A flag is a 4-byte symbol that may follow a BTF ID in a set8. This is
used in the kernel to tag kfuncs in BTF sets with certain flags. Add
support to adjust the sorting code so that it passes size as 8 bytes
for 8-byte BTF sets.
Cc: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20220721134245.2450-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
tools/runqslower use bpftool for vmlinux.h, skeleton, and static linking
only. So we can use lightweight bootstrap version of bpftool to handle
these, and it will be faster.
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220714024612.944071-3-pulehui@huawei.com
The feature test to detect the availability of zlib in bpftool's
Makefile does not bring much. The library is not optional: it may or may
not be required along libbfd for disassembling instructions, but in any
case it is necessary to build feature.o or even libbpf, on which bpftool
depends.
If we remove the feature test, we lose the nicely formatted error
message, but we get a compiler error about "zlib.h: No such file or
directory", which is equally informative. Let's get rid of the test.
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220705200456.285943-1-quentin@isovalent.com
bpftool needs to know about the newly introduced BPF_CORE_TYPE_MATCHES
relocation for its 'gen min_core_btf' command to work properly in the
present of this relocation.
Specifically, we need to make sure to mark types and fields so that they
are present in the minimized BTF for "type match" checks to work out.
However, contrary to the existing btfgen_record_field_relo, we need to
rely on the BTF -- and not the spec -- to find fields. With this change
we handle this new variant correctly. The functionality will be tested
with follow on changes to BPF selftests, which already run against a
minimized BTF created with bpftool.
Signed-off-by: Daniel Müller <deso@posteo.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20220628160127.607834-3-deso@posteo.net
To make it more explicit that the features listed with "bpftool feature
list" are known to bpftool, but not necessary available on the system
(as opposed to the probed features), rename the "feature list" command
into "feature list_builtins".
Note that "bpftool feature list" still works as before given that we
recognise arguments from their prefixes; but the real name of the
subcommand, in particular as displayed in the man page or the
interactive help, will now include "_builtins".
Since we update the bash completion accordingly, let's also take this
chance to redirect error output to /dev/null in the completion script,
to avoid displaying unexpected error messages when users attempt to
tab-complete.
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220701093805.16920-1-quentin@isovalent.com
For example, /sys/fs/bpf/maps.debug is a BPF link. When you run `bpftool map show`
to show it:
Before:
$ bpftool map show pinned /sys/fs/bpf/maps.debug
Error: incorrect object type: unknown
After:
$ bpftool map show pinned /sys/fs/bpf/maps.debug
Error: incorrect object type: link
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20220629154832.56986-5-laoar.shao@gmail.com
Now that bpftool is able to produce a list of known program, map, attach
types, let's use as much of this as we can in the bash completion file,
so that we don't have to expand the list each time a new type is added
to the kernel.
Also update the relevant test script to remove some checks that are no
longer needed.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Müller <deso@posteo.net>
Link: https://lore.kernel.org/bpf/20220629203637.138944-3-quentin@isovalent.com
Add a "bpftool feature list" subcommand to list BPF "features".
Contrarily to "bpftool feature probe", this is not about the features
available on the system. Instead, it lists all features known to bpftool
from compilation time; in other words, all program, map, attach, link
types known to the libbpf version in use, and all helpers found in the
UAPI BPF header.
The first use case for this feature is bash completion: running the
command provides a list of types that can be used to produce the list of
candidate map types, for example.
Now that bpftool uses "standard" names provided by libbpf for the
program, map, link, and attach types, having the ability to list these
types and helpers could also be useful in scripts to loop over existing
items.
Sample output:
# bpftool feature list prog_types | grep -vw unspec | head -n 6
socket_filter
kprobe
sched_cls
sched_act
tracepoint
xdp
# bpftool -p feature list map_types | jq '.[1]'
"hash"
# bpftool feature list attach_types | grep '^cgroup_'
cgroup_inet_ingress
cgroup_inet_egress
[...]
cgroup_inet_sock_release
# bpftool feature list helpers | grep -vw bpf_unspec | wc -l
207
The "unspec" types and helpers are not filtered out by bpftool, so as to
remain closer to the enums, and to preserve the indices in the JSON
arrays (e.g. "hash" at index 1 == BPF_MAP_TYPE_HASH in map types list).
