Modify several functions in tools/bpf/bpftool/common.c to allow
specification of requested access for file descriptors, such as
read-only access.
Update bpftool to request only read access for maps when write
access is not required. This fixes errors when reading from maps
that are protected from modification via security_bpf_map.
Signed-off-by: Slava Imameev <slava.imameev@crowdstrike.com>
Reviewed-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/r/20250620151812.13952-1-slava.imameev@crowdstrike.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The size of struct bpf_map::name is BPF_OBJ_NAME_LEN (16).
bpf(2) {
map_create() {
bpf_obj_name_cpy(map->name, attr->map_name, sizeof(attr->map_name));
}
}
When specifying a map name using bpftool map create name, no error is
reported if the name length is greater than 15.
$ sudo bpftool map create /sys/fs/bpf/12345678901234567890 \
type array key 4 value 4 entries 5 name 12345678901234567890
Users will think that 12345678901234567890 is legal, but this name cannot
be used to index a map.
$ sudo bpftool map show name 12345678901234567890
Error: can't parse name
$ sudo bpftool map show
...
1249: array name 123456789012345 flags 0x0
key 4B value 4B max_entries 5 memlock 304B
$ sudo bpftool map show name 123456789012345
1249: array name 123456789012345 flags 0x0
key 4B value 4B max_entries 5 memlock 304B
The map name provided in the command line is truncated, but no warning is
reported. This submission checks the length of the map name.
Reviewed-by: Quentin Monnet <qmo@kernel.org>
Signed-off-by: Rong Tao <rongtao@cestc.cn>
Link: https://lore.kernel.org/r/tencent_B44B3A95F0D7C2512DC40D831DA1FA2C9907@qq.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add ability to specify a network interface used to resolve XDP hints
kfuncs when loading program through bpftool.
Usage:
bpftool prog load [...] xdpmeta_dev <ifname>
Writing just 'dev <ifname>' instead of 'xdpmeta_dev' is a very probable
mistake that results in not very descriptive errors,
so 'bpftool prog load [...] dev <ifname>' syntax becomes deprecated,
followed by 'bpftool map create [...] dev <ifname>' for consistency.
Now, to offload program, execute:
bpftool prog load [...] offload_dev <ifname>
To offload map:
bpftool map create [...] offload_dev <ifname>
'dev <ifname>' still performs offloading in the commands above, but now
triggers a warning and is excluded from bash completion.
'xdpmeta_dev' and 'offload_dev' are mutually exclusive options, because
'xdpmeta_dev' basically makes a program device-bound without loading it
onto the said device. For now, offloaded programs cannot use XDP hints [0],
but if this changes, using 'offload_dev <ifname>' should cover this case.
[0] https://lore.kernel.org/bpf/a5a636cc-5b03-686f-4be0-000383b05cfc@linux.dev
Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20230517160103.1088185-1-larysa.zaremba@intel.com
When using `bpftool map dump` with map_of_maps, it is usually
more convenient to show the inner map id instead of raw value.
We are changing the plain print behavior to show inner_map_id
instead of hex value, this would help with quick look up of
inner map with `bpftool map dump id <inner_map_id>`.
To avoid disrupting scripted behavior, we will add a new
`inner_map_id` field to json output instead of replacing value.
plain print:
```
$ bpftool map dump id 138
Without Patch:
key:
fc 00 00 00 00 00 00 00 00 00 00 00 00 00 00 05
27 16 06 00
value:
8b 00 00 00
Found 1 element
With Patch:
key:
fc 00 00 00 00 00 00 00 00 00 00 00 00 00 00 05
27 16 06 00
inner_map_id:
139
Found 1 element
```
json print:
```
$ bpftool -p map dump id 567
Without Patch:
[{
"key": ["0xc0","0x00","0x02","0x05","0x27","0x16","0x06","0x00"
],
"value": ["0x38","0x02","0x00","0x00"
]
}
]
With Patch:
[{
"key": ["0xc0","0x00","0x02","0x05","0x27","0x16","0x06","0x00"
],
"value": ["0x38","0x02","0x00","0x00"
],
"inner_map_id": 568
}
]
```
Signed-off-by: Xueming Feng <kuro@kuroa.me>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20230427120313.43574-1-kuro@kuroa.me
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Use the new type-safe wrappers around bpf_obj_get_info_by_fd().
Split the bpf_obj_get_info_by_fd() call in build_btf_type_table() in
two, since knowing the type helps with the Memory Sanitizer.
Improve map_parse_fd_and_info() type safety by using
struct bpf_map_info * instead of void * for info.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20230214231221.249277-4-iii@linux.ibm.com
bpftool is now totally compliant with libbpf 1.0 mode and is not
expected to be compiled with pre-1.0, let's clean-up the usage of
libbpf_get_error().
The changes stay aligned with returned errors always negative.
- In tools/bpf/bpftool/btf.c This fixes an uninitialized local
variable `err` in function do_dump() because it may now be returned
without having been set.
- This also removes the checks on NULL pointers before calling
btf__free() because that function already does the check.
