Re: [GIT PULL] hash addresses printed with %p

[Dave Young <dyoung@redhat.com>]

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.

> 
> 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