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Müller <deso@posteo.net>
Link: https://lore.kernel.org/bpf/20220629203637.138944-2-quentin@isovalent.com
The attach_type_name definition was removed in commit 1ba5ad36e0
("bpftool: Use libbpf_bpf_attach_type_str"). Remove its forward
declaration in main.h as well.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20220630093638.25916-1-tklauser@distanz.ch
Bpftool used to bump the memlock rlimit to make sure to be able to load
BPF objects. After the kernel has switched to memcg-based memory
accounting [0] in 5.11, bpftool has relied on libbpf to probe the system
for memcg-based accounting support and for raising the rlimit if
necessary [1]. But this was later reverted, because the probe would
sometimes fail, resulting in bpftool not being able to load all required
objects [2].
Here we add a more efficient probe, in bpftool itself. We first lower
the rlimit to 0, then we attempt to load a BPF object (and finally reset
the rlimit): if the load succeeds, then memcg-based memory accounting is
supported.
This approach was earlier proposed for the probe in libbpf itself [3],
but given that the library may be used in multithreaded applications,
the probe could have undesirable consequences if one thread attempts to
lock kernel memory while memlock rlimit is at 0. Since bpftool is
single-threaded and the rlimit is process-based, this is fine to do in
bpftool itself.
This probe was inspired by the similar one from the cilium/ebpf Go
library [4].
[0] commit 97306be45f ("Merge branch 'switch to memcg-based memory accounting'")
[1] commit a777e18f1b ("bpftool: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK")
[2] commit 6b4384ff10 ("Revert "bpftool: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK"")
[3] https://lore.kernel.org/bpf/20220609143614.97837-1-quentin@isovalent.com/t/#u
[4] https://github.com/cilium/ebpf/blob/v0.9.0/rlimit/rlimit.go#L39
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/bpf/20220629111351.47699-1-quentin@isovalent.com
The function always returns 0, so we don't need to check whether the
return value is 0 or not.
This change was first introduced in commit a777e18f1b ("bpftool: Use
libbpf 1.0 API mode instead of RLIMIT_MEMLOCK"), but later reverted to
restore the unconditional rlimit bump in bpftool. Let's re-add it.
Co-developed-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220610112648.29695-3-quentin@isovalent.com
This reverts commit a777e18f1b.
In commit a777e18f1b ("bpftool: Use libbpf 1.0 API mode instead of
RLIMIT_MEMLOCK"), we removed the rlimit bump in bpftool, because the
kernel has switched to memcg-based memory accounting. Thanks to the
LIBBPF_STRICT_AUTO_RLIMIT_MEMLOCK, we attempted to keep compatibility
with other systems and ask libbpf to raise the limit for us if
necessary.
How do we know if memcg-based accounting is supported? There is a probe
in libbpf to check this. But this probe currently relies on the
availability of a given BPF helper, bpf_ktime_get_coarse_ns(), which
landed in the same kernel version as the memory accounting change. This
works in the generic case, but it may fail, for example, if the helper
function has been backported to an older kernel. This has been observed
for Google Cloud's Container-Optimized OS (COS), where the helper is
available but rlimit is still in use. The probe succeeds, the rlimit is
not raised, and probing features with bpftool, for example, fails.
A patch was submitted [0] to update this probe in libbpf, based on what
the cilium/ebpf Go library does [1]. It would lower the soft rlimit to
0, attempt to load a BPF object, and reset the rlimit. But it may induce
some hard-to-debug flakiness if another process starts, or the current
application is killed, while the rlimit is reduced, and the approach was
discarded.
As a workaround to ensure that the rlimit bump does not depend on the
availability of a given helper, we restore the unconditional rlimit bump
in bpftool for now.
