tools/scripts/Makefile.include may expand EXTRA_CFLAGS in a future
change.  This could alter the initialization of CFLAGS, as the default
options "-g -O2" would never be set once EXTRA_CFLAGS is expanded.

Prepare for this by moving the CFLAGS initialization before including
tools/scripts/Makefile.include, so it is not affected by the extended
EXTRA_CFLAGS.

Append EXTRA_CFLAGS to CFLAGS only after including Makefile.include and
place it last so that the extra flags propagate properly and can
override the default options.

tools/scripts/Makefile.include already appends $(CLANG_CROSS_FLAGS) to
CFLAGS, the Makefile appends $(CLANG_CROSS_FLAGS) again, remove the
redundant append.

Signed-off-by: Leo Yan <leo.yan@arm.com>
Acked-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Link: https://lore.kernel.org/r/20260602-tools_build_fix_zero_init_bpf_only-v2-4-c76e5250ea1c@arm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Adding the path_fd field to struct bpf_link_create_opts and passing it
through kernel attr interface.

Assisted-by: Codex:GPT-5.4
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260611114230.950379-5-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Adding bpf_program__attach_tracing_multi function for attaching
tracing program to multiple functions.

  struct bpf_link *
  bpf_program__attach_tracing_multi(const struct bpf_program *prog,
                                    const char *pattern,
                                    const struct bpf_tracing_multi_opts *opts);

User can specify functions to attach with 'pattern' argument that
allows wildcards (*?' supported) or provide BTF ids of functions
in array directly via opts argument. These options are mutually
exclusive.

When using BTF ids, user can also provide cookie value for each
provided id/function, that can be retrieved later in bpf program
with bpf_get_attach_cookie helper. Each cookie value is paired with
provided BTF id with the same array index.

Adding support to auto attach programs with following sections:

  fsession.multi/<pattern>
  fsession.multi.s/<pattern>
  fentry.multi/<pattern>
  fexit.multi/<pattern>
  fentry.multi.s/<pattern>
  fexit.multi.s/<pattern>

The provided <pattern> is used as 'pattern' argument in
bpf_program__attach_kprobe_multi_opts function.

The <pattern> allows to specify optional kernel module name with
following syntax:

  <module>:<function_pattern>

In order to attach tracing_multi link to a module functions:
- program must be loaded with 'module' btf fd
  (in attr::attach_btf_obj_fd)
- bpf_program__attach_tracing_multi must either have
  pattern with module spec or BTF ids from the module

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260606123955.345967-21-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Adding btf_type_is_traceable_func function to perform same checks
as the kernel's btf_distill_func_proto function to prevent attachment
on some of the functions.

Exporting the function via libbpf_internal.h because it will be used
by benchmark test in following changes.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260606123955.345967-20-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Adding bpf_link_create support for tracing_multi link with
new tracing_multi record in struct bpf_link_create_opts.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260606123955.345967-19-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Adding bpf_object_cleanup_btf function to cleanup btf objects.
It will be used in following changes.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260606123955.345967-18-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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 <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260606123955.345967-16-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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 <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260606123955.345967-14-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Adding new program attach types multi tracing attachment:
  BPF_TRACE_FENTRY_MULTI
  BPF_TRACE_FEXIT_MULTI

and their base support in verifier code.

Programs with such attach type will use specific link attachment
interface coming in following changes.

This was suggested by Andrii some (long) time ago and turned out
to be easier than having special program flag for that.

Bpf programs with such types have 'bpf_multi_func' function set as
their attach_btf_id and keep module reference when it's specified
by attach_prog_fd.

They are also accepted as sleepable programs during verification,
and the real validation for specific BTF_IDs/functions will happen
during the multi link attachment in following changes.

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260606123955.345967-11-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Add BPF_MAP_TYPE_RHASH to libbpf's map type name table and feature
probing so that libbpf-based tools can create and identify resizable
hash maps.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Link: https://lore.kernel.org/r/20260605-rhash-v7-8-5b8e05f8630d@meta.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>