From: Andrii Nakryiko <andrii@kernel.org>
Date: Fri, 14 May 2021 19:55:34 +0000 (-0700)
Subject: libbpf: Reject static entry-point BPF programs
X-Git-Tag: accepted/tizen/unified/20230118.172025~6942^2~501^2~9
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=513f485ca5163c6cba869602d076a8e2f04d1ca1;p=platform%2Fkernel%2Flinux-rpi.git

libbpf: Reject static entry-point BPF programs

Detect use of static entry-point BPF programs (those with SEC() markings) and
emit error message. This is similar to
c1cccec9c636 ("libbpf: Reject static maps") but for BPF programs.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210514195534.1440970-1-andrii@kernel.org
---

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 182bd3d..e58f51b 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -677,6 +677,11 @@ bpf_object__add_programs(struct bpf_object *obj, Elf_Data *sec_data,
 			return -LIBBPF_ERRNO__FORMAT;
 		}
 
+		if (sec_idx != obj->efile.text_shndx && GELF_ST_BIND(sym.st_info) == STB_LOCAL) {
+			pr_warn("sec '%s': program '%s' is static and not supported\n", sec_name, name);
+			return -ENOTSUP;
+		}
+
 		pr_debug("sec '%s': found program '%s' at insn offset %zu (%zu bytes), code size %zu insns (%zu bytes)\n",
 			 sec_name, name, sec_off / BPF_INSN_SZ, sec_off, prog_sz / BPF_INSN_SZ, prog_sz);