[0] https://lore.kernel.org/bpf/20220609143614.97837-1-quentin@isovalent.com/
[1] https://github.com/cilium/ebpf/blob/v0.9.0/rlimit/rlimit.go#L39
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Yafang Shao <laoar.shao@gmail.com>
Cc: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20220610112648.29695-2-quentin@isovalent.com
This change adjusts the Makefile to use "HOSTAR" as the archive tool
to keep the sanity of the build process for the bootstrap part in
check. For the rationale, please continue reading.
When cross compiling bpftool with buildroot, it leads to an invocation
like:
$ AR="/path/to/buildroot/host/bin/arc-linux-gcc-ar" \
CC="/path/to/buildroot/host/bin/arc-linux-gcc" \
...
make
Which in return fails while building the bootstrap section:
----------------------------------8<----------------------------------
make: Entering directory '/src/bpftool-v6.7.0/src'
... libbfd: [ on ]
... disassembler-four-args: [ on ]
... zlib: [ on ]
... libcap: [ OFF ]
... clang-bpf-co-re: [ on ] <-- triggers bootstrap
.
.
.
LINK /src/bpftool-v6.7.0/src/bootstrap/bpftool
/usr/bin/ld: /src/bpftool-v6.7.0/src/bootstrap/libbpf/libbpf.a:
error adding symbols: archive has no index; run ranlib
to add one
collect2: error: ld returned 1 exit status
make: *** [Makefile:211: /src/bpftool-v6.7.0/src/bootstrap/bpftool]
Error 1
make: *** Waiting for unfinished jobs....
AR /src/bpftool-v6.7.0/src/libbpf/libbpf.a
make[1]: Leaving directory '/src/bpftool-v6.7.0/libbpf/src'
make: Leaving directory '/src/bpftool-v6.7.0/src'
---------------------------------->8----------------------------------
This occurs because setting "AR" confuses the build process for the
bootstrap section and it calls "arc-linux-gcc-ar" to create and index
"libbpf.a" instead of the host "ar".
Signed-off-by: Shahab Vahedi <shahab@synopsys.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/bpf/8d297f0c-cfd0-ef6f-3970-6dddb3d9a87a@synopsys.com
Add BTF_KIND_ENUM64 support.
For example, the following enum is defined in uapi bpf.h.
$ cat core.c
enum A {
BPF_F_INDEX_MASK = 0xffffffffULL,
BPF_F_CURRENT_CPU = BPF_F_INDEX_MASK,
BPF_F_CTXLEN_MASK = (0xfffffULL << 32),
} g;
Compiled with
clang -target bpf -O2 -g -c core.c
Using bpftool to dump types and generate format C file:
$ bpftool btf dump file core.o
...
[1] ENUM64 'A' encoding=UNSIGNED size=8 vlen=3
'BPF_F_INDEX_MASK' val=4294967295ULL
'BPF_F_CURRENT_CPU' val=4294967295ULL
'BPF_F_CTXLEN_MASK' val=4503595332403200ULL
$ bpftool btf dump file core.o format c
...
enum A {
BPF_F_INDEX_MASK = 4294967295ULL,
BPF_F_CURRENT_CPU = 4294967295ULL,
BPF_F_CTXLEN_MASK = 4503595332403200ULL,
};
...
Note that for raw btf output, the encoding (UNSIGNED or SIGNED)
is printed out as well. The 64bit value is also represented properly
in BTF and C dump.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20220607062652.3722649-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf_object__btf() can return a NULL value. If bpf_object__btf returns
null, do not progress through codegen_asserts(). This avoids a null ptr
dereference at the call btf__type_cnt() in the function find_type_for_map()
Signed-off-by: Michael Mullin <masmullin@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220523194917.igkgorco42537arb@jup
This change switches bpftool over to using the recently introduced
libbpf_bpf_link_type_str function instead of maintaining its own string
representation for the bpf_link_type enum.
