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The MMU_NO_CONTEXT checks are an unnecessary complication. Make
these warn to prepare to remove them in future.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230203111718.1149852-3-npiggin@gmail.com
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need_flush_all is only set by arch code to instruct generic tlb_flush
to flush all. It is never set by powerpc, so it can be removed.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230203111718.1149852-2-npiggin@gmail.com
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If a relocatable kernel is loaded at a non-zero address and told not to
relocate to zero (kdump or RELOCATABLE_TEST), the mapping of the
interrupt code at zero is left with RWX permissions.
That is a security weakness, and leads to a warning at boot if
CONFIG_DEBUG_WX is enabled:
powerpc/mm: Found insecure W+X mapping at address 00000000056435bc/0xc000000000000000
WARNING: CPU: 1 PID: 1 at arch/powerpc/mm/ptdump/ptdump.c:193 note_page+0x484/0x4c0
CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.2.0-rc1-00001-g8ae8e98aea82-dirty #175
Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,git-dd0dca hv:linux,kvm pSeries
NIP: c0000000004a1c34 LR: c0000000004a1c30 CTR: 0000000000000000
REGS: c000000003503770 TRAP: 0700 Not tainted (6.2.0-rc1-00001-g8ae8e98aea82-dirty)
MSR: 8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE> CR: 24000220 XER: 00000000
CFAR: c000000000545a58 IRQMASK: 0
...
NIP note_page+0x484/0x4c0
LR note_page+0x480/0x4c0
Call Trace:
note_page+0x480/0x4c0 (unreliable)
ptdump_pmd_entry+0xc8/0x100
walk_pgd_range+0x618/0xab0
walk_page_range_novma+0x74/0xc0
ptdump_walk_pgd+0x98/0x170
ptdump_check_wx+0x94/0x100
mark_rodata_ro+0x30/0x70
kernel_init+0x78/0x1a0
ret_from_kernel_thread+0x5c/0x64
The fix has two parts. Firstly the pages from zero up to the end of
interrupts need to be marked read-only, so that they are left with R-X
permissions. Secondly the mapping logic needs to be taught to ensure
there is a page boundary at the end of the interrupt region, so that the
permission change only applies to the interrupt text, and not the region
following it.
Fixes: c55d7b5e6426 ("powerpc: Remove STRICT_KERNEL_RWX incompatibility with RELOCATABLE")
Reported-by: Sachin Sant <sachinp@linux.ibm.com>
Tested-by: Sachin Sant <sachinp@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230110124753.1325426-2-mpe@ellerman.id.au
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If a relocatable kernel is loaded at an address that is not 2MB aligned
and told not to relocate to zero, the kernel can crash due to
mark_rodata_ro() incorrectly changing some read-write data to read-only.
Scenarios where the misalignment can occur are when the kernel is
loaded by kdump or using the RELOCATABLE_TEST config option.
Example crash with the kernel loaded at 5MB:
Run /sbin/init as init process
BUG: Unable to handle kernel data access on write at 0xc000000000452000
Faulting instruction address: 0xc0000000005b6730
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
CPU: 1 PID: 1 Comm: init Not tainted 6.2.0-rc1-00011-g349188be4841 #166
Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,git-5b4c5a hv:linux,kvm pSeries
NIP: c0000000005b6730 LR: c000000000ae9ab8 CTR: 0000000000000380
REGS: c000000004503250 TRAP: 0300 Not tainted (6.2.0-rc1-00011-g349188be4841)
MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 44288480 XER: 00000000
CFAR: c0000000005b66ec DAR: c000000000452000 DSISR: 0a000000 IRQMASK: 0
...
NIP memset+0x68/0x104
LR zero_user_segments.constprop.0+0xa8/0xf0
Call Trace:
ext4_mpage_readpages+0x7f8/0x830
ext4_readahead+0x48/0x60
read_pages+0xb8/0x380
page_cache_ra_unbounded+0x19c/0x250
filemap_fault+0x58c/0xae0
__do_fault+0x60/0x100
__handle_mm_fault+0x1230/0x1a40
handle_mm_fault+0x120/0x300
___do_page_fault+0x20c/0xa80
do_page_fault+0x30/0xc0
data_access_common_virt+0x210/0x220
This happens because mark_rodata_ro() tries to change permissions on the
range _stext..__end_rodata, but _stext sits in the middle of the 2MB
page from 4MB to 6MB:
radix-mmu: Mapped 0x0000000000000000-0x0000000000200000 with 2.00 MiB pages (exec)
radix-mmu: Mapped 0x0000000000200000-0x0000000000400000 with 2.00 MiB pages
radix-mmu: Mapped 0x0000000000400000-0x0000000002400000 with 2.00 MiB pages (exec)
The logic that changes the permissions assumes the linear mapping was
split correctly at boot, so it marks the entire 2MB page read-only. That
leads to the write fault above.
To fix it, the boot time mapping logic needs to consider that if the
kernel is running at a non-zero address then _stext is a boundary where
it must split the mapping.
