On Sun, Jul 14, 2019 at 5:37 PM Josh Poimboeuf <jpoim...@redhat.com> wrote: > > After an objtool improvement, it's complaining about the CLAC in > copy_user_handle_tail(): > > arch/x86/lib/copy_user_64.o: warning: objtool: .altinstr_replacement+0x12: > redundant UACCESS disable > arch/x86/lib/copy_user_64.o: warning: objtool: > copy_user_handle_tail()+0x6: (alt) > arch/x86/lib/copy_user_64.o: warning: objtool: > copy_user_handle_tail()+0x2: (alt) > arch/x86/lib/copy_user_64.o: warning: objtool: > copy_user_handle_tail()+0x0: <=== (func) > > copy_user_handle_tail() is incorrectly marked as a callable function, so > objtool is rightfully concerned about the CLAC with no corresponding > STAC. > > Remove the ELF function annotation. The copy_user_handle_tail() code > path is already verified by objtool because it's jumped to by other > callable asm code (which does the corresponding STAC).
What is CLAC and STAC? > > Signed-off-by: Josh Poimboeuf <jpoim...@redhat.com> > --- > arch/x86/lib/copy_user_64.S | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S > index 378a1f70ae7d..4fe1601dbc5d 100644 > --- a/arch/x86/lib/copy_user_64.S > +++ b/arch/x86/lib/copy_user_64.S > @@ -239,7 +239,7 @@ copy_user_handle_tail: > ret > > _ASM_EXTABLE_UA(1b, 2b) > -ENDPROC(copy_user_handle_tail) > +END(copy_user_handle_tail) > > /* > * copy_user_nocache - Uncached memory copy with exception handling > -- > 2.20.1 > -- Thanks, ~Nick Desaulniers
