. If not, a bug in LLVM causes an error. See
[1]. Also, if an incorrect BPF script uses both global variable and
map, global variable whould be treated as map and be relocated without
error.
This patch saves the id of the map section into obj->efile and compare
target section of a relocation symbol against it during relocation.
Previous patch introduces a test case about this problem. After this
patch:
# ~/perf test BPF
37: Test BPF filter :
37.1: Test basic BPF filtering : Ok
37.2: Test BPF prologue generation : Ok
37.3: Test BPF relocation checker : Ok
# perf test -v BPF
...
37.3: Test BPF relocation checker :
...
libbpf: loading object '[bpf_relocation_test]' from buffer
libbpf: section .strtab, size 126, link 0, flags 0, type=3
libbpf: section .text, size 0, link 0, flags 6, type=1
libbpf: section .data, size 0, link 0, flags 3, type=1
libbpf: section .bss, size 0, link 0, flags 3, type=8
libbpf: section func=sys_write, size 104, link 0, flags 6, type=1
libbpf: found program func=sys_write
libbpf: section .relfunc=sys_write, size 16, link 10, flags 0, type=9
libbpf: section maps, size 16, link 0, flags 3, type=1
libbpf: maps in [bpf_relocation_test]: 16 bytes
libbpf: section license, size 4, link 0, flags 3, type=1
libbpf: license of [bpf_relocation_test] is GPL
libbpf: section version, size 4, link 0, flags 3, type=1
libbpf: kernel version of [bpf_relocation_test] is 40400
libbpf: section .symtab, size 144, link 1, flags 0, type=2
libbpf: map 0 is "my_table"
libbpf: collecting relocating info for: 'func=sys_write'
libbpf: Program 'func=sys_write' contains non-map related relo data pointing to section 65522
bpf: failed to load buffer
Compile BPF program failed.
test child finished with 0
---- end ----
Test BPF filter subtest 2: Ok
[1] https://llvm.org/bugs/show_bug.cgi?id=26243
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1453715801-7732-3-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Namhyung Kim pointed out a potential problem in original code that it
fetches names of maps from section header string table, which is used
to store section names.
Original code doesn't cause error because of a LLVM behavior that, it
combines shstrtab into strtab. For example:
$ echo 'int func() {return 0;}' | x86_64-oe-linux-clang -x c -o temp.o -c -
$ readelf -h ./temp.o
ELF Header:
Magic: 7f 45 4c 46 02 01 01 03 00 00 00 00 00 00 00 00
...
Section header string table index: 1
$ readelf -S ./temp.o
There are 10 section headers, starting at offset 0x288:
Section Headers:
[Nr] Name Type Address Offset
Size EntSize Flags Link Info Align
[ 0] NULL 0000000000000000 00000000
0000000000000000 0000000000000000 0 0 0
[ 1] .strtab STRTAB 0000000000000000 00000230
0000000000000051 0000000000000000 0 0 1
...
$ readelf -p .strtab ./temp.o
String dump of section '.strtab':
[ 1] .text
[ 7] .comment
[ 10] .bss
[ 15] .note.GNU-stack
[ 25] .rela.eh_frame
[ 34] func
[ 39] .strtab
[ 41] .symtab
[ 49] .data
[ 4f] -
$ readelf -p .shstrtab ./temp.o
readelf: Warning: Section '.shstrtab' was not dumped because it does not exist!
Where, 'section header string table index' points to '.strtab', and
symbol names are also stored there.
However, in case of gcc:
$ echo 'int func() {return 0;}' | gcc -x c -o temp.o -c -
$ readelf -p .shstrtab ./temp.o
String dump of section '.shstrtab':
[ 1] .symtab
[ 9] .strtab
[ 11] .shstrtab
[ 1b] .text
[ 21] .data
[ 27] .bss
[ 2c] .comment
[ 35] .note.GNU-stack
[ 45] .rela.eh_frame
$ readelf -p .strtab ./temp.o
String dump of section '.strtab':
[ 1] func
They are separated sections.
