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In note_page(), the pg_state is updated the same way in two places.
Add note_page_update_state() to do it.
Also include the display of boundary markers there as it is missing
"no level" leg, leading to a mismatch when the first two markers
are at the same address and the first displayed area uses that
address.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a284a809f01c705bbaab303b06fda216f147a99a.1593429426.git.christophe.leroy@csgroup.eu
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st->last_pa is always updated in note_page() so it can
be done outside the if/elseif/else block.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/610d6b1a60ad0bedef865a90153c1110cfaa507e.1593429426.git.christophe.leroy@csgroup.eu
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When STRICT_KERNEL_RWX is set, we want to set NX bit on vmalloc
segments. But modules require exec.
Use a dedicated segment for modules. There is not much space
above kernel, and we don't waste vmalloc space to do alignment.
Therefore, we take the segment before PAGE_OFFSET for modules.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/eb8faba9148b6cf17c696ba776b4e8ee2f6313bf.1593428200.git.christophe.leroy@csgroup.eu
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Kernel space starts at TASK_SIZE. Select kernel page table
when address is over TASK_SIZE.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/893425e32cd0a003539573b2d115e0ffa98bc26c.1593428200.git.christophe.leroy@csgroup.eu
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User space stops at TASK_SIZE. At the moment, kernel space starts
at PAGE_OFFSET.
In order to use space between TASK_SIZE and PAGE_OFFSET for modules,
make TASK_SIZE the limit between user and kernel space.
Note that fault.c already considers TASK_SIZE as the boundary between
user and kernel space.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b38b52cd8dabbb56fbd6f9219d6f3cdccbb43b44.1593428200.git.christophe.leroy@csgroup.eu
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Instead of leaving NX unset on all segments above the start
of vmalloc space, only leave NX unset on segments used for
modules.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/7172c0f5253419315e434a1816ee3d6ed6505bc0.1593428200.git.christophe.leroy@csgroup.eu
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In order to allow allocation of modules outside of vmalloc space,
use MODULES_VADDR and MODULES_END when MODULES_VADDR is defined.
Redefine module_alloc() when MODULES_VADDR defined.
Unmap corresponding KASAN shadow memory.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/7ecf5fff1eef67d450e73fc412b6ec3818483d75.1593428200.git.christophe.leroy@csgroup.eu
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MAX_NUMNODES is a theoretical maximum number of nodes thats is
supported by the kernel. Device tree properties exposes the number of
possible nodes on the current platform. The kernel would detected this
and would use it for most of its resource allocations. If the platform
now increases the nodes to over what was already exposed, then it may
lead to inconsistencies. Hence limit it to the already exposed nodes.
Suggested-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200724105809.24733-1-srikar@linux.vnet.ibm.com
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POWER6 only supports AMR update via privileged mode (MSR[PR] = 0,
SPRN_AMR=29) The PR=1 (userspace) alias for that SPR (SPRN_AMR=13) was
only supported from POWER7. Since we don't allow userspace modifying
of AMR value we should disable pkey support on P6 and before.
The hypervisor will still report pkey support via
"ibm,processor-storage-keys". Hence also check for P7 CPU_FTR bit to
decide on pkey support.
Fixes: f491fe3fb41e ("powerpc/book3s64/pkeys: Simplify the key initialization")
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200726132517.399076-1-aneesh.kumar@linux.ibm.com
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hash_low_64.S was removed in commit a43c0eb8364c ("powerpc/mm: Convert
4k insert from asm to C") and flush_hash_page() is no longer called
from any assembly routine.
Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
[mpe: Tweak comment wording]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200721091915.205006-1-santosh@fossix.org
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ISA v3.1 does not support the SAO storage control attribute required to
implement PROT_SAO. PROT_SAO was used by specialised system software
(Lx86) that has been discontinued for about 7 years, and is not thought
to be used elsewhere, so removal should not cause problems.
