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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
- Add HOTPLUG_SMT support (/sys/devices/system/cpu/smt) and honour the
configured SMT state when hotplugging CPUs into the system
- Combine final TLB flush and lazy TLB mm shootdown IPIs when using the
Radix MMU to avoid a broadcast TLBIE flush on exit
- Drop the exclusion between ptrace/perf watchpoints, and drop the now
unused associated arch hooks
- Add support for the "nohlt" command line option to disable CPU idle
- Add support for -fpatchable-function-entry for ftrace, with GCC >=
13.1
- Rework memory block size determination, and support 256MB size on
systems with GPUs that have hotpluggable memory
- Various other small features and fixes
Thanks to Andrew Donnellan, Aneesh Kumar K.V, Arnd Bergmann, Athira
Rajeev, Benjamin Gray, Christophe Leroy, Frederic Barrat, Gautam
Menghani, Geoff Levand, Hari Bathini, Immad Mir, Jialin Zhang, Joel
Stanley, Jordan Niethe, Justin Stitt, Kajol Jain, Kees Cook, Krzysztof
Kozlowski, Laurent Dufour, Liang He, Linus Walleij, Mahesh Salgaonkar,
Masahiro Yamada, Michal Suchanek, Nageswara R Sastry, Nathan Chancellor,
Nathan Lynch, Naveen N Rao, Nicholas Piggin, Nick Desaulniers, Omar
Sandoval, Randy Dunlap, Reza Arbab, Rob Herring, Russell Currey, Sourabh
Jain, Thomas Gleixner, Trevor Woerner, Uwe Kleine-König, Vaibhav Jain,
Xiongfeng Wang, Yuan Tan, Zhang Rui, and Zheng Zengkai.
* tag 'powerpc-6.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (135 commits)
macintosh/ams: linux/platform_device.h is needed
powerpc/xmon: Reapply "Relax frame size for clang"
powerpc/mm/book3s64: Use 256M as the upper limit with coherent device memory attached
powerpc/mm/book3s64: Fix build error with SPARSEMEM disabled
powerpc/iommu: Fix notifiers being shared by PCI and VIO buses
powerpc/mpc5xxx: Add missing fwnode_handle_put()
powerpc/config: Disable SLAB_DEBUG_ON in skiroot
powerpc/pseries: Remove unused hcall tracing instruction
powerpc/pseries: Fix hcall tracepoints with JUMP_LABEL=n
powerpc: dts: add missing space before {
powerpc/eeh: Use pci_dev_id() to simplify the code
powerpc/64s: Move CPU -mtune options into Kconfig
powerpc/powermac: Fix unused function warning
powerpc/pseries: Rework lppaca_shared_proc() to avoid DEBUG_PREEMPT
powerpc: Don't include lppaca.h in paca.h
powerpc/pseries: Move hcall_vphn() prototype into vphn.h
powerpc/pseries: Move VPHN constants into vphn.h
cxl: Drop unused detach_spa()
powerpc: Drop zalloc_maybe_bootmem()
powerpc/powernv: Use struct opal_prd_msg in more places
...
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- Some swap cleanups from Ma Wupeng ("fix WARN_ON in
add_to_avail_list")
- Peter Xu has a series (mm/gup: Unify hugetlb, speed up thp") which
reduces the special-case code for handling hugetlb pages in GUP. It
also speeds up GUP handling of transparent hugepages.
- Peng Zhang provides some maple tree speedups ("Optimize the fast path
of mas_store()").
- Sergey Senozhatsky has improved te performance of zsmalloc during
compaction (zsmalloc: small compaction improvements").
- Domenico Cerasuolo has developed additional selftest code for zswap
("selftests: cgroup: add zswap test program").
- xu xin has doe some work on KSM's handling of zero pages. These
changes are mainly to enable the user to better understand the
effectiveness of KSM's treatment of zero pages ("ksm: support
tracking KSM-placed zero-pages").
- Jeff Xu has fixes the behaviour of memfd's
MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED sysctl ("mm/memfd: fix sysctl
MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED").
