The ESSA instruction has a new option that allows to tag pages that
are not used as a page table. Without the tag the hypervisor has to
assume that any guest page could be used in a page table inside the
guest. This forces the hypervisor to flush all guest TLB entries
whenever a host page table entry is invalidated. With the tag
the host can skip the TLB flush if the page is tagged as normal page.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Sebastian reported a crash caused by a jump label mismatch after resume.
This happens because we do not save the kernel text section during suspend
and therefore also do not restore it during resume, but use the kernel image
that restores the old system.
This means that after a suspend/resume cycle we lost all modifications done
to the kernel text section.
The reason for this is the pfn_is_nosave() function, which incorrectly
returns that read-only pages don't need to be saved. This is incorrect since
we mark the kernel text section read-only.
We still need to make sure to not save and restore pages contained within
NSS and DCSS segment.
To fix this add an extra case for the kernel text section and only save
those pages if they are not contained within an NSS segment.
Fixes the following crash (and the above bugs as well):
Jump label code mismatch at netif_receive_skb_internal+0x28/0xd0
Found: c0 04 00 00 00 00
Expected: c0 f4 00 00 00 11
New: c0 04 00 00 00 00
Kernel panic - not syncing: Corrupted kernel text
CPU: 0 PID: 9 Comm: migration/0 Not tainted 3.19.0-01975-gb1b096e70f23 #4
Call Trace:
[<0000000000113972>] show_stack+0x72/0xf0
[<000000000081f15e>] dump_stack+0x6e/0x90
[<000000000081c4e8>] panic+0x108/0x2b0
[<000000000081be64>] jump_label_bug.isra.2+0x104/0x108
[<0000000000112176>] __jump_label_transform+0x9e/0xd0
[<00000000001121e6>] __sm_arch_jump_label_transform+0x3e/0x50
[<00000000001d1136>] multi_cpu_stop+0x12e/0x170
[<00000000001d1472>] cpu_stopper_thread+0xb2/0x168
[<000000000015d2ac>] smpboot_thread_fn+0x134/0x1b0
[<0000000000158baa>] kthread+0x10a/0x110
[<0000000000824a86>] kernel_thread_starter+0x6/0xc
Reported-and-tested-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The different architectures used their own (and different) declarations:
extern __visible const void __nosave_begin, __nosave_end;
extern const void __nosave_begin, __nosave_end;
extern long __nosave_begin, __nosave_end;
Consolidate them using the first variant in <asm/sections.h>.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make various functions static, add declarations to header files to
fix a couple of sparse findings.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Function handles may change while the system was in hibernation
use list pci functions and update the function handles.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Some functions that do arch specific resume actions are called
directly from swsusp_asm64.S . Before we add another function call
provide a generic s390_early_resume function which can be used
for this purpose.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Since commit 5f954c34 ([S390] hibernation: fix lowcore handling)
the absolute zero lowcore is lost during suspend/resume.
For example, this leads to the problem that the re-IPL device
for kdump is no longer set after resume.
With this patch during suspend a buffer is allocated in the new PM
notifier "suspend_pm_cb" and then the absolute zero lowcore is saved
to that buffer. The resume code then copies back this buffer to
absolute zero and afterwards the PM notifier releases the memory.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
For s390 there is one additional byte associated with each page,
the storage key. This byte contains the referenced and changed
bits and needs to be included into the hibernation image.
If the storage keys are not restored to their previous state all
original pages would appear to be dirty. This can cause
inconsistencies e.g. with read-only filesystems.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
pfn_is_nosave doesn't return the correct value for the second lowcore
page if lowcore protection is enabled. Make sure it always returns
the correct value.
While at it simplify the whole thing.
NSS special handling is done by the tprot check like it already works
for DCSS as well. So remove the extra code for NSS.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Merge the nearly empty C files and move everything from power/ to
kernel/. That way the files are easier to handle.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Martin Schwidefsky
Bjorn Helgaas
Heiko Carstens
Geert Uytterhoeven
Sebastian Ott
Michael Holzheu
David Howells