Concentrate code to modify totalram_pages into the mm core, so the arch
memory initialized code doesn't need to take care of it. With these
changes applied, only following functions from mm core modify global
variable totalram_pages: free_bootmem_late(), free_all_bootmem(),
free_all_bootmem_node(), adjust_managed_page_count().
With this patch applied, it will be much more easier for us to keep
totalram_pages and zone->managed_pages in consistence.
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Acked-by: David Howells <dhowells@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: <sworddragon2@aol.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michel Lespinasse <walken@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Address more review comments from last round of code review.
1) Enhance free_reserved_area() to support poisoning freed memory with
pattern '0'. This could be used to get rid of poison_init_mem()
on ARM64.
2) A previous patch has disabled memory poison for initmem on s390
by mistake, so restore to the original behavior.
3) Remove redundant PAGE_ALIGN() when calling free_reserved_area().
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: <sworddragon2@aol.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michel Lespinasse <walken@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change signature of free_reserved_area() according to Russell King's
suggestion to fix following build warnings:
arch/arm/mm/init.c: In function 'mem_init':
arch/arm/mm/init.c:603:2: warning: passing argument 1 of 'free_reserved_area' makes integer from pointer without a cast [enabled by default]
free_reserved_area(__va(PHYS_PFN_OFFSET), swapper_pg_dir, 0, NULL);
^
In file included from include/linux/mman.h:4:0,
from arch/arm/mm/init.c:15:
include/linux/mm.h:1301:22: note: expected 'long unsigned int' but argument is of type 'void *'
extern unsigned long free_reserved_area(unsigned long start, unsigned long end,
mm/page_alloc.c: In function 'free_reserved_area':
>> mm/page_alloc.c:5134:3: warning: passing argument 1 of 'virt_to_phys' makes pointer from integer without a cast [enabled by default]
In file included from arch/mips/include/asm/page.h:49:0,
from include/linux/mmzone.h:20,
from include/linux/gfp.h:4,
from include/linux/mm.h:8,
from mm/page_alloc.c:18:
arch/mips/include/asm/io.h:119:29: note: expected 'const volatile void *' but argument is of type 'long unsigned int'
mm/page_alloc.c: In function 'free_area_init_nodes':
mm/page_alloc.c:5030:34: warning: array subscript is below array bounds [-Warray-bounds]
Also address some minor code review comments.
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: <sworddragon2@aol.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michel Lespinasse <walken@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On the x86 side, there are some optimizations and documentation updates.
The big ARM/KVM change for 3.11, support for AArch64, will come through
Catalin Marinas's tree. s390 and PPC have misc cleanups and bugfixes.
There is a conflict due to "s390/pgtable: fix ipte notify bit" having
entered 3.10 through Martin Schwidefsky's s390 tree. This pull request
has additional changes on top, so this tree's version is the correct one.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.13 (GNU/Linux)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=1zpG
-----END PGP SIGNATURE-----
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:
"On the x86 side, there are some optimizations and documentation
updates. The big ARM/KVM change for 3.11, support for AArch64, will
come through Catalin Marinas's tree. s390 and PPC have misc cleanups
and bugfixes"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (87 commits)
KVM: PPC: Ignore PIR writes
KVM: PPC: Book3S PR: Invalidate SLB entries properly
KVM: PPC: Book3S PR: Allow guest to use 1TB segments
KVM: PPC: Book3S PR: Don't keep scanning HPTEG after we find a match
KVM: PPC: Book3S PR: Fix invalidation of SLB entry 0 on guest entry
KVM: PPC: Book3S PR: Fix proto-VSID calculations
KVM: PPC: Guard doorbell exception with CONFIG_PPC_DOORBELL
KVM: Fix RTC interrupt coalescing tracking
kvm: Add a tracepoint write_tsc_offset
KVM: MMU: Inform users of mmio generation wraparound
KVM: MMU: document fast invalidate all mmio sptes
KVM: MMU: document fast invalidate all pages
KVM: MMU: document fast page fault
KVM: MMU: document mmio page fault
KVM: MMU: document write_flooding_count
KVM: MMU: document clear_spte_count
KVM: MMU: drop kvm_mmu_zap_mmio_sptes
KVM: MMU: init kvm generation close to mmio wrap-around value
KVM: MMU: add tracepoint for check_mmio_spte
KVM: MMU: fast invalidate all mmio sptes
...
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.19 (GNU/Linux)
iQEcBAABAgAGBQJR0K2gAAoJEHm+PkMAQRiGWsEH+gMZSN1qRm34hZ82q1Tx7HvL
Eb/Gsl3Qw/7G2TlTqgjBUs36IdqV9O2cui/aa3/TfXvdvrx+0GlhRkEwQPc+ygcO
Mvoyoke4tT4+4jVFdCg1J8avREsa28/6oaHs0ZZxuVmJBBLTJH7aXaNsGn6eU1q9
9+p798MQis6naIiPC63somlZcCIiBhsuWCPWpEfLMn8G1HWAFTM3xXIbNBqe/brS
bmIOfhomlIZ5dcdaXGvjtP3+KJhkNDwhkPC4tVYu8JqqgSlrE+a+EGyEuuGqKk10
U+swiqyuD31uBI9ga54u/2FzSqDiAu6YOcMXevjo/m3g9XLdYbYLvN+nvN8alCQ=
=Ob6Z
-----END PGP SIGNATURE-----
Merge tag 'v3.10' into next
Merge 3.10 in order to get some of the last minute powerpc
changes, resolve conflicts and add additional fixes on top
of them.
From time to time we need to set the guest storage key. Lets
provide a helper function that handles the changes with all the
right locking and checking.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This will be later used by powerpc THP support. In powerpc we want to use
pgtable for storing the hash index values. So instead of adding them to
mm_context list, we would like to store them in the second half of pmd
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
With git commit 996b4a7d "s390/mem_detect: remove artificial kdump
memory types" the memory detection code got simplified.
As a side effect the array that describes memory chunks may now
contain empty (zeroed) entries.
All call sites can handle this except for
drivers/s390/char/zcore.c::zcore_memmap_open
which has a really odd user space interface. The easiest fix is to
change the memory hole handling code, so that no empty entries exist
before the last valid entry is reached.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
From time to time we need to set the guest storage key. Lets
provide a helper function that handles the changes with all the
right locking and checking.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The address of the gmap notifier was broken, resulting in
unhandled validity intercepts in KVM. Fix the rmap->vmaddr
to be on a segment boundary.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
On heavy paging load some guest cpus started to loop in gmap_ipte_notify.
This was visible as stalled cpus inside the guest. The gmap_ipte_notifier
tries to map a user page and then made sure that the pte is valid and
writable. Turns out that with the software change bit tracking the pte
can become read-only (and only software writable) if the page is clean.
Since we loop in this code, the page would stay clean and, therefore,
be never writable again.
