bpftool: Specify XDP Hints ifname when loading program

Add ability to specify a network interface used to resolve XDP hints
kfuncs when loading program through bpftool.

Usage:

bpftool prog load

bpftool: Specify XDP Hints ifname when loading program

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

show more ...

bpftool: Dump map id instead of value for map_of_maps types

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 chang

bpftool: Dump map id instead of value for map_of_maps types

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>

show more ...

bpftool: Use bpf_{btf,link,map,prog}_get_info_by_fd()

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

bpftool: Use bpf_{btf,link,map,prog}_get_info_by_fd()

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

show more ...

bpftool: remove function free_btf_vmlinux()

The function contains a single btf__free() call which can be
inlined. Credits to Yonghong Song.

Signed-off-by: Sahid Orentino Ferdjaoui <sahid.ferdjaoui@

bpftool: remove function free_btf_vmlinux()

The function contains a single btf__free() call which can be
inlined. Credits to Yonghong Song.

Signed-off-by: Sahid Orentino Ferdjaoui <sahid.ferdjaoui@industrialdiscipline.com>
Acked-by: Yonghong Song <yhs@fb.com>
Suggested-by: Yonghong Song <yhs@fb.com>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/r/20221120112515.38165-6-sahid.ferdjaoui@industrialdiscipline.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

show more ...

bpftool: clean-up usage of libbpf_get_error()

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().

bpftool: clean-up usage of libbpf_get_error()

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>

show more ...

libbpf: Hashmap interface update to allow both long and void* keys/values

An update for libbpf's hashmap interface from void* -> void* to a
polymorphic one, allowing both long and void* keys and val

libbpf: Hashmap interface update to allow both long and void* keys/values

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

show more ...

bpftool: Support new cgroup local storage

Add support for new cgroup local storage

Acked-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kern

bpftool: Support new cgroup local storage

Add support for new cgroup local storage

Acked-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221026042901.674177-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

show more ...

bpftool: Remove asserts from JIT disassembler

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

bpftool: Remove asserts from JIT disassembler

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>

show more ...

bpf: Define new BPF_MAP_TYPE_USER_RINGBUF map type

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

bpf: Define new BPF_MAP_TYPE_USER_RINGBUF map type

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

show more ...

Revert "bpftool: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK"

This reverts commit a777e18f1bcd32528ff5dfd10a6629b655b05eb8.

In commit a777e18f1bcd ("bpftool: Use libbpf 1.0 API mode instead o

Revert "bpftool: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK"

This reverts commit a777e18f1bcd32528ff5dfd10a6629b655b05eb8.

In commit a777e18f1bcd ("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

show more ...

bpftool: Use libbpf_bpf_map_type_str

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

bpftool: Use libbpf_bpf_map_type_str

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

show more ...

bpftool: Use libbpf_bpf_prog_type_str

This change switches bpftool over to using the recently introduced
libbpf_bpf_prog_type_str function instead of maintaining its own string
representation for th

bpftool: Use libbpf_bpf_prog_type_str

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

show more ...

bpftool: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK

We have switched to memcg-based memory accouting and thus the rlimit is
not needed any more. LIBBPF_STRICT_AUTO_RLIMIT_MEMLOCK was introduc

bpftool: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK

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

show more ...

bpftool: Fix print error when show bpf map

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:

$ ./bp

bpftool: Fix print error when show bpf map

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: 9330986c0300 ("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

show more ...

bpftool: Ensure bytes_memlock json output is correct

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

bpftool: Ensure bytes_memlock json output is correct

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

show more ...

bpftool: Fix pretty print dump for maps without BTF loaded

The commit e5043894b21f ("bpftool: Use libbpf_get_error() to check error")
fails to dump map without BTF loaded in pretty mode (-p option).

bpftool: Fix pretty print dump for maps without BTF loaded

The commit e5043894b21f ("bpftool: Use libbpf_get_error() to check error")
fails to dump map without BTF loaded in pretty mode (-p option).

Fixing this by making sure get_map_kv_btf won't fail in case there's
no BTF available for the map.

