commit d3f7b1bb20 upstream.
Currently to make sure that every page table entry is read just once
gup_fast walks perform READ_ONCE and pass pXd value down to the next
gup_pXd_range function by value e.g.:
static int gup_pud_range(p4d_t p4d, unsigned long addr, unsigned long end,
unsigned int flags, struct page **pages, int *nr)
...
pudp = pud_offset(&p4d, addr);
This function passes a reference on that local value copy to pXd_offset,
and might get the very same pointer in return. This happens when the
level is folded (on most arches), and that pointer should not be
iterated.
On s390 due to the fact that each task might have different 5,4 or
3-level address translation and hence different levels folded the logic
is more complex and non-iteratable pointer to a local copy leads to
severe problems.
Here is an example of what happens with gup_fast on s390, for a task
with 3-level paging, crossing a 2 GB pud boundary:
// addr = 0x1007ffff000, end = 0x10080001000
static int gup_pud_range(p4d_t p4d, unsigned long addr, unsigned long end,
unsigned int flags, struct page **pages, int *nr)
{
unsigned long next;
pud_t *pudp;
// pud_offset returns &p4d itself (a pointer to a value on stack)
pudp = pud_offset(&p4d, addr);
do {
// on second iteratation reading "random" stack value
pud_t pud = READ_ONCE(*pudp);
// next = 0x10080000000, due to PUD_SIZE/MASK != PGDIR_SIZE/MASK on s390
next = pud_addr_end(addr, end);
...
} while (pudp++, addr = next, addr != end); // pudp++ iterating over stack
return 1;
}
This happens since s390 moved to common gup code with commit
d1874a0c28 ("s390/mm: make the pxd_offset functions more robust") and
commit 1a42010cdc ("s390/mm: convert to the generic
get_user_pages_fast code").
s390 tried to mimic static level folding by changing pXd_offset
primitives to always calculate top level page table offset in pgd_offset
and just return the value passed when pXd_offset has to act as folded.
What is crucial for gup_fast and what has been overlooked is that
PxD_SIZE/MASK and thus pXd_addr_end should also change correspondingly.
And the latter is not possible with dynamic folding.
To fix the issue in addition to pXd values pass original pXdp pointers
down to gup_pXd_range functions. And introduce pXd_offset_lockless
helpers, which take an additional pXd entry value parameter. This has
already been discussed in
https://lkml.kernel.org/r/20190418100218.0a4afd51@mschwideX1
Fixes: 1a42010cdc ("s390/mm: convert to the generic get_user_pages_fast code")
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: <stable@vger.kernel.org> [5.2+]
Link: https://lkml.kernel.org/r/patch.git-943f1e5dcff2.your-ad-here.call-01599856292-ext-8676@work.hours
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 582b4e5540 upstream.
On s390 there currently is no implementation of pud_write(). That was ok
as long as we had our own implementation of get_user_pages_fast() which
checked for pud protection by testing the bit directly w/o using
pud_write(). The other callers of pud_write() are not reachable on s390.
After commit 1a42010cdc ("s390/mm: convert to the generic
get_user_pages_fast code") we use the generic get_user_pages_fast(), which
does call pud_write() in pud_access_permitted() for FOLL_WRITE access on
a large pud. Without an s390 specific pud_write(), the generic version is
called, which contains a BUG() statement to remind us that we don't have a
proper implementation. This results in a kernel panic.
Fix this by providing an implementation of pud_write().
Cc: <stable@vger.kernel.org> # 5.2+
Fixes: 1a42010cdc ("s390/mm: convert to the generic get_user_pages_fast code")
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ab874f22d3 upstream.
On older HW or under a hypervisor, w/o the instruction-execution-
protection (IEP) facility, and also w/o EDAT-1, a translation-specification
exception may be recognized when bit 55 of a pte is one (_PAGE_NOEXEC).
