Sometimes Clang arm64 code jumps to the end of the function for UB. No need to make that an error for checksum runs, which are only run manually by klp-build, and for which caring about UB is out of scope.
Such UBs are still reported for normal validate branch runs (for arches which do that). Signed-off-by: Josh Poimboeuf <[email protected]> --- tools/objtool/check.c | 38 +++++++++++++++++++++----------------- 1 file changed, 21 insertions(+), 17 deletions(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index b353c7d6cd893..c034676e1b8c7 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -38,6 +38,22 @@ struct disas_context *objtool_disas_ctx; size_t sym_name_max_len; +static bool validate_branch_enabled(void) +{ + return opts.stackval || + opts.orc || + opts.uaccess; +} + +static bool alts_needed(void) +{ + return validate_branch_enabled() || + opts.noinstr || + opts.hack_jump_label || + opts.disas || + opts.checksum; +} + struct instruction *find_insn(struct objtool_file *file, struct section *sec, unsigned long offset) { @@ -1595,8 +1611,12 @@ static int add_jump_destinations(struct objtool_file *file) /* * GCOV/KCOV dead code can jump to the end of * the function/section. + * + * Clang on arm64 also does this sometimes for + * undefined behavior. */ - if (file->ignore_unreachables && func && + if ((!validate_branch_enabled() || file->ignore_unreachables) && + func && dest_sec == insn->sec && dest_off == func->offset + func->len) continue; @@ -2586,22 +2606,6 @@ static void mark_holes(struct objtool_file *file) } } -static bool validate_branch_enabled(void) -{ - return opts.stackval || - opts.orc || - opts.uaccess; -} - -static bool alts_needed(void) -{ - return validate_branch_enabled() || - opts.noinstr || - opts.hack_jump_label || - opts.disas || - opts.checksum; -} - int decode_file(struct objtool_file *file) { arch_initial_func_cfi_state(&initial_func_cfi); -- 2.54.0
