linux-toradex.git/include/linux/sysfs.h, branch v6.16-rc6

sysfs: constify attribute_group::bin_attrs

2025-04-15T16:46:10+00:00

All users of this field have been migrated to bin_attrs_new.
It can now be constified.

Signed-off-by: Thomas Weißschuh 
Link: https://lore.kernel.org/r/20250313-sysfs-const-bin_attr-final-v2-2-96284e1e88ce@weissschuh.net
Signed-off-by: Greg Kroah-Hartman

sysfs: constify bin_attribute argument of bin_attribute::read/write()

2025-04-15T16:45:32+00:00

All callback implementers have been moved to the const variant of the
callbacks. The signature of the original callbacks can now be changed.
Also remove the now unnecessary transition machinery inside __BIN_ATTR().

Signed-off-by: Thomas Weißschuh 
Link: https://lore.kernel.org/r/20250313-sysfs-const-bin_attr-final-v2-1-96284e1e88ce@weissschuh.net
Signed-off-by: Greg Kroah-Hartman

sysfs: constify bin_attribute argument of sysfs_bin_attr_simple_read()

2025-01-09T09:43:58+00:00

Most users use this function through the BIN_ATTR_SIMPLE* macros,
they can handle the switch transparently.
Also adapt the two non-macro users in the same change.

Signed-off-by: Thomas Weißschuh 
Acked-by: Madhavan Srinivasan 
Reviewed-by: Mahesh Salgaonkar 
Tested-by: Aditya Gupta 
Link: https://lore.kernel.org/r/20241228-sysfs-const-bin_attr-simple-v2-1-7c6f3f1767a3@weissschuh.net
Signed-off-by: Greg Kroah-Hartman

sysfs: constify macro BIN_ATTRIBUTE_GROUPS()

2025-01-07T16:01:13+00:00

As there is only one in-tree user, avoid a transition phase and switch
that user in the same commit. As there are some interdependencies
between the constness of the different symbols in the s390 driver,
covert the whole driver at once.

Signed-off-by: Thomas Weißschuh 
Link: https://lore.kernel.org/r/20241205-sysfs-const-bin_attr-groups_macro-v1-1-ac5e855031e8@weissschuh.net
Signed-off-by: Greg Kroah-Hartman

sysfs: attribute_group: allow registration of const bin_attribute

2024-11-15T18:29:16+00:00

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

sysfs: bin_attribute: add const read/write callback variants

2024-11-05T13:00:28+00:00

To make it possible to put struct bin_attribute into read-only memory,
the sysfs core has to stop passing mutable pointers to the read() and
write() callbacks.
As there are numerous implementors of these callbacks throughout the
tree it's not possible to change all of them at once.
To enable a step-by-step transition, add new variants of the read() and
write() callbacks which differ only in the constness of the struct
bin_attribute argument.

As most binary attributes are defined through macros, extend these
macros to transparently handle both variants of callbacks to minimize
the churn during the transition.
As soon as all handlers are switch to the const variant, the non-const
one can be removed together with the transition machinery.

Signed-off-by: Thomas Weißschuh 
Acked-by: Krzysztof Wilczyński 
Link: https://lore.kernel.org/r/20241103-sysfs-const-bin_attr-v2-9-71110628844c@weissschuh.net
Signed-off-by: Greg Kroah-Hartman

sysfs: implement all BIN_ATTR_* macros in terms of __BIN_ATTR()

2024-11-05T13:00:28+00:00

The preparations for the upcoming constification of struct bin_attribute
requires some logic in the structure definition macros.
To avoid duplication of that logic in multiple macros, reimplement all
other macros in terms of __BIN_ATTR().

Signed-off-by: Thomas Weißschuh 
Acked-by: Krzysztof Wilczyński 
Link: https://lore.kernel.org/r/20241103-sysfs-const-bin_attr-v2-8-71110628844c@weissschuh.net
Signed-off-by: Greg Kroah-Hartman

sysfs: treewide: constify attribute callback of bin_attribute::llseek()

2024-11-05T13:00:28+00:00

The llseek() callbacks should not modify the struct
bin_attribute passed as argument.
Enforce this by marking the argument as const.

As there are not many callback implementers perform this change
throughout the tree at once.

Signed-off-by: Thomas Weißschuh 
Acked-by: Krzysztof Wilczyński 
Link: https://lore.kernel.org/r/20241103-sysfs-const-bin_attr-v2-7-71110628844c@weissschuh.net
Signed-off-by: Greg Kroah-Hartman

sysfs: treewide: constify attribute callback of bin_attribute::mmap()

2024-11-05T13:00:28+00:00

The mmap() callbacks should not modify the struct
bin_attribute passed as argument.
Enforce this by marking the argument as const.

As there are not many callback implementers perform this change
throughout the tree at once.

Signed-off-by: Thomas Weißschuh 
Acked-by: Andrew Donnellan  # ocxl
Acked-by: Krzysztof Wilczyński 
Link: https://lore.kernel.org/r/20241103-sysfs-const-bin_attr-v2-6-71110628844c@weissschuh.net
Signed-off-by: Greg Kroah-Hartman

sysfs: treewide: constify attribute callback of bin_is_visible()

2024-11-05T13:00:28+00:00

The is_bin_visible() callbacks should not modify the struct
bin_attribute passed as argument.
Enforce this by marking the argument as const.

As there are not many callback implementers perform this change
throughout the tree at once.

Signed-off-by: Thomas Weißschuh 
Acked-by: Martin K. Petersen 
Acked-by: Jason Gunthorpe 
Acked-by: Ira Weiny 
Acked-by: Krzysztof Wilczyński 
Link: https://lore.kernel.org/r/20241103-sysfs-const-bin_attr-v2-5-71110628844c@weissschuh.net
Signed-off-by: Greg Kroah-Hartman