The current code tries to prevent setting _PAGE_NOEXEC in such cases,
by removing it within set_pte_at(). However, ptep_set_access_flags()
will modify a pte directly, w/o using set_pte_at(). There is at least
one scenario where this can result in an active pte with _PAGE_NOEXEC
set, which would then lead to a panic due to a translation-specification
exception (write to swapped out page):
do_swap_page
pte = mk_pte (with _PAGE_NOEXEC bit)
set_pte_at (will remove _PAGE_NOEXEC bit in page table, but keep it
in local variable pte)
vmf->orig_pte = pte (pte still contains _PAGE_NOEXEC bit)
do_wp_page
wp_page_reuse
entry = vmf->orig_pte (still with _PAGE_NOEXEC bit)
ptep_set_access_flags (writes entry with _PAGE_NOEXEC bit)
Fix this by clearing _PAGE_NOEXEC already in mk_pte_phys(), where the
pgprot value is applied, so that no pte with _PAGE_NOEXEC will ever be
visible, if it is not supported. The check in set_pte_at() can then also
be removed.
Cc: <stable@vger.kernel.org> # 4.11+
Fixes: 57d7f939e7 ("s390: add no-execute support")
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Always inline asm inlines with variable operands for "i" constraints,
since they won't compile if the compiler would decide to not inline
them.
Reported-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Convert two functions to static inline to get ride of W=1 GCC warnings
like,
mm/gup.c: In function 'gup_pte_range':
mm/gup.c:1816:16: warning: variable 'ptem' set but not used
[-Wunused-but-set-variable]
pte_t *ptep, *ptem;
^~~~
mm/mmap.c: In function 'acct_stack_growth':
mm/mmap.c:2322:16: warning: variable 'new_start' set but not used
[-Wunused-but-set-variable]
unsigned long new_start;
^~~~~~~~~
Signed-off-by: Qian Cai <cai@lca.pw>
Link: https://lore.kernel.org/lkml/1570138596-11913-1-git-send-email-cai@lca.pw/
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Both pgtable_cache_init() and pgd_cache_init() are used to initialize kmem
cache for page table allocations on several architectures that do not use
PAGE_SIZE tables for one or more levels of the page table hierarchy.
Most architectures do not implement these functions and use __weak default
NOP implementation of pgd_cache_init(). Since there is no such default
for pgtable_cache_init(), its empty stub is duplicated among most
architectures.
Rename the definitions of pgd_cache_init() to pgtable_cache_init() and
drop empty stubs of pgtable_cache_init().
Link: http://lkml.kernel.org/r/1566457046-22637-1-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Will Deacon <will@kernel.org> [arm64]
Acked-by: Thomas Gleixner <tglx@linutronix.de> [x86]
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: remove quicklist page table caches".
A while ago Nicholas proposed to remove quicklist page table caches [1].
I've rebased his patch on the curren upstream and switched ia64 and sh to
use generic versions of PTE allocation.
[1] https://lore.kernel.org/linux-mm/20190711030339.20892-1-npiggin@gmail.com
This patch (of 3):
Remove page table allocator "quicklists". These have been around for a
long time, but have not got much traction in the last decade and are only
used on ia64 and sh architectures.
The numbers in the initial commit look interesting but probably don't
apply anymore. If anybody wants to resurrect this it's in the git
history, but it's unhelpful to have this code and divergent allocator
behaviour for minor archs.
Also it might be better to instead make more general improvements to page
allocator if this is still so slow.
Link: http://lkml.kernel.org/r/1565250728-21721-2-git-send-email-rppt@linux.ibm.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Few other crucial memory setup options are already handled in
the startup code. Those values are needed by kaslr and kasan
implementations. "vmalloc" is the last piece required for future
improvements such as early decision on kernel page levels depth required
for actual memory setup, as well as vmalloc memory area access monitoring
in kasan.
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Pass in the already calculated end value instead of recomputing it, and
leave the end > start check in the callers instead of duplicating them in
the arch code.