That leads to the mapping being split correctly, allowing the rodata
permission change to take happen correctly, with no spillover:
radix-mmu: Mapped 0x0000000000000000-0x0000000000200000 with 2.00 MiB pages (exec)
radix-mmu: Mapped 0x0000000000200000-0x0000000000400000 with 2.00 MiB pages
radix-mmu: Mapped 0x0000000000400000-0x0000000000500000 with 64.0 KiB pages
radix-mmu: Mapped 0x0000000000500000-0x0000000000600000 with 64.0 KiB pages (exec)
radix-mmu: Mapped 0x0000000000600000-0x0000000002400000 with 2.00 MiB pages (exec)
If the kernel is loaded at a 2MB aligned address, the mapping continues
to use 2MB pages as before:
radix-mmu: Mapped 0x0000000000000000-0x0000000000200000 with 2.00 MiB pages (exec)
radix-mmu: Mapped 0x0000000000200000-0x0000000000400000 with 2.00 MiB pages
radix-mmu: Mapped 0x0000000000400000-0x0000000002c00000 with 2.00 MiB pages (exec)
radix-mmu: Mapped 0x0000000002c00000-0x0000000100000000 with 2.00 MiB pages
Fixes: c55d7b5e6426 ("powerpc: Remove STRICT_KERNEL_RWX incompatibility with RELOCATABLE")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230110124753.1325426-1-mpe@ellerman.id.au
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stress_hpt_timer_fn() is only used in hash_utils.c, make it static.
Fixes: 6b34a099faa1 ("powerpc/64s/hash: add stress_hpt kernel boot option to increase hash faults")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221228093603.3166599-1-yangyingliang@huawei.com
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This option increases the number of hash misses by limiting the number
of kernel HPT entries, by keeping a per-CPU record of the last kernel
HPTEs installed, and removing that from the hash table on the next hash
insertion. A timer round-robins CPUs removing remaining kernel HPTEs and
clearing the TLB (in the case of bare metal) to increase and slightly
randomise kernel fault activity.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Add comment about NR_CPUS usage, fixup whitespace]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221024030150.852517-1-npiggin@gmail.com
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Merge our fixes branch to bring in some changes that are prerequisites
for work in next.
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Last usage of find_current_mm_pte() was removed by
commit 15759cb054ef ("powerpc/perf/callchain: Use
__get_user_pages_fast in read_user_stack_slow")
Remove it.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ec79f462a3bfa8365b7df505e574d5d85246bc68.1646818177.git.christophe.leroy@csgroup.eu
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stop_machine_cpuslocked takes a mutex so it must be called in a
preemptible context, so it can't simply be fixed by disabling
preemption.
This is not a bug, because CPU hotplug is locked, so this processor will
call in to the stop machine function. So raw_smp_processor_id() could be
used. This leaves a small chance that this thread will be migrated to
another CPU, so the master work would be done by a CPU from a different
context. Better for test coverage to make that a common case by just
having the first CPU to call in become the master.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221013151647.1857994-2-npiggin@gmail.com
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This lock is taken while the raw kfence_freelist_lock is held, so it
must also be a raw spinlock, as reported by lockdep when raw lock
nesting checking is enabled.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221013230710.1987253-3-npiggin@gmail.com
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With kfence enabled, there are several cases where HPTE and TLBIE locks
are called from softirq context, for example:
WARNING: inconsistent lock state
6.0.0-11845-g0cbbc95b12ac #1 Tainted: G N
--------------------------------
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
swapper/0/1 [HC0[0]:SC0[0]:HE1:SE1] takes:
c000000002734de8 (native_tlbie_lock){+.?.}-{2:2}, at: .native_hpte_updateboltedpp+0x1a4/0x600
{IN-SOFTIRQ-W} state was registered at:
.lock_acquire+0x20c/0x520
._raw_spin_lock+0x4c/0x70
.native_hpte_invalidate+0x62c/0x840
.hash__kernel_map_pages+0x450/0x640
.kfence_protect+0x58/0xc0
.kfence_guarded_free+0x374/0x5a0
.__slab_free+0x3d0/0x630
.put_cred_rcu+0xcc/0x120
.rcu_core+0x3c4/0x14e0
.__do_softirq+0x1dc/0x7dc
.do_softirq_own_stack+0x40/0x60
Fix this by consistently disabling irqs while taking either of these
locks. Don't just disable bh because several of the more common cases
already disable irqs, so this just makes the locks always irq-safe.
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221013230710.1987253-2-npiggin@gmail.com
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Add lockdep annotation for the HPTE bit-spinlock. Modern systems don't
take the tlbie lock, so this shows up some of the same lockdep warnings
that were being reported by the ppc970. And they're not taken in exactly
the same places so this is nice to have in its own right.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221013230710.1987253-1-npiggin@gmail.com
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
linux-next for a couple of months without, to my knowledge, any
negative reports (or any positive ones, come to that).
- Also the Maple Tree from Liam Howlett. An overlapping range-based
tree for vmas. It it apparently slightly more efficient in its own
right, but is mainly targeted at enabling work to reduce mmap_lock
contention.
Liam has identified a number of other tree users in the kernel which
could be beneficially onverted to mapletrees.
Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
at [1]. This has yet to be addressed due to Liam's unfortunately
timed vacation. He is now back and we'll get this fixed up.
- Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses
clang-generated instrumentation to detect used-unintialized bugs down
to the single bit level.
KMSAN keeps finding bugs. New ones, as well as the legacy ones.
- Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
memory into THPs.
- Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to
support file/shmem-backed pages.
- userfaultfd updates from Axel Rasmussen
- zsmalloc cleanups from Alexey Romanov
- cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and
memory-failure
- Huang Ying adds enhancements to NUMA balancing memory tiering mode's
page promotion, with a new way of detecting hot pages.
- memcg updates from Shakeel Butt: charging optimizations and reduced
memory consumption.
- memcg cleanups from Kairui Song.
- memcg fixes and cleanups from Johannes Weiner.