- David Howells has fixed an fscache optimization ("mm, netfs, fscache:
Stop read optimisation when folio removed from pagecache").
- Axel Rasmussen has given userfaultfd the ability to simulate memory
poisoning ("add UFFDIO_POISON to simulate memory poisoning with
UFFD").
- Miaohe Lin has contributed some routine maintenance work on the
memory-failure code ("mm: memory-failure: remove unneeded PageHuge()
check").
- Peng Zhang has contributed some maintenance work on the maple tree
code ("Improve the validation for maple tree and some cleanup").
- Hugh Dickins has optimized the collapsing of shmem or file pages into
THPs ("mm: free retracted page table by RCU").
- Jiaqi Yan has a patch series which permits us to use the healthy
subpages within a hardware poisoned huge page for general purposes
("Improve hugetlbfs read on HWPOISON hugepages").
- Kemeng Shi has done some maintenance work on the pagetable-check code
("Remove unused parameters in page_table_check").
- More folioification work from Matthew Wilcox ("More filesystem folio
conversions for 6.6"), ("Followup folio conversions for zswap"). And
from ZhangPeng ("Convert several functions in page_io.c to use a
folio").
- page_ext cleanups from Kemeng Shi ("minor cleanups for page_ext").
- Baoquan He has converted some architectures to use the
GENERIC_IOREMAP ioremap()/iounmap() code ("mm: ioremap: Convert
architectures to take GENERIC_IOREMAP way").
- Anshuman Khandual has optimized arm64 tlb shootdown ("arm64: support
batched/deferred tlb shootdown during page reclamation/migration").
- Better maple tree lockdep checking from Liam Howlett ("More strict
maple tree lockdep"). Liam also developed some efficiency
improvements ("Reduce preallocations for maple tree").
- Cleanup and optimization to the secondary IOMMU TLB invalidation,
from Alistair Popple ("Invalidate secondary IOMMU TLB on permission
upgrade").
- Ryan Roberts fixes some arm64 MM selftest issues ("selftests/mm fixes
for arm64").
- Kemeng Shi provides some maintenance work on the compaction code
("Two minor cleanups for compaction").
- Some reduction in mmap_lock pressure from Matthew Wilcox ("Handle
most file-backed faults under the VMA lock").
- Aneesh Kumar contributes code to use the vmemmap optimization for DAX
on ppc64, under some circumstances ("Add support for DAX vmemmap
optimization for ppc64").
- page-ext cleanups from Kemeng Shi ("add page_ext_data to get client
data in page_ext"), ("minor cleanups to page_ext header").
- Some zswap cleanups from Johannes Weiner ("mm: zswap: three
cleanups").
- kmsan cleanups from ZhangPeng ("minor cleanups for kmsan").
- VMA handling cleanups from Kefeng Wang ("mm: convert to
vma_is_initial_heap/stack()").
- DAMON feature work from SeongJae Park ("mm/damon/sysfs-schemes:
implement DAMOS tried total bytes file"), ("Extend DAMOS filters for
address ranges and DAMON monitoring targets").
- Compaction work from Kemeng Shi ("Fixes and cleanups to compaction").
- Liam Howlett has improved the maple tree node replacement code
("maple_tree: Change replacement strategy").
- ZhangPeng has a general code cleanup - use the K() macro more widely
("cleanup with helper macro K()").
- Aneesh Kumar brings memmap-on-memory to ppc64 ("Add support for
memmap on memory feature on ppc64").
- pagealloc cleanups from Kemeng Shi ("Two minor cleanups for pcp list
in page_alloc"), ("Two minor cleanups for get pageblock
migratetype").
- Vishal Moola introduces a memory descriptor for page table tracking,
"struct ptdesc" ("Split ptdesc from struct page").
- memfd selftest maintenance work from Aleksa Sarai ("memfd: cleanups
for vm.memfd_noexec").
- MM include file rationalization from Hugh Dickins ("arch: include
asm/cacheflush.h in asm/hugetlb.h").
- THP debug output fixes from Hugh Dickins ("mm,thp: fix sloppy text
output").
