On Mon, Jan 14, 2019 at 10:02:21AM +0000, Suzuki K Poulose wrote: > > > On 09/01/2019 23:55, Jeremy Linton wrote: > > As suggested on the list, https://lkml.org/lkml/2019/1/4/282, there are > > a number of cases where its useful for a system to avoid exporting a > > sysfs entry for a given vulnerability. This set adds an architecture > > specific callback which returns the bitmap of vulnerabilities the > > architecture would like to advertise. > > > > Signed-off-by: Jeremy Linton <jeremy.lin...@arm.com> > > Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org> > > Cc: Rafael J. Wysocki <raf...@kernel.org> > > Cc: Thomas Gleixner <t...@linutronix.de> > > Cc: Josh Poimboeuf <jpoim...@redhat.com> > > Cc: Konrad Rzeszutek Wilk <konrad.w...@oracle.com> > > Cc: Ingo Molnar <mi...@kernel.org> > > Cc: Waiman Long <long...@redhat.com> > > Cc: Andi Kleen <a...@linux.intel.com> > > Cc: Jiri Kosina <jkos...@suse.cz> > > --- > > drivers/base/cpu.c | 19 +++++++++++++++++++ > > include/linux/cpu.h | 7 +++++++ > > 2 files changed, 26 insertions(+) > > > > diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c > > index eb9443d5bae1..35f6dfb24cd6 100644 > > --- a/drivers/base/cpu.c > > +++ b/drivers/base/cpu.c > > @@ -561,6 +561,11 @@ static struct attribute > > *cpu_root_vulnerabilities_attrs[] = { > > NULL > > }; > > +uint __weak arch_supported_vuln_attr_fields(void) > > +{ > > + return VULN_MELTDOWN|VULN_SPECTREV1|VULN_SPECTREV2|VULN_SSB|VULN_L1TF; > > +} > > + > > static const struct attribute_group cpu_root_vulnerabilities_group = { > > .name = "vulnerabilities", > > .attrs = cpu_root_vulnerabilities_attrs, > > @@ -568,6 +573,20 @@ static const struct attribute_group > > cpu_root_vulnerabilities_group = { > > static void __init cpu_register_vulnerabilities(void) > > { > > + int fld; > > + int max_fields = ARRAY_SIZE(cpu_root_vulnerabilities_attrs) - 1; > > + struct attribute **hd = cpu_root_vulnerabilities_attrs; > > + uint enabled_fields = arch_supported_vuln_attr_fields(); > > + > > + /* only enable entries requested by the arch code */ > > + for (fld = 0; fld < max_fields; fld++) { > > + if (enabled_fields & 1 << fld) { > > + *hd = cpu_root_vulnerabilities_attrs[fld]; > > + hd++; > > + } > > + } > > + *hd = NULL; > > + > > nit: Could we use "is_visible" callback in the attribute group to check this > dynamically ?
You should, that is what it is there for. thanks, greg k-h
