Commit Graph

934 Commits

Author SHA1 Message Date
Luo Yifan
4b15354201 tools/bpf: Fix the wrong format specifier in bpf_jit_disasm
There is a static checker warning that the %d in format string is
mismatched with the corresponding argument type, which could result in
incorrect printed data. This patch fixes it.

Signed-off-by: Luo Yifan <luoyifan@cmss.chinamobile.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241111021004.272293-1-luoyifan@cmss.chinamobile.com
2024-11-11 20:04:59 -08:00
Viktor Malik
0513eeee86 bpftool: Prevent setting duplicate _GNU_SOURCE in Makefile
When building selftests with CFLAGS set via env variable, the value of
CFLAGS is propagated into bpftool Makefile (called from selftests
Makefile). This makes the compilation fail as _GNU_SOURCE is defined two
times - once from selftests Makefile (by including lib.mk) and once from
bpftool Makefile (by calling `llvm-config --cflags`):

    $ CFLAGS="" make -C tools/testing/selftests/bpf
    [...]
    CC      /bpf-next/tools/testing/selftests/bpf/tools/build/bpftool/btf.o
    <command-line>: error: "_GNU_SOURCE" redefined [-Werror]
    <command-line>: note: this is the location of the previous definition
    cc1: all warnings being treated as errors
    [...]

Filter out -D_GNU_SOURCE from the result of `llvm-config --cflags` in
bpftool Makefile to prevent this error.

Signed-off-by: Viktor Malik <vmalik@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <qmo@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/acec3108b62d4df1436cda777e58e93e033ac7a7.1730449390.git.vmalik@redhat.com
2024-11-01 12:37:01 -07:00
Leon Hwang
4d99e509c1 bpf, bpftool: Fix incorrect disasm pc
This patch addresses the bpftool issue "Wrong callq address displayed"[0].

The issue stemmed from an incorrect program counter (PC) value used during
disassembly with LLVM or libbfd.

For LLVM: The PC argument must represent the actual address in the kernel
to compute the correct relative address.

For libbfd: The relative address can be adjusted by adding func_ksym within
the custom info->print_address_func to yield the correct address.

Links:
[0] https://github.com/libbpf/bpftool/issues/109

Changes:
v2 -> v3:
  * Address comment from Quentin:
    * Remove the typedef.

v1 -> v2:
  * Fix the broken libbfd disassembler.

Fixes: e1947c750f ("bpftool: Refactor disassembler for JIT-ed programs")
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Quentin Monnet <qmo@kernel.org>
Reviewed-by: Quentin Monnet <qmo@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20241031152844.68817-1-leon.hwang@linux.dev
2024-11-01 12:31:44 -07:00
Eder Zulian
2c3d022abe resolve_btfids: Fix compiler warnings
Initialize 'set' and 'set8' pointers to NULL in sets_patch to prevent
possible compiler warnings which are issued for various optimization
levels, but do not happen when compiling with current default
compilation options.

For example, when compiling resolve_btfids with

  $ make "HOSTCFLAGS=-O2 -Wall" -C tools/bpf/resolve_btfids/ clean all

Clang version 17.0.6 and GCC 13.3.1 issue following
-Wmaybe-uninitialized warnings for variables 'set8' and 'set':

  In function ‘sets_patch’,
      inlined from ‘symbols_patch’ at main.c:748:6,
      inlined from ‘main’ at main.c:823:6:
  main.c:163:9: warning: ‘set8’ may be used uninitialized [-Wmaybe-uninitialized]
    163 |         eprintf(1, verbose, pr_fmt(fmt), ##__VA_ARGS__)
        |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  main.c:729:17: note: in expansion of macro ‘pr_debug’
    729 |                 pr_debug("sorting  addr %5lu: cnt %6d [%s]\n",
        |                 ^~~~~~~~
  main.c: In function ‘main’:
  main.c:682:37: note: ‘set8’ was declared here
    682 |                 struct btf_id_set8 *set8;
        |                                     ^~~~
  In function ‘sets_patch’,
      inlined from ‘symbols_patch’ at main.c:748:6,
      inlined from ‘main’ at main.c:823:6:
  main.c:163:9: warning: ‘set’ may be used uninitialized [-Wmaybe-uninitialized]
    163 |         eprintf(1, verbose, pr_fmt(fmt), ##__VA_ARGS__)
        |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  main.c:729:17: note: in expansion of macro ‘pr_debug’
    729 |                 pr_debug("sorting  addr %5lu: cnt %6d [%s]\n",
        |                 ^~~~~~~~
  main.c: In function ‘main’:
  main.c:683:36: note: ‘set’ was declared here
    683 |                 struct btf_id_set *set;
        |                                    ^~~

Signed-off-by: Eder Zulian <ezulian@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20241022172329.3871958-2-ezulian@redhat.com
2024-10-23 14:38:17 -07:00
Eduard Zingerman
bf7ce5416f bpftool: __bpf_fastcall for kfuncs marked with special decl_tag
Generate __attribute__((bpf_fastcall)) for kfuncs marked with
"bpf_fastcall" decl tag. E.g. for the following BTF:

    $ bpftool btf dump file vmlinux
    ...
    [A] FUNC 'bpf_rdonly_cast' type_id=...
    ...
    [B] DECL_TAG 'bpf_kfunc' type_id=A component_idx=-1
    [C] DECL_TAG 'bpf_fastcall' type_id=A component_idx=-1

Generate the following vmlinux.h:

    #ifndef __VMLINUX_H__
    #define __VMLINUX_H__
    ...
    #ifndef __bpf_fastcall
    #if __has_attribute(bpf_fastcall)
    #define __bpf_fastcall __attribute__((bpf_fastcall))
    #else
    #define __bpf_fastcall
    #endif
    #endif
    ...
    __bpf_fastcall extern void *bpf_rdonly_cast(...) ...;

The "bpf_fastcall" / "bpf_kfunc" tags pair would generated by pahole
when constructing vmlinux BTF.

