3bc753c06d
Recently, some compile-time checking I added to the clamp_t family of functions triggered a build error when a poorly written driver was compiled on ARM, because the driver assumed that the naked `char` type is signed, but ARM treats it as unsigned, and the C standard says it's architecture-dependent. I doubt this particular driver is the only instance in which unsuspecting authors make assumptions about `char` with no `signed` or `unsigned` specifier. We were lucky enough this time that that driver used `clamp_t(char, negative_value, positive_value)`, so the new checking code found it, and I've sent a patch to fix it, but there are likely other places lurking that won't be so easily unearthed. So let's just eliminate this particular variety of heisensign bugs entirely. Set `-funsigned-char` globally, so that gcc makes the type unsigned on all architectures. This will break things in some places and fix things in others, so this will likely cause a bit of churn while reconciling the type misuse. Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/lkml/202210190108.ESC3pc3D-lkp@intel.com/ Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> |
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| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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.