- Vishal Moola provides more folio conversions
- Zhang Yi removed ll_rw_block() :(
- migration enhancements from Peter Xu
- migration error-path bugfixes from Huang Ying
- Aneesh Kumar added ability for a device driver to alter the memory
tiering promotion paths. For optimizations by PMEM drivers, DRM
drivers, etc.
- vma merging improvements from Jakub Matěn.
- NUMA hinting cleanups from David Hildenbrand.
- xu xin added aditional userspace visibility into KSM merging
activity.
- THP & KSM code consolidation from Qi Zheng.
- more folio work from Matthew Wilcox.
- KASAN updates from Andrey Konovalov.
- DAMON cleanups from Kaixu Xia.
- DAMON work from SeongJae Park: fixes, cleanups.
- hugetlb sysfs cleanups from Muchun Song.
- Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.
Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1]
* tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits)
hugetlb: allocate vma lock for all sharable vmas
hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer
hugetlb: fix vma lock handling during split vma and range unmapping
mglru: mm/vmscan.c: fix imprecise comments
mm/mglru: don't sync disk for each aging cycle
mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol
mm: memcontrol: use do_memsw_account() in a few more places
mm: memcontrol: deprecate swapaccounting=0 mode
mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled
mm/secretmem: remove reduntant return value
mm/hugetlb: add available_huge_pages() func
mm: remove unused inline functions from include/linux/mm_inline.h
selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory
selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
selftests/vm: add thp collapse shmem testing
selftests/vm: add thp collapse file and tmpfs testing
selftests/vm: modularize thp collapse memory operations
selftests/vm: dedup THP helpers
mm/khugepaged: add tracepoint to hpage_collapse_scan_file()
mm/madvise: add file and shmem support to MADV_COLLAPSE
...
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
- Remove our now never-true definitions for pgd_huge() and p4d_leaf().
- Add pte_needs_flush() and huge_pmd_needs_flush() for 64-bit.
- Add support for syscall wrappers.
- Add support for KFENCE on 64-bit.
- Update 64-bit HV KVM to use the new guest state entry/exit accounting
API.
- Support execute-only memory when using the Radix MMU (P9 or later).
- Implement CONFIG_PARAVIRT_TIME_ACCOUNTING for pseries guests.
- Updates to our linker script to move more data into read-only
sections.
- Allow the VDSO to be randomised on 32-bit.
- Many other small features and fixes.
Thanks to Andrew Donnellan, Aneesh Kumar K.V, Arnd Bergmann, Athira
Rajeev, Christophe Leroy, David Hildenbrand, Disha Goel, Fabiano Rosas,
Gaosheng Cui, Gustavo A. R. Silva, Haren Myneni, Hari Bathini, Jilin
Yuan, Joel Stanley, Kajol Jain, Kees Cook, Krzysztof Kozlowski, Laurent
Dufour, Liang He, Li Huafei, Lukas Bulwahn, Madhavan Srinivasan, Nathan
Chancellor, Nathan Lynch, Nicholas Miehlbradt, Nicholas Piggin, Pali
Rohár, Rohan McLure, Russell Currey, Sachin Sant, Segher Boessenkool,
Shrikanth Hegde, Tyrel Datwyler, Wolfram Sang, ye xingchen, and Zheng
Yongjun.
* tag 'powerpc-6.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (214 commits)
KVM: PPC: Book3S HV: Fix stack frame regs marker
powerpc: Don't add __powerpc_ prefix to syscall entry points
powerpc/64s/interrupt: Fix stack frame regs marker
powerpc/64: Fix msr_check_and_set/clear MSR[EE] race
powerpc/64s/interrupt: Change must-hard-mask interrupt check from BUG to WARN
powerpc/pseries: Add firmware details to the hardware description
powerpc/powernv: Add opal details to the hardware description
powerpc: Add device-tree model to the hardware description
powerpc/64: Add logical PVR to the hardware description
powerpc: Add PVR & CPU name to hardware description
powerpc: Add hardware description string
powerpc/configs: Enable PPC_UV in powernv_defconfig
powerpc/configs: Update config files for removed/renamed symbols
powerpc/mm: Fix UBSAN warning reported on hugetlb
powerpc/mm: Always update max/min_low_pfn in mem_topology_setup()
powerpc/mm/book3s/hash: Rename flush_tlb_pmd_range
powerpc: Drops STABS_DEBUG from linker scripts
powerpc/64s: Remove lost/old comment
powerpc/64s: Remove old STAB comment
powerpc: remove orphan systbl_chk.sh
...
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This function does the hash page table update. Hence rename it to
indicate this better to avoid confusion with flush_pmd_tlb_range()
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
[mpe: Drop unnecessary extern]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220907081941.209501-1-aneesh.kumar@linux.ibm.com
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KFENCE support was added for ppc32 in commit 90cbac0e995d
("powerpc: Enable KFENCE for PPC32").
Enable KFENCE on ppc64 architecture with hash and radix MMUs.
It uses the same mechanism as debug pagealloc to
protect/unprotect pages. All KFENCE kunit tests pass on both
MMUs.
KFENCE memory is initially allocated using memblock but is
later marked as SLAB allocated. This necessitates the change
to __pud_free to ensure that the KFENCE pages are freed
appropriately.
Based on previous work by Christophe Leroy and Jordan Niethe.
