From 906c508afdca3487c4273bfeda8abedc8e21047b Mon Sep 17 00:00:00 2001 From: =?utf8?q?Thomas=20Wei=C3=9Fschuh?= Date: Fri, 15 Nov 2024 17:42:48 +0100 Subject: [PATCH] sysfs: attribute_group: allow registration of const bin_attribute MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit To be able to constify instances of struct bin_attribute it has to be possible to add them to string attribute_group. The current type of the bin_attrs member however is not compatible with that. Introduce a union that allows registration of both const and non-const attributes to enable a piecewise transition. As both union member types are compatible no logic needs to be adapted. Technically it is now possible register a const struct bin_attribute and receive it as mutable pointer in the callbacks. This is a soundness issue. But this same soundness issue already exists today in sysfs_create_bin_file(). Also the struct definition and callback implementation are always closely linked and are meant to be moved to const in lockstep. Signed-off-by: Thomas Weißschuh Link: https://lore.kernel.org/r/20241115-b4-sysfs-const-bin_attr-group-v1-1-2c9bb12dfc48@weissschuh.net Signed-off-by: Greg Kroah-Hartman --- include/linux/sysfs.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index d713a6445a62..0f2fcd244523 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -106,7 +106,10 @@ struct attribute_group { const struct bin_attribute *, int); struct attribute **attrs; - struct bin_attribute **bin_attrs; + union { + struct bin_attribute **bin_attrs; + const struct bin_attribute *const *bin_attrs_new; + }; }; #define SYSFS_PREALLOC 010000 -- 2.25.1