Fixes: e5043894b21f ("bpftool: Use libbpf_get_error() to check error")
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220216092102.125448-1-jolsa@kernel.org

show more ...

bpftool: Fix the error when lookup in no-btf maps

When reworking btf__get_from_id() in commit a19f93cfafdf the error
handling when calling bpf_btf_get_fd_by_id() changed. Before the rework
if bpf_bt

bpftool: Fix the error when lookup in no-btf maps

When reworking btf__get_from_id() in commit a19f93cfafdf 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: a19f93cfafdf ("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

show more ...

bpftool: Fix error check when calling hashmap__new()

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

bpftool: Fix error check when calling hashmap__new()

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: 8f184732b60b ("bpftool: Switch to libbpf's hashmap for pinned paths of BPF objects")
Fixes: 2828d0d75b73 ("bpftool: Switch to libbpf's hashmap for programs/maps in BTF listing")
Fixes: d6699f8e0f83 ("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

show more ...

bpftool: Migrate off of deprecated bpf_create_map_xattr() API

Switch to bpf_map_create() API instead.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kerne

bpftool: Migrate off of deprecated bpf_create_map_xattr() API

Switch to bpf_map_create() API instead.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211201232824.3166325-4-andrii@kernel.org

show more ...

bpftool: Use libbpf_get_error() to check error

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

bpftool: Use libbpf_get_error() to check error

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

show more ...

bpftool: Update the lists of names for maps and prog-attach types

To support the different BPF map or attach types, bpftool must remain
up-to-date with the types supported by the kernel. Let's updat

bpftool: Update the lists of names for maps and prog-attach types

To support the different BPF map or attach types, bpftool must remain
up-to-date with the types supported by the kernel. Let's update the
lists, by adding the missing Bloom filter map type and the perf_event
attach type.

Both missing items were found with test_bpftool_synctypes.py.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211110114632.24537-6-quentin@isovalent.com

show more ...

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

In order to show PIDs and names for processes holding references to BPF
programs, maps, links, or BTF objects, bpftool creates hash maps

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

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

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

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

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

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

show more ...

bpftool: Switch to libbpf's hashmap for pinned paths of BPF objects

In order to show pinned paths for BPF programs, maps, or links when
listing them with the "-f" option, bpftool creates hash maps t

bpftool: Switch to libbpf's hashmap for pinned paths of BPF objects

In order to show pinned paths for BPF programs, maps, or links when
listing them with the "-f" option, bpftool creates hash maps to store
all relevant paths under the bpffs. So far, it would rely on the
kernel implementation (from tools/include/linux/hashtable.h).

We can make bpftool rely on libbpf's implementation instead. The
motivation is to make bpftool less dependent of kernel headers, to ease
the path to a potential out-of-tree mirror, like libbpf has.

This commit is the first step of the conversion: the hash maps for
pinned paths for programs, maps, and links are converted to libbpf's
hashmap.{c,h}. Other hash maps used for the PIDs of process holding
references to BPF objects are left unchanged for now. On the build side,
this requires adding a dependency to a second header internal to libbpf,
and making it a dependency for the bootstrap bpftool version as well.
The rest of the changes are a rather straightforward conversion.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211023205154.6710-4-quentin@isovalent.com

show more ...

bpftool: Do not expose and init hash maps for pinned path in main.c

BPF programs, maps, and links, can all be listed with their pinned paths
by bpftool, when the "-f" option is provided. To do so, b

bpftool: Do not expose and init hash maps for pinned path in main.c

BPF programs, maps, and links, can all be listed with their pinned paths
by bpftool, when the "-f" option is provided. To do so, bpftool builds
hash maps containing all pinned paths for each kind of objects.

These three hash maps are always initialised in main.c, and exposed
through main.h. There appear to be no particular reason to do so: we can
just as well make them static to the files that need them (prog.c,
map.c, and link.c respectively), and initialise them only when we want
to show objects and the "-f" switch is provided.

This may prevent unnecessary memory allocations if the implementation of
the hash maps was to change in the future.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211023205154.6710-3-quentin@isovalent.com

show more ...

bpftool: Fix the error when lookup in no-btf maps

[ Upstream commit edc21dc909c6c133a2727f063eadd7907af51f94 ]

When reworking btf__get_from_id() in commit a19f93cfafdf the error
handling when calli

bpftool: Fix the error when lookup in no-btf maps

[ Upstream commit edc21dc909c6c133a2727f063eadd7907af51f94 ]

When reworking btf__get_from_id() in commit a19f93cfafdf 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: a19f93cfafdf ("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
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...