linux-stable.git/tools/bpf, branch v5.16.3

bpftool: Fix indent in option lists in the documentation

2022-01-27T11:02:54+00:00

commit 986dec18bbf41f50edc2e0aa4ac5ef8e0f64f328 upstream.

Mixed indentation levels in the lists of options in bpftool's
documentation produces some unexpected results. For the "bpftool" man
page, it prints a warning:

    $ make -C bpftool.8
      GEN     bpftool.8
    :26: (ERROR/3) Unexpected indentation.

For other pages, there is no warning, but it results in a line break
appearing in the option lists in the generated man pages.

RST paragraphs should have a uniform indentation level. Let's fix it.

Fixes: c07ba629df97 ("tools: bpftool: Update and synchronise option list in doc and help msg")
Fixes: 8cc8c6357c8f ("tools: bpftool: Document and add bash completion for -L, -B options")
Signed-off-by: Quentin Monnet 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20211110114632.24537-5-quentin@isovalent.com
Signed-off-by: Greg Kroah-Hartman

bpftool: Remove inclusion of utilities.mak from Makefiles

2022-01-27T11:02:54+00:00

commit 48f5aef4c458c19ab337eed8c95a6486cc014aa3 upstream.

Bpftool's Makefile, and the Makefile for its documentation, both include
scripts/utilities.mak, but they use none of the items defined in this
file. Remove the includes.

Fixes: 71bb428fe2c1 ("tools: bpf: add bpftool")
Signed-off-by: Quentin Monnet 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20211110114632.24537-3-quentin@isovalent.com
Signed-off-by: Greg Kroah-Hartman

bpftool: Enable line buffering for stdout

2022-01-27T11:01:51+00:00

[ Upstream commit 1a1a0b0364ad291bd8e509da104ac8b5b1afec5d ]

The output of bpftool prog tracelog is currently buffered, which is
inconvenient when piping the output into other commands. A simple
tracelog | grep will typically not display anything. This patch fixes it
by enabling line buffering on stdout for the whole bpftool binary.

Fixes: 30da46b5dc3a ("tools: bpftool: add a command to dump the trace pipe")
Signed-off-by: Quentin Monnet 
Signed-off-by: Paul Chaignon 
Signed-off-by: Andrii Nakryiko 
Acked-by: Yonghong Song 
Link: https://lore.kernel.org/bpf/20211220214528.GA11706@Mem
Signed-off-by: Sasha Levin

tools/resolve_btf_ids: Close ELF file on error

2022-01-27T11:01:34+00:00

[ Upstream commit 1144ab9bdf3430e1b5b3f22741e5283841951add ]

Fix one case where we don't do explicit clean up.

Fixes: fbbb68de80a4 ("bpf: Add resolve_btfids tool to resolve BTF IDs in ELF object")
Signed-off-by: Andrii Nakryiko 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20211124002325.1737739-2-andrii@kernel.org
Signed-off-by: Sasha Levin

bpftool: Fix memory leak in prog_dump()

2022-01-27T11:01:28+00:00

[ Upstream commit ebbd7f64a3fbe9e0f235e39fc244ee9735e2a52a ]

Following the extraction of prog_dump() from do_dump(), the struct btf
allocated in prog_dump() is no longer freed on error; the struct
bpf_prog_linfo is not freed at all. Make sure we release them before
exiting the function.

Fixes: ec2025095cf6 ("bpftool: Match several programs with same tag")
Signed-off-by: Quentin Monnet 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20211110114632.24537-2-quentin@isovalent.com
Signed-off-by: Sasha Levin

tools/resolve_btfids: Skip unresolved symbol warning for empty BTF sets

2021-12-02T21:39:46+00:00

resolve_btfids prints a warning when it finds an unresolved symbol,
(id == 0) in id_patch. This can be the case for BTF sets that are empty
(due to disabled config options), hence printing warnings for certain
builds, most recently seen in [0].

The reason behind this is because id->cnt aliases id->id in btf_id
struct, leading to empty set showing up as ID 0 when we get to id_patch,
which triggers the warning. Since sets are an exception here, accomodate
by reusing hole in btf_id for bool is_set member, setting it to true for
BTF set when setting id->cnt, and use that to skip extraneous warning.

  [0]: https://lore.kernel.org/all/1b99ae14-abb4-d18f-cc6a-d7e523b25542@gmail.com

Before:

; ./tools/bpf/resolve_btfids/resolve_btfids -v -b vmlinux net/ipv4/tcp_cubic.ko
adding symbol tcp_cubic_kfunc_ids
WARN: resolve_btfids: unresolved symbol tcp_cubic_kfunc_ids
patching addr     0: ID       0 [tcp_cubic_kfunc_ids]
sorting  addr     4: cnt      0 [tcp_cubic_kfunc_ids]
update ok for net/ipv4/tcp_cubic.ko

After:

; ./tools/bpf/resolve_btfids/resolve_btfids -v -b vmlinux net/ipv4/tcp_cubic.ko
adding symbol tcp_cubic_kfunc_ids
patching addr     0: ID       0 [tcp_cubic_kfunc_ids]
sorting  addr     4: cnt      0 [tcp_cubic_kfunc_ids]
update ok for net/ipv4/tcp_cubic.ko

