On 4/22/22 12:00 PM, Jiri Olsa wrote:
Adding bpf_program__set_insns that allows to set new
instructions for program.
Also moving bpf_program__attach_kprobe_multi_opts on
the proper name sorted place in map file.
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
tools/lib/bpf/libbpf.c | 8 ++++++++
tools/lib/bpf/libbpf.h | 12 ++++++++++++
tools/lib/bpf/libbpf.map | 3 ++-
3 files changed, 22 insertions(+), 1 deletion(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 809fe209cdcc..284790d81c1b 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -8457,6 +8457,14 @@ size_t bpf_program__insn_cnt(const struct bpf_program *prog)
return prog->insns_cnt;
}
+void bpf_program__set_insns(struct bpf_program *prog,
+ struct bpf_insn *insns, size_t insns_cnt)
+{
+ free(prog->insns);
+ prog->insns = insns;
+ prog->insns_cnt = insns_cnt;
+}
+
int bpf_program__set_prep(struct bpf_program *prog, int nr_instances,
bpf_program_prep_t prep)
{
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 05dde85e19a6..b31ad58d335f 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -323,6 +323,18 @@ struct bpf_insn;
* different.
*/
LIBBPF_API const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog);
+
+/**
+ * @brief **bpf_program__set_insns()** can set BPF program's underlying
+ * BPF instructions.
+ * @param prog BPF program for which to return instructions
+ * @param insn a pointer to an array of BPF instructions
+ * @param insns_cnt number of `struct bpf_insn`'s that form
+ * specified BPF program
+ */
+LIBBPF_API void bpf_program__set_insns(struct bpf_program *prog,
+ struct bpf_insn *insns, size_t insns_cnt);
+
Iiuc, patch 2 should be squashed into this one given they logically belong to the
same change?
Fwiw, I think the API description should be elaborated a bit more, in particular that
the passed-in insns need to be from allocated dynamic memory which is later on passed
to free(), and maybe also constraints at which point in time bpf_program__set_insns()
may be called.. (as well as high-level description on potential use cases e.g. around
patch 4).
/**
* @brief **bpf_program__insn_cnt()** returns number of `struct bpf_insn`'s
* that form specified BPF program.
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index dd35ee58bfaa..afa10d24ab41 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -444,7 +444,8 @@ LIBBPF_0.8.0 {
global:
bpf_object__destroy_subskeleton;
bpf_object__open_subskeleton;
+ bpf_program__attach_kprobe_multi_opts;
+ bpf_program__set_insns;
libbpf_register_prog_handler;
libbpf_unregister_prog_handler;
- bpf_program__attach_kprobe_multi_opts;
} LIBBPF_0.7.0;
