On 12/05/17 at 04:45pm, Dave Young wrote:
> On 12/05/17 at 09:09am, Greg Kroah-Hartman wrote:
> > On Tue, Dec 05, 2017 at 01:14:34PM +0800, Dave Young wrote:
> > > On 12/04/17 at 03:00pm, Greg Kroah-Hartman wrote:
> > > > On Mon, Dec 04, 2017 at 12:51:13PM +0000, David Laight wrote:
> > > > > From: Ard Biesheuvel
> > > > > > Sent: 04 December 2017 10:03
> > > > > ...
> > > > > > and uses __ATTR_RO() to emit initializers for it. __ATTR()
> > > > > > initializes
> > > > > > the .store member as well, which does not exists, and so it cannot
> > > > > > be
> > > > > > used directly.
> > > > > >
> > > > > > So we should either add a .store member that is always NULL, or we
> > > > > > should add our own
> > > > > >
> > > > > > #define __ATTR_0400(_name) { \
> > > > > > .attr = { .name = __stringify(_name), .mode = 0400 }, \
> > > > > > .show = _name##_show, \
> > > > > > }
> > > > >
> > > > > What about an __ATTR_RO_MODE(name, mode) that doesn't set the .store
> > > > > member.
> > > > > Even if the mode allowed write, writes wouldn't happen.
> > > >
> > > > Ah, that might work, could you convert the other users of __ATTR() in
> > > > the efi code to use it as well?
> > >
> > > $ grep __ATTR * -RI
> > > efi.c: __ATTR(systab, 0400, systab_show, NULL);
> > > efi.c:static struct kobj_attribute efi_attr_fw_vendor =
> > > __ATTR_RO(fw_vendor);
> > > efi.c:static struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime);
> > > efi.c:static struct kobj_attribute efi_attr_config_table =
> > > __ATTR_RO(config_table);
> > > efi.c: __ATTR_RO(fw_platform_size);
> > > esrt.c:static struct esre_attribute esre_fw_class = __ATTR(fw_class, 0400,
> > > esrt.c:static struct esre_attribute esre_##name = __ATTR(name, 0400, \
> > > esrt.c:static struct kobj_attribute esrt_##name = __ATTR(name, 0400, \
> > > runtime-map.c:static struct map_attribute map_type_attr = __ATTR_RO(type);
> > > runtime-map.c:static struct map_attribute map_phys_addr_attr =
> > > __ATTR_RO(phys_addr);
> > > runtime-map.c:static struct map_attribute map_virt_addr_attr =
> > > __ATTR_RO(virt_addr);
> > > runtime-map.c:static struct map_attribute map_num_pages_attr =
> > > __ATTR_RO(num_pages);
> > > runtime-map.c:static struct map_attribute map_attribute_attr =
> > > __ATTR_RO(attribute);
> > >
> > > Above is all the __ATTR users for drivers/firmware/efi/*, it makes sense
> > > to update all __ATTR_RO to __ATTR_RO_MODE, so efi.c, runtime-map.c, and
> > > drivers/firmware/dmi-sysfs.c can be updated. But esrt.c __ATTR seems
> > > not necessary.
> > >
> > > And if so __ATTR_RO_MODE(name, mode) still needs go to sysfs.h.
> > >
> > > I can do it but need confirm, Is this what you prefer?
> >
> > Yes, how about the patch below, it builds for me, haven't done anything
> > other than that to test it :)
>
> Thanks! Let me do a kexec test and a boot test for esrt.
It works for me. esrt part only did a boot test and cat/ls.
>
> >
> > Also, what's with the multi-line sysfs file systab? That's really not
> > allowed, can you please remove it? Also the first check for !kobj and
> > !buf is funny, that can never happen.
>
> I thought to do that, but later worried about it will break things:
> http://lists.infradead.org/pipermail/kexec/2013-December/010759.html
>
> I also thought to add code comment to avoid future expanding of this
> file. Maybe we can do this now.
>
> >
> > Please turn all of those different values into different sysfs files.