Signed-off-by: Daniel Müller <deso@posteo.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220523230428.3077108-13-deso@posteo.net
This change switches bpftool over to using the recently introduced
libbpf_bpf_attach_type_str function instead of maintaining its own
string representation for the bpf_attach_type enum.
Note that contrary to other enum types, the variant names that bpftool
maps bpf_attach_type to do not adhere a simple to follow rule. With
bpf_prog_type, for example, the textual representation can easily be
inferred by stripping the BPF_PROG_TYPE_ prefix and lowercasing the
remaining string. bpf_attach_type violates this rule for various
variants.
We decided to fix up this deficiency with this change, meaning that
bpftool uses the same textual representations as libbpf. Supporting
tests, completion scripts, and man pages have been adjusted accordingly.
However, we did add support for accepting (the now undocumented)
original attach type names when they are provided by users.
For the test (test_bpftool_synctypes.py), I have removed the enum
representation checks, because we no longer mirror the various enum
variant names in bpftool source code. For the man page, help text, and
completion script checks we are now using enum definitions from
uapi/linux/bpf.h as the source of truth directly.
Signed-off-by: Daniel Müller <deso@posteo.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20220523230428.3077108-10-deso@posteo.net
This change switches bpftool over to using the recently introduced
libbpf_bpf_map_type_str function instead of maintaining its own string
representation for the bpf_map_type enum.
Signed-off-by: Daniel Müller <deso@posteo.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20220523230428.3077108-7-deso@posteo.net
This change switches bpftool over to using the recently introduced
libbpf_bpf_prog_type_str function instead of maintaining its own string
representation for the bpf_prog_type enum.
Signed-off-by: Daniel Müller <deso@posteo.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20220523230428.3077108-4-deso@posteo.net
Currently, dumping almost all BTFs specified by id requires
using the -B option to pass the base BTF. For kernel module
BTFs the vmlinux BTF sysfs path should work.
This patch simplifies dumping by ID usage by loading
vmlinux BTF from sysfs as base, if base BTF was not specified
and the ID corresponds to a kernel module BTF.
Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Link: https://lore.kernel.org/bpf/20220513121743.12411-1-larysa.zaremba@intel.com
Replace struct bpf_tramp_progs with struct bpf_tramp_links to collect
struct bpf_tramp_link(s) for a trampoline. struct bpf_tramp_link
extends bpf_link to act as a linked list node.
arch_prepare_bpf_trampoline() accepts a struct bpf_tramp_links to
collects all bpf_tramp_link(s) that a trampoline should call.
Change BPF trampoline and bpf_struct_ops to pass bpf_tramp_links
instead of bpf_tramp_progs.
Signed-off-by: Kui-Feng Lee <kuifeng@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220510205923.3206889-2-kuifeng@fb.com
bpf_link_get_from_fd currently returns a NULL fd for LSM programs.
LSM programs are similar to tracing programs and can also use
skel_raw_tracepoint_open.
Signed-off-by: KP Singh <kpsingh@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220509214905.3754984-1-kpsingh@kernel.org
Currently in libbpf, we have hardcoded program types that are not
supported for helper function probing (e.g. tracing, ext, lsm).
Due to this (and other legitimate failures), bpftool feature probe returns
empty for those program type helper functions.
Instead of implying to the user that there are no helper functions
available for a program type, we output a message to the user explaining
that helper function probing failed for that program type.
Signed-off-by: Milan Landaverde <milan@mdaverde.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220504161356.3497972-3-milan@mdaverde.com
musl nftw implementation does not support FTW_ACTIONRETVAL. There have been
multiple attempts at pushing the feature in musl upstream, but it has been
refused or ignored all the times:
https://www.openwall.com/lists/musl/2021/03/26/1https://www.openwall.com/lists/musl/2022/01/22/1
In this case we only care about /proc/<pid>/fd/<fd>, so it's not too difficult
to reimplement directly instead, and the new implementation makes 'bpftool perf'
slightly faster because it doesn't needlessly stat/readdir unneeded directories
(54ms -> 13ms on my machine).
