From ec2025095cf6acda3233a4301809596938b47da5 Mon Sep 17 00:00:00 2001 From: Paul Chaignon Date: Fri, 13 Dec 2019 20:10:04 +0100 Subject: bpftool: Match several programs with same tag When several BPF programs have the same tag, bpftool matches only the first (in ID order). This patch changes that behavior such that dump and show commands return all matched programs. Commands that require a single program (e.g., pin and attach) will error out if given a tag that matches several. bpftool prog dump will also error out if file or visual are given and several programs have the given tag. In the case of the dump command, a program header is added before each dump only if the tag matches several programs; this patch doesn't change the output if a single program matches. The output when several programs match thus looks as follows. $ ./bpftool prog dump xlated tag 6deef7357e7b4530 3: cgroup_skb tag 6deef7357e7b4530 gpl 0: (bf) r6 = r1 [...] 7: (95) exit 4: cgroup_skb tag 6deef7357e7b4530 gpl 0: (bf) r6 = r1 [...] 7: (95) exit Signed-off-by: Paul Chaignon Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/fb1fe943202659a69cd21dd5b907c205af1e1e22.1576263640.git.paul.chaignon@gmail.com --- tools/bpf/bpftool/Documentation/bpftool-prog.rst | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) (limited to 'tools/bpf/bpftool/Documentation/bpftool-prog.rst') diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst index 7a374b3c851d..d377d0cb7923 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst @@ -53,8 +53,10 @@ DESCRIPTION =========== **bpftool prog { show | list }** [*PROG*] Show information about loaded programs. If *PROG* is - specified show information only about given program, otherwise - list all programs currently loaded on the system. + specified show information only about given programs, + otherwise list all programs currently loaded on the system. + In case of **tag**, *PROG* may match several programs which + will all be shown. Output will start with program ID followed by program type and zero or more named attributes (depending on kernel version). @@ -68,11 +70,15 @@ DESCRIPTION performed via the **kernel.bpf_stats_enabled** sysctl knob. **bpftool prog dump xlated** *PROG* [{ **file** *FILE* | **opcodes** | **visual** | **linum** }] - Dump eBPF instructions of the program from the kernel. By + Dump eBPF instructions of the programs from the kernel. By default, eBPF will be disassembled and printed to standard output in human-readable format. In this case, **opcodes** controls if raw opcodes should be printed as well. + In case of **tag**, *PROG* may match several programs which + will all be dumped. However, if **file** or **visual** is + specified, *PROG* must match a single program. + If **file** is specified, the binary image will instead be written to *FILE*. @@ -80,15 +86,17 @@ DESCRIPTION built instead, and eBPF instructions will be presented with CFG in DOT format, on standard output. - If the prog has line_info available, the source line will + If the programs have line_info available, the source line will be displayed by default. If **linum** is specified, the filename, line number and line column will also be displayed on top of the source line. **bpftool prog dump jited** *PROG* [{ **file** *FILE* | **opcodes** | **linum** }] Dump jited image (host machine code) of the program. + If *FILE* is specified image will be written to a file, otherwise it will be disassembled and printed to stdout. + *PROG* must match a single program when **file** is specified. **opcodes** controls if raw opcodes will be printed. -- cgit v1.2.3