kernel/linux.git/samples/bpf/map_perf_test_user.c, branch v6.12.80

bpf: Replace bpf_lpm_trie_key 0-length array with flexible array

2024-02-29T21:52:43+00:00

Replace deprecated 0-length array in struct bpf_lpm_trie_key with flexible array. Found with GCC 13: ../kernel/bpf/lpm_trie.c:207:51: warning: array subscript i is outside array bounds of 'const __u8[0]' {aka 'const unsigned char[]'} [-Warray-bounds=] 207 | *(__be16 *)&key->data[i]); | ^~~~~~~~~~~~~ ../include/uapi/linux/swab.h:102:54: note: in definition of macro '__swab16' 102 | #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x)) | ^ ../include/linux/byteorder/generic.h:97:21: note: in expansion of macro '__be16_to_cpu' 97 | #define be16_to_cpu __be16_to_cpu | ^~~~~~~~~~~~~ ../kernel/bpf/lpm_trie.c:206:28: note: in expansion of macro 'be16_to_cpu' 206 | u16 diff = be16_to_cpu(*(__be16 *)&node->data[i] ^ | ^~~~~~~~~~~ In file included from ../include/linux/bpf.h:7: ../include/uapi/linux/bpf.h:82:17: note: while referencing 'data' 82 | __u8 data[0]; /* Arbitrary size */ | ^~~~ And found at run-time under CONFIG_FORTIFY_SOURCE: UBSAN: array-index-out-of-bounds in kernel/bpf/lpm_trie.c:218:49 index 0 is out of range for type '__u8 [*]' Changing struct bpf_lpm_trie_key is difficult since has been used by userspace. For example, in Cilium: struct egress_gw_policy_key { struct bpf_lpm_trie_key lpm_key; __u32 saddr; __u32 daddr; }; While direct references to the "data" member haven't been found, there are static initializers what include the final member. For example, the "{}" here: struct egress_gw_policy_key in_key = { .lpm_key = { 32 + 24, {} }, .saddr = CLIENT_IP, .daddr = EXTERNAL_SVC_IP & 0Xffffff, }; To avoid the build time and run time warnings seen with a 0-sized trailing array for struct bpf_lpm_trie_key, introduce a new struct that correctly uses a flexible array for the trailing bytes, struct bpf_lpm_trie_key_u8. As part of this, include the "header" portion (which is just the "prefixlen" member), so it can be used by anything building a bpf_lpr_trie_key that has trailing members that aren't a u8 flexible array (like the self-test[1]), which is named struct bpf_lpm_trie_key_hdr. Unfortunately, C++ refuses to parse the __struct_group() helper, so it is not possible to define struct bpf_lpm_trie_key_hdr directly in struct bpf_lpm_trie_key_u8, so we must open-code the union directly. Adjust the kernel code to use struct bpf_lpm_trie_key_u8 through-out, and for the selftest to use struct bpf_lpm_trie_key_hdr. Add a comment to the UAPI header directing folks to the two new options. Reported-by: Mark Rutland Signed-off-by: Kees Cook Signed-off-by: Daniel Borkmann Acked-by: Gustavo A. R. Silva Closes: https://paste.debian.net/hidden/ca500597/ Link: https://lore.kernel.org/all/202206281009.4332AA33@keescook/ [1] Link: https://lore.kernel.org/bpf/20240222155612.it.533-kees@kernel.org

samples/bpf: Change _kern suffix to .bpf with syscall tracing program

2022-12-29T22:22:34+00:00

Currently old compile rule (CLANG-bpf) doesn't contains VMLINUX_H define flag which is essential for the bpf program that includes "vmlinux.h". Also old compile rule doesn't directly specify the compile target as bpf, instead it uses bunch of extra options with clang followed by long chain of commands. (e.g. clang | opt | llvm-dis | llc) In Makefile, there is already new compile rule which is more simple and neat. And it also has -D__VMLINUX_H__ option. By just changing the _kern suffix to .bpf will inherit the benefit of the new CLANG-BPF compile target. Also, this commit adds dummy gnu/stub.h to the samples/bpf directory. As commit 1c2dd16add7e ("selftests/bpf: get rid of -D__x86_64__") noted, compiling with 'clang -target bpf' will raise an error with stubs.h unless workaround (-D__x86_64) is used. This commit solves this problem by adding dummy stub.h to make /usr/include/features.h to follow the expected path as the same way selftests/bpf dealt with. Signed-off-by: Daniel T. Lee Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20221224071527.2292-4-danieltimlee@gmail.com

samples/bpf: Reduce syscall overhead in map_perf_test.

