Catalin Marinas ec663d967b arm64: Improve detection of user/non-user mappings in set_pte(_at)
Commit cab15ce604 ("arm64: Introduce execute-only page access
permissions") allowed a valid user PTE to have the PTE_USER bit clear.
As a consequence, the pte_valid_not_user() macro in set_pte() was
replaced with pte_valid_global() under the assumption that only user
pages have the nG bit set. EFI mappings, however, also have the nG bit
set and set_pte() wrongly ignores issuing the DSB+ISB.

This patch reinstates the pte_valid_not_user() macro and adds the
PTE_UXN bit check since all kernel mappings have this bit set. For
clarity, pte_exec() is renamed to pte_user_exec() as it only checks for
the absence of PTE_UXN. Consequently, the user executable check in
set_pte_at() drops the pte_ng() test since pte_user_exec() is
sufficient.

Fixes: cab15ce604 ("arm64: Introduce execute-only page access permissions")
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-31 16:44:07 +00:00
2005-09-10 10:06:29 -07:00
2016-05-23 17:04:14 -07:00
2017-01-08 14:18:17 -08:00

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

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.
Description
No description provided
Readme 3.6 GiB
Languages
C 97%
Assembly 1%
Shell 0.6%
Rust 0.5%
Python 0.4%
Other 0.3%