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1036b89580
Tag all references to assembly functions with SYM_TYPED_FUNC_START() and SYM_FUNC_END() so they also become CFI-safe. When we add SYM_TYPED_FUNC_START() to assembly calls, a function prototype signature will be emitted into the object file at (pc-4) at the call site, so that the KCFI runtime check can compare this to the expected call. Example: 8011ae38: a540670c .word 0xa540670c 8011ae3c <v7_flush_icache_all>: 8011ae3c: e3a00000 mov r0, #0 8011ae40: ee070f11 mcr 15, 0, r0, cr7, cr1, {0} 8011ae44: e12fff1e bx lr This means no "fallthrough" code can enter a SYM_TYPED_FUNC_START() call from above it: there will be a function prototype signature there, so those are consistently converted to a branch or ret lr depending on context. Tested-by: Kees Cook <keescook@chromium.org> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
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 reStructuredText 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.