While at it, sort printed kfuncs by name for better vmlinux.h
stability.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240916091712.2929279-5-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-03 17:47:53 -07:00
Zhu Jun
89abc40803 tools/bpf: Remove unused variable from runqslower
This variable is never referenced in the code, just remove it.

Signed-off-by: Zhu Jun <zhujun2@cmss.chinamobile.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240925100005.3989-1-zhujun2@cmss.chinamobile.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-03 17:47:35 -07:00
Kuan-Wei Chiu
f04e2ad394 bpftool: Fix undefined behavior in qsort(NULL, 0, ...)
When netfilter has no entry to display, qsort is called with
qsort(NULL, 0, ...). This results in undefined behavior, as UBSan
reports:

net.c:827:2: runtime error: null pointer passed as argument 1, which is declared to never be null

Although the C standard does not explicitly state whether calling qsort
with a NULL pointer when the size is 0 constitutes undefined behavior,
Section 7.1.4 of the C standard (Use of library functions) mentions:

"Each of the following statements applies unless explicitly stated
otherwise in the detailed descriptions that follow: If an argument to a
function has an invalid value (such as a value outside the domain of
the function, or a pointer outside the address space of the program, or
a null pointer, or a pointer to non-modifiable storage when the
corresponding parameter is not const-qualified) or a type (after
promotion) not expected by a function with variable number of
arguments, the behavior is undefined."

To avoid this, add an early return when nf_link_info is NULL to prevent
calling qsort with a NULL pointer.

Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240910150207.3179306-1-visitorckw@gmail.com
2024-09-10 11:40:55 -07:00
Andrew Kreimer
f028d7716c bpftool: Fix typos
Fix typos in documentation.

Reported-by: Matthew Wilcox <willy@infradead.org>
Reported-by: Quentin Monnet <qmo@kernel.org>
Signed-off-by: Andrew Kreimer <algonell@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240909092452.4293-1-algonell@gmail.com
2024-09-09 15:57:52 -07:00
Kuan-Wei Chiu
4cdc0e4ce5 bpftool: Fix undefined behavior caused by shifting into the sign bit
Replace shifts of '1' with '1U' in bitwise operations within
__show_dev_tc_bpf() to prevent undefined behavior caused by shifting
into the sign bit of a signed integer. By using '1U', the operations
are explicitly performed on unsigned integers, avoiding potential
integer overflow or sign-related issues.

Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240908140009.3149781-1-visitorckw@gmail.com
2024-09-09 15:57:09 -07:00
Mykyta Yatsenko
f8c6b7913d bpftool: Improve btf c dump sorting stability
Existing algorithm for BTF C dump sorting uses only types and names of
the structs and unions for ordering. As dump contains structs with the
same names but different contents, relative to each other ordering of
those structs will be accidental.
This patch addresses this problem by introducing a new sorting field
that contains hash of the struct/union field names and types to
disambiguate comparison of the non-unique named structs.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240906132453.146085-1-mykyta.yatsenko5@gmail.com
2024-09-06 14:06:30 -07:00
Lin Yikai
a86857d254 bpftool: fix some typos in bpftool
Hi, fix some spelling errors in bpftool, the details are as follows:

-in file "bpftool-gen.rst"
	libppf->libbpf
-in the code comments:
	ouptut->output

Signed-off-by: Lin Yikai <yikai.lin@vivo.com>
Link: https://lore.kernel.org/r/20240905110354.3274546-2-yikai.lin@vivo.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-05 13:07:47 -07:00
Mykyta Yatsenko
b0222d1d9e bpftool: Fix handling enum64 in btf dump sorting
Wrong function is used to access the first enum64 element. Substituting btf_enum(t)
with btf_enum64(t) for BTF_KIND_ENUM64.

Fixes: 94133cf24b ("bpftool: Introduce btf c dump sorting")
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240902171721.105253-1-mykyta.yatsenko5@gmail.com
2024-09-02 22:44:51 +02:00
Quentin Monnet
5d2784e25d bpftool: Add missing blank lines in bpftool-net doc example
In bpftool-net documentation, two blank lines are missing in a
recently added example, causing docutils to complain:

    $ cd tools/bpf/bpftool
    $ make doc
      DESCEND Documentation
      GEN     bpftool-btf.8
      GEN     bpftool-cgroup.8
      GEN     bpftool-feature.8
      GEN     bpftool-gen.8
      GEN     bpftool-iter.8
      GEN     bpftool-link.8
      GEN     bpftool-map.8
      GEN     bpftool-net.8
    <stdin>:189: (INFO/1) Possible incomplete section title.
    Treating the overline as ordinary text because it's so short.
    <stdin>:192: (INFO/1) Blank line missing before literal block (after the "::")? Interpreted as a definition list item.
    <stdin>:199: (INFO/1) Possible incomplete section title.
    Treating the overline as ordinary text because it's so short.
    <stdin>:201: (INFO/1) Blank line missing before literal block (after the "::")? Interpreted as a definition list item.
      GEN     bpftool-perf.8
      GEN     bpftool-prog.8
      GEN     bpftool.8
      GEN     bpftool-struct_ops.8

Add the missing blank lines.