- kmemleak improvements from Xiaolei Wang ("mm/kmemleak: use
object_cache instead of kmemleak_initialized").
- More folio-related cleanups from Matthew Wilcox ("Remove _folio_dtor
and _folio_order").
- A VMA locking scalability improvement from Suren Baghdasaryan
("Per-VMA lock support for swap and userfaults").
- pagetable handling cleanups from Matthew Wilcox ("New page table
range API").
- A batch of swap/thp cleanups from David Hildenbrand ("mm/swap: stop
using page->private on tail pages for THP_SWAP + cleanups").
- Cleanups and speedups to the hugetlb fault handling from Matthew
Wilcox ("Change calling convention for ->huge_fault").
- Matthew Wilcox has also done some maintenance work on the MM
subsystem documentation ("Improve mm documentation").
* tag 'mm-stable-2023-08-28-18-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (489 commits)
maple_tree: shrink struct maple_tree
maple_tree: clean up mas_wr_append()
secretmem: convert page_is_secretmem() to folio_is_secretmem()
nios2: fix flush_dcache_page() for usage from irq context
hugetlb: add documentation for vma_kernel_pagesize()
mm: add orphaned kernel-doc to the rst files.
mm: fix clean_record_shared_mapping_range kernel-doc
mm: fix get_mctgt_type() kernel-doc
mm: fix kernel-doc warning from tlb_flush_rmaps()
mm: remove enum page_entry_size
mm: allow ->huge_fault() to be called without the mmap_lock held
mm: move PMD_ORDER to pgtable.h
mm: remove checks for pte_index
memcg: remove duplication detection for mem_cgroup_uncharge_swap
mm/huge_memory: work on folio->swap instead of page->private when splitting folio
mm/swap: inline folio_set_swap_entry() and folio_swap_entry()
mm/swap: use dedicated entry for swap in folio
mm/swap: stop using page->private on tail pages for THP_SWAP
selftests/mm: fix WARNING comparing pointer to 0
selftests: cgroup: fix test_kmem_memcg_deletion kernel mem check
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf event updates from Ingo Molnar:
- AMD IBS improvements
- Intel PMU driver updates
- Extend core perf facilities & the ARM PMU driver to better handle ARM big.LITTLE events
- Micro-optimize software events and the ring-buffer code
- Misc cleanups & fixes
* tag 'perf-core-2023-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/uncore: Remove unnecessary ?: operator around pcibios_err_to_errno() call
perf/x86/intel: Add Crestmont PMU
x86/cpu: Update Hybrids
x86/cpu: Fix Crestmont uarch
x86/cpu: Fix Gracemont uarch
perf: Remove unused extern declaration arch_perf_get_page_size()
perf: Remove unused PERF_PMU_CAP_HETEROGENEOUS_CPUS capability
arm_pmu: Remove unused PERF_PMU_CAP_HETEROGENEOUS_CPUS capability
perf/x86: Remove unused PERF_PMU_CAP_HETEROGENEOUS_CPUS capability
arm_pmu: Add PERF_PMU_CAP_EXTENDED_HW_TYPE capability
perf/x86/ibs: Set mem_lvl_num, mem_remote and mem_hops for data_src
perf/mem: Add PERF_MEM_LVLNUM_NA to PERF_MEM_NA
perf/mem: Introduce PERF_MEM_LVLNUM_UNC
perf/ring_buffer: Use local_try_cmpxchg in __perf_output_begin
locking/arch: Avoid variable shadowing in local_try_cmpxchg()
perf/core: Use local64_try_cmpxchg in perf_swevent_set_period
perf/x86: Use local64_try_cmpxchg
perf/amd: Prevent grouping of IBS events
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Use the helpers to simplify code, also kill unneeded goto cpy_name.
Link: https://lkml.kernel.org/r/20230728050043.59880-5-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian Göttsche <cgzones@googlemail.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@gmail.com>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Felix Kuehling <felix.kuehling@amd.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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mmu_notifier_invalidate_range_end()
Secondary TLBs are now invalidated from the architecture specific TLB
invalidation functions. Therefore there is no need to explicitly notify
or invalidate as part of the range end functions. This means we can
remove mmu_notifier_invalidate_range_end_only() and some of the
ptep_*_notify() functions.