Let us just use fixup_user_fault, that guarantees to call handle_mm_fault.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
The RCP byte is a part of the PGSTE value, the existing RCP_xxx names
are inaccurate. As the defines describe bits and pieces of the PGSTE,
the names should start with PGSTE_. The KVM_UR_BIT and KVM_UC_BIT are
part of the PGSTE as well, give them better names as well.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
On heavy paging load some guest cpus started to loop in gmap_ipte_notify.
This was visible as stalled cpus inside the guest. The gmap_ipte_notifier
tries to map a user page and then made sure that the pte is valid and
writable. Turns out that with the software change bit tracking the pte
can become read-only (and only software writable) if the page is clean.
Since we loop in this code, the page would stay clean and, therefore,
be never writable again.
Let us just use fixup_user_fault, that guarantees to call handle_mm_fault.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Simplify the memory detection code a bit by removing the CHUNK_OLDMEM
and CHUNK_CRASHK memory types.
They are not needed. Everything that is needed is a mechanism to
insert holes into the detected memory.
Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add a notifier for kvm to get control before a page table entry is
invalidated. The notifier is only called for ptes of an address space
with pgstes that have been explicitly marked to require notification.
Kvm will use this to get control before prefix pages of virtual CPU
are unmapped.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Commit 0c2c99b1b "memory hotplug: Allow memory blocks to span
multiple memory sections" introduced a weak memory_block_size_bytes()
function which can be used to set the size of a memory block as
seen in sysfs.
Provide an s390 specific override which makes sure that each
memory block has at least a size of 256MB or the increment size of
of a memory increment, whatever is larger.
This way we can make sure that the number of memory sysfs objects
doesn't explode for very large memory configurations.
Reported-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The current memory detection loop will detect all present memory of
a machine. This is true even if the user specified the "mem=" parameter
on the kernel command line.
This can be a problem since the memory detection may cause a fully
populated host page table for the guest, even for those parts of the
memory that the guest will never use afterwards.
So fix this and only detect memory up to a user supplied "mem=" limit
if specified.
Reported-by: Michael Johanssen <johanssn@de.ibm.com>
Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add sanity check: verify if the passed in array resides in vmalloc space.
If so print a warning and return to caller.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
When disabling and enabling interrupts we must tell lockdep.
So use local_irq_save()/restore() to disable and enable interrupts.
The DAT disabling/enabling get handled separately now.
Note: we may not call trace_hardirqs_on() with DAT disabled, since
the generic code may access vmalloc'ed data structures.
Reported-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The sparse code, when asking the architecture to populate the vmemmap,
specifies the section range as a starting page and a number of pages.
This is an awkward interface, because none of the arch-specific code
actually thinks of the range in terms of 'struct page' units and always
translates it to bytes first.
In addition, later patches mix huge page and regular page backing for
the vmemmap. For this, they need to call vmemmap_populate_basepages()
on sub-section ranges with PAGE_SIZE and PMD_SIZE in mind. But these
are not necessarily multiples of the 'struct page' size and so this unit
is too coarse.
Just translate the section range into bytes once in the generic sparse
code, then pass byte ranges down the stack.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Bernhard Schmidt <Bernhard.Schmidt@lrz.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: David S. Miller <davem@davemloft.net>
Tested-by: David S. Miller <davem@davemloft.net>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit abf09bed3c ("s390/mm: implement software dirty bits")
introduced another difference in the pte layout vs. the pmd layout on
s390, thoroughly breaking the s390 support for hugetlbfs. This requires
replacing some more pte_xxx functions in mm/hugetlbfs.c with a
huge_pte_xxx version.
This patch introduces those huge_pte_xxx functions and their generic
implementation in asm-generic/hugetlb.h, which will now be included on
all architectures supporting hugetlbfs apart from s390. This change
will be a no-op for those architectures.
[akpm@linux-foundation.org: fix warning]
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Hillf Danton <dhillf@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.cz> [for !s390 parts]
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use common help functions to free reserved pages.
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The gmap_map_segment function creates a special invalid segment table
entry with the address of the requested target location in the process
address space. The first access will create the connection between the
gmap segment table and the target page table of the main process.
If two threads do this concurrently both will walk the page tables and
allocate a gmap_rmap structure for the same segment table entry.
To avoid the race recheck the segment table entry after taking to page
table lock.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Implement gmap_translate() function which translates a guest absolute address
to a user space process address without establishing the guest page table
entries.
This is useful for kvm guest address translations where no memory access
is expected to happen soon (e.g. tprot exception handler).
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use sske with multiple block control to initialize storage keys within
a 1 MB frame at once.
It turned out that the sske with mb=1 is an order of magnitude faster
than pfmf. This is only an issue for very large systems (several 100GB)
where storage key initialization could last more than a minute.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Rewrote conditional statement and eliminated the out_kthread label.
Signed-off-by: Alexandru Gheorghiu <gheorghiuandru@gmail.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
To avoid cache synonyms on System zEC12 32 independent zero pages are
required, one for each combination for bits 2**12 to 2**16 of the virtual
address. To avoid wasting too much memory on small virtual systems the
number of zero pages is limited to 4 if the memory size is less or equal
to 64MB.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Protection exception usually are suppressing and the fault handler
needs to rewind the PSW by the instruction length to get the correct
fault address. Except for protection exceptions while the CPU is in
the middle of a transaction. The CPU stores the transaction abort
PSW at the start of the transaction, if the transaction is aborted
the PSW is already correct and may not be modified by the fault
handler.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add hint to the page tables that we don't care about the change bit
in storage keys that belong to vmemmap pages.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Introduce a new API vmemmap_free() to free and remove vmemmap
pagetables. Since pagetable implements are different, each architecture
has to provide its own version of vmemmap_free(), just like
vmemmap_populate().
Note: vmemmap_free() is not implemented for ia64, ppc, s390, and sparc.
[mhocko@suse.cz: fix implicit declaration of remove_pagetable]
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Wu Jianguo <wujianguo@huawei.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For removing memory, we need to remove page tables. But it depends on
architecture. So the patch introduce arch_remove_memory() for removing
page table. Now it only calls __remove_pages().
Note: __remove_pages() for some archtecuture is not implemented
(I don't know how to implement it for s390).
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Wu Jianguo <wujianguo@huawei.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
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>
The s390 architecture is unique in respect to dirty page detection,
it uses the change bit in the per-page storage key to track page
modifications. All other architectures track dirty bits by means
of page table entries. This property of s390 has caused numerous
problems in the past, e.g. see git commit ef5d437f71
"mm: fix XFS oops due to dirty pages without buffers on s390".
To avoid future issues in regard to per-page dirty bits convert
s390 to a fault based software dirty bit detection mechanism. All
user page table entries which are marked as clean will be hardware
read-only, even if the pte is supposed to be writable. A write by
the user process will trigger a protection fault which will cause
the user pte to be marked as dirty and the hardware read-only bit
is removed.
With this change the dirty bit in the storage key is irrelevant
for Linux as a host, but the storage key is still required for
KVM guests. The effect is that page_test_and_clear_dirty and the
related code can be removed. The referenced bit in the storage
key is still used by the page_test_and_clear_young primitive to
provide page age information.
