diff options
| -rw-r--r-- | tools/objtool/check.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 9016ae1c0c55..b038de2ccd71 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -768,6 +768,27 @@ static int handle_group_alt(struct objtool_file *file, insn->ignore = orig_insn->ignore_alts; insn->func = orig_insn->func; + /* + * Since alternative replacement code is copy/pasted by the + * kernel after applying relocations, generally such code can't + * have relative-address relocation references to outside the + * .altinstr_replacement section, unless the arch's + * alternatives code can adjust the relative offsets + * accordingly. + * + * The x86 alternatives code adjusts the offsets only when it + * encounters a branch instruction at the very beginning of the + * replacement group. + */ + if ((insn->offset != special_alt->new_off || + (insn->type != INSN_CALL && !is_static_jump(insn))) && + find_rela_by_dest_range(insn->sec, insn->offset, insn->len)) { + + WARN_FUNC("unsupported relocation in alternatives section", + insn->sec, insn->offset); + return -1; + } + if (!is_static_jump(insn)) continue; |