Link: http://lkml.kernel.org/r/20190625143715.1689-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: James Hogan <jhogan@kernel.org>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With git commit d1874a0c28
"s390/mm: make the pxd_offset functions more robust" and a 2-level page
table it can now happen that pgd_bad() gets asked to verify a large
segment table entry. If the entry is marked as dirty pgd_bad() will
incorrectly return true.
Change the pgd_bad(), p4d_bad(), pud_bad() and pmd_bad() functions to
first verify the table type, return false if the table level is lower
than what the function is suppossed to check, return true if the table
level is too high, and otherwise check the relevant region and segment
table bits. pmd_bad() has to check against ~SEGMENT_ENTRY_BITS for
normal page table pointers or ~SEGMENT_ENTRY_BITS_LARGE for large
segment table entries. Same for pud_bad() which has to check against
~_REGION_ENTRY_BITS or ~_REGION_ENTRY_BITS_LARGE.
Fixes: d1874a0c28 ("s390/mm: make the pxd_offset functions more robust")
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Define the gup_fast_permitted to check against the asce_limit of the
mm attached to the current task, then replace the s390 specific gup
code with the generic implementation in mm/gup.c.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Change the way how pgd_offset, p4d_offset, pud_offset and pmd_offset
walk the page tables. pgd_offset now always calculates the index for
the top-level page table and adds it to the pgd, this is either a
segment table offset for a 2-level setup, a region-3 offset for 3-levels,
region-2 offset for 4-levels, or a region-1 offset for a 5-level setup.
The other three functions p4d_offset, pud_offset and pmd_offset will
only add the respective offset if they dereference the passed pointer.
With the new way of walking the page tables a sequence like this from
mm/gup.c now works:
pgdp = pgd_offset(current->mm, addr);
pgd = READ_ONCE(*pgdp);
p4dp = p4d_offset(&pgd, addr);
p4d = READ_ONCE(*p4dp);
pudp = pud_offset(&p4d, addr);
pud = READ_ONCE(*pudp);
pmdp = pmd_offset(&pud, addr);
pmd = READ_ONCE(*pmdp);
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Architectures like ppc64 require to do a conditional tlb flush based on
the old and new value of pte. Enable that by passing old pte value as
the arg.
Link: http://lkml.kernel.org/r/20190116085035.29729-3-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "NestMMU pte upgrade workaround for mprotect", v5.
We can upgrade pte access (R -> RW transition) via mprotect. We need to
make sure we follow the recommended pte update sequence as outlined in
commit bd5050e38a ("powerpc/mm/radix: Change pte relax sequence to
handle nest MMU hang") for such updates. This patch series does that.
This patch (of 5):
Some architectures may want to call flush_tlb_range from these helpers.
Link: http://lkml.kernel.org/r/20190116085035.29729-2-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In case a fork or a clone system fails in copy_process and the error
handling does the mmput() at the bad_fork_cleanup_mm label, the
following warning messages will appear on the console:
BUG: non-zero pgtables_bytes on freeing mm: 16384
The reason for that is the tricks we play with mm_inc_nr_puds() and
mm_inc_nr_pmds() in init_new_context().
A normal 64-bit process has 3 levels of page table, the p4d level and
the pud level are folded. On process termination the free_pud_range()
function in mm/memory.c will subtract 16KB from pgtable_bytes with a
mm_dec_nr_puds() call, but there actually is not really a pud table.
One issue with this is the fact that pgtable_bytes is usually off
by a few kilobytes, but the more severe problem is that for a failed
fork or clone the free_pgtables() function is not called. In this case
there is no mm_dec_nr_puds() or mm_dec_nr_pmds() that go together with
the mm_inc_nr_puds() and mm_inc_nr_pmds in init_new_context().
The pgtable_bytes will be off by 16384 or 32768 bytes and we get the
BUG message. The message itself is purely cosmetic, but annoying.
To fix this override the mm_pmd_folded, mm_pud_folded and mm_p4d_folded
function to check for the true size of the address space.
Reported-by: Li Wang <liwang@redhat.com>
Tested-by: Li Wang <liwang@redhat.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
To lower memory footprint and speed up kasan initialisation detect
EDAT availability and use large pages if possible. As we know how
much memory is needed for initialisation, another simplistic large
page allocator is introduced to avoid memory fragmentation.