Link: https://lkml.kernel.org/r/90d749d03cbab256ca0edeb5287069599566d783.1690292440.git-series.apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Andrew Donnellan <ajd@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Cc: Frederic Barrat <fbarrat@linux.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Nicolin Chen <nicolinc@nvidia.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Will Deacon <will@kernel.org>
Cc: Zhi Wang <zhi.wang.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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PowerPC was the only user of these hooks, and has been refactored to no
longer require them. There is no need to keep them around, so remove
them to reduce complexity.
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230801011744.153973-8-bgray@linux.ibm.com
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strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89
Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230703165817.2840457-1-azeemshaikh38@gmail.com
Signed-off-by: Kees Cook <keescook@chromium.org>
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Use local_try_cmpxchg instead of local_cmpxchg (*ptr, old, new) == old
in __perf_output_begin. x86 CMPXCHG instruction returns success in ZF
flag, so this change saves a compare after cmpxchg (and related move
instruction in front of cmpxchg).
Also, try_cmpxchg implicitly assigns old *ptr value to "old" when cmpxchg
fails. There is no need to re-read the value in the loop.
No functional change intended.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20230708090048.63046-2-ubizjak@gmail.com
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Use local64_try_cmpxchg instead of local64_cmpxchg (*ptr, old, new) == old
in perf_swevent_set_period. x86 CMPXCHG instruction returns success in ZF
flag, so this change saves a compare after cmpxchg (and related move
instruction in front of cmpxchg).
Also, try_cmpxchg implicitly assigns old *ptr value to "old" when cmpxchg
fails. There is no need to re-read the value in the loop.
No functional change intended.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20230708081129.45915-1-ubizjak@gmail.com
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Pull CXL updates from Dan Williams:
"The highlights in terms of new functionality are support for the
standard CXL Performance Monitor definition that appeared in CXL 3.0,
support for device sanitization (wiping all data from a device),
secure-erase (re-keying encryption of user data), and support for
firmware update. The firmware update support is notable as it reuses
the simple sysfs_upload interface to just cat(1) a blob to a sysfs
file and pipe that to the device.
Additionally there are a substantial number of cleanups and
reorganizations to get ready for RCH error handling (RCH == Restricted
CXL Host == current shipping hardware generation / pre CXL-2.0
topologies) and type-2 (accelerator / vendor specific) devices.
For vendor specific devices they implement a subset of what the
generic type-3 (generic memory expander) driver expects. As a result
the rework decouples optional infrastructure from the core driver
context.
For RCH topologies, where the specification working group did not want
to confuse pre-CXL-aware operating systems, many of the standard
registers are hidden which makes support standard bus features like
AER (PCIe Advanced Error Reporting) difficult. The rework arranges for
the driver to help the PCI-AER core. Bjorn is on board with this
direction but a late regression disocvery means the completion of this
functionality needs to cook a bit longer, so it is code
reorganizations only for now.
Summary:
- Add infrastructure for supporting background commands along with
support for device sanitization and firmware update
- Introduce a CXL performance monitoring unit driver based on the
common definition in the specification.
- Land some preparatory cleanup and refactoring for the anticipated
arrival of CXL type-2 (accelerator devices) and CXL RCH (CXL-v1.1
topology) error handling.