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20220424051022.2619648-4-asmadeus@codewreck.org
We have switched to memcg-based memory accouting and thus the rlimit is
not needed any more. LIBBPF_STRICT_AUTO_RLIMIT_MEMLOCK was introduced in
libbpf for backward compatibility, so we can use it instead now.
libbpf_set_strict_mode always return 0, so we don't need to check whether
the return value is 0 or not.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220409125958.92629-4-laoar.shao@gmail.com
Daniel Borkmann says:
====================
pull-request: bpf-next 2022-04-09
We've added 63 non-merge commits during the last 9 day(s) which contain
a total of 68 files changed, 4852 insertions(+), 619 deletions(-).
The main changes are:
1) Add libbpf support for USDT (User Statically-Defined Tracing) probes.
USDTs are an abstraction built on top of uprobes, critical for tracing
and BPF, and widely used in production applications, from Andrii Nakryiko.
2) While Andrii was adding support for x86{-64}-specific logic of parsing
USDT argument specification, Ilya followed-up with USDT support for s390
architecture, from Ilya Leoshkevich.
3) Support name-based attaching for uprobe BPF programs in libbpf. The format
supported is `u[ret]probe/binary_path:[raw_offset|function[+offset]]`, e.g.
attaching to libc malloc can be done in BPF via SEC("uprobe/libc.so.6:malloc")
now, from Alan Maguire.
4) Various load/store optimizations for the arm64 JIT to shrink the image
size by using arm64 str/ldr immediate instructions. Also enable pointer
authentication to verify return address for JITed code, from Xu Kuohai.
5) BPF verifier fixes for write access checks to helper functions, e.g.
rd-only memory from bpf_*_cpu_ptr() must not be passed to helpers that
write into passed buffers, from Kumar Kartikeya Dwivedi.
6) Fix overly excessive stack map allocation for its base map structure and
buckets which slipped-in from cleanups during the rlimit accounting removal
back then, from Yuntao Wang.
7) Extend the unstable CT lookup helpers for XDP and tc/BPF to report netfilter
connection tracking tuple direction, from Lorenzo Bianconi.
8) Improve bpftool dump to show BPF program/link type names, Milan Landaverde.
9) Minor cleanups all over the place from various others.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (63 commits)
bpf: Fix excessive memory allocation in stack_map_alloc()
selftests/bpf: Fix return value checks in perf_event_stackmap test
selftests/bpf: Add CO-RE relos into linked_funcs selftests
libbpf: Use weak hidden modifier for USDT BPF-side API functions
libbpf: Don't error out on CO-RE relos for overriden weak subprogs
samples, bpf: Move routes monitor in xdp_router_ipv4 in a dedicated thread
libbpf: Allow WEAK and GLOBAL bindings during BTF fixup
libbpf: Use strlcpy() in path resolution fallback logic
libbpf: Add s390-specific USDT arg spec parsing logic
libbpf: Make BPF-side of USDT support work on big-endian machines
libbpf: Minor style improvements in USDT code
libbpf: Fix use #ifdef instead of #if to avoid compiler warning
libbpf: Potential NULL dereference in usdt_manager_attach_usdt()
selftests/bpf: Uprobe tests should verify param/return values
libbpf: Improve string parsing for uprobe auto-attach
libbpf: Improve library identification for uprobe binary path resolution
selftests/bpf: Test for writes to map key from BPF helpers
selftests/bpf: Test passing rdonly mem to global func
bpf: Reject writes for PTR_TO_MAP_KEY in check_helper_mem_access
bpf: Check PTR_TO_MEM | MEM_RDONLY in check_helper_mem_access
...
