libbpf: Use proper errno value in linker

Return values of the linker_append_sec_data() and the
linker_append_elf_relos() functions are propagated all the
way up to users of libbpf API. In some error cases these
functions return -1 which will be seen as -EPERM from user's
point of view. Instead, return a more reasonable -EINVAL.

Fixes: faf6ed321cf6 ("libbpf: Add BPF static linker APIs")
Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250430120820.2262053-1-a.s.protopopov@gmail.com

diff --git a/tools/lib/bpf/linker.c b/tools/lib/bpf/linker.c
index 56f5068..a469e5d 100644 (file)
--- a/tools/lib/bpf/linker.c
+++ b/tools/lib/bpf/linker.c
@@ -1376,7 +1376,7 @@ static int linker_append_sec_data(struct bpf_linker *linker, struct src_obj *obj
                } else {
                        if (!secs_match(dst_sec, src_sec)) {
                                pr_warn("ELF sections %s are incompatible\n", src_sec->sec_name);
-                               return -1;
+                               return -EINVAL;
                        }
 
                        /* "license" and "version" sections are deduped */
@@ -2223,7 +2223,7 @@ static int linker_append_elf_relos(struct bpf_linker *linker, struct src_obj *ob
                        }
                } else if (!secs_match(dst_sec, src_sec)) {
                        pr_warn("sections %s are not compatible\n", src_sec->sec_name);
-                       return -1;
+                       return -EINVAL;
                }
 
                /* shdr->sh_link points to SYMTAB */