Although original code doesn't cause error, we'd better use canonical
method for fetching symbol names to avoid potential behavior changing.
This patch learns from readelf's code, fetches string from sh_link
of .symbol section.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Reported-and-Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1449541544-67621-3-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Commit 561bbccac7 ("tools lib bpf:
Extract and collect map names from BPF object file") forgets checking
return value of strdup(). This patch fixes it. It also checks names
pointer before strcmp() for safety.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Fixes: 561bbccac7 ("tools lib bpf: Extract and collect map names from BPF object file")
Link: http://lkml.kernel.org/r/1449541544-67621-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch collects name of maps in BPF object files and saves them into
'maps' field in 'struct bpf_object'. 'bpf_object__get_map_by_name' is
introduced to retrive fd and definitions of a map through its name.
Signed-off-by: He Kuang <hekuang@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: He Kuang <hekuang@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1448614067-197576-3-git-send-email-wangnan0@huawei.com
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch collects more information from maps sections in BPF object
files into 'struct bpf_object', enables later patches access those
information (such as the type and size of the map).
In this patch, a new handler 'struct bpf_map' is extracted in parallel
with bpf_object and bpf_program. Its iterator and accessor is also
created.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1448614067-197576-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch is a preparation for BPF prologue support which allows
generating a series of BPF bytecode for fetching kernel data before
calling program code. With the newly introduced multiple instances
support, perf is able to create different prologues for different kprobe
points.
Before this patch, a bpf_program can be loaded into kernel only once,
and get the only resulting fd. What this patch does is to allow creating
and loading different variants of one bpf_program, then fetching their
fds.
Here we describe the basic idea in this patch. The detailed description
of the newly introduced APIs can be found in comments in the patch body.
The key of this patch is the new mechanism in bpf_program__load().
Instead of loading BPF program into kernel directly, it calls a
'pre-processor' to generate program instances which would be finally
loaded into the kernel based on the original code. To enable the
generation of multiple instances, libbpf passes an index to the
pre-processor so it know which instance is being loaded.
Pre-processor should be called from libbpf's user (perf) using
bpf_program__set_prep(). The number of instances and the relationship
between indices and the target instance should be clear when calling
bpf_program__set_prep().
To retrieve a fd for a specific instance of a program,
bpf_program__nth_fd() is introduced. It returns the resulting fd
according to index.
Signed-off-by: He Kuang <hekuang@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: He Kuang <hekuang@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1447675815-166222-8-git-send-email-wangnan0@huawei.com
Signed-off-by: Wang Nan <wangnan0@huawei.com>
[ Enclosed multi-line if/else blocks with {}, (*func_ptr)() -> func_ptr() ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
bpf_object__get_kversion() can be used to fetch value of object's
'version' section. Following patch will use it for error reporting.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1446817783-86722-3-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
In this patch, a series of libbpf specific error numbers and
libbpf_strerror() are introduced to help reporting errors.
Functions are updated to pass correct the error number through the
CHECK_ERR() macro.
All users of bpf_object__open{_buffer}() and bpf_program__title() in
perf are modified accordingly. In addition, due to the error codes
changing, bpf__strerror_load() is also modified to use them.
bpf__strerror_head() is also changed accordingly so it can parse libbpf
errors. bpf_loader_strerror() is introduced for that purpose, and will
be improved by the following patch.
load_program() is improved not to dump log buffer if it is empty. log
buffer is also used to deduce whether the error was caused by an invalid
program or other problem.
v1 -> v2:
- Using macro for error code.
- Fetch error message based on array index, eliminate for-loop.
- Use log buffer to detect the reason of failure. 3 new error code
are introduced to replace LIBBPF_ERRNO__LOAD.