====================
Link: https://lore.kernel.org/r/20220408231741.19116-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In addition to displaying the program type in bpftool prog show
this enables us to be able to query bpf_prog_type_syscall
availability through feature probe as well as see
which helpers are available in those programs (such as
bpf_sys_bpf and bpf_sys_close)
Signed-off-by: Milan Landaverde <milan@mdaverde.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20220331154555.422506-2-milan@mdaverde.com
- Add new environment variables, USERCFLAGS and USERLDFLAGS to allow
additional flags to be passed to user-space programs.
- Fix missing fflush() bugs in Kconfig and fixdep
- Fix a minor bug in the comment format of the .config file
- Make kallsyms ignore llvm's local labels, .L*
- Fix UAPI compile-test for cross-compiling with Clang
- Extend the LLVM= syntax to support LLVM=<suffix> form for using a
particular version of LLVm, and LLVM=<prefix> form for using custom
LLVM in a particular directory path.
- Clean up Makefiles
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Merge tag 'kbuild-v5.18-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- Add new environment variables, USERCFLAGS and USERLDFLAGS to allow
additional flags to be passed to user-space programs.
- Fix missing fflush() bugs in Kconfig and fixdep
- Fix a minor bug in the comment format of the .config file
- Make kallsyms ignore llvm's local labels, .L*
- Fix UAPI compile-test for cross-compiling with Clang
- Extend the LLVM= syntax to support LLVM=<suffix> form for using a
particular version of LLVm, and LLVM=<prefix> form for using custom
LLVM in a particular directory path.
- Clean up Makefiles
* tag 'kbuild-v5.18-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: Make $(LLVM) more flexible
kbuild: add --target to correctly cross-compile UAPI headers with Clang
fixdep: use fflush() and ferror() to ensure successful write to files
arch: syscalls: simplify uapi/kapi directory creation
usr/include: replace extra-y with always-y
certs: simplify empty certs creation in certs/Makefile
certs: include certs/signing_key.x509 unconditionally
kallsyms: ignore all local labels prefixed by '.L'
kconfig: fix missing '# end of' for empty menu
kconfig: add fflush() before ferror() check
kbuild: replace $(if A,A,B) with $(or A,B)
kbuild: Add environment variables for userprogs flags
kbuild: unify cmd_copy and cmd_shipped
Andrii noticed that since f97b8b9bd6 ("bpftool: Fix a bug in subskeleton
code generation") the subskeleton code allows bpf_object__destroy_subskeleton
to overwrite the errno that subskeleton__open would return with. While this
is not currently an issue, let's make it future-proof.
This patch explicitly tracks err in subskeleton__open and skeleton__create
(i.e. calloc failure is explicitly ENOMEM) and ensures that errno is -err on
the error return path. The skeleton code had to be changed since maps and
progs codegen is shared with subskeletons.
Fixes: f97b8b9bd6 ("bpftool: Fix a bug in subskeleton code generation")
Signed-off-by: Delyan Kratunov <delyank@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/3b6bfbb770c79ae64d8de26c1c1bd9d53a4b85f8.camel@fb.com
Arnaldo reported perf compilation fail with:
$ make -k BUILD_BPF_SKEL=1 CORESIGHT=1 PYTHON=python3
...
In file included from util/bpf_counter.c:28:
/tmp/build/perf//util/bpf_skel/bperf_leader.skel.h: In function ‘bperf_leader_bpf__assert’:
/tmp/build/perf//util/bpf_skel/bperf_leader.skel.h:351:51: error: unused parameter ‘s’ [-Werror=unused-parameter]
351 | bperf_leader_bpf__assert(struct bperf_leader_bpf *s)
| ~~~~~~~~~~~~~~~~~~~~~~~~~^
cc1: all warnings being treated as errors
If there's nothing to generate in the new assert function,
we will get unused 's' warn/error, adding 'unused' attribute to it.