For page cache pages of mappings with mapping_cap_account_dirty
there will not be any change in behavior as the dirty bit tracking
already uses read-only ptes to control the amount of dirty pages.
Only for swap cache pages and pages of mappings without
mapping_cap_account_dirty there can be additional protection faults.
To avoid an excessive number of additional faults the mk_pte
primitive checks for PageDirty if the pgprot value allows for writes
and pre-dirties the pte. That avoids all additional faults for
tmpfs and shmem pages until these pages are added to the swap cache.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Right now the page table upgrade does not happen if the end address
of a fixed mapping is greater than TASK_SIZE.
Enhance s390_mmap_check() to handle MAP_FIXED mappings correctly.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Now that irq sum accounting for /proc/stat's "intr" line works again we
have the oddity that the sum field (first field) contains only the sum
of the second (external irqs) and third field (I/O interrupts).
The reason for that is that these two fields are already sums of all other
fields. So if we would sum up everything we would count every interrupt
twice.
This is broken since the split interrupt accounting was merged two years
ago: 052ff461c8 "[S390] irq: have detailed
statistics for interrupt types".
To fix this remove the split interrupt fields from /proc/stat's "intr"
line again and only have them in /proc/interrupts.
This restores the old behaviour, seems to be the only sane fix and mimics
a behaviour from other architectures where /proc/interrupts also contains
more than /proc/stat's "intr" line does.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The current single step code is racy in regard to concurrent delivery
of signals. If a signal is delivered after a PER program check occurred
but before the TIF_PER_TRAP bit has been checked in entry[64].S the code
clears TIF_PER_TRAP and then calls do_signal. This is wrong, if the
instruction completed (or has been suppressed) a SIGTRAP should be
delivered to the debugger in any case. Only if the instruction has been
nullified the SIGTRAP may not be send.
The new logic always sets TIF_PER_TRAP if the program check indicates PER
tracing but removes it again for all program checks that are nullifying.
The effect is that for each change in the PSW address we now get a
single SIGTRAP.
Reported-by: Andreas Arnez <arnez@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Keep related functions together and move to appropriate file.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Move and rename init_storage_keys() to pageattr.c, so it can also be
used from the sclp memory hotplug code in order to initialize
storage keys.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Just convert fault_init() to an early initcall. That's still early
enough since it only needs be called before user space processes get
executed. No reason to externalize it.
Also add the function to the init section and move the store_indication
variable to the read_mostly section.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use 1MB frames for vmemmap if EDAT1 is available in order to
reduce TLB pressure
Always use a 1MB frame even if its only partially needed for
struct pages. Otherwise we would end up with a mix of large
frame and page mappings, because vmemmap_populate gets called
for each section (256MB -> 3.5MB memmap) separately.
Worst case is that we would waste 512KB.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use 2GB frames for indentity mapping if EDAT2 is
available to reduce TLB pressure.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
access_ok() returns always "true" on s390. Therefore all access_ok()
invocations are rather pointless.
However when walking page tables we need to make sure that everything
is within bounds of the ASCE limit of the task's address space.
So remove the access_ok() call and add the same check we have in
get_user_pages_fast().
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
When walking page tables we need to make sure that everything
is within bounds of the ASCE limit of the task's address space.
Otherwise we might calculate e.g. a pud pointer which is not
within a pud and dereference it.
So check against TASK_SIZE (which is the ASCE limit) before
walking page tables.
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.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>
Without CONFIG_HUGETLB_PAGE, pmd_huge() will always return 0. So
pmd_large() should be used instead in places where both transparent
huge pages and hugetlbfs pages can occur.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
vmem_add_mem() should only then insert a large page if pmd_none() is true
for the specific entry. We might have a leftover from a previous mapping.
In addition make vmem_remove_range()'s page table walk code more complete
and fix a couple of potential endless loops (which can never happen :).
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add a special module area on top of the vmalloc area, which may be only
used for modules and bpf jit generated code.
This makes sure that inter module branches will always happen without a
trampoline and in addition having all the code within a 2GB frame is
branch prediction unit friendly.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Within the identity mapping the kernel text section is mapped read-only.
However when mapping the first and last page of the text section we must
round upwards and downwards respectively, if only parts of a page belong
to the section.
Otherwise potential rw data can be mapped read-only. So the rounding must
be done just the other way we have it right now.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This is more or less the same as the x86 page table dumper which was
merged four years ago: 926e5392 "x86: add code to dump the (kernel)
page tables for visual inspection by kernel developers".
We add a file at /sys/kernel/debug/kernel_page_tables for debugging
purposes so it's quite easy to see the kernel page table layout and
possible odd mappings:
---[ Identity Mapping ]---
0x0000000000000000-0x0000000000100000 1M PTE RW
---[ Kernel Image Start ]---
0x0000000000100000-0x0000000000800000 7M PMD RO
0x0000000000800000-0x00000000008a9000 676K PTE RO
0x00000000008a9000-0x0000000000900000 348K PTE RW
0x0000000000900000-0x0000000001500000 12M PMD RW
---[ Kernel Image End ]---
0x0000000001500000-0x0000000280000000 10219M PMD RW
0x0000000280000000-0x000003d280000000 3904G PUD I
---[ vmemmap Area ]---
0x000003d280000000-0x000003d288c00000 140M PTE RW
0x000003d288c00000-0x000003d300000000 1908M PMD I
0x000003d300000000-0x000003e000000000 52G PUD I
---[ vmalloc Area ]---
0x000003e000000000-0x000003e000009000 36K PTE RW
0x000003e000009000-0x000003e0000ee000 916K PTE I
0x000003e0000ee000-0x000003e000146000 352K PTE RW
0x000003e000146000-0x000003e000200000 744K PTE I
0x000003e000200000-0x000003e080000000 2046M PMD I
0x000003e080000000-0x0000040000000000 126G PUD I
This usually makes only sense for kernel developers. The output
with CONFIG_DEBUG_PAGEALLOC is not very helpful, because of the
huge number of mapped out pages, however I decided for the time
being to not add a !DEBUG_PAGEALLOC dependency.
Maybe it's helpful for somebody even with that option.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Remove some EXPORT_SYMBOLs. There is no module code anywhere
which calls these pageattr functions.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The current page table walk code in pageattr.c only checks for large pages
while walking the kernel page table, but happily assumes that everything
else is just fine.
Add more checks so we never access invalid memory regions.
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
pmd_huge() will always return 0 on !HUGETLBFS, however we use that helper
function when walking the kernel page tables to decide if we have a
1MB page frame or not.
Since we create 1MB frames for the kernel 1:1 mapping independently of
HUGETLBFS this can lead to incorrect storage accesses since the code
can assume that we have a pointer to a page table instead of a pointer
to a 1MB frame.
Fix this by adding a pmd_large() primitive like other architectures have
it already and remove all references to HUGETLBFS/HUGETLBPAGE from the
code that walks kernel page tables.
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
.fault now can retry. The retry can break state machine of .fault. In
filemap_fault, if page is miss, ra->mmap_miss is increased. In the second
try, since the page is in page cache now, ra->mmap_miss is decreased. And
these are done in one fault, so we can't detect random mmap file access.
