Re: [PATCH] objtool: Add fortify_panic as __noreturn function

[Stephen Rothwell]

Hi all,

On Thu, 15 Jun 2017 14:05:22 +1000 Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
>
> On Wed, 14 Jun 2017 19:18:51 -0700 Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> >
> > CONFIG_FORTIFY_SOURCE implements fortify_panic() as a __noreturn function,
> > so objtool needs to know about it too.
> > 
> > Suggested-by: Daniel Micay <danielmicay@xxxxxxxxx>
> > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
> > Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> > ---
> >  tools/objtool/builtin-check.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c
> > index 282a60368b14..5f66697fe1e0 100644
> > --- a/tools/objtool/builtin-check.c
> > +++ b/tools/objtool/builtin-check.c
> > @@ -192,7 +192,8 @@ static int __dead_end_function(struct objtool_file *file, struct symbol *func,
> >  		"complete_and_exit",
> >  		"kvm_spurious_fault",
> >  		"__reiserfs_panic",
> > -		"lbug_with_loc"
> > +		"lbug_with_loc",
> > +		"fortify_panic",
> >  	};
> >  
> >  	if (func->bind == STB_WEAK)
> > -- 
> > 2.7.4  
> 
> OK, I have added this to the end of linux-next today (in the part of
> Andrew's tree afte the linux-next merge).  I also move the fortify
> string patch to after it (but I assume I will still need to revert it).

So after that the errors (x86_64 allmodconfig build) are only:

In file included from include/linux/bitmap.h:8:0,
                 from include/linux/cpumask.h:11,
                 from arch/x86/include/asm/cpumask.h:4,
                 from arch/x86/include/asm/msr.h:10,
                 from arch/x86/include/asm/processor.h:20,
                 from arch/x86/include/asm/cpufeature.h:4,
                 from arch/x86/include/asm/thread_info.h:52,
                 from include/linux/thread_info.h:37,
                 from arch/x86/include/asm/preempt.h:6,
                 from include/linux/preempt.h:80,
                 from include/linux/spinlock.h:50,
                 from include/linux/mmzone.h:7,
                 from include/linux/gfp.h:5,
                 from arch/x86/power/hibernate_64.c:11:
In function 'memcpy',
    inlined from 'relocate_restore_code' at arch/x86/power/hibernate_64.c:150:2,
    inlined from 'swsusp_arch_resume' at arch/x86/power/hibernate_64.c:186:8:
include/linux/string.h:309:4: error: call to '__read_overflow2' declared with attribute error: detected read beyond size of object passed as 2nd parameter
    __read_overflow2();
    ^
In file included from include/linux/bitmap.h:8:0,
                 from include/linux/cpumask.h:11,
                 from arch/x86/include/asm/cpumask.h:4,
                 from arch/x86/include/asm/msr.h:10,
                 from arch/x86/include/asm/processor.h:20,
                 from arch/x86/include/asm/cpufeature.h:4,
                 from arch/x86/include/asm/thread_info.h:52,
                 from include/linux/thread_info.h:37,
                 from arch/x86/include/asm/preempt.h:6,
                 from include/linux/preempt.h:80,
                 from include/linux/spinlock.h:50,
                 from include/linux/mmzone.h:7,
                 from include/linux/gfp.h:5,
                 from include/linux/mm.h:9,
                 from kernel/kexec_file.c:15:
In function 'memcmp',
    inlined from 'kexec_load_purgatory' at kernel/kexec_file.c:900:6:
include/linux/string.h:348:4: error: call to '__read_overflow' declared with attribute error: detected read beyond size of object passed as 1st parameter
    __read_overflow();
    ^

-- 
Cheers,
Stephen Rothwell