Fixes: 08d4dba6ae ("bpftool: Bpf skeletons assert type sizes")
Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/bpf/20220328083703.2880079-1-jolsa@kernel.org
Compiled with clang by adding LLVM=1 both kernel and selftests/bpf
build, I hit the following compilation error:
In file included from /.../tools/testing/selftests/bpf/prog_tests/subskeleton.c:6:
./test_subskeleton_lib.subskel.h:168:6: error: variable 'err' is used uninitialized whenever
'if' condition is true [-Werror,-Wsometimes-uninitialized]
if (!s->progs)
^~~~~~~~~
./test_subskeleton_lib.subskel.h:181:11: note: uninitialized use occurs here
errno = -err;
^~~
./test_subskeleton_lib.subskel.h:168:2: note: remove the 'if' if its condition is always false
if (!s->progs)
^~~~~~~~~~~~~~
The compilation error is triggered by the following code
...
int err;
obj = (struct test_subskeleton_lib *)calloc(1, sizeof(*obj));
if (!obj) {
errno = ENOMEM;
goto err;
}
...
err:
test_subskeleton_lib__destroy(obj);
errno = -err;
...
in test_subskeleton_lib__open(). The 'err' is not initialized, yet it
is used in 'errno = -err' later.
The fix is to remove 'errno = -err' since errno has been set properly
in all incoming branches.
Fixes: 00389c58ff ("bpftool: Add support for subskeletons")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220320032009.3106133-1-yhs@fb.com
If there is no btf_id or frozen, it will not show the pids, but the pids don't
depend on any one of them.
Below is the result after this change:
$ ./bpftool map show
2: lpm_trie flags 0x1
key 8B value 8B max_entries 1 memlock 4096B
pids systemd(1)
3: lpm_trie flags 0x1
key 20B value 8B max_entries 1 memlock 4096B
pids systemd(1)
While before this change, the 'pids systemd(1)' can't be displayed.
Fixes: 9330986c03 ("bpf: Add bloom filter map implementation")
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220320060815.7716-1-laoar.shao@gmail.com
BPF_TRACE_KPROBE_MULTI is a new attach type name, add it to bpftool's
table. This fixes a currently failing CI bpftool check.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220318150106.2933343-1-andrii@kernel.org
Subskeletons are headers which require an already loaded program to
operate.
For example, when a BPF library is linked into a larger BPF object file,
the library userspace needs a way to access its own global variables
without requiring knowledge about the larger program at build time.
As a result, subskeletons require a loaded bpf_object to open().
Further, they find their own symbols in the larger program by
walking BTF type data at run time.
At this time, programs, maps, and globals are supported through
non-owning pointers.
Signed-off-by: Delyan Kratunov <delyank@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/ca8a48b4841c72d285ecce82371bef4a899756cb.1647473511.git.delyank@fb.com
The top-level (bpftool.8) man page was missing docs for a few
subcommands and their respective sub-sub-commands.
This commit brings the top level man page up to date. Note that I've
kept the ordering of the subcommands the same as in `bpftool help`.
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/3049ef5dc509c0d1832f0a8b2dba2ccaad0af688.1647213551.git.dxu@dxuuu.xyz
Commit 82e6b1eee6 ("bpf: Allow to specify user-provided bpf_cookie for
BPF perf links") introduced the concept of user specified bpf_cookie,
which could be accessed by BPF programs using bpf_get_attach_cookie().
For troubleshooting purposes it is convenient to expose bpf_cookie via
bpftool as well, so there is no need to meddle with the target BPF
program itself.
Implemented using the pid iterator BPF program to actually fetch
bpf_cookies, which allows constraining code changes only to bpftool.
$ bpftool link
1: type 7 prog 5
bpf_cookie 123
pids bootstrap(81)
Signed-off-by: Dmitrii Dolgov <9erthalion6@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20220309163112.24141-1-9erthalion6@gmail.com
If a BPF map is created over 2^32 the memlock value as displayed in JSON
format will be incorrect. Use atoll instead of atoi so that the correct
number is displayed.