In v1:
# perf record -e ./test_ill_program.o ls
event syntax error: './test_ill_program.o'
\___ Failed to load program: Validate your program and check 'license'/'version' sections in your object
SKIP
# perf record -e ./test_kversion_nomatch_program.o ls
event syntax error: './test_kversion_nomatch_program.o'
\___ Failed to load program: Validate your program and check 'license'/'version' sections in your object
SKIP
# perf record -e ./test_big_program.o ls
event syntax error: './test_big_program.o'
\___ Failed to load program: Validate your program and check 'license'/'version' sections in your object
SKIP
In v2:
# perf record -e ./test_ill_program.o ls
event syntax error: './test_ill_program.o'
\___ Kernel verifier blocks program loading
SKIP
# perf record -e ./test_kversion_nomatch_program.o
event syntax error: './test_kversion_nomatch_program.o'
\___ Incorrect kernel version
SKIP
(Will be further improved by following patches)
# perf record -e ./test_big_program.o
event syntax error: './test_big_program.o'
\___ Program too big
SKIP
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1446817783-86722-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
CC libbpf.o
cc1: warnings being treated as errors
libbpf.c: In function 'bpf_program__title':
libbpf.c:1037: error: declaration of 'dup' shadows a global declaration
/usr/include/unistd.h:528: error: shadowed declaration is here
mv: cannot stat `./.libbpf.o.tmp': No such file or directory
make[3]: *** [libbpf.o] Error 1
make[2]: *** [libbpf-in.o] Error 2
make[1]: *** [/linux/tools/lib/bpf/libbpf.a] Error 2
make[1]: *** Waiting for unfinished jobs....
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1446549665-2342-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Before this patch there's no way to connect a loaded bpf object
to its source file. However, during applying perf's '--filter' to BPF
object, without this connection makes things harder, because perf loads
all programs together, but '--filter' setting is for each object.
The API of bpf_object__open_buffer() is changed to allow passing a name.
Fortunately, at this time there's only one user of it (perf test LLVM),
so we change it together.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1440742821-44548-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To allow enumeration of all bpf_objects, keep them in a list (hidden to
caller). bpf_object__for_each_safe() is introduced to do this iteration.
It is safe even user close the object during iteration.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-23-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch introduces accessors for user of libbpf to retrieve section
name and fd of a opened/loaded eBPF program. 'struct bpf_prog_handler'
is used for that purpose. Accessors of programs section name and file
descriptor are provided. Set/get private data are also impelmented.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Link: http://lkml.kernel.org/r/1435716878-189507-21-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch utilizes previous introduced bpf_load_program to load
programs in the ELF file into kernel. Result is stored in 'fd' field in
'struct bpf_program'.
During loading, it allocs a log buffer and free it before return. Note
that that buffer is not passed to bpf_load_program() if the first
loading try is successful. Doesn't use a statically allocated log buffer
to avoid potention multi-thread problem.
Instructions collected during opening is cleared after loading.
load_program() is created for loading a 'struct bpf_insn' array into
kernel, bpf_program__load() calls it. By this design we have a function
loads instructions into kernel. It will be used by further patches,
which creates different instances from a program and load them into
kernel.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-20-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
If an eBPF program accesses a map, LLVM generates a load instruction
which loads an absolute address into a register, like this:
ld_64 r1, <MCOperand Expr:(mymap)>
...
call 2
That ld_64 instruction will be recorded in relocation section.
To enable the usage of that map, relocation must be done by replacing
the immediate value by real map file descriptor so it can be found by
eBPF map functions.
This patch to the relocation work based on information collected by
patches:
'bpf tools: Collect symbol table from SHT_SYMTAB section',
'bpf tools: Collect relocation sections from SHT_REL sections'
and
'bpf tools: Record map accessing instructions for each program'.
For each instruction which needs relocation, it inject corresponding
file descriptor to imm field. As a part of protocol, src_reg is set to
BPF_PSEUDO_MAP_FD to notify kernel this is a map loading instruction.