- Rework CPU cache management with respect to region configuration
(device hotplug or other dynamic changes to memory interleaving)
- Fix region reconfiguration vs CXL decoder ordering rules"
* tag 'cxl-for-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (51 commits)
cxl: Fix one kernel-doc comment
cxl/pci: Use correct flag for sanitize polling
docs: perf: Minimal introduction the the CXL PMU device and driver
perf: CXL Performance Monitoring Unit driver
tools/testing/cxl: add firmware update emulation to CXL memdevs
tools/testing/cxl: Use named effects for the Command Effect Log
tools/testing/cxl: Fix command effects for inject/clear poison
cxl: add a firmware update mechanism using the sysfs firmware loader
cxl/test: Add Secure Erase opcode support
cxl/mem: Support Secure Erase
cxl/test: Add Sanitize opcode support
cxl/mem: Wire up Sanitization support
cxl/mbox: Add sanitization handling machinery
cxl/mem: Introduce security state sysfs file
cxl/mbox: Allow for IRQ_NONE case in the isr
Revert "cxl/port: Enable the HDM decoder capability for switch ports"
cxl/memdev: Formalize endpoint port linkage
cxl/pci: Unconditionally unmask 256B Flit errors
cxl/region: Manage decoder target_type at decoder-attach time
cxl/hdm: Default CXL_DEVTYPE_DEVMEM decoders to CXL_DECODER_DEVMEM
...
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull mm updates from Andrew Morton:
- Yosry Ahmed brought back some cgroup v1 stats in OOM logs
- Yosry has also eliminated cgroup's atomic rstat flushing
- Nhat Pham adds the new cachestat() syscall. It provides userspace
with the ability to query pagecache status - a similar concept to
mincore() but more powerful and with improved usability
- Mel Gorman provides more optimizations for compaction, reducing the
prevalence of page rescanning
- Lorenzo Stoakes has done some maintanance work on the
get_user_pages() interface
- Liam Howlett continues with cleanups and maintenance work to the
maple tree code. Peng Zhang also does some work on maple tree
- Johannes Weiner has done some cleanup work on the compaction code
- David Hildenbrand has contributed additional selftests for
get_user_pages()
- Thomas Gleixner has contributed some maintenance and optimization
work for the vmalloc code
- Baolin Wang has provided some compaction cleanups,
- SeongJae Park continues maintenance work on the DAMON code
- Huang Ying has done some maintenance on the swap code's usage of
device refcounting
- Christoph Hellwig has some cleanups for the filemap/directio code
- Ryan Roberts provides two patch series which yield some
rationalization of the kernel's access to pte entries - use the
provided APIs rather than open-coding accesses
- Lorenzo Stoakes has some fixes to the interaction between pagecache
and directio access to file mappings
- John Hubbard has a series of fixes to the MM selftesting code
- ZhangPeng continues the folio conversion campaign
- Hugh Dickins has been working on the pagetable handling code, mainly
with a view to reducing the load on the mmap_lock
- Catalin Marinas has reduced the arm64 kmalloc() minimum alignment
from 128 to 8
- Domenico Cerasuolo has improved the zswap reclaim mechanism by
reorganizing the LRU management
- Matthew Wilcox provides some fixups to make gfs2 work better with the
buffer_head code
- Vishal Moola also has done some folio conversion work
- Matthew Wilcox has removed the remnants of the pagevec code - their
functionality is migrated over to struct folio_batch
* tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (380 commits)
mm/hugetlb: remove hugetlb_set_page_subpool()
mm: nommu: correct the range of mmap_sem_read_lock in task_mem()
hugetlb: revert use of page_cache_next_miss()
Revert "page cache: fix page_cache_next/prev_miss off by one"
mm/vmscan: fix root proactive reclaim unthrottling unbalanced node
mm: memcg: rename and document global_reclaim()
mm: kill [add|del]_page_to_lru_list()
mm: compaction: convert to use a folio in isolate_migratepages_block()
mm: zswap: fix double invalidate with exclusive loads
mm: remove unnecessary pagevec includes
mm: remove references to pagevec
mm: rename invalidate_mapping_pagevec to mapping_try_invalidate
mm: remove struct pagevec
net: convert sunrpc from pagevec to folio_batch
i915: convert i915_gpu_error to use a folio_batch
pagevec: rename fbatch_count()
mm: remove check_move_unevictable_pages()
drm: convert drm_gem_put_pages() to use a folio_batch
i915: convert shmem_sg_free_table() to use a folio_batch
scatterlist: add sg_set_folio()
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf events updates from Ingo Molnar:
- Rework & fix the event forwarding logic by extending the core
interface.
