Re: [PATCH 1/2] powerpc/64s: Work around spurious warning on old gccs with -fsanitize-coverage

[Andrew Donnellan]

On 9/2/19 2:41 am, Segher Boessenkool wrote:

On Fri, Feb 08, 2019 at 02:02:24PM +1100, Michael Ellerman wrote:

diff --git a/arch/powerpc/kernel/dt_cpu_ftrs.c 
b/arch/powerpc/kernel/dt_cpu_ftrs.c
index 8be3721d9302..a1acccd25839 100644
--- a/arch/powerpc/kernel/dt_cpu_ftrs.c
+++ b/arch/powerpc/kernel/dt_cpu_ftrs.c
@@ -675,12 +675,10 @@ static bool __init cpufeatures_process_feature(struct 
dt_cpu_feature *f)
                }
        }

- if (!known && enable_unknown) {

-               if (!feat_try_enable_unknown(f)) {
-                       pr_info("not enabling: %s (unknown and unsupported by 
kernel)\n",
-                               f->name);
-                       return false;
-               }
+       if (!known && (!enable_unknown || !feat_try_enable_unknown(f))) {
+               pr_info("not enabling: %s (unknown and unsupported by 
kernel)\n",
+                       f->name);
+               return false;
        }

if (m->cpu_ftr_bit_mask)

                cur_cpu_spec->cpu_features |= m->cpu_ftr_bit_mask;

This still set the wrong mask here, which is the bug you're trying to fix.
It should only do this if "known", afaics.

I've got a v2 ready to send which fixes both things.

Segher

--
Andrew Donnellan              OzLabs, ADL Canberra
andrew.donnel...@au1.ibm.com  IBM Australia Limited