From 32fa058398624166dd04ff4af49cfef69c94abbc Mon Sep 17 00:00:00 2001 From: Sergei Trofimovich Date: Fri, 8 Dec 2023 21:51:00 +0000 Subject: libbpf: Add pr_warn() for EINVAL cases in linker_sanity_check_elf Before the change on `i686-linux` `systemd` build failed as: $ bpftool gen object src/core/bpf/socket_bind/socket-bind.bpf.o src/core/bpf/socket_bind/socket-bind.bpf.unstripped.o Error: failed to link 'src/core/bpf/socket_bind/socket-bind.bpf.unstripped.o': Invalid argument (22) After the change it fails as: $ bpftool gen object src/core/bpf/socket_bind/socket-bind.bpf.o src/core/bpf/socket_bind/socket-bind.bpf.unstripped.o libbpf: ELF section #9 has inconsistent alignment addr=8 != d=4 in src/core/bpf/socket_bind/socket-bind.bpf.unstripped.o Error: failed to link 'src/core/bpf/socket_bind/socket-bind.bpf.unstripped.o': Invalid argument (22) Now it's slightly easier to figure out what is wrong with an ELF file. Signed-off-by: Sergei Trofimovich Signed-off-by: Andrii Nakryiko Acked-by: Eduard Zingerman Link: https://lore.kernel.org/bpf/20231208215100.435876-1-slyich@gmail.com --- tools/lib/bpf/linker.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) (limited to 'tools/lib') diff --git a/tools/lib/bpf/linker.c b/tools/lib/bpf/linker.c index 5ced96d99f8c..52a2901e8bd0 100644 --- a/tools/lib/bpf/linker.c +++ b/tools/lib/bpf/linker.c @@ -719,13 +719,25 @@ static int linker_sanity_check_elf(struct src_obj *obj) return -EINVAL; } - if (sec->shdr->sh_addralign && !is_pow_of_2(sec->shdr->sh_addralign)) + if (sec->shdr->sh_addralign && !is_pow_of_2(sec->shdr->sh_addralign)) { + pr_warn("ELF section #%zu alignment %llu is non pow-of-2 alignment in %s\n", + sec->sec_idx, (long long unsigned)sec->shdr->sh_addralign, + obj->filename); return -EINVAL; - if (sec->shdr->sh_addralign != sec->data->d_align) + } + if (sec->shdr->sh_addralign != sec->data->d_align) { + pr_warn("ELF section #%zu has inconsistent alignment addr=%llu != d=%llu in %s\n", + sec->sec_idx, (long long unsigned)sec->shdr->sh_addralign, + (long long unsigned)sec->data->d_align, obj->filename); return -EINVAL; + } - if (sec->shdr->sh_size != sec->data->d_size) + if (sec->shdr->sh_size != sec->data->d_size) { + pr_warn("ELF section #%zu has inconsistent section size sh=%llu != d=%llu in %s\n", + sec->sec_idx, (long long unsigned)sec->shdr->sh_size, + (long long unsigned)sec->data->d_size, obj->filename); return -EINVAL; + } switch (sec->shdr->sh_type) { case SHT_SYMTAB: @@ -737,8 +749,12 @@ static int linker_sanity_check_elf(struct src_obj *obj) break; case SHT_PROGBITS: if (sec->shdr->sh_flags & SHF_EXECINSTR) { - if (sec->shdr->sh_size % sizeof(struct bpf_insn) != 0) + if (sec->shdr->sh_size % sizeof(struct bpf_insn) != 0) { + pr_warn("ELF section #%zu has unexpected size alignment %llu in %s\n", + sec->sec_idx, (long long unsigned)sec->shdr->sh_size, + obj->filename); return -EINVAL; + } } break; case SHT_NOBITS: -- cgit