Re: [PATCH] powerpc/64s: Enhance the information in cpu_show_spectre_v1()

[Christophe Leroy]

On 05/29/2018 02:46 PM, Michal SuchÃnek wrote:
> On Tue, 29 May 2018 16:13:49 +0200
> Christophe LEROY <christophe.leroy@xxxxxx> wrote:
>
> > Le 28/05/2018 Ã 15:19, Michal Suchanek a ÃcritÂ:
> > > We now have barrier_nospec as mitigation so print it in
> > > cpu_show_spectre_v1 when enabled.
> > >
> > > Signed-off-by: Michal Suchanek <msuchanek@xxxxxxx>
> > > ---
> > >    arch/powerpc/kernel/security.c | 5 ++++-
> > >    1 file changed, 4 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/arch/powerpc/kernel/security.c
> > > b/arch/powerpc/kernel/security.c index 0239383c7e4d..a0c32d53980b
> > > 100644 --- a/arch/powerpc/kernel/security.c
> > > +++ b/arch/powerpc/kernel/security.c
> > > @@ -120,7 +120,10 @@ ssize_t cpu_show_spectre_v1(struct device
> > > *dev, struct device_attribute *attr, c if
> > > (!security_ftr_enabled(SEC_FTR_BNDS_CHK_SPEC_BAR)) return
> > > sprintf(buf, "Not affected\n");
> > > -	return sprintf(buf, "Vulnerable\n");
> > > +	if (barrier_nospec_enabled)
> >
> > > +		return sprintf(buf, "Mitigation: __user pointer
> > > sanitization\n");
> > > +	else
> > > +		return sprintf(buf, "Vulnerable\n");
> >
> > Checkpatch would tell you that an else is unneeded after a return. So
> > just leave it as it was before.
>
> Where did you get your copy of checkpatch? The one in Linux tree does
> not do that.

Strange, it should, as checkpatch.pl includes the following code:

# check indentation of any line with a bare else
# (but not if it is a multiple line "if (foo) return bar; else return baz;")
# if the previous line is a break or return and is indented 1 tab more...
		if ($sline =~ /^\+([\t]+)(?:}[ \t]*)?else(?:[ \t]*{)?\s*$/) {
			my $tabs = length($1) + 1;
			if ($prevline =~ /^\+\t{$tabs,$tabs}break\b/ ||
			    ($prevline =~ /^\+\t{$tabs,$tabs}return\b/ &&
			     defined $lines[$linenr] &&
			     $lines[$linenr] !~ /^[ \+]\t{$tabs,$tabs}return/)) {
				WARN("UNNECESSARY_ELSE",
				     "else is not generally useful after a break or return\n" . 
$hereprev);
			}
		}


Anyway, you should remove that 'else' in your patch.
And the other sprintf line is over 80 characters.

Christophe

> Thanks
>
> Michal