Fixes: 0d7c06125c ("bpftool: Add document for net attach/detach on tcx subcommand")
Signed-off-by: Quentin Monnet <qmo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240901210742.25758-1-qmo@kernel.org
2024-09-02 18:25:16 +02:00
Zhu Jun
781f0bbbda tools/bpf: Fix the wrong format specifier
The format specifier of "unsigned int" in printf() should be "%u", not
"%d".

Signed-off-by: Zhu Jun <zhujun2@cmss.chinamobile.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240724111120.11625-1-zhujun2@cmss.chinamobile.com
2024-07-30 13:41:20 -07:00
Tony Ambardar
f86601c366 tools/runqslower: Fix LDFLAGS and add LDLIBS support
Actually use previously defined LDFLAGS during build and add support for
LDLIBS to link extra standalone libraries e.g. 'argp' which is not provided
by musl libc.

Fixes: 585bf4640e ("tools: runqslower: Add EXTRA_CFLAGS and EXTRA_LDFLAGS support")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/bpf/20240723003045.2273499-1-tony.ambardar@gmail.com
2024-07-29 15:05:05 -07:00
Tao Chen
0d7c06125c bpftool: Add document for net attach/detach on tcx subcommand
This commit adds sample output for net attach/detach on
tcx subcommand.

Signed-off-by: Tao Chen <chen.dylane@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240721144252.96264-1-chen.dylane@gmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2024-07-29 12:54:08 -07:00
Tao Chen
4f88dde0e1 bpftool: Add bash-completion for tcx subcommand
This commit adds bash-completion for attaching tcx program on interface.

Signed-off-by: Tao Chen <chen.dylane@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240721144238.96246-1-chen.dylane@gmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2024-07-29 12:54:04 -07:00
Tao Chen
3b9d4fee8a bpftool: Add net attach/detach command to tcx prog
Now, attach/detach tcx prog supported in libbpf, so we can add new
command 'bpftool attach/detach tcx' to attach tcx prog with bpftool
for user.

 # bpftool prog load tc_prog.bpf.o /sys/fs/bpf/tc_prog
 # bpftool prog show
	...
	192: sched_cls  name tc_prog  tag 187aeb611ad00cfc  gpl
	loaded_at 2024-07-11T15:58:16+0800  uid 0
	xlated 152B  jited 97B  memlock 4096B  map_ids 100,99,97
	btf_id 260
 # bpftool net attach tcx_ingress name tc_prog dev lo
 # bpftool net
	...
	tc:
	lo(1) tcx/ingress tc_prog prog_id 29

 # bpftool net detach tcx_ingress dev lo
 # bpftool net
	...
	tc:
 # bpftool net attach tcx_ingress name tc_prog dev lo
 # bpftool net
	tc:
	lo(1) tcx/ingress tc_prog prog_id 29

Test environment: ubuntu_22_04, 6.7.0-060700-generic

Signed-off-by: Tao Chen <chen.dylane@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240721144221.96228-1-chen.dylane@gmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2024-07-29 12:54:00 -07:00
Tao Chen
b7264f87f7 bpftool: Refactor xdp attach/detach type judgment
This commit no logical changed, just increases code readability and
facilitates TCX prog expansion, which will be implemented in the next
patch.

Signed-off-by: Tao Chen <chen.dylane@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240721143353.95980-2-chen.dylane@gmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2024-07-29 12:53:50 -07:00
Liwei Song
13c9b702e6 tools/resolve_btfids: Fix comparison of distinct pointer types warning in resolve_btfids
Add a type cast for set8->pairs to fix below compile warning:

main.c: In function 'sets_patch':
main.c:699:50: warning: comparison of distinct pointer types lacks a cast
  699 |        BUILD_BUG_ON(set8->pairs != &set8->pairs[0].id);
      |                                 ^~

Fixes: 9707ac4fe2 ("tools/resolve_btfids: Refactor set sorting with types from btf_ids.h")
Signed-off-by: Liwei Song <liwei.song.lsong@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20240722083305.4009723-1-liwei.song.lsong@gmail.com
2024-07-22 16:35:30 +02:00
Donald Hunter
3c870059e9 bpftool: Fix typo in usage help
The usage help for "bpftool prog help" contains a ° instead of the _
symbol for cgroup/sendmsg_unix. Fix the typo.

Fixes: 8b3cba987e ("bpftool: Add support for cgroup unix socket address hooks")
Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240717134508.77488-1-donald.hunter@gmail.com
2024-07-17 22:45:58 +02:00
Andrii Nakryiko
06e71ad534 bpftool: improve skeleton backwards compat with old buggy libbpfs
Old versions of libbpf don't handle varying sizes of bpf_map_skeleton
struct correctly. As such, BPF skeleton generated by newest bpftool
might not be compatible with older libbpf (though only when libbpf is
used as a shared library), even though it, by design, should.