Signed-off-by: Nicholas Miehlbradt <nicholas@linux.ibm.com>
Reviewed-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220926075726.2846-4-nicholas@linux.ibm.com
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If the page is already mapped resp. already unmapped, bail out.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Nicholas Miehlbradt <nicholas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220926075726.2846-3-nicholas@linux.ibm.com
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debug_pagealloc_enabled() is always defined and constant folds to
'false' when CONFIG_DEBUG_PAGEALLOC is not enabled.
Remove the #ifdefs, the code and associated static variables will
be optimised out by the compiler when CONFIG_DEBUG_PAGEALLOC is
not defined.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Nicholas Miehlbradt <nicholas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220926075726.2846-2-nicholas@linux.ibm.com
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There is support for DEBUG_PAGEALLOC on hash but not on radix.
Add support on radix.
Signed-off-by: Nicholas Miehlbradt <nicholas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220926075726.2846-1-nicholas@linux.ibm.com
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Use the VMA iterator instead.
Link: https://lkml.kernel.org/r/20220906194824.2110408-34-Liam.Howlett@oracle.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The IPI broadcast is used to serialize against fast-GUP, but fast-GUP will
move to use RCU instead of disabling local interrupts in fast-GUP. Using
an IPI is the old-styled way of serializing against fast-GUP although it
still works as expected now.
And fast-GUP now fixed the potential race with THP collapse by checking
whether PMD is changed or not. So IPI broadcast in radix pmd collapse
flush is not necessary anymore. But it is still needed for hash TLB.
Link: https://lkml.kernel.org/r/20220907180144.555485-2-shy828301@gmail.com
Suggested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Yang Shi <shy828301@gmail.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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update_mmu_cache() voids when hash page tables are not used.
On PPC32 that means when MMU_FTR_HPTE_TABLE is not defined.
On PPC64 that means when RADIX is enabled.
Rename core part of update_mmu_cache() as __update_mmu_cache()
and include the initial verification in an inlined caller.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/bea5ad0de7f83eff256116816d46c84fa0a444de.1662370698.git.christophe.leroy@csgroup.eu
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powerpc has a number of read-only sections and tables that are put after
RO_DATA(). Move the __end_rodata symbol to cover these as well.
Setting memory to read-only at boot is done using __init_begin, change
that to use __end_rodata.
This makes is_kernel_rodata() exactly cover the read-only region, as
well as other things using __end_rodata (e.g., kernel/dma/debug.c).
Boot dmesg also prints the rodata size more accurately.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916040755.2398112-2-npiggin@gmail.com
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Currently __init_begin is used as the boundary for strict RWX between
executable/read-only text and data, and non-executable (after boot) code
and data.
But that's a little subtle, so add an explicit symbol to document that
the SRWX boundary lies there, and add a comment making it clear that
__init_begin must also begin there.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916131422.318752-2-mpe@ellerman.id.au
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Add support for execute-only memory (XOM) for the Radix MMU by using an
execute-only mapping, as opposed to the RX mapping used by powerpc's
other MMUs.
The Hash MMU already supports XOM through the execute-only pkey,
which is a separate mechanism shared with x86. A PROT_EXEC-only mapping
will map to RX, and then the pkey will be applied on top of it.
mmap() and mprotect() consumers in userspace should observe the same
behaviour on Hash and Radix despite the differences in implementation.
Replacing the vma_is_accessible() check in access_error() with a read
check should be functionally equivalent for non-Radix MMUs, since it
follows write and execute checks. For Radix, the change enables
detecting faults on execute-only mappings where vma_is_accessible() would
return true.
Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220817050640.406017-1-ruscur@russell.cc
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|
The nest MMU in POWER9 does not re-fetch the PTE in response to
permission mismatch, contrary to the architecture[*] and unlike the core
MMU. This requires a TLB flush before upgrading permissions of valid
PTEs, for any address space with a coprocessor attached.
Per (non-public) Nest MMU Workbook, POWER10 nest MMU conforms to the
architecture in this regard, so skip the workaround.
[*] See: Power ISA Version 3.1B, 6.10.1.2 Modifying a Translation Table
Entry, Setting a Reference or Change Bit or Upgrading Access
Authority (PTE Subject to Atomic Hardware Updates):
"If the only change being made to a valid PTE that is subject to
atomic hardware updates is to set the Reference or Change bit to
1 or to upgrade access authority, a simpler sequence suffices
because the translation hardware will refetch the PTE if an
access is attempted for which the only problems were reference
and/or change bits needing to be set or insufficient access
authority."
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220525022358.780745-3-npiggin@gmail.com
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Per (non-public) Nest MMU Workbook, POWER10 and POWER9P NMMU does not
cache PTEs in PWC, so does not require PWC flush to invalidate these
translations.
Skip the workaround on POWER10 and later.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220525022358.780745-2-npiggin@gmail.com
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Since commit 87c78b612f4f ("powerpc: Fix all occurences of "the the"")
fixed "the the", there's now a steady stream of patches fixing other
duplicate words.
Just fix them all at once, to save the overhead of dealing with
individual patches for each case.
This leaves a few cases of "that that", which in some contexts is
correct.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220718095158.326606-1-mpe@ellerman.id.au
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Trying to remove asm/ppc_asm.h from all places that don't need it
leads to several failures linked to firmware_has_feature().
