4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Josh Poimboeuf <[email protected]> commit 39b735332cb8b33a27c28592d969e4016c86c3ea upstream. A direct jump to a retpoline thunk is really an indirect jump in disguise. Change the objtool instruction type accordingly. Objtool needs to know where indirect branches are so it can detect switch statement jump tables. This fixes a bunch of warnings with CONFIG_RETPOLINE like: arch/x86/events/intel/uncore_nhmex.o: warning: objtool: nhmex_rbox_msr_enable_event()+0x44: sibling call from callable instruction with modified stack frame kernel/signal.o: warning: objtool: copy_siginfo_to_user()+0x91: sibling call from callable instruction with modified stack frame ... Signed-off-by: Josh Poimboeuf <[email protected]> Signed-off-by: David Woodhouse <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: Rik van Riel <[email protected]> Cc: Andi Kleen <[email protected]> Cc: [email protected] Cc: Peter Zijlstra <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Jiri Kosina <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Kees Cook <[email protected]> Cc: Tim Chen <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Paul Turner <[email protected]> Link: https://lkml.kernel.org/r/[email protected] [dwmw2: Applies to tools/objtool/builtin-check.c not check.c] Signed-off-by: David Woodhouse <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- tools/objtool/builtin-check.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c @@ -382,6 +382,13 @@ static int add_jump_destinations(struct } else if (rela->sym->sec->idx) { dest_sec = rela->sym->sec; dest_off = rela->sym->sym.st_value + rela->addend + 4; + } else if (strstr(rela->sym->name, "_indirect_thunk_")) { + /* + * Retpoline jumps are really dynamic jumps in + * disguise, so convert them accordingly. + */ + insn->type = INSN_JUMP_DYNAMIC; + continue; } else { /* sibling call */ insn->jump_dest = 0;