Going forward libbpf will be fixed, plus we'll release bug fixed
versions of relevant old libbpfs, but meanwhile try to mitigate from
bpftool side by conservatively assuming older and smaller definition of
bpf_map_skeleton, if possible. Meaning, if there are no struct_ops maps.

If there are struct_ops, then presumably user would like to have
auto-attaching logic and struct_ops map link placeholders, so use the
full bpf_map_skeleton definition in that case.

Acked-by: Quentin Monnet <qmo@kernel.org>
Co-developed-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240708204540.4188946-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-07-09 19:03:05 -07:00
Tao Chen
da5f8fd1f0 bpftool: Mount bpffs when pinmaps path not under the bpffs
As Quentin said [0], BPF map pinning will fail if the pinmaps path is not
under the bpffs, like:

  libbpf: specified path /home/ubuntu/test/sock_ops_map is not on BPF FS
  Error: failed to pin all maps

  [0] https://github.com/libbpf/bpftool/issues/146

Fixes: 3767a94b32 ("bpftool: add pinmaps argument to the load/loadall")
Signed-off-by: Tao Chen <chen.dylane@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Quentin Monnet <qmo@kernel.org>
Reviewed-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240702131150.15622-1-chen.dylane@gmail.com
2024-07-02 18:20:32 +02:00
Andrii Nakryiko
651337c7ca bpftool: Allow compile-time checks of BPF map auto-attach support in skeleton
New versions of bpftool now emit additional link placeholders for BPF
maps (struct_ops maps are the only maps right now that support
attachment), and set up BPF skeleton in such a way that libbpf will
auto-attach BPF maps automatically, assumming libbpf is recent enough
(v1.5+). Old libbpf will do nothing with those links and won't attempt
to auto-attach maps. This allows user code to handle both pre-v1.5 and
v1.5+ versions of libbpf at runtime, if necessary.

But if users don't have (or don't want to) control bpftool version that
generates skeleton, then they can't just assume that skeleton will have
link placeholders. To make this detection possible and easy, let's add
the following to generated skeleton header file:

  #define BPF_SKEL_SUPPORTS_MAP_AUTO_ATTACH 1

This can be used during compilation time to guard code that accesses
skel->links.<map> slots.

Note, if auto-attachment is undesirable, libbpf allows to disable this
through bpf_map__set_autoattach(map, false). This is necessary only on
libbpf v1.5+, older libbpf doesn't support map auto-attach anyways.

Libbpf version can be detected at compilation time using
LIBBPF_MAJOR_VERSION and LIBBPF_MINOR_VERSION macros, or at runtime with
libbpf_major_version() and libbpf_minor_version() APIs.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240618183832.2535876-1-andrii@kernel.org
2024-06-21 19:53:09 +02:00
Alan Maguire
6ba77385f3 resolve_btfids: Handle presence of .BTF.base section
Now that btf_parse_elf() handles .BTF.base section presence,
we need to ensure that resolve_btfids uses .BTF.base when present
rather than the vmlinux base BTF passed in via the -B option.
Detect .BTF.base section presence and unset the base BTF path
to ensure that BTF ELF parsing will do the right thing.

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20240613095014.357981-7-alan.maguire@oracle.com
2024-06-17 14:38:31 -07:00
Daniel Xu
770abbb5a2 bpftool: Support dumping kfunc prototypes from BTF
This patch enables dumping kfunc prototypes from bpftool. This is useful
b/c with this patch, end users will no longer have to manually define
kfunc prototypes. For the kernel tree, this also means we can optionally
drop kfunc prototypes from:

        tools/testing/selftests/bpf/bpf_kfuncs.h
        tools/testing/selftests/bpf/bpf_experimental.h

Example usage:

        $ make PAHOLE=/home/dxu/dev/pahole/build/pahole -j30 vmlinux

        $ ./tools/bpf/bpftool/bpftool btf dump file ./vmlinux format c | rg "__ksym;" | head -3
        extern void cgroup_rstat_updated(struct cgroup *cgrp, int cpu) __weak __ksym;
        extern void cgroup_rstat_flush(struct cgroup *cgrp) __weak __ksym;
        extern struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) __weak __ksym;

Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/r/bf6c08f9263c4bd9d10a717de95199d766a13f61.1718207789.git.dxu@dxuuu.xyz
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-06-12 11:01:32 -07:00
Kenta Tada
98b303c9bf bpftool: Query only cgroup-related attach types
When CONFIG_NETKIT=y,
bpftool-cgroup shows error even if the cgroup's path is correct:

$ bpftool cgroup tree /sys/fs/cgroup
CgroupPath
ID       AttachType      AttachFlags     Name
Error: can't query bpf programs attached to /sys/fs/cgroup: No such device or address

>From strace and kernel tracing, I found netkit returned ENXIO and this command failed.
I think this AttachType(BPF_NETKIT_PRIMARY) is not relevant to cgroup.

bpftool-cgroup should query just only cgroup-related attach types.

v2->v3:
  - removed an unnecessary check

v1->v2:
  - used an array of cgroup attach types

Signed-off-by: Kenta Tada <tadakentaso@gmail.com>
Reviewed-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/r/20240607111704.6716-1-tadakentaso@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-06-11 11:39:09 -07:00
Jakub Kicinski
b1156532bc bpf-next-for-netdev
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 =WMhY
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-06-06

We've added 54 non-merge commits during the last 10 day(s) which contain
a total of 50 files changed, 1887 insertions(+), 527 deletions(-).