Add a new flag to indicate .fault is tried once. In the second try, skip
ra->mmap_miss decreasing. The filemap_fault state machine is ok with it.
I only tested x86, didn't test other archs, but looks the change for other
archs is obvious, but who knows :)
Signed-off-by: Shaohua Li <shaohua.li@fusionio.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch is part of the architecture backend for thp on s390. It
disables thp for kvm hosts, because there is no kvm host hugepage support
so far. Existing thp mappings are split by follow_page() with FOLL_SPLIT,
and future thp mappings are prevented by setting VM_NOHUGEPAGE in
mm->def_flags.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch is part of the architecture backend for thp on s390. It
provides the pagetable pre-allocation functions
pgtable_trans_huge_deposit() and pgtable_trans_huge_withdraw(). Unlike
other archs, s390 has no struct page * as pgtable_t, but rather a pointer
to the page table. So instead of saving the pagetable pre- allocation
list info inside the struct page, it is being saved within the pagetable
itself.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch is part of the architecture backend for thp on s390. It
provides the functions related to thp splitting, including serialization
against gup. Unlike other archs, pmdp_splitting_flush() cannot use a tlb
flushing operation to serialize against gup on s390, because that wouldn't
be stopped by the disabled IRQs. So instead, smp_call_function() is
called with an empty function, which will have the expected effect.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Same as 0d26d1d8 "x86/mm: Mark free_initrd_mem() as __init".
In addition also add the __init annotation to setup_zero_pages().
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Get rid of these:
arch/s390/kernel/smp.c:134:19: warning: ‘status’ may be used uninitialized in this function [-Wuninitialized]
arch/s390/mm/pgtable.c:641:10: warning: ‘table’ may be used uninitialized in this function [-Wuninitialized]
arch/s390/mm/pgtable.c:644:12: warning: ‘page’ may be used uninitialized in this function [-Wuninitialized]
drivers/s390/cio/cio.c:1037:14: warning: ‘schid’ may be used uninitialized in this function [-Wuninitialized]
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This is the s390 port of 70627654 "x86, extable: Switch to relative
exception table entries".
Reduces the size of our exception tables by 50% on 64 bit builds.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch introduces the __get_user_pages_fast() function on s390,
which will be needed with CONFIG_TRANSPARENT_HUGEPAGE and futex.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Renaming the globally visible variable "user_mode" to "addressing_mode" in
order to fix a name clash was not a good idea. (Commit 37fe1d73 "s390/mm:
rename user_mode variable to addressing_mode")
Looking at the code after a couple of weeks one thinks: addressing mode of
what?
So rename the variable again. This time to s390_user_mode. Which hopefully
makes more sense.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Unify all our cpu hotplug notifiers to mask out the CPU_TASKS_FROZEN
bit, so we don't have to add all the *_FROZEN variant cases to the
notifiers.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
So far, large page support was completely disabled with
CONFIG_DEBUG_PAGEALLOC, although it would be sufficient if only the
large page kernel mapping was disabled. This patch enables large page
support with CONFIG_DEBUG_PAGEALLOC, while it prevents the large kernel
mapping in that case.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
We use the user_mode() helper already at several places but also
have the open coded variant at other places.
Convert the code to always use the helper function.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fix name clash with user_mode() define which is also used in common code.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Make sure the kernel does not incorrectly create a SIGBUS signal during
user space accesses:
For user space accesses in the switched addressing mode case the kernel
may walk page tables and access user address space via the kernel
mapping. If a page table entry is invalid the function __handle_fault()
gets called in order to emulate a page fault and trigger all the usual
actions like paging in a missing page etc. by calling handle_mm_fault().
If handle_mm_fault() returns with an error fixup handling is necessary.
For the switched addressing mode case all errors need to be mapped to
-EFAULT, so that the calling uaccess function can return -EFAULT to
user space.
Unfortunately the __handle_fault() incorrectly calls do_sigbus() if
VM_FAULT_SIGBUS is set. This however should only happen if a page fault
was triggered by a user space instruction. For kernel mode uaccesses
the correct action is to only return -EFAULT.
So user space may incorrectly see SIGBUS signals because of this bug.
For current machines this would only be possible for the switched
addressing mode case in conjunction with futex operations.
Cc: stable@vger.kernel.org
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This is the s390 variant of 37b23e05 "x86,mm: make pagefault killable".
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The downgrade of the 4 level page table created by init_new_context is
currently done only in start_thread31. If a 31 bit process forks the
new mm uses a 4 level page table, including the task size of 2<<42
that goes along with it. This is incorrect as now a 31 bit process
can map memory beyond 2GB. Define arch_dup_mmap to do the downgrade
after fork.
Cc: stable@vger.kernel.org
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Remove the file name from the comment at top of many files. In most
cases the file name was wrong anyway, so it's rather pointless.
Also unify the IBM copyright statement. We did have a lot of sightly
different statements and wanted to change them one after another
whenever a file gets touched. However that never happened. Instead
people start to take the old/"wrong" statements to use as a template
for new files.
So unify all of them in one go.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
This patch introduces the new function memcpy_absolute() that allows to
copy memory using absolute addressing. This means that the prefix swap
does not apply when this function is used.
With this patch also all s390 kernel code that accesses absolute zero
now uses the new memcpy_absolute() function. The old and less generic
copy_to_absolute_zero() function is removed.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Replace __s390x__ with CONFIG_64BIT in all places that are not exported
to userspace or guarded with #ifdef __KERNEL__.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If the task that was found on an initial interrupt doesn't match the
current task execute a WARN_ON_ONCE() and don't put the task to sleep.
When this happened something went wrong between the interface of the
hypervisor and the kernel. In such a case keep the tasks alive to
avoid a hanging system.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use __set_task_state() instead of set_task_state(). Saves a couple of
instructions, since the memory barrier is not needed here.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Make the code a bit more symmetric and always search for the task of the
reported pid. This simplifies the code a bit.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
When setting the current task state to TASK_UNINTERRUPTIBLE this can
race with a different cpu. The other cpu could set the task state after
it inspected it (while it was still TASK_RUNNING) to TASK_RUNNING which
would change the state from TASK_UNINTERRUPTIBLE to TASK_RUNNING again.
This race was always present in the pfault interrupt code but didn't
cause anything harmful before commit f2db2e6c "[S390] pfault: cpu hotplug
vs missing completion interrupts" which relied on the fact that after
setting the task state to TASK_UNINTERRUPTIBLE the task would really
sleep.
Since this is not necessarily the case the result may be a list corruption
of the pfault_list or, as observed, a use-after-free bug while trying to
access the task_struct of a task which terminated itself already.