Signed-off-by: Sahid Orentino Ferdjaoui <sahid.ferdjaoui@industrialdiscipline.com>
Link: https://lore.kernel.org/r/20221120112515.38165-5-sahid.ferdjaoui@industrialdiscipline.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
An update for libbpf's hashmap interface from void* -> void* to a
polymorphic one, allowing both long and void* keys and values.
This simplifies many use cases in libbpf as hashmaps there are mostly
integer to integer.
Perf copies hashmap implementation from libbpf and has to be
updated as well.
Changes to libbpf, selftests/bpf and perf are packed as a single
commit to avoid compilation issues with any future bisect.
Polymorphic interface is acheived by hiding hashmap interface
functions behind auxiliary macros that take care of necessary
type casts, for example:
#define hashmap_cast_ptr(p) \
({ \
_Static_assert((p) == NULL || sizeof(*(p)) == sizeof(long),\
#p " pointee should be a long-sized integer or a pointer"); \
(long *)(p); \
})
bool hashmap_find(const struct hashmap *map, long key, long *value);
#define hashmap__find(map, key, value) \
hashmap_find((map), (long)(key), hashmap_cast_ptr(value))
- hashmap__find macro casts key and value parameters to long
and long* respectively
- hashmap_cast_ptr ensures that value pointer points to a memory
of appropriate size.
This hack was suggested by Andrii Nakryiko in [1].
This is a follow up for [2].
[1] https://lore.kernel.org/bpf/CAEf4BzZ8KFneEJxFAaNCCFPGqp20hSpS2aCj76uRk3-qZUH5xg@mail.gmail.com/
[2] https://lore.kernel.org/bpf/af1facf9-7bc8-8a3d-0db4-7b3f333589a2@meta.com/T/#m65b28f1d6d969fcd318b556db6a3ad499a42607d
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221109142611.879983-2-eddyz87@gmail.com
The JIT disassembler in bpftool is the only components (with the JSON
writer) using asserts to check the return values of functions. But it
does not do so in a consistent way, and diasm_print_insn() returns no
value, although sometimes the operation failed.
Remove the asserts, and instead check the return values, print messages
on errors, and propagate the error to the caller from prog.c.
Remove the inclusion of assert.h from jit_disasm.c, and also from map.c
where it is unused.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Tested-by: Niklas Söderlund <niklas.soderlund@corigine.com>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20221025150329.97371-3-quentin@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
We want to support a ringbuf map type where samples are published from
user-space, to be consumed by BPF programs. BPF currently supports a
kernel -> user-space circular ring buffer via the BPF_MAP_TYPE_RINGBUF
map type. We'll need to define a new map type for user-space -> kernel,
as none of the helpers exported for BPF_MAP_TYPE_RINGBUF will apply
to a user-space producer ring buffer, and we'll want to add one or
more helper functions that would not apply for a kernel-producer
ring buffer.
This patch therefore adds a new BPF_MAP_TYPE_USER_RINGBUF map type
definition. The map type is useless in its current form, as there is no
way to access or use it for anything until we one or more BPF helpers. A
follow-on patch will therefore add a new helper function that allows BPF
programs to run callbacks on samples that are published to the ring
buffer.
Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220920000100.477320-2-void@manifault.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
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
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
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
When reworking btf__get_from_id() in commit a19f93cfaf the error
handling when calling bpf_btf_get_fd_by_id() changed. Before the rework
if bpf_btf_get_fd_by_id() failed the error would not be propagated to
callers of btf__get_from_id(), after the rework it is. This lead to a
change in behavior in print_key_value() that now prints an error when
trying to lookup keys in maps with no btf available.
Fix this by following the way used in dumping maps to allow to look up
keys in no-btf maps, by which it decides whether and where to get the
btf info according to the btf value type.
Fixes: a19f93cfaf ("libbpf: Add internal helper to load BTF data by FD")
Signed-off-by: Yinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund@corigine.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/1644249625-22479-1-git-send-email-yinjun.zhang@corigine.com
hashmap__new() encodes errors with ERR_PTR(), hence it's not valid to
check the returned pointer against NULL and IS_ERR() has to be used
instead.
libbpf_get_error() can't be used in this case as hashmap__new() is not
part of the public libbpf API and it'll continue using ERR_PTR() after
libbpf 1.0.
Fixes: 8f184732b6 ("bpftool: Switch to libbpf's hashmap for pinned paths of BPF objects")
Fixes: 2828d0d75b ("bpftool: Switch to libbpf's hashmap for programs/maps in BTF listing")
Fixes: d6699f8e0f ("bpftool: Switch to libbpf's hashmap for PIDs/names references")
Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20220107152620.192327-2-mauricio@kinvolk.io
Currently, LIBBPF_STRICT_ALL mode is enabled by default for
bpftool which means on error cases, some libbpf APIs would
return NULL pointers. This makes IS_ERR check failed to detect
such cases and result in segfault error. Use libbpf_get_error()
instead like we do in libbpf itself.
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211115012436.3143318-1-hengqi.chen@gmail.com