The main changes are:

1) Add a user space notification mechanism via epoll when a struct_ops
   object is getting detached/unregistered, from Kui-Feng Lee.

2) Big batch of BPF selftest refactoring for sockmap and BPF congctl
   tests, from Geliang Tang.

3) Add BTF field (type and string fields, right now) iterator support
   to libbpf instead of using existing callback-based approaches,
   from Andrii Nakryiko.

4) Extend BPF selftests for the latter with a new btf_field_iter
   selftest, from Alan Maguire.

5) Add new kfuncs for a generic, open-coded bits iterator,
   from Yafang Shao.

6) Fix BPF selftests' kallsyms_find() helper under kernels configured
   with CONFIG_LTO_CLANG_THIN, from Yonghong Song.

7) Remove a bunch of unused structs in BPF selftests,
   from David Alan Gilbert.

8) Convert test_sockmap section names into names understood by libbpf
   so it can deduce program type and attach type, from Jakub Sitnicki.

9) Extend libbpf with the ability to configure log verbosity
   via LIBBPF_LOG_LEVEL environment variable, from Mykyta Yatsenko.

10) Fix BPF selftests with regards to bpf_cookie and find_vma flakiness
    in nested VMs, from Song Liu.

11) Extend riscv32/64 JITs to introduce shift/add helpers to generate Zba
    optimization, from Xiao Wang.

12) Enable BPF programs to declare arrays and struct fields with kptr,
    bpf_rb_root, and bpf_list_head, from Kui-Feng Lee.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (54 commits)
  selftests/bpf: Drop useless arguments of do_test in bpf_tcp_ca
  selftests/bpf: Use start_test in test_dctcp in bpf_tcp_ca
  selftests/bpf: Use start_test in test_dctcp_fallback in bpf_tcp_ca
  selftests/bpf: Add start_test helper in bpf_tcp_ca
  selftests/bpf: Use connect_to_fd_opts in do_test in bpf_tcp_ca
  libbpf: Auto-attach struct_ops BPF maps in BPF skeleton
  selftests/bpf: Add btf_field_iter selftests
  selftests/bpf: Fix send_signal test with nested CONFIG_PARAVIRT
  libbpf: Remove callback-based type/string BTF field visitor helpers
  bpftool: Use BTF field iterator in btfgen
  libbpf: Make use of BTF field iterator in BTF handling code
  libbpf: Make use of BTF field iterator in BPF linker code
  libbpf: Add BTF field iterator
  selftests/bpf: Ignore .llvm.<hash> suffix in kallsyms_find()
  selftests/bpf: Fix bpf_cookie and find_vma in nested VM
  selftests/bpf: Test global bpf_list_head arrays.
  selftests/bpf: Test global bpf_rb_root arrays and fields in nested struct types.
  selftests/bpf: Test kptr arrays and kptrs in nested struct fields.
  bpf: limit the number of levels of a nested struct type.
  bpf: look into the types of the fields of a struct type recursively.
  ...
====================

Link: https://lore.kernel.org/r/20240606223146.23020-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-10 18:02:14 -07:00
Mykyta Yatsenko
08ac454e25 libbpf: Auto-attach struct_ops BPF maps in BPF skeleton
Similarly to `bpf_program`, support `bpf_map` automatic attachment in
`bpf_object__attach_skeleton`. Currently only struct_ops maps could be
attached.

On bpftool side, code-generate links in skeleton struct for struct_ops maps.
Similarly to `bpf_program_skeleton`, set links in `bpf_map_skeleton`.

On libbpf side, extend `bpf_map` with new `autoattach` field to support
enabling or disabling autoattach functionality, introducing
getter/setter for this field.

`bpf_object__(attach|detach)_skeleton` is extended with
attaching/detaching struct_ops maps logic.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240605175135.117127-1-yatsenko@meta.com
2024-06-06 10:06:05 -07:00
Andrii Nakryiko
e1a8630291 bpftool: Use BTF field iterator in btfgen
Switch bpftool's code which is using libbpf-internal
btf_type_visit_type_ids() helper to new btf_field_iter functionality.

This makes bpftool code simpler, but also unblocks removing libbpf's
btf_type_visit_type_ids() helper completely.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Quentin Monnet <qmo@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20240605001629.4061937-5-andrii@kernel.org
2024-06-05 16:54:41 +02:00
Swan Beaujard
ce5249b91e bpftool: Fix typo in MAX_NUM_METRICS macro name
Correct typo in bpftool profiler and change all instances of 'MATRICS' to
'METRICS' in the profiler.bpf.c file.

