Kristen found a hang in objtool when building with -ffunction-sections. It was caused by evergreen_pcie_gen2_enable.cold() being laid out immediately before evergreen_pcie_gen2_enable(). Since their "pfunc" is always the same, find_jump_table() got into an infinite loop because it didn't recognize the boundary between the two functions.
Fix that with a new prev_insn_same_sym() helper, which doesn't cross subfunction boundaries. Reported-by: Kristen Carlson Accardi <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> --- tools/objtool/check.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 0c732d586924..4b51a06c7683 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -73,6 +73,17 @@ static struct instruction *next_insn_same_func(struct objtool_file *file, return find_insn(file, func->cfunc->sec, func->cfunc->offset); } +static struct instruction *prev_insn_same_sym(struct objtool_file *file, + struct instruction *insn) +{ + struct instruction *prev = list_prev_entry(insn, list); + + if (&prev->list != &file->insn_list && prev->func == insn->func) + return prev; + + return NULL; +} + #define func_for_each_insn(file, func, insn) \ for (insn = find_insn(file, func->sec, func->offset); \ insn; \ @@ -1096,8 +1107,8 @@ static struct rela *find_jump_table(struct objtool_file *file, * it. */ for (; - &insn->list != &file->insn_list && insn->func && insn->func->pfunc == func; - insn = insn->first_jump_src ?: list_prev_entry(insn, list)) { + insn && insn->func && insn->func->pfunc == func; + insn = insn->first_jump_src ?: prev_insn_same_sym(file, insn)) { if (insn != orig_insn && insn->type == INSN_JUMP_DYNAMIC) break; -- 2.21.1