To fix this, we need to get a reference of the affected task when receiving
the initial pfault interrupt and add special handling if we receive yet
another initial pfault interrupt when the task is already enqueued in the
pfault list.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: <stable@vger.kernel.org> # needed for v3.0 and newer
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
commit c3f0327f8e
mm: add rss counters consistency check
detected the following problem with kvm on s390:
BUG: Bad rss-counter state mm:00000004f73ef000 idx:0 val:-10
BUG: Bad rss-counter state mm:00000004f73ef000 idx:1 val:-5
We have to make sure that we accumulate all rss values into
the mm before we replace the mm to avoid triggering this (harmless)
bug message.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The software large page emulation on s390 did not clear the the
pre-allocated page table in arch_release_hugepage() before freeing
it. This could trigger the WARN_ON(!pte_none(*pte) in mm/vmalloc.c:106
and make vmap_pte_range() fail, because the page table could be reused
in page_table_alloc(). This is fixed now by calling clear_table()
before page_table_free().
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Replace the check for TIF_SIE in the fault handler by a check for PF_VCPU.
With the last user of TIF_SIE gone we can now remove the bit.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Currently dev/mem for s390 provides only real memory access. This means
that the CPU prefix pages are swapped. The prefix swap for real memory
works as follows:
Each CPU owns a prefix register that points to a page aligned memory
location "P". If this CPU accesses the address range [0,0x1fff], it is
translated by the hardware to [P,P+0x1fff]. Accordingly if this CPU
accesses the address range [P,P+0x1fff], it is translated by the hardware
to [0,0x1fff]. Therefore, if [P,P+0x1fff] or [0,0x1fff] is read from
the current /dev/mem device, the incorrectly swapped memory content is
returned.
With this patch the /dev/mem architecture code is modified to provide
absolute memory access. This is done via the arch specific functions
xlate_dev_mem_ptr() and unxlate_dev_mem_ptr(). For swapped pages on
s390 the function xlate_dev_mem_ptr() now returns a new buffer with a
copy of the requested absolute memory. In case the buffer was allocated,
the unxlate_dev_mem_ptr() function frees it after /dev/mem code has
called copy_to_user().
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Git commit 36409f6353 "use generic RCU
page-table freeing code" introduced a tlb flushing bug. Partially revert
the above git commit and go back to s390 specific page table flush code.
For s390 the TLB can contain three types of entries, "normal" TLB
page-table entries, TLB combined region-and-segment-table (CRST) entries
and real-space entries. Linux does not use real-space entries which
leaves normal TLB entries and CRST entries. The CRST entries are
intermediate steps in the page-table translation called translation paths.
For example a 4K page access in a three-level page table setup will
create two CRST TLB entries and one page-table TLB entry. The advantage
of that approach is that a page access next to the previous one can reuse
the CRST entries and needs just a single read from memory to create the
page-table TLB entry. The disadvantage is that the TLB flushing rules are
more complicated, before any page-table may be freed the TLB needs to be
flushed.
In short: the generic RCU page-table freeing code is incorrect for the
CRST entries, in particular the check for mm_users < 2 is troublesome.
This is applicable to 3.0+ kernels.
Cc: <stable@vger.kernel.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Currently in the memcpy_real() function interrupts are disabled with
__arch_local_irq_stnsm(). In order to notify lockdep that interrupts
are disabled, with this patch local_irq_save() is used instead. The
function __arch_local_irq_stnsm() is still used for switching to
real mode.
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)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=G9mT
-----END PGP SIGNATURE-----
Merge tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system
Pull "Disintegrate and delete asm/system.h" from David Howells:
"Here are a bunch of patches to disintegrate asm/system.h into a set of
separate bits to relieve the problem of circular inclusion
dependencies.
I've built all the working defconfigs from all the arches that I can
and made sure that they don't break.
The reason for these patches is that I recently encountered a circular
dependency problem that came about when I produced some patches to
optimise get_order() by rewriting it to use ilog2().
This uses bitops - and on the SH arch asm/bitops.h drags in
asm-generic/get_order.h by a circuituous route involving asm/system.h.
The main difficulty seems to be asm/system.h. It holds a number of
low level bits with no/few dependencies that are commonly used (eg.
memory barriers) and a number of bits with more dependencies that
aren't used in many places (eg. switch_to()).
These patches break asm/system.h up into the following core pieces:
(1) asm/barrier.h
Move memory barriers here. This already done for MIPS and Alpha.
(2) asm/switch_to.h
Move switch_to() and related stuff here.
(3) asm/exec.h
Move arch_align_stack() here. Other process execution related bits
could perhaps go here from asm/processor.h.
(4) asm/cmpxchg.h
Move xchg() and cmpxchg() here as they're full word atomic ops and
frequently used by atomic_xchg() and atomic_cmpxchg().
(5) asm/bug.h
Move die() and related bits.
(6) asm/auxvec.h
Move AT_VECTOR_SIZE_ARCH here.
Other arch headers are created as needed on a per-arch basis."
Fixed up some conflicts from other header file cleanups and moving code
around that has happened in the meantime, so David's testing is somewhat
weakened by that. We'll find out anything that got broken and fix it..
* tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits)
Delete all instances of asm/system.h
Remove all #inclusions of asm/system.h
Add #includes needed to permit the removal of asm/system.h
Move all declarations of free_initmem() to linux/mm.h
Disintegrate asm/system.h for OpenRISC
Split arch_align_stack() out from asm-generic/system.h
Split the switch_to() wrapper out of asm-generic/system.h
Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h
Create asm-generic/barrier.h
Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h
Disintegrate asm/system.h for Xtensa
Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt]
Disintegrate asm/system.h for Tile
Disintegrate asm/system.h for Sparc
Disintegrate asm/system.h for SH
Disintegrate asm/system.h for Score
Disintegrate asm/system.h for S390
Disintegrate asm/system.h for PowerPC
Disintegrate asm/system.h for PA-RISC
Disintegrate asm/system.h for MN10300
...
This function is defined for use in exec, not in modules.
No other architecture exports its implementation.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The external interrupt handlers have a parameter called ext_int_code.
Besides the name this paramter does not only contain the ext_int_code
but in addition also the "cpu address" (POP) which caused the external
interrupt.
To make the code a bit more obvious pass a struct instead so the called
function can easily distinguish between external interrupt code and
cpu address. The cpu address field however is named "subcode" since
some external interrupt sources do not pass a cpu address but a
different parameter (or none at all).
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Pull s390 fixes from Martin Schwidefsky
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
[S390] memory hotplug: prevent memory zone interleave
[S390] crash_dump: remove duplicate include
[S390] KEYS: Enable the compat keyctl wrapper on s390x
The new is_compat_task() define for the !COMPAT case in
include/linux/compat.h conflicts with a similar define in
arch/s390/include/asm/compat.h.
This is the minimal patch which fixes the build issues.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This fixes a kernel oops with CONFIG_DEBUG_VM triggered by a
VM_BUG_ON(bad_range()): kernel BUG at mm/page_alloc.c:748.