Signed-off-by: Swan Beaujard <beaujardswan@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240602225812.81171-1-beaujardswan@gmail.com
2024-06-03 16:58:27 +02:00
Jakub Kicinski
e19de2064f Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

drivers/net/ethernet/ti/icssg/icssg_classifier.c
  abd5576b9c ("net: ti: icssg-prueth: Add support for ICSSG switch firmware")
  56a5cf538c ("net: ti: icssg-prueth: Fix start counter for ft1 filter")
https://lore.kernel.org/all/20240531123822.3bb7eadf@canb.auug.org.au/

No other adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-31 14:10:28 -07:00
Kui-Feng Lee
d14c1fac0c bpftool: Change pid_iter.bpf.c to comply with the change of bpf_link_fops.
To support epoll, a new instance of file_operations, bpf_link_fops_poll,
has been added for links that support epoll. The pid_iter.bpf.c checks
f_ops for links and other BPF objects. The check should fail for struct_ops
links without this patch.

Acked-by: Quentin Monnet <qmo@kernel.org>
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240530065946.979330-9-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-05-30 15:34:14 -07:00
Friedrich Vock
44382b3ed6 bpf: Fix potential integer overflow in resolve_btfids
err is a 32-bit integer, but elf_update returns an off_t, which is 64-bit
at least on 64-bit platforms. If symbols_patch is called on a binary between
2-4GB in size, the result will be negative when cast to a 32-bit integer,
which the code assumes means an error occurred. This can wrongly trigger
build failures when building very large kernel images.

Fixes: fbbb68de80 ("bpf: Add resolve_btfids tool to resolve BTF IDs in ELF object")
Signed-off-by: Friedrich Vock <friedrich.vock@gmx.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240514070931.199694-1-friedrich.vock@gmx.de
2024-05-24 17:12:12 +02:00
Ivan Babrou
f4aba3471c bpftool: Un-const bpf_func_info to fix it for llvm 17 and newer
LLVM 17 started treating const structs as constants:

* https://github.com/llvm/llvm-project/commit/0b2d5b967d98

Combined with pointer laundering via ptr_to_u64, which takes a const ptr,
but in reality treats the underlying memory as mutable, this makes clang
always pass zero to btf__type_by_id, which breaks full name resolution.

Disassembly before (LLVM 16) and after (LLVM 17):

    -    8b 75 cc                 mov    -0x34(%rbp),%esi
    -    e8 47 8d 02 00           call   3f5b0 <btf__type_by_id>
    +    31 f6                    xor    %esi,%esi
    +    e8 a9 8c 02 00           call   3f510 <btf__type_by_id>

It's a bigger project to fix this properly (and a question whether LLVM
itself should detect this), but for right now let's just fix bpftool.

For more information, see this thread in bpf mailing list:

* https://lore.kernel.org/bpf/CABWYdi0ymezpYsQsPv7qzpx2fWuTkoD1-wG1eT-9x-TSREFrQg@mail.gmail.com/T/

Fixes: b662000aff ("bpftool: Adding support for BTF program names")
Signed-off-by: Ivan Babrou <ivan@cloudflare.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20240520225149.5517-1-ivan@cloudflare.com
2024-05-21 10:36:28 -07:00
Artem Savkov
e7b64f9d3f bpftool: Fix make dependencies for vmlinux.h
With pre-generated vmlinux.h there is no dependency on neither vmlinux
nor bootstrap bpftool. Define dependencies separately for both modes.
This avoids needless rebuilds in some corner cases.

Suggested-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240513112658.43691-1-asavkov@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-05-18 10:46:16 -07:00
Mykyta Yatsenko
94133cf24b bpftool: Introduce btf c dump sorting
Sort bpftool c dump output; aiming to simplify vmlinux.h diffing and
forcing more natural type definitions ordering.

Definitions are sorted first by their BTF kind ranks, then by their base
type name and by their own name.

Type ranks

Assign ranks to btf kinds (defined in function btf_type_rank) to set
next order:
1. Anonymous enums/enums64
2. Named enums/enums64
3. Trivial types typedefs (ints, then floats)
4. Structs/Unions
5. Function prototypes
6. Forward declarations

Type rank is set to maximum for unnamed reference types, structs and
unions to avoid emitting those types early. They will be emitted as
part of the type chain starting with named type.

Lexicographical ordering

Each type is assigned a sort_name and own_name.
sort_name is the resolved name of the final base type for reference
types (typedef, pointer, array etc). Sorting by sort_name allows to
group typedefs of the same base type. sort_name for non-reference type
is the same as own_name. own_name is a direct name of particular type,
is used as final sorting step.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Quentin Monnet <qmo@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240514131221.20585-1-yatsenko@meta.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-05-18 10:46:16 -07:00
John Hubbard
41b307ad75 bpftool, selftests/hid/bpf: Fix 29 clang warnings
When building either tools/bpf/bpftool, or tools/testing/selftests/hid,
(the same Makefile is used for these), clang generates many instances of
the following:

    "clang: warning: -lLLVM-17: 'linker' input unused"

Quentin points out that the LLVM version is only required in $(LIBS),
not in $(CFLAGS), so the fix is to remove it from CFLAGS.