We rather remove it than keep support for older processors, because
live migrating guest partitions to newer processors may not be possible
if SAO is in use (or worse allowed with silent races).
- PROT_SAO stays in the uapi header so code using it would still build.
- arch_validate_prot() is removed, the generic version rejects PROT_SAO
so applications would get a failure at mmap() time.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Drop KVM change for the time being]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200703011958.1166620-3-npiggin@gmail.com
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There is only one caller to this function and the function is wrongly
named. Avoid further confusion w.r.t name and open code this at the
only call site. Also remove read_uamor(). There are no users for
the same after this.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709032946.881753-24-aneesh.kumar@linux.ibm.com
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UAMOR values are not application-specific. The kernel initializes
its value based on different reserved keys. Remove the thread-specific
UAMOR value and don't switch the UAMOR on context switch.
Move UAMOR initialization to key initialization code and remove
thread_struct.uamor because it is not used anymore.
Before commit: 4a4a5e5d2aad ("powerpc/pkeys: key allocation/deallocation must not change pkey registers")
we used to update uamor based on key allocation and free.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709032946.881753-20-aneesh.kumar@linux.ibm.com
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As we kexec across kernels that use AMR/IAMR for different purposes
we need to ensure that new kernels get kexec'd with a reset value
of AMR/IAMR. For ex: the new kernel can use key 0 for kernel mapping and the old
AMR value prevents access to key 0.
This patch also removes reset if IAMR and AMOR in kexec_sequence. Reset of AMOR
is not needed and the IAMR reset is partial (it doesn't do the reset
on secondary cpus) and is redundant with this patch.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709032946.881753-19-aneesh.kumar@linux.ibm.com
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Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709032946.881753-18-aneesh.kumar@linux.ibm.com
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Instead of pkey_disabled static key use mmu feature MMU_FTR_PKEY.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709032946.881753-17-aneesh.kumar@linux.ibm.com
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Use pkey_execute_disable_supported to check for execute key support instead
of pkey_disabled.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709032946.881753-16-aneesh.kumar@linux.ibm.com
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This will be used to enable/disable Kernel Userspace Execution
Prevention (KUEP).
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709032946.881753-15-aneesh.kumar@linux.ibm.com
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Parse storage keys related device tree entry in early_init_devtree
and enable MMU feature MMU_FTR_PKEY if pkeys are supported.
MMU feature is used instead of CPU feature because this enables us
to group MMU_FTR_KUAP and MMU_FTR_PKEY in asm feature fixup code.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709032946.881753-14-aneesh.kumar@linux.ibm.com
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The hypervisor can return less than max allowed pkey (for ex: 31) instead
of 32. We should mark all the pkeys above max allowed as reserved so
that we avoid the allocation of the wrong pkey(for ex: key 31 in the above
case) by userspace.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709032946.881753-13-aneesh.kumar@linux.ibm.com
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initial_allocation_mask is not used outside this file.
Also mark reserved_allocation_mask and initial_allocation_mask __ro_after_init;
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709032946.881753-12-aneesh.kumar@linux.ibm.com
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num_pkey now represents max number of keys supported such that we return
to userspace 0 - num_pkey - 1.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709032946.881753-11-aneesh.kumar@linux.ibm.com
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Make the default value FALSE (pkey enabled) and set to TRUE when we
find the total number of keys supported to be zero.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709032946.881753-10-aneesh.kumar@linux.ibm.com
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Key 1 is marked reserved by ISA. Setup uamor to prevent userspace modification
of the same.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709032946.881753-8-aneesh.kumar@linux.ibm.com
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Add documentation explaining the execute_only_key. The reservation and initialization mask
details are also explained in this patch.
No functional change in this patch.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709032946.881753-7-aneesh.kumar@linux.ibm.com
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This explains the details w.r.t key 1.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709032946.881753-6-aneesh.kumar@linux.ibm.com
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We are wrongly using CPU_FTRS_POWER8 to check for P8 support. Instead, we should
use PVR value. Now considering we are using CPU_FTRS_POWER8, that
implies we returned true for P9 with older firmware. Keep the same behavior
by checking for P9 PVR value.