Since facilities list is retrieved anyhow, detect noexec support and
adjust pages attributes. Handle noexec kernel option to avoid inconsistent
kasan shadow memory pages flags.
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Kasan needs 1/8 of kernel virtual address space to be reserved as the
shadow area. And eventually it requires the shadow memory offset to be
known at compile time (passed to the compiler when full instrumentation
is enabled). Any value picked as the shadow area offset for 3-level
paging would eat up identity mapping on 4-level paging (with 1PB
shadow area size). So, the kernel sticks to 3-level paging when kasan
is enabled. 3TB border is picked as the shadow offset. The memory
layout is adjusted so, that physical memory border does not exceed
KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END.
Due to the fact that on s390 paging is set up very late and to cover
more code with kasan instrumentation, temporary identity mapping and
final shadow memory are set up early. The shadow memory mapping is
later carried over to init_mm.pgd during paging_init.
For the needs of paging structures allocation and shadow memory
population a primitive allocator is used, which simply chops off
memory blocks from the end of the physical memory.
Kasan currenty doesn't track vmemmap and vmalloc areas.
Current memory layout (for 3-level paging, 2GB physical memory).
---[ Identity Mapping ]---
0x0000000000000000-0x0000000000100000
---[ Kernel Image Start ]---
0x0000000000100000-0x0000000002b00000
---[ Kernel Image End ]---
0x0000000002b00000-0x0000000080000000 2G <- physical memory border
0x0000000080000000-0x0000030000000000 3070G PUD I
---[ Kasan Shadow Start ]---
0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory
0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page
0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules
---[ Kasan Shadow End ]---
0x0000038000000000-0x000003d100000000 324G PUD I
---[ vmemmap Area ]---
0x000003d100000000-0x000003e080000000
---[ vmalloc Area ]---
0x000003e080000000-0x000003ff80000000
---[ Modules Area ]---
0x000003ff80000000-0x0000040000000000 2G
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add pgd_page primitive which is required by kasan common code.
Also fixes typo in p4d_page definition.
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Kasan common code requires MAX_PTRS_PER_P4D definition, which in case
of s390 is always PTRS_PER_P4D.
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
To do dirty loging with huge pages, we protect huge pmds in the
gmap. When they are written to, we unprotect them and mark them dirty.
We introduce the function gmap_test_and_clear_dirty_pmd which handles
dirty sync for huge pages.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
If the host invalidates a pmd, we also have to invalidate the
corresponding gmap pmds, as well as flush them from the TLB. This is
necessary, as we don't share the pmd tables between host and guest as
we do with ptes.
The clearing part of these three new functions sets a guest pmd entry
to _SEGMENT_ENTRY_EMPTY, so the guest will fault on it and we will
re-link it.
Flushing the gmap is not necessary in the host's lazy local and csp
cases. Both purge the TLB completely.
Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Let's allow pmds to be linked into gmap for the upcoming s390 KVM huge
page support.
Before this patch we copied the full userspace pmd entry. This is not
correct, as it contains SW defined bits that might be interpreted
differently in the GMAP context. Now we only copy over all hardware
relevant information leaving out the software bits.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
* ARM: lazy context-switching of FPSIMD registers on arm64, "split"
regions for vGIC redistributor
* s390: cleanups for nested, clock handling, crypto, storage keys and
control register bits
* x86: many bugfixes, implement more Hyper-V super powers,
implement lapic_timer_advance_ns even when the LAPIC timer
is emulated using the processor's VMX preemption timer. Two
security-related bugfixes at the top of the branch.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
"Small update for KVM:
ARM:
- lazy context-switching of FPSIMD registers on arm64
- "split" regions for vGIC redistributor
s390:
- cleanups for nested
- clock handling
- crypto
- storage keys
- control register bits
x86:
- many bugfixes
- implement more Hyper-V super powers
- implement lapic_timer_advance_ns even when the LAPIC timer is
emulated using the processor's VMX preemption timer.