Fixes: 0e32dfc80bae ("bpf: Enable TCP congestion control kfunc from modules")
Reported-by: Pavel Skripkin 
Signed-off-by: Kumar Kartikeya Dwivedi 
Signed-off-by: Andrii Nakryiko 
Acked-by: Song Liu 
Link: https://lore.kernel.org/bpf/20211122144742.477787-4-memxor@gmail.com

tools/runqslower: Fix cross-build

2021-11-13T01:23:16+00:00

Commit be79505caf3f ("tools/runqslower: Install libbpf headers when
building") uses the target libbpf to build the host bpftool, which
doesn't work when cross-building:

  make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- -C tools/bpf/runqslower O=/tmp/runqslower
  ...
    LINK    /tmp/runqslower/bpftool/bpftool
  /usr/bin/ld: /tmp/runqslower/libbpf/libbpf.a(libbpf-in.o): Relocations in generic ELF (EM: 183)
  /usr/bin/ld: /tmp/runqslower/libbpf/libbpf.a: error adding symbols: file in wrong format
  collect2: error: ld returned 1 exit status

When cross-building, the target architecture differs from the host. The
bpftool used for building runqslower is executed on the host, and thus
must use a different libbpf than that used for runqslower itself.
Remove the LIBBPF_OUTPUT and LIBBPF_DESTDIR parameters, so the bpftool
build makes its own library if necessary.

In the selftests, pass the host bpftool, already a prerequisite for the
runqslower recipe, as BPFTOOL_OUTPUT. The runqslower Makefile will use
the bpftool that's already built for selftests instead of making a new
one.

Fixes: be79505caf3f ("tools/runqslower: Install libbpf headers when building")
Signed-off-by: Jean-Philippe Brucker 
Signed-off-by: Daniel Borkmann 
Reviewed-by: Quentin Monnet 
Link: https://lore.kernel.org/bpf/20211112155128.565680-1-jean-philippe@linaro.org
Signed-off-by: Alexei Starovoitov

bpftool: Install libbpf headers for the bootstrap version, too

2021-11-05T15:19:48+00:00

We recently changed bpftool's Makefile to make it install libbpf's
headers locally instead of pulling them from the source directory of the
library. Although bpftool needs two versions of libbpf, a "regular" one
and a "bootstrap" version, we would only install headers for the regular
libbpf build. Given that this build always occurs before the bootstrap
build when building bpftool, this is enough to ensure that the bootstrap
bpftool will have access to the headers exported through the regular
libbpf build.

However, this did not account for the case when we only want the
bootstrap version of bpftool, through the "bootstrap" target. For
example, perf needs the bootstrap version only, to generate BPF
skeletons. In that case, when are the headers installed? For some time,
the issue has been masked, because we had a step (the installation of
headers internal to libbpf) which would depend on the regular build of
libbpf and hence trigger the export of the headers, just for the sake of
creating a directory. But this changed with commit 8b6c46241c77
("bpftool: Remove Makefile dep. on $(LIBBPF) for
$(LIBBPF_INTERNAL_HDRS)"), where we cleaned up that stage and removed
the dependency on the regular libbpf build. As a result, when we only
want the bootstrap bpftool version, the regular libbpf is no longer
built. The bootstrap libbpf version is built, but headers are not
exported, and the bootstrap bpftool build fails because of the missing
headers.

To fix this, we also install the library headers for the bootstrap
version of libbpf, to use them for the bootstrap bpftool and for
generating the skeletons.

Fixes: f012ade10b34 ("bpftool: Install libbpf headers instead of including the dir")
Reported-by: Arnaldo Carvalho de Melo 
Signed-off-by: Quentin Monnet 
Signed-off-by: Daniel Borkmann 
Tested-by: Arnaldo Carvalho de Melo 
Link: https://lore.kernel.org/bpf/20211105015813.6171-1-quentin@isovalent.com

bpftool: Switch to libbpf's hashmap for PIDs/names references

2021-10-26T00:31:39+00:00

In order to show PIDs and names for processes holding references to BPF
programs, maps, links, or BTF objects, bpftool creates hash maps to
store all relevant information. This commit is part of a set that
transitions from the kernel's hash map implementation to the one coming
with libbpf.

The motivation is to make bpftool less dependent of kernel headers, to
ease the path to a potential out-of-tree mirror, like libbpf has.

This is the third and final step of the transition, in which we convert
the hash maps used for storing the information about the processes
holding references to BPF objects (programs, maps, links, BTF), and at
last we drop the inclusion of tools/include/linux/hashtable.h.

Note: Checkpatch complains about the use of __weak declarations, and the
missing empty lines after the bunch of empty function declarations when
compiling without the BPF skeletons (none of these were introduced in
this patch). We want to keep things as they are, and the reports should
be safe to ignore.

Signed-off-by: Quentin Monnet 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20211023205154.6710-6-quentin@isovalent.com

bpftool: Switch to libbpf's hashmap for programs/maps in BTF listing

2021-10-26T00:31:39+00:00

In order to show BPF programs and maps using BTF objects when the latter
are being listed, bpftool creates hash maps to store all relevant items.
This commit is part of a set that transitions from the kernel's hash map
implementation to the one coming with libbpf.

The motivation is to make bpftool less dependent of kernel headers, to
ease the path to a potential out-of-tree mirror, like libbpf has.

This commit focuses on the two hash maps used by bpftool when listing
BTF objects to store references to programs and maps, and convert them
to the libbpf's implementation.

Signed-off-by: Quentin Monnet 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20211023205154.6710-5-quentin@isovalent.com