Fixes: cf43d3b26452 ("powerpc: Enable pkey subsystem")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709032946.881753-2-aneesh.kumar@linux.ibm.com
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To enable memory unplug without splitting kernel page table
mapping, we force the max mapping size to the LMB size. LMB
size is the unit in which hypervisor will do memory add/remove
operation.
Pseries systems supports max LMB size of 256MB. Hence on pseries,
we now end up mapping memory with 2M page size instead of 1G. To improve
that we want hypervisor to hint the kernel about the hotplug
memory range. That was added that as part of
commit b6eca183e23e ("powerpc/kernel: Enables memory
hot-remove after reboot on pseries guests")
But PowerVM doesn't provide that hint yet. Once we get PowerVM
updated, we can then force the 2M mapping only to hot-pluggable
memory region using memblock_is_hotpluggable(). Till then
let's depend on LMB size for finding the mapping page size
for linear range.
With this change KVM guest will also be doing linear mapping with
2M page size.
The actual TLB benefit of mapping guest page table entries with
hugepage size can only be materialized if the partition scoped
entries are also using the same or higher page size. A guest using
1G hugetlbfs backing guest memory can have a performance impact with
the above change.
Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
[mpe: Fold in fix from Aneesh spotted by lkp@intel.com]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709131925.922266-5-aneesh.kumar@linux.ibm.com
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We split the page table mapping on memory unplug if the
linear range was mapped with huge page mapping (for ex: 1G)
The page table splitting code has a few issues:
1. Recursive locking
--------------------
Memory unplug path takes cpu_hotplug_lock and calls stop_machine()
for splitting the mappings. However stop_machine() takes
cpu_hotplug_lock again causing deadlock.
2. BUG: sleeping function called from in_atomic() context
---------------------------------------------------------
Memory unplug path (remove_pagetable) takes init_mm.page_table_lock
spinlock and later calls stop_machine() which does wait_for_completion()
3. Bad unlock unbalance
-----------------------
Memory unplug path takes init_mm.page_table_lock spinlock and calls
stop_machine(). The stop_machine thread function runs in a different
thread context (migration thread) which tries to release and reaquire
ptl. Releasing ptl from a different thread than which acquired it
causes bad unlock unbalance.
These problems can be avoided if we avoid mapping hot-plugged memory
with 1G mapping, thereby removing the need for splitting them during
unplug. The kernel always make sure the minimum unplug request is
SUBSECTION_SIZE for device memory and SECTION_SIZE for regular memory.
In preparation for such a change remove page table splitting support.
This essentially is a revert of
commit 4dd5f8a99e791 ("powerpc/mm/radix: Split linear mapping on hot-unplug")
Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709131925.922266-4-aneesh.kumar@linux.ibm.com
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remove_pagetable() isn't freeing PUD table. This causes memory
leak during memory unplug. Fix this.
Fixes: 4b5d62ca17a1 ("powerpc/mm: add radix__remove_section_mapping()")
Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709131925.922266-3-aneesh.kumar@linux.ibm.com
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We can hit the following BUG_ON during memory unplug:
kernel BUG at arch/powerpc/mm/book3s64/pgtable.c:342!
Oops: Exception in kernel mode, sig: 5 [#1]
LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
NIP [c000000000093308] pmd_fragment_free+0x48/0xc0
LR [c00000000147bfec] remove_pagetable+0x578/0x60c
Call Trace:
0xc000008050000000 (unreliable)
remove_pagetable+0x384/0x60c
radix__remove_section_mapping+0x18/0x2c
remove_section_mapping+0x1c/0x3c
arch_remove_memory+0x11c/0x180
try_remove_memory+0x120/0x1b0
__remove_memory+0x20/0x40
dlpar_remove_lmb+0xc0/0x114
dlpar_memory+0x8b0/0xb20
handle_dlpar_errorlog+0xc0/0x190
pseries_hp_work_fn+0x2c/0x60
process_one_work+0x30c/0x810
worker_thread+0x98/0x540
kthread+0x1c4/0x1d0
ret_from_kernel_thread+0x5c/0x74
This occurs when unplug is attempted for such memory which has
been mapped using memblock pages as part of early kernel page
table setup. We wouldn't have initialized the PMD or PTE fragment
count for those PMD or PTE pages.