With memory hotplug on System z, it is possible that the memory
online/offline state is preserved over a system restart, e.g. there
may be offline memory blocks in ZONE_DMA or ZONE_NORMAL. So far,
the offline memory range has always been added to ZONE_MOVABLE during
system start, so that it was possible to have ZONE_MOVABLE interleave
with ZONE_DMA or ZONE_NORMAL. This patch fixes that by checking for
zone overlap before adding memory.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The page_table_free_pgste function is used for kvm processes to free page
tables that have the pgste extension. It calls pgtable_page_ctor instead of
pgtable_page_dtor which increases NR_PAGETABLE instead of decreasing it.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Move the program interruption code and the translation exception identifier
to the pt_regs structure as 'int_code' and 'int_parm_long' and make the
first level interrupt handler in entry[64].S store the two values. That
makes it possible to drop 'prot_addr' and 'trap_no' from the thread_struct
and to reduce the number of arguments to a lot of functions. Finally
un-inline do_trap. Overall this saves 5812 bytes in the .text section of
the 64 bit kernel.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch disables the check for MACHINE_IS_VM when initializing the
pfault infrastructure. The code checks for successful completion of
diag 258 anyway, thus it's safe to try initialization on LPAR anyway.
This is needed to use pfault on kvm
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The kernel address space of a 64 bit kernel currently uses a three level
page table and the vmemmap array has a fixed address and a fixed maximum
size. A three level page table is good enough for systems with less than
3.8TB of memory, for bigger systems four page table levels need to be
used. Each page table level costs a bit of performance, use 3 levels for
normal systems and 4 levels only for the really big systems.
To avoid bloating sparse.o too much set MAX_PHYSMEM_BITS to 46 for a
maximum of 64TB of memory.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Ignore completion interrupts if the initial interrupt hasn't been
received and the addressed task is not running. This case can only
happen if leftover (pending) completion interrupt gets delivered
which wasn't removed with the PFAULT CANCEL operation during cpu
hotplug.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
Revert "tracing: Include module.h in define_trace.h"
irq: don't put module.h into irq.h for tracking irqgen modules.
bluetooth: macroize two small inlines to avoid module.h
ip_vs.h: fix implicit use of module_get/module_put from module.h
nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
include: replace linux/module.h with "struct module" wherever possible
include: convert various register fcns to macros to avoid include chaining
crypto.h: remove unused crypto_tfm_alg_modname() inline
uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
pm_runtime.h: explicitly requires notifier.h
linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
miscdevice.h: fix up implicit use of lists and types
stop_machine.h: fix implicit use of smp.h for smp_processor_id
of: fix implicit use of errno.h in include/linux/of.h
of_platform.h: delete needless include <linux/module.h>
acpi: remove module.h include from platform/aclinux.h
miscdevice.h: delete unnecessary inclusion of module.h
device_cgroup.h: delete needless include <linux/module.h>
net: sch_generic remove redundant use of <linux/module.h>
net: inet_timewait_sock doesnt need <linux/module.h>
...
Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in
- drivers/media/dvb/frontends/dibx000_common.c
- drivers/media/video/{mt9m111.c,ov6650.c}
- drivers/mfd/ab3550-core.c
- include/linux/dmaengine.h
This avoids duplicating the function in every arch gup_fast.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
s390 didn't return 0 in that case, if it's rolling back the *nr pointer it
should also return zero to avoid adding pages to the array at the wrong
offset.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Up to this point the code assumed old refcounting for hugepages (pre-thp).
This updates the code directly to the thp mapcount tail page refcounting.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix several compile errors on s390 caused by splitting module.h.
Some include additions [e.g. qdio_setup.c, zfcp_qdio.c] are in
anticipation of pending changes queued for s390 that increase
the modular use footprint.
[PG: added additional obvious changes since Heiko's original patch]
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Linux on System z uses a ballooner based on diagnose 0x10. (aka as
collaborative memory management). This patch implements diagnose
0x10 on the guest address space.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
gmap_fault needs to walk the guest page table. However, parts of
that may change if some other thread does munmap. In that case
gmap_unmap_notifier will also unmap the corresponding parts from
the guest page table. We need to take mmap_sem in order to serialize
these operations.
do_exception now calls __gmap_fault with mmap_sem held which does
not get exported to modules. The exported function, which is called
from KVM, now takes mmap_sem.
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This introduces locking via mm->page_table_lock to protect
the rmap list for guest mappings from being corrupted by concurrent
operations.
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fix possible deadlock reported by lockdep:
qemu-system-s39/2963 is trying to acquire lock:
(&mm->mmap_sem){++++++}, at: gmap_alloc_table+0x9c/0x120
but task is already holding lock:
(&mm->mmap_sem){++++++}, at: gmap_map_segment+0xa6/0x27c
Actually gmap_alloc_table is the only called in gmap_map_segment with
mmap_sem held, thus it's safe to simply remove the inner lock.
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Split out addressing mode bits from PSW_BASE_BITS, rename PSW_BASE_BITS
to PSW_MASK_BASE, get rid of psw_user32_bits, remove unused function
enabled_wait(), introduce PSW_MASK_USER, and drop PSW_MASK_MERGE macros.
Change psw_kernel_bits / psw_user_bits to contain only the bits that
are always set in the respective mode.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
An instruction with an address right below the adress limit for the
current addressing mode will wrap. The instruction restart logic in
the protection fault handler and the signal code need to follow the
wrapping rules to find the correct instruction address.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch provides the architecture specific part of the s390 kdump
support.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add access function for real memory needed by s390 kdump backend.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The rcu page table free code uses a couple of bits in the page table
pointer passed to tlb_remove_table to discern the different page table
types. __tlb_remove_table extracts the type with an incorrect mask which
leads to memory leaks. The correct mask is ((FRAG_MASK << 4) | FRAG_MASK).
Cc: stable@kernel.org
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If gmap_unmap_segment figures that the segment was not mapped in the
first place, it need to up mmap_sem on exit.
Cc: <stable@kernel.org>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
598841ca99 ([S390] use gmap address
spaces for kvm guest images) changed kvm to use a separate address
space for kvm guests. This address space was switched in __vcpu_run
In some cases (preemption, page fault) there is the possibility that
this address space switch is lost.
The typical symptom was a huge amount of validity intercepts or
random guest addressing exceptions.
Fix this by doing the switch in sie_loop and sie_exit and saving the
address space in the gmap structure itself. Also use the preempt
notifier.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
With this patch a new S390 shutdown trigger "restart" is added. If under
z/VM "systerm restart" is entered or under the HMC the "PSW restart" button
is pressed, the PSW located at 0 (31 bit) or 0x1a0 (64 bit) bit is loaded.
Now we execute do_restart() that processes the restart action that is
defined under /sys/firmware/shutdown_actions/on_restart. Currently the
following actions are possible: reipl (default), stop, vmcmd, dump, and
dump_reipl.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Fix the following compile warning for !CONFIG_PGSTE:
CC arch/s390/mm/pgtable.o
arch/s390/mm/pgtable.c: In function ‘page_table_alloc_pgste’:
arch/s390/mm/pgtable.c:531:1: warning: no return statement in function returning non-void [-Wreturn-type]
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Add code that allows KVM to control the virtual memory layout that
is seen by a guest. The guest address space uses a second page table
that shares the last level pte-tables with the process page table.
