Linux kernel modifications for the Kernel Hacking exam
fb43d6cb91
A PTE is constructed from a physical address and a pgprotval_t. __PAGE_KERNEL, for instance, is a pgprot_t and must be converted into a pgprotval_t before it can be used to create a PTE. This is done implicitly within functions like pfn_pte() by massage_pgprot(). However, this makes it very challenging to set bits (and keep them set) if your bit is being filtered out by massage_pgprot(). This moves the bit filtering out of pfn_pte() and friends. For users of PAGE_KERNEL*, filtering will be done automatically inside those macros but for users of __PAGE_KERNEL*, they need to do their own filtering now. Note that we also just move pfn_pte/pmd/pud() over to check_pgprot() instead of massage_pgprot(). This way, we still *look* for unsupported bits and properly warn about them if we find them. This might happen if an unfiltered __PAGE_KERNEL* value was passed in, for instance. - printk format warning fix from: Arnd Bergmann <arnd@arndb.de> - boot crash fix from: Tom Lendacky <thomas.lendacky@amd.com> - crash bisected by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reported-and-fixed-by: Arnd Bergmann <arnd@arndb.de> Fixed-by: Tom Lendacky <thomas.lendacky@amd.com> Bisected-by: Mike Galbraith <efault@gmx.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hugh Dickins <hughd@google.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nadav Amit <namit@vmware.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20180406205509.77E1D7F6@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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.