ARMv8M introduces support for Security extension to M class, among other things it affects exception handling, especially, encoding of EXC_RETURN. The new bits have been added: Bit [6] Secure or Non-secure stack Bit [5] Default callee register stacking Bit [0] Exception Secure which conflicts with hard-coded value of EXC_RETURN: In fact, we only care of few bits: Bit [3] Mode (0 - Handler, 1 - Thread) Bit [2] Stack pointer selection (0 - Main, 1 - Process) We can toggle only those bits and left other bits as they were on exception entry. It is basically, what patch does - saves EXC_RETURN when we do transition form Thread to Handler mode (it is first svc), so later saved value is used instead of EXC_RET_THREADMODE_PROCESSSTACK. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> |
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| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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.