2022-09-05T13:33:05+00:00

Make map_perf_test for preallocated and non-preallocated hash map spend more time inside bpf program to focus performance analysis on the speed of update/lookup/delete operations performed by bpf program. It makes 'perf report' of bpf_mem_alloc look like: 11.76% map_perf_test [k] _raw_spin_lock_irqsave 11.26% map_perf_test [k] htab_map_update_elem 9.70% map_perf_test [k] _raw_spin_lock 9.47% map_perf_test [k] htab_map_delete_elem 8.57% map_perf_test [k] memcpy_erms 5.58% map_perf_test [k] alloc_htab_elem 4.09% map_perf_test [k] __htab_map_lookup_elem 3.44% map_perf_test [k] syscall_exit_to_user_mode 3.13% map_perf_test [k] lookup_nulls_elem_raw 3.05% map_perf_test [k] migrate_enable 3.04% map_perf_test [k] memcmp 2.67% map_perf_test [k] unit_free 2.39% map_perf_test [k] lookup_elem_raw Reduce default iteration count as well to make 'map_perf_test' quick enough even on debug kernels. Signed-off-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann Acked-by: Kumar Kartikeya Dwivedi Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220902211058.60789-5-alexei.starovoitov@gmail.com

samples/bpf: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK

2022-04-11T03:17:15+00:00

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. This patch also removes the useless header sys/resource.h from many files in samples/bpf. Signed-off-by: Yafang Shao Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220409125958.92629-2-laoar.shao@gmail.com

samples/bpf: use preferred getters/setters instead of deprecated ones

2022-01-26T01:59:07+00:00

Use preferred setter and getter APIs instead of deprecated ones. Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20220124194254.2051434-7-andrii@kernel.org Signed-off-by: Alexei Starovoitov

samples/bpf: Get rid of deprecated libbpf API uses

2021-12-02T23:23:40+00:00

Replace deprecated APIs with new ones. Also mute source code using deprecated AF_XDP (xsk.h). Figuring out what to do with all the AF_XDP stuff is a separate problem that should be solved with its own set of changes. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20211201232824.3166325-9-andrii@kernel.org

bpf: samples: Do not touch RLIMIT_MEMLOCK

2020-12-03T02:32:47+00:00

Since bpf is not using rlimit memlock for the memory accounting and control, do not change the limit in sample applications. Signed-off-by: Roman Gushchin Signed-off-by: Alexei Starovoitov Acked-by: Song Liu Link: https://lore.kernel.org/bpf/20201201215900.3569844-35-guro@fb.com

samples: bpf: Refactor BPF map performance test with libbpf

2020-07-07T23:33:14+00:00

Previously, in order to set the numa_node attribute at the time of map creation using "libbpf", it was necessary to call bpf_create_map_node() directly (bpf_load approach), instead of calling bpf_object_load() that handles everything on its own, including map creation. And because of this problem, this sample had problems with refactoring from bpf_load to libbbpf. However, by commit 1bdb6c9a1c43 ("libbpf: Add a bunch of attribute getters/setters for map definitions") added the numa_node attribute and allowed it to be set in the map. By using libbpf instead of bpf_load, the inner map definition has been explicitly declared with BTF-defined format. Also, the element of ARRAY_OF_MAPS was also statically specified using the BTF format. And for this reason some logic in fixup_map() was not needed and changed or removed. Signed-off-by: Daniel T. Lee Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200707184855.30968-4-danieltimlee@gmail.com

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206

2019-05-30T18:29:53+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of version 2 of the gnu general public license as published by the free software foundation extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 107 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Richard Fontana Reviewed-by: Steve Winslow Reviewed-by: Alexios Zavras Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190528171438.615055994@linutronix.de Signed-off-by: Greg Kroah-Hartman

samples: bpf: include bpf/bpf.h instead of local libbpf.h

2018-05-15T05:52:10+00:00

There are two files in the tree called libbpf.h which is becoming problematic. Most samples don't actually need the local libbpf.h they simply include it to get to bpf/bpf.h. Include bpf/bpf.h directly instead. Signed-off-by: Jakub Kicinski Acked-by: Jesper Dangaard Brouer Signed-off-by: Alexei Starovoitov