linux-next.git/kernel/trace/bpf_trace.c, branch master

bpf: Add tracing_multi link info support

2026-07-01T19:44:12+00:00

Adding BPF_OBJ_GET_INFO_BY_FD support for tracing_multi links. We expose following tracing_multi link data: - attach_type of the program - number of ids - array of BTF ids - array of its related kernel addresses - array of cookies The change follows the kprobe_multi and uprobe_multi link-info convention of optional output arrays with an in/out count, On top of standard tracing link data we also expose addresses, because they are useful info for user (especially when the attachment was done via pattern). This data is hidden when kallsyms does not allow exposing kernel pointer values. Assisted-by: Codex:GPT-5 Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Acked-by: Leon Hwang Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20260629212208.895962-2-jolsa@kernel.org

bpf: Add missing access_ok call to copy_user_syms

2026-06-22T01:01:33+00:00

As reported by sashiko we use __get_user without prior access_ok call on the user space pointer. Adding the missing call for the whole pointer array. Plus removing the err check in the error path, because it's not needed and also we can return -ENOMEM directly from the first kvmalloc_array fail path. Cc: stable@vger.kernel.org [1] https://lore.kernel.org/bpf/20260611115503.AC16D1F00893@smtp.kernel.org/ Fixes: 0236fec57a15 ("bpf: Resolve symbols with ftrace_lookup_symbols for kprobe multi link") Reported-by: Sashiko Closes: https://lore.kernel.org/bpf/20260611115503.AC16D1F00893@smtp.kernel.org/ Signed-off-by: Jiri Olsa Reviewed-by: Emil Tsalapatis Link: https://lore.kernel.org/r/20260616083056.405652-1-jolsa@kernel.org Signed-off-by: Alexei Starovoitov

bpf: Add support to specify uprobe_multi target via file descriptor

2026-06-15T00:24:25+00:00

Allow uprobe_multi link to identify the target binary by an already opened file descriptor. Adding new BPF_F_UPROBE_MULTI_PATH_FD flag and the path_fd field for the attr.link_create.uprobe_multi struct. When the flag is set, we resolve the target from path_fd, without the flag, we keep the existing string path behavior. I don't see a use case for supporting O_PATH file descriptors, because we need to read the binary first to get probes offsets, so I'm using the CLASS(fd, f), which fails for O_PATH fds. Assisted-by: Codex:GPT-5.4 Signed-off-by: Jiri Olsa Link: https://lore.kernel.org/r/20260611114230.950379-4-jolsa@kernel.org Signed-off-by: Alexei Starovoitov

bpf: Use user_path_at for path resolution in uprobe_multi

2026-06-15T00:24:25+00:00

Resolve the uprobe_multi user path with user_path_at() instead of copying the string with strndup_user() and passing it to kern_path(). This removes the temporary allocation and keeps the lookup logic in one helper. Signed-off-by: Jiri Olsa Link: https://lore.kernel.org/r/20260611114230.950379-3-jolsa@kernel.org Signed-off-by: Alexei Starovoitov

bpf: Guard __get_user acesss with access_ok for uprobe_multi data

2026-06-15T00:24:25+00:00

As reported by sashiko [1] we need to use access_ok to check the user space data bounds before we use __get-user to get it. [1] https://lore.kernel.org/bpf/20260610145235.CB1441F00893@smtp.kernel.org/ Fixes: 0b779b61f651 ("bpf: Add cookies support for uprobe_multi link") Fixes: 89ae89f53d20 ("bpf: Add multi uprobe link") Signed-off-by: Jiri Olsa Link: https://lore.kernel.org/r/20260611114230.950379-2-jolsa@kernel.org Signed-off-by: Alexei Starovoitov

bpf: Add support for tracing_multi link fdinfo

2026-06-07T17:03:02+00:00

Adding tracing_multi link fdinfo support with following output: pos: 0 flags: 02000000 mnt_id: 19 ino: 3087 link_type: tracing_multi link_id: 9 prog_tag: 599ba0e317244f86 prog_id: 94 attach_type: 59 cnt: 10 obj-id btf-id cookie func 1 91593 8 bpf_fentry_test1+0x4/0x10 1 91595 9 bpf_fentry_test2+0x4/0x10 1 91596 7 bpf_fentry_test3+0x4/0x20 1 91597 5 bpf_fentry_test4+0x4/0x20 1 91598 4 bpf_fentry_test5+0x4/0x20 1 91599 2 bpf_fentry_test6+0x4/0x20 1 91600 3 bpf_fentry_test7+0x4/0x10 1 91601 1 bpf_fentry_test8+0x4/0x10 1 91602 10 bpf_fentry_test9+0x4/0x10 1 91594 6 bpf_fentry_test10+0x4/0x10 Signed-off-by: Jiri Olsa Link: https://lore.kernel.org/r/20260606123955.345967-17-jolsa@kernel.org Signed-off-by: Alexei Starovoitov

bpf: Add support for tracing_multi link session

2026-06-07T17:03:01+00:00

Adding support to use session attachment with tracing_multi link. Adding new BPF_TRACE_FSESSION_MULTI program attach type, that follows the BPF_TRACE_FSESSION behaviour but on the tracing_multi link. Such program is called on entry and exit of the attached function and allows to pass cookie value from entry to exit execution. Signed-off-by: Jiri Olsa Link: https://lore.kernel.org/r/20260606123955.345967-16-jolsa@kernel.org Signed-off-by: Alexei Starovoitov

bpf: Add support for tracing_multi link cookies

2026-06-07T17:03:01+00:00

Add support to specify cookies for tracing_multi link. Cookies are provided in array where each value is paired with provided BTF ID value with the same array index. Such cookie can be retrieved by bpf program with bpf_get_attach_cookie helper call. We need to sort cookies array together with ids array in check_dup_ids, to keep the id->cookie relation. Signed-off-by: Jiri Olsa Link: https://lore.kernel.org/r/20260606123955.345967-15-jolsa@kernel.org Signed-off-by: Alexei Starovoitov

bpf: Add support for tracing multi link

2026-06-07T17:03:01+00:00

Adding new link to allow to attach program to multiple function BTF IDs. The link is represented by struct bpf_tracing_multi_link. To configure the link, new fields are added to bpf_attr::link_create to pass array of BTF IDs; struct { __aligned_u64 ids; __u32 cnt; } tracing_multi; Each BTF ID represents function (BTF_KIND_FUNC) that the link will attach bpf program to. We use previously added bpf_trampoline_multi_attach/detach functions to attach/detach the link. The linkinfo/fdinfo callbacks will be implemented in following changes. Note this is supported only for archs (x86_64) with ftrace direct and have single ops support. CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS && CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS Note using sort_r (instead of plain sort) in check_dup_ids, because we will use the swap callback in following changes. Signed-off-by: Jiri Olsa Link: https://lore.kernel.org/r/20260606123955.345967-14-jolsa@kernel.org Signed-off-by: Alexei Starovoitov

Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 7.1-rc5

2026-05-25T13:33:30+00:00

Cross-merge BPF and other fixes after downstream PR. Signed-off-by: Alexei Starovoitov