This fixes AMD PMU events that have to be forwarded from the
core PMU to the IBS PMU.
- Add self-tests to test AMD IBS invocation via core PMU events
- Clean up Intel FixCntrCtl MSR encoding & handling
* tag 'perf-core-2023-06-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Re-instate the linear PMU search
perf/x86/intel: Define bit macros for FixCntrCtl MSR
perf test: Add selftest to test IBS invocation via core pmu events
perf/core: Remove pmu linear searching code
perf/ibs: Fix interface via core pmu events
perf/core: Rework forwarding of {task|cpu}-clock events
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Convert all instances of direct pte_t* dereferencing to instead use
ptep_get() helper. This means that by default, the accesses change from a
C dereference to a READ_ONCE(). This is technically the correct thing to
do since where pgtables are modified by HW (for access/dirty) they are
volatile and therefore we should always ensure READ_ONCE() semantics.
But more importantly, by always using the helper, it can be overridden by
the architecture to fully encapsulate the contents of the pte. Arch code
is deliberately not converted, as the arch code knows best. It is
intended that arch code (arm64) will override the default with its own
implementation that can (e.g.) hide certain bits from the core code, or
determine young/dirty status by mixing in state from another source.
Conversion was done using Coccinelle:
----
// $ make coccicheck \
// COCCI=ptepget.cocci \
// SPFLAGS="--include-headers" \
// MODE=patch
virtual patch
@ depends on patch @
pte_t *v;
@@
- *v
+ ptep_get(v)
----
Then reviewed and hand-edited to avoid multiple unnecessary calls to
ptep_get(), instead opting to store the result of a single call in a
variable, where it is correct to do so. This aims to negate any cost of
READ_ONCE() and will benefit arch-overrides that may be more complex.
Included is a fix for an issue in an earlier version of this patch that
was pointed out by kernel test robot. The issue arose because config
MMU=n elides definition of the ptep helper functions, including
ptep_get(). HUGETLB_PAGE=n configs still define a simple
huge_ptep_clear_flush() for linking purposes, which dereferences the ptep.
So when both configs are disabled, this caused a build error because
ptep_get() is not defined. Fix by continuing to do a direct dereference
when MMU=n. This is safe because for this config the arch code cannot be
trying to virtualize the ptes because none of the ptep helpers are
defined.
Link: https://lkml.kernel.org/r/20230612151545.3317766-4-ryan.roberts@arm.com
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/oe-kbuild-all/202305120142.yXsNEo6H-lkp@intel.com/
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: SeongJae Park <sj@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
In rare transient cases, not yet made possible, pte_offset_map() and
pte_offet_map_lock() may not find a page table: handle appropriately.
[hughd@google.com: __wp_page_copy_user(): don't call update_mmu_tlb() with NULL]
Link: https://lkml.kernel.org/r/1a4db221-7872-3594-57ce-42369945ec8d@google.com
Link: https://lkml.kernel.org/r/a194441b-63f3-adb6-5964-7ca3171ae7c2@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Song Liu <song@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zack Rusin <zackr@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The only instances of get_user_pages_remote() invocations which used the
vmas parameter were for a single page which can instead simply look up the
VMA directly. In particular:-
- __update_ref_ctr() looked up the VMA but did nothing with it so we simply
remove it.
- __access_remote_vm() was already using vma_lookup() when the original
lookup failed so by doing the lookup directly this also de-duplicates the
code.
We are able to perform these VMA operations as we already hold the
mmap_lock in order to be able to call get_user_pages_remote().
As part of this work we add get_user_page_vma_remote() which abstracts the
VMA lookup, error handling and decrementing the page reference count should
the VMA lookup fail.
This forms part of a broader set of patches intended to eliminate the vmas
parameter altogether.
[akpm@linux-foundation.org: avoid passing NULL to PTR_ERR]
Link: https://lkml.kernel.org/r/d20128c849ecdbf4dd01cc828fcec32127ed939a.1684350871.git.lstoakes@gmail.com
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> (for arm64)
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com> (for s390)
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Christian König <christian.koenig@amd.com>
Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Sean Christopherson <seanjc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Full revert of commit 9551fbb64d09 ("perf/core: Remove pmu linear
searching code").