> >
> > thanks,
> >
> > greg k-h
> >
> >
> > diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> > index f70febf680c3..c3eefa126e3b 100644
> > --- a/drivers/firmware/efi/efi.c
> > +++ b/drivers/firmware/efi/efi.c
> > @@ -143,8 +143,7 @@ static ssize_t systab_show(struct kobject *kobj,
> > return str - buf;
> > }
> >
> > -static struct kobj_attribute efi_attr_systab =
> > - __ATTR(systab, 0400, systab_show, NULL);
> > +static struct kobj_attribute efi_attr_systab = __ATTR_RO_MODE(systab,
> > 0400);
> >
> > #define EFI_FIELD(var) efi.var
> >
> > diff --git a/drivers/firmware/efi/esrt.c b/drivers/firmware/efi/esrt.c
> > index bd7ed3c1148a..7aae2483fcb9 100644
> > --- a/drivers/firmware/efi/esrt.c
> > +++ b/drivers/firmware/efi/esrt.c
> > @@ -106,7 +106,7 @@ static const struct sysfs_ops esre_attr_ops = {
> > };
> >
> > /* Generic ESRT Entry ("ESRE") support. */
> > -static ssize_t esre_fw_class_show(struct esre_entry *entry, char *buf)
> > +static ssize_t fw_class_show(struct esre_entry *entry, char *buf)
> > {
> > char *str = buf;
> >
> > @@ -117,18 +117,16 @@ static ssize_t esre_fw_class_show(struct esre_entry
> > *entry, char *buf)
> > return str - buf;
> > }
> >
> > -static struct esre_attribute esre_fw_class = __ATTR(fw_class, 0400,
> > - esre_fw_class_show, NULL);
> > +static struct esre_attribute esre_fw_class = __ATTR_RO_MODE(fw_class,
> > 0400);
> >
> > #define esre_attr_decl(name, size, fmt) \
> > -static ssize_t esre_##name##_show(struct esre_entry *entry, char *buf) \
> > +static ssize_t name##_show(struct esre_entry *entry, char *buf) \
> > { \
> > return sprintf(buf, fmt "\n", \
> > le##size##_to_cpu(entry->esre.esre1->name)); \
> > } \
> > \
> > -static struct esre_attribute esre_##name = __ATTR(name, 0400, \
> > - esre_##name##_show, NULL)
> > +static struct esre_attribute esre_##name = __ATTR_RO_MODE(name, 0400)
> >
> > esre_attr_decl(fw_type, 32, "%u");
> > esre_attr_decl(fw_version, 32, "%u");
> > @@ -193,14 +191,13 @@ static int esre_create_sysfs_entry(void *esre, int
> > entry_num)
> >
> > /* support for displaying ESRT fields at the top level */
> > #define esrt_attr_decl(name, size, fmt) \
> > -static ssize_t esrt_##name##_show(struct kobject *kobj, \
> > +static ssize_t name##_show(struct kobject *kobj, \
> > struct kobj_attribute *attr, char *buf)\
> > { \
> > return sprintf(buf, fmt "\n", le##size##_to_cpu(esrt->name)); \
> > } \
> > \
> > -static struct kobj_attribute esrt_##name = __ATTR(name, 0400, \
> > - esrt_##name##_show, NULL)
> > +static struct kobj_attribute esrt_##name = __ATTR_RO_MODE(name, 0400)
> >
> > esrt_attr_decl(fw_resource_count, 32, "%u");
> > esrt_attr_decl(fw_resource_count_max, 32, "%u");
> > diff --git a/drivers/firmware/efi/runtime-map.c
> > b/drivers/firmware/efi/runtime-map.c
> > index 8e64b77aeac9..f377609ff141 100644
> > --- a/drivers/firmware/efi/runtime-map.c
> > +++ b/drivers/firmware/efi/runtime-map.c
> > @@ -63,11 +63,11 @@ static ssize_t map_attr_show(struct kobject *kobj,
> > struct attribute *attr,
> > return map_attr->show(entry, buf);
> > }
> >
> > -static struct map_attribute map_type_attr = __ATTR_RO(type);
> > -static struct map_attribute map_phys_addr_attr = __ATTR_RO(phys_addr);
> > -static struct map_attribute map_virt_addr_attr = __ATTR_RO(virt_addr);
> > -static struct map_attribute map_num_pages_attr = __ATTR_RO(num_pages);
> > -static struct map_attribute map_attribute_attr = __ATTR_RO(attribute);
> > +static struct map_attribute map_type_attr = __ATTR_RO_MODE(type, 0400);
> > +static struct map_attribute map_phys_addr_attr = __ATTR_RO_MODE(phys_addr,
> > 0400);
> > +static struct map_attribute map_virt_addr_attr = __ATTR_RO_MODE(virt_addr,
> > 0400);
> > +static struct map_attribute map_num_pages_attr = __ATTR_RO_MODE(num_pages,
> > 0400);
> > +static struct map_attribute map_attribute_attr = __ATTR_RO_MODE(attribute,
> > 0400);
> >
> > /*
> > * These are default attributes that are added for every memmap entry.
> > diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
> > index e32dfe098e82..a886133ae15c 100644
> > --- a/include/linux/sysfs.h
> > +++ b/include/linux/sysfs.h
> > @@ -117,6 +117,11 @@ struct attribute_group {
> > .show = _name##_show, \
> > }
> >
> > +#define __ATTR_RO_MODE(_name, _mode) {
> > \
> > + .attr = { .name = __stringify(_name), .mode = _mode }, \
> > + .show = _name##_show, \
> > +}
> > +
> > #define __ATTR_WO(_name) { \
> > .attr = { .name = __stringify(_name), .mode = S_IWUSR }, \
> > .store = _name##_store, \
>
> Thanks
> Dave
