linux.git/tools/lib/bpf/libbpf.h, branch v6.5 Linux kernel source tree libbpf: Add capability for resizing datasec maps 2023-05-24T18:44:16+00:00 JP Kobryn inwardvessel@gmail.com 2023-05-24T00:45:36+00:00 9d0a23313b1aa107df857e8441ea2ed74811ea17 This patch updates bpf_map__set_value_size() so that if the given map is memory mapped, it will attempt to resize the mapped region. Initial contents of the mapped region are preserved. BTF is not required, but after the mapping is resized an attempt is made to adjust the associated BTF information if the following criteria is met: - BTF info is present - the map is a datasec - the final variable in the datasec is an array ... the resulting BTF info will be updated so that the final array variable is associated with a new BTF array type sized to cover the requested size. Note that the initial resizing of the memory mapped region can succeed while the subsequent BTF adjustment can fail. In this case, BTF info is dropped from the map by clearing the key and value type. Signed-off-by: JP Kobryn <inwardvessel@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/bpf/20230524004537.18614-2-inwardvessel@gmail.com 
This patch updates bpf_map__set_value_size() so that if the given map is
memory mapped, it will attempt to resize the mapped region. Initial
contents of the mapped region are preserved. BTF is not required, but
after the mapping is resized an attempt is made to adjust the associated
BTF information if the following criteria is met:
 - BTF info is present
 - the map is a datasec
 - the final variable in the datasec is an array

... the resulting BTF info will be updated so that the final array
variable is associated with a new BTF array type sized to cover the
requested size.

Note that the initial resizing of the memory mapped region can succeed
while the subsequent BTF adjustment can fail. In this case, BTF info is
dropped from the map by clearing the key and value type.

Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20230524004537.18614-2-inwardvessel@gmail.com
libbpf: Ensure print callback usage is thread-safe 2023-03-27T18:33:43+00:00 JP Kobryn inwardvessel@gmail.com 2023-03-25T01:08:45+00:00 f1cb927cdb6280e0ce283174cc1bf395dffc43d4 This patch prevents races on the print function pointer, allowing the libbpf_set_print() function to become thread-safe. Signed-off-by: JP Kobryn <inwardvessel@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230325010845.46000-1-inwardvessel@gmail.com 
This patch prevents races on the print function pointer, allowing the
libbpf_set_print() function to become thread-safe.

Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230325010845.46000-1-inwardvessel@gmail.com
libbpf: Update a bpf_link with another struct_ops. 2023-03-23T05:53:02+00:00 Kui-Feng Lee kuifeng@meta.com 2023-03-23T03:24:03+00:00 912dd4b0c2a50a839301520badb241f36664ae07 Introduce bpf_link__update_map(), which allows to atomically update underlying struct_ops implementation for given struct_ops BPF link. Also add old_map_fd to struct bpf_link_update_opts to handle BPF_F_REPLACE feature. Signed-off-by: Kui-Feng Lee <kuifeng@meta.com> Link: https://lore.kernel.org/r/20230323032405.3735486-7-kuifeng@meta.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> 
Introduce bpf_link__update_map(), which allows to atomically update
underlying struct_ops implementation for given struct_ops BPF link.

Also add old_map_fd to struct bpf_link_update_opts to handle
BPF_F_REPLACE feature.

Signed-off-by: Kui-Feng Lee <kuifeng@meta.com>
Link: https://lore.kernel.org/r/20230323032405.3735486-7-kuifeng@meta.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
libbpf: Add support to set kprobe/uprobe attach mode 2023-03-06T17:38:04+00:00 Menglong Dong imagedong@tencent.com 2023-03-06T06:48:31+00:00 f8b299bc6a0f8695d4005ecff29773c79a1d29af By default, libbpf will attach the kprobe/uprobe BPF program in the latest mode that supported by kernel. In this patch, we add the support to let users manually attach kprobe/uprobe in legacy or perf mode. There are 3 mode that supported by the kernel to attach kprobe/uprobe: LEGACY: create perf event in legacy way and don't use bpf_link PERF: create perf event with perf_event_open() and don't use bpf_link Signed-off-by: Menglong Dong <imagedong@tencent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Biao Jiang <benbjiang@tencent.com> Link: create perf event with perf_event_open() and use bpf_link Link: https://lore.kernel.org/bpf/20230113093427.1666466-1-imagedong@tencent.com/ Link: https://lore.kernel.org/bpf/20230306064833.7932-2-imagedong@tencent.com Users now can manually choose the mode with bpf_program__attach_uprobe_opts()/bpf_program__attach_kprobe_opts(). 
By default, libbpf will attach the kprobe/uprobe BPF program in the
latest mode that supported by kernel. In this patch, we add the support
to let users manually attach kprobe/uprobe in legacy or perf mode.

