kernel/linux.git/tools/bpf/bpftool/feature.c, branch linux-7.0.y

bpftool: Refactor kernel config reading into common helper

2025-09-02T15:20:54+00:00

Extract the kernel configuration file parsing logic from feature.c into a new read_kernel_config() function in common.c. This includes: 1. Moving the config file handling and option parsing code 2. Adding required headers and struct definition 3. Keeping all existing functionality The refactoring enables sharing this logic with other components while maintaining current behavior. This will be used by subsequent patches that need to check kernel config options. Signed-off-by: Yuan Chen Signed-off-by: Daniel Borkmann Acked-by: Quentin Monnet Acked-by: Yonghong Song Acked-by: Jiri Olsa Link: https://lore.kernel.org/bpf/20250829061107.23905-2-chenyuan_fl@163.com

bpftool: Probe for ISA v4 instruction set extension

2024-12-12T16:25:17+00:00

This patch introduces a new probe to check whether the kernel supports instruction set extensions v4. The v4 extension comprises several new instructions: BPF_{SDIV,SMOD} (signed div and mod), BPF_{LD,LDX,ST,STX,MOV} (sign-extended load/store/move), 32-bit BPF_JA (unconditional jump), target-independent BPF_ALU64 BSWAP (byte-swapping 16/32/64). These have been introduced in the following commits respectively: * ec0e2da95f72 ("bpf: Support new signed div/mod instructions.") * 1f9a1ea821ff ("bpf: Support new sign-extension load insns") * 8100928c8814 ("bpf: Support new sign-extension mov insns") * 4cd58e9af8b9 ("bpf: Support new 32bit offset jmp instruction") * 0845c3db7bf5 ("bpf: Support new unconditional bswap instruction") Support in bpftool for previous ISA extensions was added in commit 0fd800b2456c ("bpftool: Probe for instruction set extensions"). These probes are useful for userspace BPF projects that want to use newer instruction set extensions on newer kernels, to reduce the programs' sizes or their complexity. LLVM provides the mcpu=v4 option since LLVM commit 8f28e8069c4b ("[BPF] support for BPF_ST instruction in codegen") [0]. Signed-off-by: Simone Magnani Signed-off-by: Daniel Borkmann Reviewed-by: Quentin Monnet Link: https://github.com/llvm/llvm-project/commit/8f28e8069c4ba1110daee8bddc4d5049b6d4646e [0] Link: https://lore.kernel.org/bpf/20241209145439.336362-1-simone.magnani@isovalent.com

bpftool: fix some typos in bpftool

2024-09-05T20:07:47+00:00

Hi, fix some spelling errors in bpftool, the details are as follows: -in file "bpftool-gen.rst" libppf->libbpf -in the code comments: ouptut->output Signed-off-by: Lin Yikai Link: https://lore.kernel.org/r/20240905110354.3274546-2-yikai.lin@vivo.com Signed-off-by: Alexei Starovoitov

bpf: improve error message for unsupported helper

2024-03-29T01:30:53+00:00

BPF verifier emits "unknown func" message when given BPF program type does not support BPF helper. This message may be confusing for users, as important context that helper is unknown only to current program type is not provided. This patch changes message to "program of this type cannot use helper " and aligns dependent code in libbpf and tests. Any suggestions on improving/changing this message are welcome. Signed-off-by: Mykyta Yatsenko Acked-by: Andrii Nakryiko Acked-by: Quentin Monnet Link: https://lore.kernel.org/r/20240325152210.377548-1-yatsenko@meta.com Signed-off-by: Alexei Starovoitov

bpfilter: remove bpfilter

2024-01-04T18:23:10+00:00

bpfilter was supposed to convert iptables filtering rules into BPF programs on the fly, from the kernel, through a usermode helper. The base code for the UMH was introduced in 2018, and couple of attempts (2, 3) tried to introduce the BPF program generate features but were abandoned. bpfilter now sits in a kernel tree unused and unusable, occasionally causing confusion amongst Linux users (4, 5). As bpfilter is now developed in a dedicated repository on GitHub (6), it was suggested a couple of times this year (LSFMM/BPF 2023, LPC 2023) to remove the deprecated kernel part of the project. This is the purpose of this patch. [1]: https://lore.kernel.org/lkml/20180522022230.2492505-1-ast@kernel.org/ [2]: https://lore.kernel.org/bpf/20210829183608.2297877-1-me@ubique.spb.ru/#t [3]: https://lore.kernel.org/lkml/20221224000402.476079-1-qde@naccy.de/ [4]: https://dxuuu.xyz/bpfilter.html [5]: https://github.com/linuxkit/linuxkit/pull/3904 [6]: https://github.com/facebook/bpfilter Signed-off-by: Quentin Deslandes Link: https://lore.kernel.org/r/20231226130745.465988-1-qde@naccy.de Signed-off-by: Alexei Starovoitov

bpftool: Use "fallthrough;" keyword instead of comments

2023-07-12T21:50:11+00:00

After using "__fallthrough;" in a switch/case block in bpftool's btf_dumper.c [0], and then turning it into a comment [1] to prevent a merge conflict in linux-next when the keyword was changed into just "fallthrough;" [2], we can now drop the comment and use the new keyword, no underscores. Also update the other occurrence of "/* fallthrough */" in bpftool. [0] commit 9fd496848b1c ("bpftool: Support inline annotations when dumping the CFG of a program") [1] commit 4b7ef71ac977 ("bpftool: Replace "__fallthrough" by a comment to address merge conflict") [2] commit f7a858bffcdd ("tools: Rename __fallthrough to fallthrough") Signed-off-by: Quentin Monnet Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20230712152322.81758-1-quentin@isovalent.com

bpftool: JIT limited misreported as negative value on aarch64

2023-05-15T19:14:48+00:00

On aarch64, "bpftool feature" reports an incorrect BPF JIT limit: $ sudo /sbin/bpftool feature Scanning system configuration... bpf() syscall restricted to privileged users JIT compiler is enabled JIT compiler hardening is disabled JIT compiler kallsyms exports are enabled for root skipping kernel config, can't open file: No such file or directory Global memory limit for JIT compiler for unprivileged users is -201326592 bytes This is because /proc/sys/net/core/bpf_jit_limit reports $ sudo cat /proc/sys/net/core/bpf_jit_limit 68169519595520 ...and an int is assumed in read_procfs(). Change read_procfs() to return a long to avoid negative value reporting. Fixes: 7a4522bbef0c ("tools: bpftool: add probes for /proc/ eBPF parameters") Reported-by: Nicky Veitch Signed-off-by: Alan Maguire Signed-off-by: Daniel Borkmann Acked-by: Jiri Olsa Acked-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20230512113134.58996-1-alan.maguire@oracle.com

bpftool: fix output for skipping kernel config check

2023-01-11T01:42:31+00:00

When bpftool feature does not find kernel config files under default path or wrong format, do not output CONFIG_XYZ is not set. Skip kernel config check and continue. Signed-off-by: Chethan Suresh Signed-off-by: Kenta Tada Acked-by: Quentin Monnet Link: https://lore.kernel.org/r/20230109023742.29657-1-chethan.suresh@sony.com Signed-off-by: Martin KaFai Lau

bpftool: Fix a typo in a comment

2022-08-15T15:29:42+00:00

This is the wrong library name: libcap, not libpcap. Signed-off-by: Quentin Monnet Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20220812153727.224500-1-quentin@isovalent.com

bpftool: Rename "bpftool feature list" into "... feature list_builtins"

2022-07-05T09:53:54+00:00

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 Signed-off-by: Quentin Monnet Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20220701093805.16920-1-quentin@isovalent.com