- two security-related bugfixes at the top of the branch"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (79 commits)
kvm: fix typo in flag name
kvm: x86: use correct privilege level for sgdt/sidt/fxsave/fxrstor access
KVM: x86: pass kvm_vcpu to kvm_read_guest_virt and kvm_write_guest_virt_system
KVM: x86: introduce linear_{read,write}_system
kvm: nVMX: Enforce cpl=0 for VMX instructions
kvm: nVMX: Add support for "VMWRITE to any supported field"
kvm: nVMX: Restrict VMX capability MSR changes
KVM: VMX: Optimize tscdeadline timer latency
KVM: docs: nVMX: Remove known limitations as they do not exist now
KVM: docs: mmu: KVM support exposing SLAT to guests
kvm: no need to check return value of debugfs_create functions
kvm: Make VM ioctl do valloc for some archs
kvm: Change return type to vm_fault_t
KVM: docs: mmu: Fix link to NPT presentation from KVM Forum 2008
kvm: x86: Amend the KVM_GET_SUPPORTED_CPUID API documentation
KVM: x86: hyperv: declare KVM_CAP_HYPERV_TLBFLUSH capability
KVM: x86: hyperv: simplistic HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE}_EX implementation
KVM: x86: hyperv: simplistic HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE} implementation
KVM: introduce kvm_make_vcpus_request_mask() API
KVM: x86: hyperv: do rep check for each hypercall separately
...
Currently the PTE special supports is turned on in per architecture
header files. Most of the time, it is defined in
arch/*/include/asm/pgtable.h depending or not on some other per
architecture static definition.
This patch introduce a new configuration variable to manage this
directly in the Kconfig files. It would later replace
__HAVE_ARCH_PTE_SPECIAL.
Here notes for some architecture where the definition of
__HAVE_ARCH_PTE_SPECIAL is not obvious:
arm
__HAVE_ARCH_PTE_SPECIAL which is currently defined in
arch/arm/include/asm/pgtable-3level.h which is included by
arch/arm/include/asm/pgtable.h when CONFIG_ARM_LPAE is set.
So select ARCH_HAS_PTE_SPECIAL if ARM_LPAE.
powerpc
__HAVE_ARCH_PTE_SPECIAL is defined in 2 files:
- arch/powerpc/include/asm/book3s/64/pgtable.h
- arch/powerpc/include/asm/pte-common.h
The first one is included if (PPC_BOOK3S & PPC64) while the second is
included in all the other cases.
So select ARCH_HAS_PTE_SPECIAL all the time.
sparc:
__HAVE_ARCH_PTE_SPECIAL is defined if defined(__sparc__) &&
defined(__arch64__) which are defined through the compiler in
sparc/Makefile if !SPARC32 which I assume to be if SPARC64.
So select ARCH_HAS_PTE_SPECIAL if SPARC64
There is no functional change introduced by this patch.
Link: http://lkml.kernel.org/r/1523433816-14460-2-git-send-email-ldufour@linux.vnet.ibm.com
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Suggested-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Albert Ou <albert@sifive.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Christophe LEROY <christophe.leroy@c-s.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Up to now we always expected to have the storage key facility
available for our (non-VSIE) KVM guests. For huge page support, we
need to be able to disable it, so let's introduce that now.
We add the use_skf variable to manage KVM storage key facility
usage. Also we rename use_skey in the mm context struct to uses_skeys
to make it more clear that it is an indication that the vm actively
uses storage keys.
Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Reviewed-by: Farhan Ali <alifm@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
The 'access_permitted' helper is used in the gup-fast path and goes
beyond the simple _PAGE_RW check to also:
- validate that the mapping is writable from a protection keys
standpoint
- validate that the pte has _PAGE_USER set since all fault paths where
pud_write is must be referencing user-memory.