This is the final part of map relocation patch. The principle of map
relocation is described in commit message of 'bpf tools: Collect symbol
table from SHT_SYMTAB section'.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-18-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch creates maps based on 'map' section in object file using
bpf_create_map(), and stores the fds into an array in 'struct
bpf_object'.
Previous patches parse ELF object file and collects required data, but
doesn't play with the kernel. They belong to the 'opening' phase. This
patch is the first patch in 'loading' phase. The 'loaded' field is
introduced in 'struct bpf_object' to avoid loading an object twice,
because the loading phase clears resources collected during the opening
which becomes useless after loading. In this patch, maps_buf is cleared.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-17-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch records the indices of instructions which are needed to be
relocated. That information is saved in the 'reloc_desc' field in
'struct bpf_program'. In the loading phase (this patch takes effect in
the opening phase), the collected instructions will be replaced by map
loading instructions.
Since we are going to close the ELF file and clear all data at the end
of the 'opening' phase, the ELF information will no longer be valid in
the 'loading' phase. We have to locate the instructions before maps are
loaded, instead of directly modifying the instruction.
'struct bpf_map_def' is introduced in this patch to let us know how many
maps are defined in the object.
This is the third part of map relocation. The principle of map relocation
is described in commit message of 'bpf tools: Collect symbol table from
SHT_SYMTAB section'.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-15-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch collects relocation sections into 'struct object'. Such
sections are used for connecting maps to bpf programs. 'reloc' field in
'struct bpf_object' is introduced for storing such information.
This patch simply store the data into 'reloc' field. Following patch
will parse them to know the exact instructions which are needed to be
relocated.
Note that the collected data will be invalid after ELF object file is
closed.
This is the second patch related to map relocation. The first one is
'bpf tools: Collect symbol table from SHT_SYMTAB section'. The
principle of map relocation is described in its commit message.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-14-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch collects all programs in an object file into an array of
'struct bpf_program' for further processing. That structure is for
representing each eBPF program. 'bpf_prog' should be a better name, but
it has been used by linux/filter.h. Although it is a kernel space name,
I still prefer to call it 'bpf_program' to prevent possible confusion.
bpf_object__add_program() creates a new 'struct bpf_program' object.
It first init a variable in stack using bpf_program__init(), then if
success, enlarges obj->programs array and copy the new object in.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-13-git-send-email-wangnan0@huawei.com
[ Made bpf_object__add_program() propagate the error (-EINVAL or -ENOMEM) ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch collects symbols section. This section is useful when linking
BPF maps.
What 'bpf_map_xxx()' functions actually require are map's file
descriptors (and the internal verifier converts fds into pointers to
'struct bpf_map'), which we don't know when compiling. Therefore, we
should make compiler generate a 'ldr_64 r1, <imm>' instruction, and
fill the 'imm' field with the actual file descriptor when loading in
libbpf.
BPF programs should be written in this way:
struct bpf_map_def SEC("maps") my_map = {
.type = BPF_MAP_TYPE_HASH,
.key_size = sizeof(unsigned long),
.value_size = sizeof(unsigned long),
.max_entries = 1000000,
};
SEC("my_func=sys_write")
int my_func(void *ctx)
{
...
bpf_map_update_elem(&my_map, &key, &value, BPF_ANY);
...
}
Compiler should convert '&my_map' into a 'ldr_64, r1, <imm>'
instruction, where imm should be the address of 'my_map'. According to
the address, libbpf knows which map it actually referenced, and then
fills the imm field with the 'fd' of that map created by it.
However, since we never really 'link' the object file, the imm field is
only a record in relocation section. Therefore libbpf should do the
relocation:
1. In relocation section (type == SHT_REL), positions of each such
'ldr_64' instruction are recorded with a reference of an entry in
symbol table (SHT_SYMTAB);
2. From records in symbol table we can find the indics of map
variables.
Libbpf first record SHT_SYMTAB and positions of each instruction which
required bu such operation. Then create file descriptor. Finally, after
map creation complete, replace the imm field.