Suggested-by: Quentin Monnet <qmo@kernel.org>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240505230054.13813-1-jhubbard@nvidia.com
2024-05-06 14:39:36 -07:00
Quentin Monnet
ad2d22b617 bpftool: Address minor issues in bash completion
This commit contains a series of clean-ups and fixes for bpftool's bash
completion file:

- Make sure all local variables are declared as such.
- Make sure variables are initialised before being read.
- Update ELF section ("maps" -> ".maps") for looking up map names in
  object files.
- Fix call to _init_completion.
- Move definition for MAP_TYPE and PROG_TYPE higher up in the scope to
  avoid defining them multiple times, reuse MAP_TYPE where relevant.
- Simplify completion for "duration" keyword in "bpftool prog profile".
- Fix completion for "bpftool struct_ops register" and "bpftool link
  (pin|detach)" where we would repeatedly suggest file names instead of
  suggesting just one name.
- Fix completion for "bpftool iter pin ... map MAP" to account for the
  "map" keyword.
- Add missing "detach" suggestion for "bpftool link".

Signed-off-by: Quentin Monnet <qmo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240413011427.14402-3-qmo@kernel.org
2024-04-16 17:58:25 +02:00
Quentin Monnet
986e7663f9 bpftool: Update documentation where progs/maps can be passed by name
When using references to BPF programs, bpftool supports passing programs
by name on the command line. The manual pages for "bpftool prog" and
"bpftool map" (for prog_array updates) mention it, but we have a few
additional subcommands that support referencing programs by name but do
not mention it in their documentation. Let's update the pages for
subcommands "btf", "cgroup", and "net".

Similarly, we can reference maps by name when passing them to "bpftool
prog load", so we update the page for "bpftool prog" as well.

Signed-off-by: Quentin Monnet <qmo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240413011427.14402-2-qmo@kernel.org
2024-04-16 17:58:25 +02:00
Thorsten Blum
23cc4fe44f bpftool: Fix typo in error message
s/at at/at a/

Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240411164258.533063-3-thorsten.blum@toblux.com
2024-04-12 18:19:09 +02:00
Yonghong Song
1f3e2091d2 bpftool: Add link dump support for BPF_LINK_TYPE_SOCKMAP
An example output looks like:
  $ bpftool link
    1776: sk_skb  prog 49730
            map_id 0  attach_type sk_skb_verdict
            pids test_progs(8424)
    1777: sk_skb  prog 49755
            map_id 0  attach_type sk_skb_stream_verdict
            pids test_progs(8424)
    1778: sk_msg  prog 49770
            map_id 8208  attach_type sk_msg_verdict
            pids test_progs(8424)

Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Reviewed-by: Quentin Monnet <qmo@kernel.org>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240410043537.3737928-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-10 19:52:25 -07:00
Sahil Siddiq
478a535ae5 bpftool: Mount bpffs on provided dir instead of parent dir
When pinning programs/objects under PATH (eg: during "bpftool prog
loadall") the bpffs is mounted on the parent dir of PATH in the
following situations:
- the given dir exists but it is not bpffs.
- the given dir doesn't exist and the parent dir is not bpffs.

Mounting on the parent dir can also have the unintentional side-
effect of hiding other files located under the parent dir.

If the given dir exists but is not bpffs, then the bpffs should
be mounted on the given dir and not its parent dir.

Similarly, if the given dir doesn't exist and its parent dir is not
bpffs, then the given dir should be created and the bpffs should be
mounted on this new dir.

Fixes: 2a36c26fe3 ("bpftool: Support bpffs mountpoint as pin path for prog loadall")
Signed-off-by: Sahil Siddiq <icegambit91@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/2da44d24-74ae-a564-1764-afccf395eeec@isovalent.com/T/#t
Link: https://lore.kernel.org/bpf/20240404192219.52373-1-icegambit91@gmail.com

Closes: https://github.com/libbpf/bpftool/issues/100

Changes since v1:
 - Split "mount_bpffs_for_pin" into two functions.
   This is done to improve maintainability and readability.

Changes since v2:
- mount_bpffs_for_pin: rename to "create_and_mount_bpffs_dir".
- mount_bpffs_given_file: rename to "mount_bpffs_given_file".
- create_and_mount_bpffs_dir:
  - introduce "dir_exists" boolean.
  - remove new dir if "mnt_fs" fails.
- improve error handling and error messages.

Changes since v3:
- Rectify function name.
- Improve error messages and formatting.
- mount_bpffs_for_file:
  - Check if dir exists before block_mount check.

Changes since v4:
- Use strdup instead of strcpy.
- create_and_mount_bpffs_dir:
  - Use S_IRWXU instead of 0700.
- Improve error handling and formatting.
2024-04-04 15:37:12 -07:00
Andrii Nakryiko
2a24e24857 bpftool: Use __typeof__() instead of typeof() in BPF skeleton
When generated BPF skeleton header is included in C++ code base, some
compiler setups will emit warning about using language extensions due to
typeof() usage, resulting in something like:

  error: extension used [-Werror,-Wlanguage-extension-token]
  obj->struct_ops.empty_tcp_ca = (typeof(obj->struct_ops.empty_tcp_ca))
                                  ^

It looks like __typeof__() is a preferred way to do typeof() with better
C++ compatibility behavior, so switch to that. With __typeof__() we get
no such warning.

Fixes: c2a0257c1e ("bpftool: Cast pointers for shadow types explicitly.")
Fixes: 00389c58ff ("bpftool: Add support for subskeletons")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Kui-Feng Lee <thinker.li@gmail.com>
Acked-by: Quentin Monnet <qmo@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20240401170713.2081368-1-andrii@kernel.org
2024-04-02 16:20:49 +02:00
Rameez Rehman
a70f5d840a bpftool: Clean-up typos, punctuation, list formatting in docs
Improve the formatting of the attach flags for cgroup programs in the
relevant man page, and fix typos ("can be on of", "an userspace inet
socket") when introducing that list. Also fix a couple of other trivial
issues in docs.