[dan.j.williams@intel.com: fix powerpc compile error]
Link: http://lkml.kernel.org/r/151129127237.37405.16073414520854722485.stgit@dwillia2-desk3.amr.corp.intel.com
Link: http://lkml.kernel.org/r/151043110453.2842.2166049702068628177.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.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>
In response to compile breakage introduced by a series that added the
pud_write helper to x86, Stephen notes:
did you consider using the other paradigm:
In arch include files:
#define pud_write pud_write
static inline int pud_write(pud_t pud)
.....
Then in include/asm-generic/pgtable.h:
#ifndef pud_write
tatic inline int pud_write(pud_t pud)
{
....
}
#endif
If you had, then the powerpc code would have worked ... ;-) and many
of the other interfaces in include/asm-generic/pgtable.h are
protected that way ...
Given that some architecture already define pmd_write() as a macro, it's
a net reduction to drop the definition of __HAVE_ARCH_PMD_WRITE.
Link: http://lkml.kernel.org/r/151129126721.37405.13339850900081557813.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Suggested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Oliver OHalloran <oliveroh@au1.ibm.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 227be799c3 ("s390/mm: uninline pmdp_xxx functions from pgtable.h")
inadvertently changed the behavior of pmdp_invalidate(), so that it now
clears the pmd instead of just marking it as invalid. Fix this by restoring
the original behavior.
A possible impact of the misbehaving pmdp_invalidate() would be the
MADV_DONTNEED races (see commits ced10803 and 58ceeb6b), although we
should not have any negative impact on the related dirty/young flags,
since those flags are not set by the hardware on s390.
Fixes: 227be799c3 ("s390/mm: uninline pmdp_xxx functions from pgtable.h")
Cc: <stable@vger.kernel.org> # v4.6+
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Right now there is a potential hang situation for postcopy migrations,
if the guest is enabling storage keys on the target system during the
postcopy process.
For storage key virtualization, we have to forbid the empty zero page as
the storage key is a property of the physical page frame. As we enable
storage key handling lazily we then drop all mappings for empty zero
pages for lazy refaulting later on.
This does not work with the postcopy migration, which relies on the
empty zero page never triggering a fault again in the future. The reason
is that postcopy migration will simply read a page on the target system
if that page is a known zero page to fault in an empty zero page. At
the same time postcopy remembers that this page was already transferred
- so any future userfault on that page will NOT be retransmitted again
to avoid races.
If now the guest enters the storage key mode while in postcopy, we will
break this assumption of postcopy.
The solution is to disable the empty zero page for KVM guests early on
and not during storage key enablement. With this change, the postcopy
migration process is guaranteed to start after no zero pages are left.
As guest pages are very likely not empty zero pages anyway the memory
overhead is also pretty small.
While at it this also adds proper page table locking to the zero page
removal.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add various defines like e.g. _REGION1_SHIFT to reflect the hardware
mmu. We have quite a bit code that does not make use of the Linux
memory management primitives but directly modifies page, segment and
region values.
Most of this is open-coded like e.g. "1UL << 53". In order to clean
this up introduce a couple of new defines. The existing Linux memory
management defines are changed, so the mapping to the hardware
implementation is reflected.
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
We have C code also outside of #ifndef __ASSEMBLY__. So these
guards seem to be quite pointless and can be removed.
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Introduce and use p?d_folded() functions to clarify the page table
code a bit more.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
_REGION3_ENTRY_ORIGIN defines a wrong mask which can be used to
extract a segment table origin from a region 3 table entry. It removes
only the lower 11 instead of 12 bits from a region 3 table entry.
Luckily this bit is currently always zero, so nothing bad happened yet.
In order to avoid future bugs just remove the region 3 specific mask
and use the correct generic _REGION_ENTRY_ORIGIN mask.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add the logic to upgrade the page table for a 64-bit process to
five levels. This increases the TASK_SIZE from 8PB to 16EB-4K.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Pull s390 updates from Martin Schwidefsky:
- three merges for KVM/s390 with changes for vfio-ccw and cpacf. The
patches are included in the KVM tree as well, let git sort it out.