This is the first patch of BPF map related stuff. It records SHT_SYMTAB
into object's efile field for further use.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-12-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
If maps are used by eBPF programs, corresponding object file(s) should
contain a section named 'map'. Which contains map definitions. This
patch copies the data of the whole section. Map data parsing should be
acted just before map loading.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-11-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Expand bpf_obj_elf_collect() to collect license and kernel version
information in eBPF object file. eBPF object file should have a section
named 'license', which contains a string. It should also have a section
named 'version', contains a u32 LINUX_VERSION_CODE.
bpf_obj_validate() is introduced to validate object file after loaded.
Currently it only check existence of 'version' section.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-10-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
bpf_obj_elf_collect() is introduced to iterate over each elf sections to
collection information in eBPF object files. This function will futher
enhanced to collect license, kernel version, programs, configs and map
information.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-9-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Check endianness according to EHDR. Code is taken from
tools/perf/util/symbol-elf.c.
Libbpf doesn't magically convert missmatched endianness. Even if we swap
eBPF instructions to correct byte order, we are unable to deal with
endianness in code logical generated by LLVM.
Therefore, libbpf should simply reject missmatched ELF object, and let
LLVM to create good code.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-8-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To support dynamic compiling, this patch allows caller to pass a
in-memory buffer to libbpf by bpf_object__open_buffer(). libbpf calls
elf_memory() to open it as ELF object file.
Because __bpf_object__open() collects all required data and won't need
that buffer anymore, libbpf uses that buffer directly instead of clone a
new buffer. Caller of libbpf can free that buffer or use it do other
things after bpf_object__open_buffer() return.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-7-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch defines basic interface of libbpf. 'struct bpf_object' will
be the handler of each object file. Its internal structure is hide to
user. eBPF object files are compiled by LLVM as ELF format. In this
patch, libelf is used to open those files, read EHDR and do basic
validation according to e_type and e_machine.
All elf related staffs are grouped together and reside in efile field of
'struct bpf_object'. bpf_object__elf_finish() is introduced to clear it.
After all eBPF programs in an object file are loaded, related ELF
information is useless. Close the object file and free those memory.
The zfree() and zclose() functions are introduced to ensure setting NULL
pointers and negative file descriptors after resources are released.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-6-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
By libbpf_set_print(), users of libbpf are allowed to register he/she
own debug, info and warning printing functions. Libbpf will use those
functions to print messages. If not provided, default info and warning
printing functions are fprintf(stderr, ...); default debug printing
is NULL.
This API is designed to be used by perf, enables it to register its own
logging functions to make all logs uniform, instead of separated
logging level control.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-5-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This is the first patch of libbpf. The goal of libbpf is to create a
standard way for accessing eBPF object files. This patch creates
'Makefile' and 'Build' for it, allows 'make' to build libbpf.a and
libbpf.so, 'make install' to put them into proper directories.
Most part of Makefile is borrowed from traceevent.
Before building, it checks the existence of libelf in Makefile, and deny
to build if not found. Instead of throwing an error if libelf not found,
the error raises in a phony target "elfdep". This design is to ensure
'make clean' still workable even if libelf is not found.
Because libbpf requires 'kern_version' field set for 'union bpf_attr'
(bpfdep" is used for that dependency), Kernel BPF API is also checked
by intruducing a new feature check 'bpf' into tools/build/feature,
which checks the existence and version of linux/bpf.h. When building
libbpf, it searches that file from include/uapi/linux in kernel source
tree (controlled by FEATURE_CHECK_CFLAGS-bpf). Since it searches kernel
source tree it reside, installing of newest kernel headers is not
required, except we are trying to port these files to an old kernel.
To avoid checking that file when perf building, the newly introduced
'bpf' feature check doesn't added into FEATURE_TESTS and
FEATURE_DISPLAY by default in tools/build/Makefile.feature, but added
into libbpf's specific.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Bcc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-4-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Andrii Nakryiko