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strncpy() is deprecated for use on NUL-terminated destination strings [1] and as such we should prefer more robust and less ambiguous string interfaces. We expect ac->name to be NUL-terminated based on its usage with format strings: surface_charger.c: 190: ac->psy_desc.name = ac->name; ... power_supply_core.c: 174: dev_dbg(&psy->dev, "%s: Found supply : %s\n", 175: psy->desc->name, epsy->desc->name); Moreover, NUL-padding is not required as ac is already zero-allocated before being passed to spwr_ac_init(): surface_charger.c: 240: ac = devm_kzalloc(&sdev->dev, sizeof(*ac), GFP_KERNEL); 241: if (!ac) 242: return -ENOMEM; 243: 244: spwr_ac_init(ac, sdev, p->registry, p->name); ... this means any future NUL-byte assignments (like the ones that strncpy() does) are redundant. Considering the above, a suitable replacement is `strscpy` [2] due to the fact that it guarantees NUL-termination on the destination buffer without unnecessarily NUL-padding. Let's also opt for the more idiomatic strscpy() usage of: (dest, src, sizeof(dest)) Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Signed-off-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20231020-strncpy-drivers-power-supply-surface_charger-c-v1-1-93ddbf668e10@google.com Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.