To fix it, include asm/firmware.h in all files using
firmware_has_feature()
All users found with:
git grep -L "firmware\.h" ` git grep -l "firmware_has_feature("`
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/11956ec181a034b51a881ac9c059eea72c679a73.1651828453.git.christophe.leroy@csgroup.eu
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
- Convert to the generic mmap support (ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT)
- Add support for outline-only KASAN with 64-bit Radix MMU (P9 or later)
- Increase SIGSTKSZ and MINSIGSTKSZ and add support for AT_MINSIGSTKSZ
- Enable the DAWR (Data Address Watchpoint) on POWER9 DD2.3 or later
- Drop support for system call instruction emulation
- Many other small features and fixes
Thanks to Alexey Kardashevskiy, Alistair Popple, Andy Shevchenko, Bagas
Sanjaya, Bjorn Helgaas, Bo Liu, Chen Huang, Christophe Leroy, Colin Ian
King, Daniel Axtens, Dwaipayan Ray, Fabiano Rosas, Finn Thain, Frank
Rowand, Fuqian Huang, Guilherme G. Piccoli, Hangyu Hua, Haowen Bai,
Haren Myneni, Hari Bathini, He Ying, Jason Wang, Jiapeng Chong, Jing
Yangyang, Joel Stanley, Julia Lawall, Kajol Jain, Kevin Hao, Krzysztof
Kozlowski, Laurent Dufour, Lv Ruyi, Madhavan Srinivasan, Magali Lemes,
Miaoqian Lin, Minghao Chi, Nathan Chancellor, Naveen N. Rao, Nicholas
Piggin, Oliver O'Halloran, Oscar Salvador, Pali Rohár, Paul Mackerras,
Peng Wu, Qing Wang, Randy Dunlap, Reza Arbab, Russell Currey, Sohaib
Mohamed, Vaibhav Jain, Vasant Hegde, Wang Qing, Wang Wensheng, Xiang
wangx, Xiaomeng Tong, Xu Wang, Yang Guang, Yang Li, Ye Bin, YueHaibing,
Yu Kuai, Zheng Bin, Zou Wei, and Zucheng Zheng.
* tag 'powerpc-5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (200 commits)
powerpc/64: Include cache.h directly in paca.h
powerpc/64s: Only set HAVE_ARCH_UNMAPPED_AREA when CONFIG_PPC_64S_HASH_MMU is set
powerpc/xics: Include missing header
powerpc/powernv/pci: Drop VF MPS fixup
powerpc/fsl_book3e: Don't set rodata RO too early
powerpc/microwatt: Add mmu bits to device tree
powerpc/powernv/flash: Check OPAL flash calls exist before using
powerpc/powermac: constify device_node in of_irq_parse_oldworld()
powerpc/powermac: add missing g5_phy_disable_cpu1() declaration
selftests/powerpc/pmu: fix spelling mistake "mis-match" -> "mismatch"
powerpc: Enable the DAWR on POWER9 DD2.3 and above
powerpc/64s: Add CPU_FTRS_POWER10 to ALWAYS mask
powerpc/64s: Add CPU_FTRS_POWER9_DD2_2 to CPU_FTRS_ALWAYS mask
powerpc: Fix all occurences of "the the"
selftests/powerpc/pmu/ebb: remove fixed_instruction.S
powerpc/platforms/83xx: Use of_device_get_match_data()
powerpc/eeh: Drop redundant spinlock initialization
powerpc/iommu: Add missing of_node_put in iommu_init_early_dart
powerpc/pseries/vas: Call misc_deregister if sysfs init fails
powerpc/papr_scm: Fix leaking nvdimm_events_map elements
...
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Implement a limited form of KASAN for Book3S 64-bit machines running under
the Radix MMU, supporting only outline mode.
- Enable the compiler instrumentation to check addresses and maintain the
shadow region. (This is the guts of KASAN which we can easily reuse.)
- Require kasan-vmalloc support to handle modules and anything else in
vmalloc space.
- KASAN needs to be able to validate all pointer accesses, but we can't
instrument all kernel addresses - only linear map and vmalloc. On boot,
set up a single page of read-only shadow that marks all iomap and
vmemmap accesses as valid.
- Document KASAN in powerpc docs.
Background
----------
KASAN support on Book3S is a bit tricky to get right:
- It would be good to support inline instrumentation so as to be able to
catch stack issues that cannot be caught with outline mode.
- Inline instrumentation requires a fixed offset.
- Book3S runs code with translations off ("real mode") during boot,
including a lot of generic device-tree parsing code which is used to
determine MMU features.
[ppc64 mm note: The kernel installs a linear mapping at effective
address c000...-c008.... This is a one-to-one mapping with physical
memory from 0000... onward. Because of how memory accesses work on
powerpc 64-bit Book3S, a kernel pointer in the linear map accesses the
same memory both with translations on (accessing as an 'effective
address'), and with translations off (accessing as a 'real
address'). This works in both guests and the hypervisor. For more
details, see s5.7 of Book III of version 3 of the ISA, in particular
the Storage Control Overview, s5.7.3, and s5.7.5 - noting that this
KASAN implementation currently only supports Radix.]
- Some code - most notably a lot of KVM code - also runs with translations
off after boot.
- Therefore any offset has to point to memory that is valid with
translations on or off.
One approach is just to give up on inline instrumentation. This way
boot-time checks can be delayed until after the MMU is set is up, and we
can just not instrument any code that runs with translations off after
booting. Take this approach for now and require outline instrumentation.
Previous attempts allowed inline instrumentation. However, they came with
some unfortunate restrictions: only physically contiguous memory could be
used and it had to be specified at compile time. Maybe we can do better in
the future.
[paulus@ozlabs.org - Rebased onto 5.17. Note that a kernel with
CONFIG_KASAN=y will crash during boot on a machine using HPT
translation because not all the entry points to the generic
KASAN code are protected with a call to kasan_arch_is_ready().]