There are 3 mode that supported by the kernel to attach kprobe/uprobe:

  LEGACY: create perf event in legacy way and don't use bpf_link
  PERF: create perf event with perf_event_open() and don't use bpf_link

Signed-off-by: Menglong Dong <imagedong@tencent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Biao Jiang <benbjiang@tencent.com>
Link: create perf event with perf_event_open() and use bpf_link
Link: https://lore.kernel.org/bpf/20230113093427.1666466-1-imagedong@tencent.com/
Link: https://lore.kernel.org/bpf/20230306064833.7932-2-imagedong@tencent.com

Users now can manually choose the mode with
bpf_program__attach_uprobe_opts()/bpf_program__attach_kprobe_opts().
libbpf: Add sample_period to creation options 2023-02-08T23:27:39+00:00 Jon Doron jond@wiz.io 2023-02-07T08:19:16+00:00 ab8684b8cecf711cc9e47c1cbb1a8f4b549f8893 Add option to set when the perf buffer should wake up, by default the perf buffer becomes signaled for every event that is being pushed to it. In case of a high throughput of events it will be more efficient to wake up only once you have X events ready to be read. So your application can wakeup once and drain the entire perf buffer. Signed-off-by: Jon Doron <jond@wiz.io> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230207081916.3398417-1-arilou@gmail.com 
Add option to set when the perf buffer should wake up, by default the
perf buffer becomes signaled for every event that is being pushed to it.

In case of a high throughput of events it will be more efficient to wake
up only once you have X events ready to be read.

So your application can wakeup once and drain the entire perf buffer.

Signed-off-by: Jon Doron <jond@wiz.io>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230207081916.3398417-1-arilou@gmail.com
libbpf: add API to get XDP/XSK supported features 2023-02-03T04:48:24+00:00 Lorenzo Bianconi lorenzo@kernel.org 2023-02-01T10:24:21+00:00 04d58f1b26a436c429581d286528ea3c01624462 Extend bpf_xdp_query routine in order to get XDP/XSK supported features of netdev over route netlink interface. Extend libbpf netlink implementation in order to support netlink_generic protocol. Co-developed-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Co-developed-by: Marek Majtyka <alardam@gmail.com> Signed-off-by: Marek Majtyka <alardam@gmail.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/a72609ef4f0de7fee5376c40dbf54ad7f13bfb8d.1675245258.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> 
Extend bpf_xdp_query routine in order to get XDP/XSK supported features
of netdev over route netlink interface.
Extend libbpf netlink implementation in order to support netlink_generic
protocol.

Co-developed-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Co-developed-by: Marek Majtyka <alardam@gmail.com>
Signed-off-by: Marek Majtyka <alardam@gmail.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/a72609ef4f0de7fee5376c40dbf54ad7f13bfb8d.1675245258.git.lorenzo@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
libbpf: Add documentation to map pinning API functions 2023-01-27T22:03:19+00:00 Grant Seltzer grantseltzer@gmail.com 2023-01-26T02:42:25+00:00 e4ce876f10a21fb4e550d1743468791021a430f5 This adds documentation for the following API functions: - bpf_map__set_pin_path() - bpf_map__pin_path() - bpf_map__is_pinned() - bpf_map__pin() - bpf_map__unpin() - bpf_object__pin_maps() - bpf_object__unpin_maps() Signed-off-by: Grant Seltzer <grantseltzer@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230126024225.520685-1-grantseltzer@gmail.com 
This adds documentation for the following API functions:

- bpf_map__set_pin_path()
- bpf_map__pin_path()
- bpf_map__is_pinned()
- bpf_map__pin()
- bpf_map__unpin()
- bpf_object__pin_maps()
- bpf_object__unpin_maps()

Signed-off-by: Grant Seltzer <grantseltzer@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230126024225.520685-1-grantseltzer@gmail.com
libbpf: Fix malformed documentation formatting 2023-01-27T22:02:03+00:00 Grant Seltzer grantseltzer@gmail.com 2023-01-26T02:47:49+00:00 139df64d26fd5bb83cd04b330f7a849eefa1a889 This fixes the doxygen format documentation above the user_ring_buffer__* APIs. There has to be a newline before the @brief, otherwise doxygen won't render them for libbpf.readthedocs.org. Signed-off-by: Grant Seltzer <grantseltzer@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230126024749.522278-1-grantseltzer@gmail.com 
This fixes the doxygen format documentation above the
user_ring_buffer__* APIs. There has to be a newline
before the @brief, otherwise doxygen won't render them
for libbpf.readthedocs.org.

Signed-off-by: Grant Seltzer <grantseltzer@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230126024749.522278-1-grantseltzer@gmail.com
libbpf: Added the description of some API functions 2022-12-29T22:32:20+00:00 Xin Liu liuxin350@huawei.com 2022-12-24T11:20:58+00:00 678a1c036199011e65b203367900f002a28da004 Currently, many API functions are not described in the document. Add add API description of the following four API functions: - libbpf_set_print; - bpf_object__open; - bpf_object__load; - bpf_object__close. Signed-off-by: Xin Liu <liuxin350@huawei.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20221224112058.12038-1-liuxin350@huawei.com 
Currently, many API functions are not described in the document.
Add add API description of the following four API functions:
  - libbpf_set_print;
  - bpf_object__open;
  - bpf_object__load;
  - bpf_object__close.

Signed-off-by: Xin Liu <liuxin350@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221224112058.12038-1-liuxin350@huawei.com
libbpf: restore memory layout of bpf_object_open_opts 2022-09-23T23:19:37+00:00 Andrii Nakryiko andrii@kernel.org 2022-09-23T23:05:59+00:00 dbdea9b36fb61da3b9a1be0dd63542e2bfd3e5d7 When attach_prog_fd field was removed in libbpf 1.0 and replaced with `long: 0` placeholder, it actually shifted all the subsequent fields by 8 byte. This is due to `long: 0` promising to adjust next field's offset to long-aligned offset. But in this case we were already long-aligned as pin_root_path is a pointer. So `long: 0` had no effect, and thus didn't feel the gap created by removed attach_prog_fd. Non-zero bitfield should have been used instead. I validated using pahole. Originally kconfig field was at offset 40. With `long: 0` it's at offset 32, which is wrong. With this change it's back at offset 40. While technically libbpf 1.0 is allowed to break backwards compatibility and applications should have been recompiled against libbpf 1.0 headers, but given how trivial it is to preserve memory layout, let's fix this. Reported-by: Grant Seltzer Richman <grantseltzer@gmail.com> Fixes: 146bf811f5ac ("libbpf: remove most other deprecated high-level APIs") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220923230559.666608-1-andrii@kernel.org Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> 
When attach_prog_fd field was removed in libbpf 1.0 and replaced with
`long: 0` placeholder, it actually shifted all the subsequent fields by
8 byte. This is due to `long: 0` promising to adjust next field's offset
to long-aligned offset. But in this case we were already long-aligned
as pin_root_path is a pointer. So `long: 0` had no effect, and thus
didn't feel the gap created by removed attach_prog_fd.

Non-zero bitfield should have been used instead. I validated using
pahole. Originally kconfig field was at offset 40. With `long: 0` it's
at offset 32, which is wrong. With this change it's back at offset 40.

While technically libbpf 1.0 is allowed to break backwards
compatibility and applications should have been recompiled against
libbpf 1.0 headers, but given how trivial it is to preserve memory
layout, let's fix this.

Reported-by: Grant Seltzer Richman <grantseltzer@gmail.com>
Fixes: 146bf811f5ac ("libbpf: remove most other deprecated high-level APIs")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220923230559.666608-1-andrii@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>