This can be fixed by allocating memory in PAGE_SIZE granularity
during early page table allocation. This makes sure a specific
page is not shared for another memblock allocation and we can
free them correctly on removing page-table pages.
Since we now do PAGE_SIZE allocations for both PUD table and
PMD table (Note that PTE table allocation is already of PAGE_SIZE),
we end up allocating more memory for the same amount of system RAM.
Here is a comparision of how much more we need for a 64T and 2G
system after this patch:
1. 64T system
-------------
64T RAM would need 64G for vmemmap with struct page size being 64B.
128 PUD tables for 64T memory (1G mappings)
1 PUD table and 64 PMD tables for 64G vmemmap (2M mappings)
With default PUD[PMD]_TABLE_SIZE(4K), (128+1+64)*4K=772K
With PAGE_SIZE(64K) table allocations, (128+1+64)*64K=12352K
2. 2G system
------------
2G RAM would need 2M for vmemmap with struct page size being 64B.
1 PUD table for 2G memory (1G mapping)
1 PUD table and 1 PMD table for 2M vmemmap (2M mappings)
With default PUD[PMD]_TABLE_SIZE(4K), (1+1+1)*4K=12K
With new PAGE_SIZE(64K) table allocations, (1+1+1)*64K=192K
Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709131925.922266-2-aneesh.kumar@linux.ibm.com
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Merge our fixes branch, primarily to bring in the ebb selftests build
fix and the pkey fix, which is a dependency for some future work.
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Since arch_update_cpu_topology() doesn't do anything on powerpc now,
remove it and associated dead code.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200612051238.1007764-15-nathanl@linux.ibm.com
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All users of this prrn_is_enabled() are gone; remove it.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200612051238.1007764-14-nathanl@linux.ibm.com
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These APIs have become no-ops, so remove them and all call sites.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200612051238.1007764-12-nathanl@linux.ibm.com
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timed_topology_update is a no-op now, so remove it and all call sites.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200612051238.1007764-11-nathanl@linux.ibm.com
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Previous changes have removed the code which sets bits in
cpu_associativity_changes_mask and thus it is never modifed at
runtime. From this we can reason that numa_update_cpu_topology()
always returns 0 without doing anything. Remove the body of
numa_update_cpu_topology() and remove all code which becomes
unreachable as a result.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200612051238.1007764-10-nathanl@linux.ibm.com
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These flags are always zero now; remove them and suitably adjust the
remaining references to them.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200612051238.1007764-9-nathanl@linux.ibm.com
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Since vphn_enabled is always 0, we can remove the call to
topology_schedule_update() and remove the code which becomes
unreachable as a result.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200612051238.1007764-8-nathanl@linux.ibm.com
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Since vphn_enabled is always 0, we can stub out
timed_topology_update() and remove the code which becomes unreachable.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200612051238.1007764-7-nathanl@linux.ibm.com
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Previous changes have made it so these flags are never changed;
enforce this by making them const.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200612051238.1007764-6-nathanl@linux.ibm.com
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Since the topology_updates_enabled flag is now always false, remove it
and the code which has become unreachable. This is the minimum change
that prevents 'defined but unused' warnings emitted by the compiler
after stubbing out the start/stop_topology_updates() functions.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200612051238.1007764-5-nathanl@linux.ibm.com
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Remove the /proc/powerpc/topology_updates interface and the
topology_updates=on/off command line argument. The internal
topology_updates_enabled flag remains for now, but always false.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200612051238.1007764-4-nathanl@linux.ibm.com
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When platform doesn't support GTSE, let TLB invalidation requests
for radix guests be off-loaded to the host using H_RPT_INVALIDATE
hcall.
