forked from Minki/linux
mainlining shenanigans
f34902c5c6
Jiri reported a resume-from-hibernation failure triggered by PCID.
The root cause appears to be rather odd. The hibernation asm
restores a CR3 value that comes from the image header. If the image
kernel has PCID on, it's entirely reasonable for this CR3 value to
have one of the low 12 bits set. The restore code restores it with
CR4.PCIDE=0, which means that those low 12 bits are accepted by the
CPU but are either ignored or interpreted as a caching mode. This
is odd, but still works. We blow up later when the image kernel
restores CR4, though, since changing CR4.PCIDE with CR3[11:0] != 0
is illegal. Boom!
FWIW, it's entirely unclear to me what's supposed to happen if a PAE
kernel restores a non-PAE image or vice versa. Ditto for LA57.
Reported-by: Jiri Kosina <jikos@kernel.org>
Tested-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes:
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|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| 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.