Originally-by: Balbir Singh <bsingharora@gmail.com> # ppc64 out-of-line radix version
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
[mpe: Update copyright year and comment formatting]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/YoTE69OQwiG7z+Gu@cleo
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Merge our KVM topic branch.
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LoPAPR defines guest visible IOMMU with hypercalls to use it -
H_PUT_TCE/etc. Implemented first on POWER7 where hypercalls would trap
in the KVM in the real mode (with MMU off). The problem with the real mode
is some memory is not available and some API usage crashed the host but
enabling MMU was an expensive operation.
The problems with the real mode handlers are:
1. Occasionally these cannot complete the request so the code is
copied+modified to work in the virtual mode, very little is shared;
2. The real mode handlers have to be linked into vmlinux to work;
3. An exception in real mode immediately reboots the machine.
If the small DMA window is used, the real mode handlers bring better
performance. However since POWER8, there has always been a bigger DMA
window which VMs use to map the entire VM memory to avoid calling
H_PUT_TCE. Such 1:1 mapping happens once and uses H_PUT_TCE_INDIRECT
(a bulk version of H_PUT_TCE) which virtual mode handler is even closer
to its real mode version.
On POWER9 hypercalls trap straight to the virtual mode so the real mode
handlers never execute on POWER9 and later CPUs.
So with the current use of the DMA windows and MMU improvements in
POWER9 and later, there is no point in duplicating the code.
The 32bit passed through devices may slow down but we do not have many
of these in practice. For example, with this applied, a 1Gbit ethernet
adapter still demostrates above 800Mbit/s of actual throughput.
This removes the real mode handlers from KVM and related code from
the powernv platform.
This updates the list of implemented hcalls in KVM-HV as the realmode
handlers are removed.
This changes ABI - kvmppc_h_get_tce() moves to the KVM module and
kvmppc_find_table() is static now.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220506053755.3820702-1-aik@ozlabs.ru
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Don't inherit headers "by chances" from asm/prom.h, asm/mpc52xx.h,
asm/pci.h etc...
Include the needed headers, and remove asm/prom.h when it was
needed exclusively for pulling necessary headers.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/be8bdc934d152a7d8ee8d1a840d5596e2f7d85e0.1646767214.git.christophe.leroy@csgroup.eu
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Various spelling mistakes in comments.
Detected with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220430185654.5855-1-Julia.Lawall@inria.fr
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arch_randomize_brk() is only needed for hash on book3s/64, for other
platforms the one provided by the default mmap layout is good enough.
Move it to hash_utils.c and use randomize_page() like the generic one.
And properly opt out the radix case instead of making an assumption
on mmu_highuser_ssize.
Also change to a 32M range like most other architectures instead of 8M.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/eafa4d18ec8ac7b98dd02b40181e61643707cc7c.1649523076.git.christophe.leroy@csgroup.eu
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Do like most other architectures and provide randomisation also to
"legacy" memory mappings, by adding the random factor to
mm->mmap_base in arch_pick_mmap_layout().
See commit 8b8addf891de ("x86/mm/32: Enable full randomization on
i386 and X86_32") for all explanations and benefits of that mmap
randomisation.
At the moment, slice_find_area_bottomup() doesn't use mm->mmap_base
but uses the fixed TASK_UNMAPPED_BASE instead.
slice_find_area_bottomup() being used as a fallback to
slice_find_area_topdown(), it can't use mm->mmap_base
directly.
Instead of always using TASK_UNMAPPED_BASE as base address, leave
it to the caller. When called from slice_find_area_topdown()
TASK_UNMAPPED_BASE is used. Otherwise mm->mmap_base is used.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/417fb10dde828534c73a03138b49621d74f4e5be.1649523076.git.christophe.leroy@csgroup.eu
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hugetlb_get_unmapped_area() is now identical to the
generic version if only RADIX is enabled, so move it
to slice.c and let it fallback on the generic one
when HASH MMU is not compiled in.
Do the same with arch_get_unmapped_area() and
arch_get_unmapped_area_topdown().
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b5d9c124e82889e0cb115c150915a0c0d84eb960.1649523076.git.christophe.leroy@csgroup.eu
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Use the generic version of arch_hugetlb_get_unmapped_area()
which is now available at all time.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/05f77014c619061638ecc52a0a4136eb04cc2799.1649523076.git.christophe.leroy@csgroup.eu
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CONFIG_PPC_MM_SLICES is always selected by hash book3s/64.
CONFIG_PPC_MM_SLICES is never selected by other platforms.
Remove it.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/dc2cdc204de8978574bf7c02329b6cfc4db0bce7.1649523076.git.christophe.leroy@csgroup.eu
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Since commit 555904d07eef ("powerpc/8xx: MM_SLICE is not needed
anymore") only book3s/64 selects CONFIG_PPC_MM_SLICES.
Move slice.c into mm/book3s64/
Move necessary stuff in asm/book3s/64/slice.h and
remove asm/slice.h
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4a0d74ef1966a5902b5fd4ac4b513a760a6d675a.1649523076.git.christophe.leroy@csgroup.eu
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This defines and exports a platform specific custom vm_get_page_prot() via
subscribing ARCH_HAS_VM_GET_PAGE_PROT. While here, this also localizes
arch_vm_get_page_prot() as __vm_get_page_prot() and moves it near
vm_get_page_prot().
Link: https://lkml.kernel.org/r/20220414062125.609297-3-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Merge yet more updates from Andrew Morton:
"This is the material which was staged after willystuff in linux-next.
