summaryrefslogtreecommitdiffstats
path: root/tools/objtool/check.c
diff options
context:
space:
mode:
Diffstat (limited to 'tools/objtool/check.c')
-rw-r--r--tools/objtool/check.c21
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;