- add the new 'trng' random number generator
- provide the secure key verification API for the pkey interface
- introduce the z13 cpu counters to perf
- add a new system call to set up the guarded storage facility
- simplify TASK_SIZE and arch_get_unmapped_area
- export the raw STSI data related to CPU topology to user space
- ... and the usual churn of bug-fixes and cleanups.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (74 commits)
s390/crypt: use the correct module alias for paes_s390.
s390/cpacf: Introduce kma instruction
s390/cpacf: query instructions use unique parameters for compatibility with KMA
s390/trng: Introduce s390 TRNG device driver.
s390/crypto: Provide s390 specific arch random functionality.
s390/crypto: Add new subfunctions to the cpacf PRNO function.
s390/crypto: Renaming PPNO to PRNO.
s390/pageattr: avoid unnecessary page table splitting
s390/mm: simplify arch_get_unmapped_area[_topdown]
s390/mm: make TASK_SIZE independent from the number of page table levels
s390/gs: add regset for the guarded storage broadcast control block
s390/kvm: Add use_cmma field to mm_context_t
s390/kvm: Add PGSTE manipulation functions
vfio: ccw: improve error handling for vfio_ccw_mdev_remove
vfio: ccw: remove unnecessary NULL checks of a pointer
s390/spinlock: remove compare and delay instruction
s390/spinlock: use atomic primitives for spinlocks
s390/cpumf: simplify detection of guest samples
s390/pci: remove forward declaration
s390/pci: increase the PCI_NR_FUNCTIONS default
...
Add PGSTE manipulation functions:
* set_pgste_bits sets specific bits in a PGSTE
* get_pgste returns the whole PGSTE
* pgste_perform_essa manipulates a PGSTE to set specific storage states
* ESSA_[SG]ET_* macros used to indicate the action for manipulate_pgste
Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Reviewed-by: Janosch Frank <frankja@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
On heavy paging with KSM I see guest data corruption. Turns out that
KSM will add pages to its tree, where the mapping return true for
pte_unused (or might become as such later). KSM will unmap such pages
and reinstantiate with different attributes (e.g. write protected or
special, e.g. in replace_page or write_protect_page)). This uncovered
a bug in our pagetable handling: We must remove the unused flag as
soon as an entry becomes present again.
Cc: stable@vger.kernel.org
Signed-of-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If an architecture uses 4level-fixup.h we don't need to do anything as
it includes 5level-fixup.h.
If an architecture uses pgtable-nop*d.h, define __ARCH_USE_5LEVEL_HACK
before inclusion of the header. It makes asm-generic code to use
5level-fixup.h.
If an architecture has 4-level paging or folds levels on its own,
include 5level-fixup.h directly.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
_SEGMENT_ENTRY_INVALID denotes the invalid bit in a segment table
entry whereas _SEGMENT_ENTRY_EMPTY means that the value of the whole
entry is only the invalid bit, as the entry is completely empty.
Therefore we use _SEGMENT_ENTRY_INVALID only to check and set the
invalid bit with bitwise operations. _SEGMENT_ENTRY_EMPTY is only used
to check for (un)equality.
Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Both MACHINE_HAS_PFMF and MACHINE_HAS_HPAGE are just an alias for
MACHINE_HAS_EDAT1. So simply use MACHINE_HAS_EDAT1 instead.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Bit 0x100 of a page table, segment table of region table entry
can be used to disallow code execution for the virtual addresses
associated with the entry.
There is one tricky bit, the system call to return from a signal
is part of the signal frame written to the user stack. With a
non-executable stack this would stop working. To avoid breaking
things the protection fault handler checks the opcode that caused
the fault for 0x0a77 (sys_sigreturn) and 0x0aad (sys_rt_sigreturn)
and injects a system call. This is preferable to the alternative
solution with a stub function in the vdso because it works for
vdso=off and statically linked binaries as well.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Merge the __p[m|u]xdp_idte and __p[m|u]dp_idte_local functions into a
single __p[m|u]dp_idte function with an additional parameter.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Vasily Gorbik