Subsystems affected by this patch series: mm (debug, selftests,
pagecache, thp, rmap, migration, kasan, hugetlb, pagemap, madvise),
and selftests"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (113 commits)
selftests: kselftest framework: provide "finished" helper
mm: madvise: MADV_DONTNEED_LOCKED
mm: fix race between MADV_FREE reclaim and blkdev direct IO read
mm: generalize ARCH_HAS_FILTER_PGPROT
mm: unmap_mapping_range_tree() with i_mmap_rwsem shared
mm: warn on deleting redirtied only if accounted
mm/huge_memory: remove stale locking logic from __split_huge_pmd()
mm/huge_memory: remove stale page_trans_huge_mapcount()
mm/swapfile: remove stale reuse_swap_page()
mm/khugepaged: remove reuse_swap_page() usage
mm/huge_memory: streamline COW logic in do_huge_pmd_wp_page()
mm: streamline COW logic in do_swap_page()
mm: slightly clarify KSM logic in do_swap_page()
mm: optimize do_wp_page() for fresh pages in local LRU pagevecs
mm: optimize do_wp_page() for exclusive pages in the swapcache
mm/huge_memory: make is_transparent_hugepage() static
userfaultfd/selftests: enable hugetlb remap and remove event testing
selftests/vm: add hugetlb madvise MADV_DONTNEED MADV_REMOVE test
mm: enable MADV_DONTNEED for hugetlb mappings
kasan: disable LOCKDEP when printing reports
...
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
"Livepatch support for 32-bit is probably the standout new feature,
otherwise mostly just lots of bits and pieces all over the board.
There's a series of commits cleaning up function descriptor handling,
which touches a few other arches as well as LKDTM. It has acks from
Arnd, Kees and Helge.
Summary:
- Enforce kernel RO, and implement STRICT_MODULE_RWX for 603.
- Add support for livepatch to 32-bit.
- Implement CONFIG_DYNAMIC_FTRACE_WITH_ARGS.
- Merge vdso64 and vdso32 into a single directory.
- Fix build errors with newer binutils.
- Add support for UADDR64 relocations, which are emitted by some
toolchains. This allows powerpc to build with the latest lld.
- Fix (another) potential userspace r13 corruption in transactional
memory handling.
- Cleanups of function descriptor handling & related fixes to LKDTM.
Thanks to Abdul Haleem, Alexey Kardashevskiy, Anders Roxell, Aneesh
Kumar K.V, Anton Blanchard, Arnd Bergmann, Athira Rajeev, Bhaskar
Chowdhury, Cédric Le Goater, Chen Jingwen, Christophe JAILLET,
Christophe Leroy, Corentin Labbe, Daniel Axtens, Daniel Henrique
Barboza, David Dai, Fabiano Rosas, Ganesh Goudar, Guo Zhengkui, Hangyu
Hua, Haren Myneni, Hari Bathini, Igor Zhbanov, Jakob Koschel, Jason
Wang, Jeremy Kerr, Joachim Wiberg, Jordan Niethe, Julia Lawall, Kajol
Jain, Kees Cook, Laurent Dufour, Madhavan Srinivasan, Mamatha Inamdar,
Maxime Bizon, Maxim Kiselev, Maxim Kochetkov, Michal Suchanek,
Nageswara R Sastry, Nathan Lynch, Naveen N. Rao, Nicholas Piggin,
Nour-eddine Taleb, Paul Menzel, Ping Fang, Pratik R. Sampat, Randy
Dunlap, Ritesh Harjani, Rohan McLure, Russell Currey, Sachin Sant,
Segher Boessenkool, Shivaprasad G Bhat, Sourabh Jain, Thierry Reding,
Tobias Waldekranz, Tyrel Datwyler, Vaibhav Jain, Vladimir Oltean,
Wedson Almeida Filho, and YueHaibing"
* tag 'powerpc-5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (179 commits)
powerpc/pseries: Fix use after free in remove_phb_dynamic()
powerpc/time: improve decrementer clockevent processing
powerpc/time: Fix KVM host re-arming a timer beyond decrementer range
powerpc/tm: Fix more userspace r13 corruption
powerpc/xive: fix return value of __setup handler
powerpc/64: Add UADDR64 relocation support
powerpc: 8xx: fix a return value error in mpc8xx_pic_init
powerpc/ps3: remove unneeded semicolons
powerpc/64: Force inlining of prevent_user_access() and set_kuap()
powerpc/bitops: Force inlining of fls()
powerpc: declare unmodified attribute_group usages const
powerpc/spufs: Fix build warning when CONFIG_PROC_FS=n
powerpc/secvar: fix refcount leak in format_show()
powerpc/64e: Tie PPC_BOOK3E_64 to PPC_FSL_BOOK3E
powerpc: Move C prototypes out of asm-prototypes.h
powerpc/kexec: Declare kexec_paca static
powerpc/smp: Declare current_set static
powerpc: Cleanup asm-prototypes.c
powerpc/ftrace: Use STK_GOT in ftrace_mprofile.S
powerpc/ftrace: Regroup PPC64 specific operations in ftrace_mprofile.S
...
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Patch series "mm/migration: Add trace events", v3.
This adds trace events for all migration scenarios including base page,
THP and HugeTLB.
This patch (of 3):
This adds two trace events for PMD based THP migration without split.
These events closely follow the implementation details like setting and
removing of PMD migration entries, which are essential operations for THP
migration. This moves CREATE_TRACE_POINTS into generic THP from powerpc
for these new trace events to be available on other platforms as well.