If a page is unmapped from the process page table it is automatically
unmapped from the guest page table as well.
The guest address space mapping starts out empty, KVM can map any
individual 1MB segments from the process virtual memory to any 1MB
aligned location in the guest virtual memory. If a target segment in
the process virtual memory does not exist or is unmapped while a
guest mapping exists the desired target address is stored as an
invalid segment table entry in the guest page table.
The population of the guest page table is fault driven.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The nmi parameter indicated if we could do wakeups from the current
context, if not, we would set some state and self-IPI and let the
resulting interrupt do the wakeup.
For the various event classes:
- hardware: nmi=0; PMI is in fact an NMI or we run irq_work_run from
the PMI-tail (ARM etc.)
- tracepoint: nmi=0; since tracepoint could be from NMI context.
- software: nmi=[0,1]; some, like the schedule thing cannot
perform wakeups, and hence need 0.
As one can see, there is very little nmi=1 usage, and the down-side of
not using it is that on some platforms some software events can have a
jiffy delay in wakeup (when arch_irq_work_raise isn't implemented).
The up-side however is that we can remove the nmi parameter and save a
bunch of conditionals in fast paths.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Michael Cree <mcree@orcon.net.nz>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/n/tip-agjev8eu666tvknpb3iaj0fg@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Replace the s390 specific rcu page-table freeing code with the
generic variant. This requires to duplicate the definition for the
struct mmu_table_batch as s390 does not use the generic tlb flush
code.
While we are at it remove the restriction that page table fragments
can not be reused after a single fragment has been freed with rcu
and split out allocation and freeing of page tables with pgstes.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Quite a few functions that get called from the tlb gather code require that
preemption must be disabled. So disable preemption inside of the called
functions instead.
The only drawback is that rcu_table_freelist_finish() doesn't get necessarily
called on the cpu(s) that filled the free lists. So we may see a delay, until
we finally see an rcu callback. However over time this shouldn't matter.
So we get rid of lots of "BUG: using smp_processor_id() in preemptible"
messages.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (25 commits)
perf: Fix SIGIO handling
perf top: Don't stop if no kernel symtab is found
perf top: Handle kptr_restrict
perf top: Remove unused macro
perf events: initialize fd array to -1 instead of 0
perf tools: Make sure kptr_restrict warnings fit 80 col terms
perf tools: Fix build on older systems
perf symbols: Handle /proc/sys/kernel/kptr_restrict
perf: Remove duplicate headers
ftrace: Add internal recursive checks
tracing: Update btrfs's tracepoints to use u64 interface
tracing: Add __print_symbolic_u64 to avoid warnings on 32bit machine
ftrace: Set ops->flag to enabled even on static function tracing
tracing: Have event with function tracer check error return
ftrace: Have ftrace_startup() return failure code
jump_label: Check entries limit in __jump_label_update
ftrace/recordmcount: Avoid STT_FUNC symbols as base on ARM
scripts/tags.sh: Add magic for trace-events for etags too
scripts/tags.sh: Fix ctags for DEFINE_EVENT()
x86/ftrace: Fix compiler warning in ftrace.c
...
Add ZONE_DMA to 31-bit config again. The performance gain is minimal
and hardly anybody cares anymore about a 31-bit kernel.
So add ZONE_DMA again to help with SLAB_CACHE_DMA removal for
!CONFIG_ZONE_DMA configurations.
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
If e.g. copy_from_user() generates a page fault and the kernel runs
into an OOM situation the system might lock up.
If the OOM killer sends a SIG_KILL to the current process it can't
handle it since it is stuck in a copy_from_user() - page fault loop.
Fix this by adding the same fix as other architectures have.
E.g. the x86 variant f86268 "x86/mm: Handle mm_fault_error() in kernel
space"
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Merge irq.c and s390_ext.c into irq.c. That way all external interrupt
related functions are together.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Interrupt sources like pfault, sclp, dasd_diag and virtio all use the
service signal external interrupt subclass mask in control register 0
to enable and disable the corresponding interrupt.
Because no reference counting is implemented each subsystem thinks it
is the only user of subclass and sets and clears the bit like it wants.
This leads to case that unloading the dasd diag module under z/VM
causes both sclp and pfault interrupts to be masked. The result will
be locked up system sooner or later.
Fix this by introducing a new way to set (register) and clear
(unregister) the service signal subclass mask bit in cr0.
Also convert all drivers.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Always enable the service signal subclass mask bit in cr0, if pfault
is available. That way we use the normal cpu hotplug way to propagate
the subclass mask bit in cr0 instead of open coding it.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The functions probe_kernel_write() and probe_kernel_read() do not modify
the src pointer. Allow const pointers to be passed in without the need
of a typecast.
Acked-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1305824936.1465.4.camel@gandalf.stny.rr.com
Fold all the mmu_gather rework patches into one for submission
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reported-by: Hugh Dickins <hughd@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Tony Luck <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rework the architecture page table functions to access the bits in the
page table extension array (pgste). There are a number of changes:
1) Fix missing pgste update if the attach_count for the mm is <= 1.
2) For every operation that affects the invalid bit in the pte or the
rcp byte in the pgste the pcl lock needs to be acquired. The function
pgste_get_lock gets the pcl lock and returns the current pgste value
for a pte pointer. The function pgste_set_unlock stores the pgste
and releases the lock. Between these two calls the bits in the pgste
can be shuffled.
3) Define two software bits in the pte _PAGE_SWR and _PAGE_SWC to avoid
calling SetPageDirty and SetPageReferenced from pgtable.h. If the
host reference backup bit or the host change backup bit has been
set the dirty/referenced state is transfered to the pte. The common
code will pick up the state from the pte.
4) Add ptep_modify_prot_start and ptep_modify_prot_commit for mprotect.
5) Remove pgd_populate_kernel, pud_populate_kernel, pmd_populate_kernel
pgd_clear_kernel, pud_clear_kernel, pmd_clear_kernel and ptep_invalidate.
6) Rename kvm_s390_test_and_clear_page_dirty to
ptep_test_and_clear_user_dirty and add ptep_test_and_clear_user_young.
7) Define mm_exclusive() and mm_has_pgste() helper to improve readability.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
On cpu hot remove a PFAULT CANCEL command is sent to the hypervisor
which in turn will cancel all outstanding pfault requests that have
been issued on that cpu (the same happens with a SIGP cpu reset).
The result is that we end up with uninterruptible processes where
the interrupt that would wake up these processes never arrives.