[ Quentin: Fixed trival issues in bpftool-gen.rst and bpftool-iter.rst ]

Signed-off-by: Rameez Rehman <rameezrehman408@hotmail.com>
Signed-off-by: Quentin Monnet <qmo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240331200346.29118-4-qmo@kernel.org
2024-04-02 15:50:23 +02:00
Rameez Rehman
ea379b3ccc bpftool: Remove useless emphasis on command description in man pages
As it turns out, the terms in definition lists in the rST file are
already rendered with bold-ish formatting when generating the man pages;
all double-star sequences we have in the commands for the command
description are unnecessary, and can be removed to make the
documentation easier to read.

The rST files were automatically processed with:

    sed -i '/DESCRIPTION/,/OPTIONS/ { /^\*/ s/\*\*//g }' b*.rst

Signed-off-by: Rameez Rehman <rameezrehman408@hotmail.com>
Signed-off-by: Quentin Monnet <qmo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240331200346.29118-3-qmo@kernel.org
2024-04-02 15:50:23 +02:00
Rameez Rehman
f7b6854364 bpftool: Use simpler indentation in source rST for documentation
The rST manual pages for bpftool would use a mix of tabs and spaces for
indentation. While this is the norm in C code, this is rather unusual
for rST documents, and over time we've seen many contributors use a
wrong level of indentation for documentation update.

Let's fix bpftool's indentation in docs once and for all:

- Let's use spaces, that are more common in rST files.
- Remove one level of indentation for the synopsis, the command
  description, and the "see also" section. As a result, all sections
  start with the same indentation level in the generated man page.
- Rewrap the paragraphs after the changes.

There is no content change in this patch, only indentation and
rewrapping changes. The wrapping in the generated source files for the
manual pages is changed, but the pages displayed with "man" remain the
same, apart from the adjusted indentation level on relevant sections.

[ Quentin: rebased on bpf-next, removed indent level for command
  description and options, updated synopsis, command summary, and "see
  also" sections. ]

Signed-off-by: Rameez Rehman <rameezrehman408@hotmail.com>
Signed-off-by: Quentin Monnet <qmo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240331200346.29118-2-qmo@kernel.org
2024-04-02 15:50:23 +02:00
Mykyta Yatsenko
786bf0e7e2 bpf: improve error message for unsupported helper
BPF verifier emits "unknown func" message when given BPF program type
does not support BPF helper. This message may be confusing for users, as
important context that helper is unknown only to current program type is
not provided.

This patch changes message to "program of this type cannot use helper "
and aligns dependent code in libbpf and tests. Any suggestions on
improving/changing this message are welcome.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/r/20240325152210.377548-1-yatsenko@meta.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-28 18:30:53 -07:00
Jakub Kicinski
5e47fbe5ce Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

No conflicts, or adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-28 17:25:57 -07:00
Quentin Monnet
cc9b22dfa7 bpftool: Clean up HOST_CFLAGS, HOST_LDFLAGS for bootstrap bpftool
Bpftool's Makefile uses $(HOST_CFLAGS) to build the bootstrap version of
bpftool, in order to pick the flags for the host (where we run the
bootstrap version) and not for the target system (where we plan to run
the full bpftool binary). But we pass too much information through this
variable.

In particular, we set HOST_CFLAGS by copying most of the $(CFLAGS); but
we do this after the feature detection for bpftool, which means that
$(CFLAGS), hence $(HOST_CFLAGS), contain all macro definitions for using
the different optional features. For example, -DHAVE_LLVM_SUPPORT may be
passed to the $(HOST_CFLAGS), even though the LLVM disassembler is not
used in the bootstrap version, and the related library may even be
missing for the host architecture.

A similar thing happens with the $(LDFLAGS), that we use unchanged for
linking the bootstrap version even though they may contains flags to
link against additional libraries.

To address the $(HOST_CFLAGS) issue, we move the definition of
$(HOST_CFLAGS) earlier in the Makefile, before the $(CFLAGS) update
resulting from the feature probing - none of which being relevant to the
bootstrap version. To clean up the $(LDFLAGS) for the bootstrap version,
we introduce a dedicated $(HOST_LDFLAGS) variable that we base on
$(LDFLAGS), before the feature probing as well.

On my setup, the following macro and libraries are removed from the
compiler invocation to build bpftool after this patch:

  -DUSE_LIBCAP
  -DHAVE_LLVM_SUPPORT
  -I/usr/lib/llvm-17/include
  -D_GNU_SOURCE
  -D__STDC_CONSTANT_MACROS
  -D__STDC_FORMAT_MACROS
  -D__STDC_LIMIT_MACROS
  -lLLVM-17
  -L/usr/lib/llvm-17/lib

Another advantage of cleaning up these flags is that displaying
available features with "bpftool version" becomes more accurate for the
bootstrap bpftool, and no longer reflects the features detected (and
available only) for the final binary.

Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Quentin Monnet <qmo@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Message-ID: <20240320014103.45641-1-qmo@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-20 23:33:49 -07:00