Link: https://lkml.kernel.org/r/1643368182-9588-1-git-send-email-anshuman.khandual@arm.com
Link: https://lkml.kernel.org/r/1643368182-9588-2-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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We originally added asm-prototypes.h in commit 42f5b4cacd78 ("powerpc:
Introduce asm-prototypes.h"). It's purpose was for prototypes of C
functions that are only called from asm, in order to fix sparse
warnings about missing prototypes.
A few months later Nick added a different use case in
commit 4efca4ed05cb ("kbuild: modversions for EXPORT_SYMBOL() for asm")
for C prototypes for exported asm functions. This is basically the
inverse of our original usage.
Since then we've added various prototypes to asm-prototypes.h for both
reasons, meaning we now need to unstitch it all.
Dispatch prototypes of C functions into relevant headers and keep
only the prototypes for functions defined in assembly.
For the time being, leave prom_init() there because moving it
into asm/prom.h or asm/setup.h conflicts with
drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowrom.o
This will be fixed later by untaggling asm/pci.h and asm/prom.h
or by renaming the function in shadowrom.c
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/62d46904eca74042097acf4cb12c175e3067f3d1.1646413435.git.christophe.leroy@csgroup.eu
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Move the check for the actual pgmap types that need the free at refcount
one behavior into the out of line helper, and thus avoid the need to
pull memremap.h into mm.h.
Link: https://lkml.kernel.org/r/20220210072828.2930359-7-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Tested-by: "Sierra Guiza, Alejandro (Alex)" <alex.sierra@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Chaitanya Kulkarni <kch@nvidia.com>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
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Hash faults are not resoved in NMI context, instead causing the access
to fail. This is done because perf interrupts can get backtraces
including walking the user stack, and taking a hash fault on those could
deadlock on the HPTE lock if the perf interrupt hits while the same HPTE
lock is being held by the hash fault code. The user-access for the stack
walking will notice the access failed and deal with that in the perf
code.
The reason to allow perf interrupts in is to better profile hash faults.
The problem with this is any hash fault on a kernel access that happens
in NMI context will crash, because kernel accesses must not fail.
Hard lockups, system reset, machine checks that access vmalloc space
including modules and including stack backtracing and symbol lookup in
modules, per-cpu data, etc could all run into this problem.
Fix this by disallowing perf interrupts in the hash fault code (the
direct hash fault is covered by MSR[EE]=0 so the PMI disable just needs
to extend to the preload case). This simplifies the tricky logic in hash
faults and perf, at the cost of reduced profiling of hash faults.
perf can still latch addresses when interrupts are disabled, it just
won't get the stack trace at that point, so it would still find hot
spots, just sometimes with confusing stack chains.
An alternative could be to allow perf interrupts here but always do the
slowpath stack walk if we are in nmi context, but that slows down all
perf interrupt stack walking on hash though and it does not remove as
much tricky code.
Reported-by: Laurent Dufour <ldufour@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Laurent Dufour <ldufour@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/20220204035348.545435-1-npiggin@gmail.com
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commit: d9c234005227 ("Do not depend on MAX_ORDER when grouping pages by mobility")
introduced pageblock_order which will be used to group pages better.
The kernel now groups pages based on the value of HPAGE_SHIFT. Hence HPAGE_SHIFT
should be set before we call set_pageblock_order.
set_pageblock_order happens early in the boot and default hugetlb page size
should be initialized before that to compute the right pageblock_order value.
Currently, default hugetlbe page size is set via arch_initcalls which happens
late in the boot as shown via the below callstack:
[c000000007383b10] [c000000001289328] hugetlbpage_init+0x2b8/0x2f8
[c000000007383bc0] [c0000000012749e4] do_one_initcall+0x14c/0x320
[c000000007383c90] [c00000000127505c] kernel_init_freeable+0x410/0x4e8
[c000000007383da0] [c000000000012664] kernel_init+0x30/0x15c
[c000000007383e10] [c00000000000cf14] ret_from_kernel_thread+0x5c/0x64
and the pageblock_order initialization is done early during the boot.
[c0000000018bfc80] [c0000000012ae120] set_pageblock_order+0x50/0x64
[c0000000018bfca0] [c0000000012b3d94] sparse_init+0x188/0x268
[c0000000018bfd60] [c000000001288bfc] initmem_init+0x28c/0x328
[c0000000018bfe50] [c00000000127b370] setup_arch+0x410/0x480
[c0000000018bfed0] [c00000000127401c] start_kernel+0xb8/0x934
[c0000000018bff90] [c00000000000d984] start_here_common+0x1c/0x98
delaying default hugetlb page size initialization implies the kernel will
initialize pageblock_order to (MAX_ORDER - 1) which is not an optimal
value for mobility grouping. IIUC we always had this issue. But it was not
a problem for hash translation mode because (MAX_ORDER - 1) is the same as
HUGETLB_PAGE_ORDER (8) in the case of hash (16MB). With radix,
HUGETLB_PAGE_ORDER will be 5 (2M size) and hence pageblock_order should be
5 instead of 8.
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/20220211065215.101767-1-aneesh.kumar@linux.ibm.com
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The llvm integrated assembler does not recognise the ISA 2.05 tlbiel
version. Work around it by switching to .long when an old arch level
detected.
Signed-off-by: Daniel Axtens <dja@axtens.net>
[aik: did "Eventually do this more smartly"]
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211221055904.555763-7-aik@ozlabs.ru
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