When checking available canonical candidates for struct/union algorithm
utilizes btf_dedup_is_equiv to determine if candidate is suitable. This
check is not enough when candidate is corresponding FWD for that
struct/union, because according to equivalence logic they are
equivalent. When it so happens that FWD and STRUCT/UNION end in hashing
to the same bucket, it's possible to create remapping loop from FWD to
STRUCT and STRUCT to same FWD, which will cause btf_dedup() to loop
forever.
This patch fixes the issue by additionally checking that type and
canonical candidate are strictly equal (utilizing btf_equal_struct).
Fixes: d5caef5b5655 ("btf: add BTF types deduplication algorithm")
Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Default size of dedup table (16k) is good enough for most binaries, even
typical vmlinux images. But there are cases of binaries with huge amount
of BTF types (e.g., allyesconfig variants of kernel), which benefit from
having bigger dedup table size to lower amount of unnecessary hash
collisions. Tools like pahole, thus, can tune this parameter to reach
optimal performance.
This change also serves double purpose of allowing tests to force hash
collisions to test some corner cases, used in follow up patch.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
The "ref_type_id" variable needs to be signed for the error handling
to work.
Fixes: d5caef5b5655 ("btf: add BTF types deduplication algorithm")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
For historical reasons the helper to loop over maps in an object
is called bpf_map__for_each while it really should be called
bpf_object__for_each_map. Rename and add a correctly named
define for backward compatibility.
Switch all in-tree users to the correct name (Quentin).
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit adds AF_XDP support to libbpf. The main reason for this is
to facilitate writing applications that use AF_XDP by offering
higher-level APIs that hide many of the details of the AF_XDP
uapi. This is in the same vein as libbpf facilitates XDP adoption by
offering easy-to-use higher level interfaces of XDP
functionality. Hopefully this will facilitate adoption of AF_XDP, make
applications using it simpler and smaller, and finally also make it
possible for applications to benefit from optimizations in the AF_XDP
user space access code. Previously, people just copied and pasted the
code from the sample application into their application, which is not
desirable.
The interface is composed of two parts:
* Low-level access interface to the four rings and the packet
* High-level control plane interface for creating and setting
up umems and af_xdp sockets as well as a simple XDP program.
Tested-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* tools/libbpf: support bigger BTF data sizes
While it's understandable why kernel limits number of BTF types to 65535
and size of string section to 64KB, in libbpf as user-space library it's
too restrictive. E.g., pahole converting DWARF to BTF type information
for Linux kernel generates more than 3 million BTF types and more than
3MB of strings, before deduplication. So to allow btf__dedup() to do its
work, we need to be able to load bigger BTF sections using btf__new().
Singed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* sync: latest libbpf changes from kernel
Syncing latest libbpf commits from kernel repository.
Baseline commit: 789f6bab849e04ea029c09b81dc8401dc0268cf9
Checkpoint commit: 5aab392c55c96f9bb26d9294f965f156a87ee81c
Andrii Nakryiko (1):
tools/libbpf: support bigger BTF data sizes
src/btf.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)
--
2.17.1
bpf_common.h is hardly ever changed so it was not installed together
with other uapi headers. Some environments are still prefer to be
consistent and install all relevant uapi headers so add bpf_common.h to
uapi headers.
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Sync with the following bug fix:
commit a8a1f7d09cfc7e18874786c7634c9e71384fcd4e (HEAD -> bpf-next2, bpf-next/master)
Author: Stanislav Fomichev <sdf@google.com>
Date: Mon Feb 4 16:20:55 2019 -0800
libbpf: fix libbpf_print
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).
......
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
sync with latest bpf-next tree.
the include/linux/filter.h is created as libbpf.c tries
to use various insn define macros.
Signed-off-by: Yonghong Song <yhs@fb.com>
* Sync from bpf-next
Sync the following commits from bpf-next:
commit ab9e08482122 ("libbpf: Per-symbol visibility for DSO")
commit c034a177d3c8 ("bpf: bpftool, add flag to allow non-compat map definitions")
Signed-off-by: Andrey Ignatov <rdna@fb.com>
* Use -fvisibility=hidden by default for DSO
This is Makefile part of:
commit ab9e08482122 ("libbpf: Per-symbol visibility for DSO")
See original commit for details.
Introduce multiple improvements to Makefile to make the build more
flexible and support install:
* Support overriding CFLAGS by user but keep required flags in place.
ALL_FLAGS is used in Makefile as recommended in [1].
* Add additional BUILD_SHARED flag to build dynamically linked flavor of
the library. If the flag is set, -fPIC is also passed to make it
possible to build .so.
* Support building in a separate directory provided by OBJDIR variable.
* Add multiple install targets. By default the library itself and libbpf
headers are installed (install target). UAPI headers can be optionally
installed by user.
* All installation paths, including PREFIX, library and include
directories can be overridden. UAPI can be made different from include
directory for libbpf headers. That makes it possible to keep latest
<linux/bpf.h> in a place that doesn't conflict with the one installed
e.g. by kernel-headers package and use it in user's build system.
* Support DESTDIR (see [2]).
* Support overriding LDFLAGS.
* Use utilities such as rm directly as recommended in [3].
* Use compiler and related programs (such as ar) via make variables as
recommended in [3].
* In clean rule remove all possible build artifacts not to rely on passed
options (e.g. if build was done w/ BUILD_SHARED, but clean w/o it).
* Document new build options in README.
[1] https://www.gnu.org/software/make/manual/html_node/Command-Variables.html#Command-Variables
[2] https://www.gnu.org/prep/standards/html_node/DESTDIR.html
[3] https://www.gnu.org/software/make/manual/html_node/Utilities-in-Makefiles.html#Utilities-in-Makefiles
Signed-off-by: Andrey Ignatov <rdna@fb.com>
This initial commit added the following files
from bpf-next repository:
src:
<files from linux:tools/lib/bpf>
bpf.c bpf.h btf.c btf.h libbpf.c libbpf.h
libbpf_errno.c netlink.c nlattr.c nlattr.h
str_error.c str_error.h
include:
<files from linux:tools/include/uapi/linux>
uapi/linux/{bpf.h, btf.h}
<files from linux:tools/include/tools>
tools/libc_compat.h
The following files are also added:
include/linux/{err.h, kernel.h, list.h, overflow.h, types.h}
These files are customized headers to satisfy compilation.
Their original counterparts are at linux:tools/include/linux
directory.
Signed-off-by: Yonghong Song <yhs@fb.com>