In order to solve this all processes which wait for a pfault
completion interrupt get woken up after a cpu hot remove. The worst
case that could happen is that they fault again and in turn need to
wait again.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Get rid of these:
arch/s390/mm/extmem.c: In function 'segment_modify_shared':
arch/s390/mm/extmem.c:622:3: warning: 'end_addr' may be used uninitialized in this function [-Wuninitialized]
arch/s390/mm/extmem.c:627:18: warning: 'start_addr' may be used uninitialized in this function [-Wuninitialized]
arch/s390/mm/extmem.c: In function 'segment_load':
arch/s390/mm/extmem.c:481:11: warning: 'end_addr' may be used uninitialized in this function [-Wuninitialized]
arch/s390/mm/extmem.c:480:18: warning: 'start_addr' may be used uninitialized in this function [-Wuninitialized]
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The noexec support on s390 does not rely on a bit in the page table
entry but utilizes the secondary space mode to distinguish between
memory accesses for instructions vs. data. The noexec code relies
on the assumption that the cpu will always use the secondary space
page table for data accesses while it is running in the secondary
space mode. Up to the z9-109 class machines this has been the case.
Unfortunately this is not true anymore with z10 and later machines.
The load-relative-long instructions lrl, lgrl and lgfrl access the
memory operand using the same addressing-space mode that has been
used to fetch the instruction.
This breaks the noexec mode for all user space binaries compiled
with march=z10 or later. The only option is to remove the current
noexec support.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
While debugging I stumbled over two problems in the code that protects module
pages.
First issue is that disabling the protection before freeing init or unload of
a module is not symmetric with the enablement. For instance, if pages are set
to RO the page range from module_core to module_core + core_ro_size is
protected. If a module is unloaded the page range from module_core to
module_core + core_size is set back to RW.
So pages that were not set to RO are also changed to RW.
This is not critical but IMHO it should be symmetric.
Second issue is that while set_memory_rw & set_memory_ro are used for
RO/RW changes only set_memory_nx is involved for NX/X. One would await that
the inverse function is called when the NX protection should be removed,
which is not the case here, unless I'm missing something.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Currently the diag10() function can only release one page. For exploiters
that have to call diag10 on a contiguous memory region this is suboptimal.
This patch replaces the diag10() function with diag10_range() that is
able to release multiple pages. In addition to that the new function now
allows to release memory with addresses higher than 2047 MiB. This was
due to a restriction of the diagnose implementation under z/VM prior to
release 5.2.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
pfault, dasd diag and virtio all use the same external interrupt number.
The respective interrupt handlers decide by the subcode if they are
meant to handle the interrupt.
Counting is currently done before looking at the subcode which means
each handler counts an interrupt even if it is not handling it.
Fix this by moving the kstat code after the code which looks at the
subcode.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
f6649a7e "[S390] cleanup lowcore access from external interrupts" changed
handling of external interrupts. Instead of letting the external interrupt
handlers accessing the per cpu lowcore the entry code of the kernel reads
already all fields that are necessary and passes them to the handlers.
The pfault interrupt handler was incorrectly converted. It tries to
dereference a value which used to be a pointer to a lowcore field. After
the conversion however it is not anymore the pointer to the field but its
content. So instead of a dereference only a cast is needed to get the
task pointer that caused the pfault.
Fixes a NULL pointer dereference and a subsequent kernel crash:
Unable to handle kernel pointer dereference at virtual kernel address (null)
Oops: 0004 [#1] SMP
Modules linked in: nfsd exportfs nfs lockd fscache nfs_acl auth_rpcgss sunrpc
loop qeth_l3 qeth vmur ccwgroup ext3 jbd mbcache dm_mod
dasd_eckd_mod dasd_diag_mod dasd_mod
CPU: 0 Not tainted 2.6.38-2-s390x #1
Process cron (pid: 1106, task: 000000001f962f78, ksp: 000000001fa0f9d0)
Krnl PSW : 0404200180000000 000000000002c03e (pfault_interrupt+0xa2/0x138)
R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:0 CC:2 PM:0 EA:3
Krnl GPRS: 0000000000000000 0000000000000001 0000000000000000 0000000000000001
000000001f962f78 0000000000518968 0000000090000002 000000001ff03280
0000000000000000 000000000064f000 000000001f962f78 0000000000002603
0000000006002603 0000000000000000 000000001ff7fe68 000000001ff7fe48
Krnl Code: 000000000002c036: 5820d010 l %r2,16(%r13)
000000000002c03a: 1832 lr %r3,%r2
000000000002c03c: 1a31 ar %r3,%r1
>000000000002c03e: ba23d010 cs %r2,%r3,16(%r13)
000000000002c042: a744fffc brc 4,2c03a
000000000002c046: a7290002 lghi %r2,2
000000000002c04a: e320d0000024 stg %r2,0(%r13)
000000000002c050: 07f0 bcr 15,%r0
Call Trace:
([<000000001f962f78>] 0x1f962f78)
[<000000000001acda>] do_extint+0xf6/0x138
[<000000000039b6ca>] ext_no_vtime+0x30/0x34
[<000000007d706e04>] 0x7d706e04
Last Breaking-Event-Address:
[<0000000000000000>] 0x0
For stable maintainers:
the first kernel which contains this bug is 2.6.37.
Reported-by: Stephen Powell <zlinuxman@wowway.com>
Cc: Jonathan Nieder <jrnieder@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The page table walk for changing page attributes used the wrong
address for pgd/pud/pmd lookups if the range was bigger than
a pmd entry. Fix the lookup by using the correct address.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Implement write protection for kernel modules text and read-only
data sections by implementing set_memory_[ro|rw] on s390.
Since s390 has no execute bit in the pte's NX is not supported.
set_memory_[ro|rw] will only work on normal pages and not on
large pages, so in case a large page should be modified bail
out with a warning.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
After page_table_free_rcu removed a page from the pgtable_list
page_table_free better not add it again. Otherwise a page_table_alloc
can reuse a page table fragment that is still in the rcu process.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Shuffle code around so it looks more like x86 and powerpc.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Historically 64 bit processes use the legacy address layout. However
there is no reason why 64 bit processes shouldn't benefit from the
flexible mmap layout advantages.
Therefore just enable it.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Reduce minimum gap between stack and mmap_base to 32MB. That way there
is a bit more space for heap and mmap for tight 31 bit address spaces.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Consider stack address randomization when calulating mmap_base for
flexible mmap layout . Because of address randomization the stack
address can be up to 8MB lower than STACK_TOP.
When calculating mmap_base this isn't taken into account, which could
lead to the case that the gap between the real stack top and mmap_base
is lower than what ulimit specifies for the maximum stack size.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use an early init call to initialize pfault. That way it is possible to
use the register_external_interrupt() instead of the early variant.
No need to enable pfault any earlier since it has only effect if user
space processes are running.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Up to now /proc/interrupts only has statistics for external and i/o
interrupts but doesn't split up them any further.
This patch adds a line for every single interrupt source so that it
is possible to easier tell what the machine is/was doing.
Part of the output now looks like this;
CPU0 CPU2 CPU4
EXT: 3898 4232 2305
I/O: 782 315 245
CLK: 1029 1964 727 [EXT] Clock Comparator
IPI: 2868 2267 1577 [EXT] Signal Processor
TMR: 0 0 0 [EXT] CPU Timer
TAL: 0 0 0 [EXT] Timing Alert
PFL: 0 0 0 [EXT] Pseudo Page Fault
[...]
NMI: 0 1 1 [NMI] Machine Checks
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