```
$ bpftool map create /sys/fs/bpf/test_bpfmap type hash key 4 \
value 1024 entries 4194304 name test_bpfmap
$ bpftool map list
1: hash name test_bpfmap flags 0x0
key 4B value 1024B max_entries 4194304 memlock 4328521728B
$ sudo bpftool map list -j | jq .[].bytes_memlock
33554432
```
Signed-off-by: Chris J Arges <carges@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/b6601087-0b11-33cc-904a-1133d1500a10@cloudflare.com
Commit 1a56c18e6c ("bpftool: Stop supporting BPF offload-enabled
feature probing") removed the support to probe for BPF offload features.
This is still something that is useful for NFP NIC that can support
offloading of BPF programs.
The reason for the dropped support was that libbpf starting with v1.0
would drop support for passing the ifindex to the BPF prog/map/helper
feature probing APIs. In order to keep this useful feature for NFP
restore the functionality by moving it directly into bpftool.
The code restored is a simplified version of the code that existed in
libbpf which supposed passing the ifindex. The simplification is that it
only targets the cases where ifindex is given and call into libbpf for
the cases where it's not.
Before restoring support for probing offload features:
# bpftool feature probe dev ens4np0
Scanning system call availability...
bpf() syscall is available
Scanning eBPF program types...
Scanning eBPF map types...
Scanning eBPF helper functions...
eBPF helpers supported for program type sched_cls:
eBPF helpers supported for program type xdp:
Scanning miscellaneous eBPF features...
Large program size limit is NOT available
Bounded loop support is NOT available
ISA extension v2 is NOT available
ISA extension v3 is NOT available
With support for probing offload features restored:
# bpftool feature probe dev ens4np0
Scanning system call availability...
bpf() syscall is available
Scanning eBPF program types...
eBPF program_type sched_cls is available
eBPF program_type xdp is available
Scanning eBPF map types...
eBPF map_type hash is available
eBPF map_type array is available
Scanning eBPF helper functions...
eBPF helpers supported for program type sched_cls:
- bpf_map_lookup_elem
- bpf_get_prandom_u32
- bpf_perf_event_output
eBPF helpers supported for program type xdp:
- bpf_map_lookup_elem
- bpf_get_prandom_u32
- bpf_perf_event_output
- bpf_xdp_adjust_head
- bpf_xdp_adjust_tail
Scanning miscellaneous eBPF features...
Large program size limit is NOT available
Bounded loop support is NOT available
ISA extension v2 is NOT available
ISA extension v3 is NOT available
Signed-off-by: Niklas Söderlund <niklas.soderlund@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20220310121846.921256-1-niklas.soderlund@corigine.com
Because the OUTPUT variable ends with a slash but CURDIR doesn't, to keep
the _OUTPUT value consistent, we add a trailing slash to CURDIR when
defining _OUTPUT variable.
Since the _OUTPUT variable holds a value ending with a trailing slash,
there is no need to add another one when defining BOOTSTRAP_OUTPUT and
LIBBPF_OUTPUT variables. Likewise, when defining LIBBPF_INCLUDE and
LIBBPF_BOOTSTRAP_INCLUDE, we shouldn't add an extra slash either for the
same reason.
When building libbpf, the value of the DESTDIR argument should also not
end with a trailing slash.
Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20220226163815.520133-1-ytcoode@gmail.com
When emitting type declarations in skeletons, bpftool will now also emit
static assertions on the size of the data/bss/rodata/etc fields. This
ensures that in situations where userspace and kernel types have the same
name but differ in size we do not silently produce incorrect results but
instead break the build.
This was reported in [1] and as expected the repro in [2] fails to build
on the new size assert after this change.
[1]: Closes: https://github.com/libbpf/libbpf/issues/433
[2]: https://github.com/fuweid/iovisor-bcc-pr-3777
Signed-off-by: Delyan Kratunov <delyank@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Hengqi Chen <hengqi.chen@gmail.com>
Acked-by: Hengqi Chen <hengqi.chen@gmail.com>
Link: https://lore.kernel.org/bpf/f562455d7b3cf338e59a7976f4690ec5a0057f7f.camel@fb.com