[hcall wrapper, error path handling and renames]
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200703053608.12884-4-bharata@linux.ibm.com
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Make GTSE an MMU feature and enable it by default for radix.
However for guest, conditionally enable it if hypervisor supports
it via OV5 vector. Let prom_init ask for radix GTSE only if the
support exists.
Having GTSE as an MMU feature will make it easy to enable radix
without GTSE. Currently radix assumes GTSE is enabled by default.
Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200703053608.12884-2-bharata@linux.ibm.com
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Doing kasan pages allocation in MMU_init is too early, kernel doesn't
have access yet to the entire memory space and memblock_alloc() fails
when the kernel is a bit big.
Do it from kasan_init() instead.
Fixes: 2edb16efc899 ("powerpc/32: Add KASAN support")
Fixes: d2a91cef9bbd ("powerpc/kasan: Fix shadow pages allocation failure")
Cc: stable@vger.kernel.org
Reported-by: Erhard F. <erhard_f@mailbox.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=208181
Link: https://lore.kernel.org/r/63048fcea8a1c02f75429ba3152f80f7853f87fc.1593690707.git.christophe.leroy@csgroup.eu
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This reverts commit d2a91cef9bbdeb87b7449fdab1a6be6000930210.
This commit moved too much work in kasan_init(). The allocation
of shadow pages has to be moved for the reason explained in that
patch, but the allocation of page tables still need to be done
before switching to the final hash table.
First revert the incorrect commit, following patch redoes it
properly.
Fixes: d2a91cef9bbd ("powerpc/kasan: Fix shadow pages allocation failure")
Cc: stable@vger.kernel.org
Reported-by: Erhard F. <erhard_f@mailbox.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=208181
Link: https://lore.kernel.org/r/3667deb0911affbf999b99f87c31c77d5e870cd2.1593690707.git.christophe.leroy@csgroup.eu
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Even if the IAMR value denies execute access, the current code returns
true from pkey_access_permitted() for an execute permission check, if
the AMR read pkey bit is cleared.
This results in repeated page fault loop with a test like below:
#define _GNU_SOURCE
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <inttypes.h>
#include <assert.h>
#include <malloc.h>
#include <unistd.h>
#include <pthread.h>
#include <sys/mman.h>
#ifdef SYS_pkey_mprotect
#undef SYS_pkey_mprotect
#endif
#ifdef SYS_pkey_alloc
#undef SYS_pkey_alloc
#endif
#ifdef SYS_pkey_free
#undef SYS_pkey_free
#endif
#undef PKEY_DISABLE_EXECUTE
#define PKEY_DISABLE_EXECUTE 0x4
#define SYS_pkey_mprotect 386
#define SYS_pkey_alloc 384
#define SYS_pkey_free 385
#define PPC_INST_NOP 0x60000000
#define PPC_INST_BLR 0x4e800020
#define PROT_RWX (PROT_READ | PROT_WRITE | PROT_EXEC)
static int sys_pkey_mprotect(void *addr, size_t len, int prot, int pkey)
{
return syscall(SYS_pkey_mprotect, addr, len, prot, pkey);
}
static int sys_pkey_alloc(unsigned long flags, unsigned long access_rights)
{
return syscall(SYS_pkey_alloc, flags, access_rights);
}
static int sys_pkey_free(int pkey)
{
return syscall(SYS_pkey_free, pkey);
}
static void do_execute(void *region)
{
/* jump to region */
asm volatile(
"mtctr %0;"
"bctrl"
: : "r"(region) : "ctr", "lr");
}
static void do_protect(void *region)
{
size_t pgsize;
int i, pkey;
pgsize = getpagesize();
pkey = sys_pkey_alloc(0, PKEY_DISABLE_EXECUTE);
assert (pkey > 0);
/* perform mprotect */
assert(!sys_pkey_mprotect(region, pgsize, PROT_RWX, pkey));
do_execute(region);
/* free pkey */
assert(!sys_pkey_free(pkey));
}
int main(int argc, char **argv)
{
size_t pgsize, numinsns;
unsigned int *region;
int i;
/* allocate memory region to protect */
pgsize = getpagesize();
region = memalign(pgsize, pgsize);
assert(region != NULL);
assert(!mprotect(region, pgsize, PROT_RWX));
/* fill page with NOPs with a BLR at the end */
numinsns = pgsize / sizeof(region[0]);
for (i = 0; i < numinsns - 1; i++)
region[i] = PPC_INST_NOP;
region[i] = PPC_INST_BLR;
do_protect(region);
return EXIT_SUCCESS;
}
The fix is to only check the IAMR for an execute check, the AMR value
is not relevant.
