On Wed, Oct 21, 2020 at 11:51:33AM +0200, Peter Zijlstra wrote: > On Tue, Oct 20, 2020 at 01:52:17PM -0500, Josh Poimboeuf wrote: > > > arch/x86/lib/retpoline.S: > > > __x86_retpoline_rdi()+0x10: return with modified stack frame > > > __x86_retpoline_rdi()+0x0: stack state mismatch: cfa1=7+32 cfa2=7+8 > > > __x86_retpoline_rdi()+0x0: stack state mismatch: cfa1=7+32 cfa2=-1+0 > > > > Is this with upstream? I thought we fixed that with > > UNWIND_HINT_RET_OFFSET. > > I can't reproduce this one either; but I do get different warnings: > > gcc (Debian 10.2.0-13) 10.2.0, x86_64-defconfig: > > defconfig-build/vmlinux.o: warning: objtool: __x86_indirect_thunk_rax() falls through to next function __x86_retpoline_rax() > defconfig-build/vmlinux.o: warning: objtool: .altinstr_replacement+0x1063: (branch) > defconfig-build/vmlinux.o: warning: objtool: __x86_indirect_thunk_rax()+0x0: (alt) > defconfig-build/vmlinux.o: warning: objtool: __x86_indirect_thunk_rax()+0x0: <=== (sym) > > (for every single register, not just rax) > > Which is daft as well, because the retpoline.o run is clean. It also > doesn't make sense because __x86_retpoline_rax isn't in fact STT_FUNC, > so WTH ?! It is STT_FUNC: SYM_FUNC_START_NOALIGN(__x86_retpoline_\reg) $ readelf -s vmlinux.o |grep __x86_retpoline_rax 129749: 0000000000000005 17 FUNC GLOBAL DEFAULT 39 __x86_retpoline_rax -- Josh