Fixes: f2407ef3ba22 ("powerpc: helper to validate key-access permissions of a pte")
Cc: stable@vger.kernel.org # v4.16+
Reported-by: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
[mpe: Add detail to change log, tweak wording & formatting]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200712132047.1038594-1-aneesh.kumar@linux.ibm.com
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Jan reported that LTP mmap03 was getting stuck in a page fault loop
after commit c46241a370a6 ("powerpc/pkeys: Check vma before returning
key fault error to the user"), as well as a minimised reproducer:
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/mman.h>
int main(int ac, char **av)
{
int page_sz = getpagesize();
int fildes;
char *addr;
fildes = open("tempfile", O_WRONLY | O_CREAT, 0666);
write(fildes, &fildes, sizeof(fildes));
close(fildes);
fildes = open("tempfile", O_RDONLY);
unlink("tempfile");
addr = mmap(0, page_sz, PROT_EXEC, MAP_FILE | MAP_PRIVATE, fildes, 0);
printf("%d\n", *addr);
return 0;
}
And noticed that access_pkey_error() in page fault handler now always
seem to return false:
__do_page_fault
access_pkey_error(is_pkey: 1, is_exec: 0, is_write: 0)
arch_vma_access_permitted
pkey_access_permitted
if (!is_pkey_enabled(pkey))
return true
return false
pkey_access_permitted() should not check if the pkey is available in
UAMOR (using is_pkey_enabled()). The kernel needs to do that check
only when allocating keys. This also makes sure the execute_only_key
which is marked as non-manageable via UAMOR is handled correctly in
pkey_access_permitted(), and fixes the bug.
Fixes: c46241a370a6 ("powerpc/pkeys: Check vma before returning key fault error to the user")
Reported-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
[mpe: Include bug report details etc. in the change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200627070147.297535-1-aneesh.kumar@linux.ibm.com
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Building the current 5.8 kernel for an e500 machine with
CONFIG_RANDOMIZE_BASE=y and CONFIG_BLOCK=n yields the following
failure:
arch/powerpc/mm/nohash/kaslr_booke.c: In function 'kaslr_early_init':
arch/powerpc/mm/nohash/kaslr_booke.c:387:2: error: implicit
declaration of function 'flush_icache_range'; did you mean 'flush_tlb_range'?
Indeed, including asm/cacheflush.h into kaslr_booke.c fixes the build.
Fixes: 2b0e86cc5de6 ("powerpc/fsl_booke/32: implement KASLR infrastructure")
Cc: stable@vger.kernel.org # v5.5+
Signed-off-by: Arseny Solokha <asolokha@kb.kras.ru>
Reviewed-by: Jason Yan <yanaijie@huawei.com>
Acked-by: Scott Wood <oss@buserror.net>
[mpe: Tweak change log to mention CONFIG_BLOCK=n]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200613162801.1946619-1-asolokha@kb.kras.ru
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