Some architectures (notably arm/arm64) still relied on the linear
search in order to find the PMU that consumes
PERF_TYPE_{HARDWARE,HW_CACHE,RAW}.
This will need a more thorought audit and cleanup.
Reported-by: Nathan Chancellor <nathan@kernel.org>
Reported-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20230605101401.GL38236@hirez.programming.kicks-ass.net
|
|
Some PMUs have well defined parents such as PCI devices.
As the device_initialize() and device_add() are all within
pmu_dev_alloc() which is called from perf_pmu_register()
there is no opportunity to set the parent from within a driver.
Add a struct device *parent field to struct pmu and use that
to set the parent.
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230526095824.16336-2-Jonathan.Cameron@huawei.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
|
|
Searching for the right pmu by iterating over all pmus is no longer
required since all pmus now *must* be present in the 'pmu_idr' list.
So, remove linear searching code.
Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20230504110003.2548-4-ravi.bangoria@amd.com
|
|
Currently, PERF_TYPE_SOFTWARE is treated specially since task-clock and
cpu-clock events are interfaced through it but internally gets forwarded
to their own pmus.
Rework this by overwriting event->attr.type in perf_swevent_init() which
will cause perf_init_event() to retry with updated type and event will
automatically get forwarded to right pmu. With the change, SW pmu no
longer needs to be treated specially and can be included in 'pmu_idr'
list.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20230504110003.2548-2-ravi.bangoria@amd.com
|
|
swevents in perf_tp_event()
data->sample_flags may be modified in perf_prepare_sample(),
in perf_tp_event(), different swevents use the same on-stack
perf_sample_data, the previous swevent may change sample_flags in
perf_prepare_sample(), as a result, some members of perf_sample_data are
not correctly initialized when next swevent_event preparing sample
(for example data->id, the value varies according to swevent).
A simple scenario triggers this problem is as follows:
# perf record -e sched:sched_switch --switch-output-event sched:sched_switch -a sleep 1
[ perf record: dump data: Woken up 0 times ]
[ perf record: Dump perf.data.2023041209014396 ]
[ perf record: dump data: Woken up 0 times ]
[ perf record: Dump perf.data.2023041209014662 ]
[ perf record: dump data: Woken up 0 times ]
[ perf record: Dump perf.data.2023041209014910 ]
[ perf record: Woken up 0 times to write data ]
[ perf record: Dump perf.data.2023041209015164 ]
[ perf record: Captured and wrote 0.069 MB perf.data.<timestamp> ]
# ls -l
total 860
-rw------- 1 root root 95694 Apr 12 09:01 perf.data.2023041209014396
-rw------- 1 root root 606430 Apr 12 09:01 perf.data.2023041209014662
-rw------- 1 root root 82246 Apr 12 09:01 perf.data.2023041209014910
-rw------- 1 root root 82342 Apr 12 09:01 perf.data.2023041209015164
# perf script -i perf.data.2023041209014396
0x11d58 [0x80]: failed to process type: 9 [Bad address]
Solution: Re-initialize perf_sample_data after each event is processed.
Note that data->raw->frag.data may be accessed in perf_tp_event_match().
Therefore, need to init sample_data and then go through swevent hlist to prevent
reference of NULL pointer, reported by [1].
After fix:
# perf record -e sched:sched_switch --switch-output-event sched:sched_switch -a sleep 1
[ perf record: dump data: Woken up 0 times ]
[ perf record: Dump perf.data.2023041209442259 ]
[ perf record: dump data: Woken up 0 times ]
[ perf record: Dump perf.data.2023041209442514 ]
[ perf record: dump data: Woken up 0 times ]
[ perf record: Dump perf.data.2023041209442760 ]
[ perf record: Woken up 0 times to write data ]
[ perf record: Dump perf.data.2023041209443003 ]
[ perf record: Captured and wrote 0.069 MB perf.data.<timestamp> ]
# ls -l
total 864
-rw------- 1 root root 100166 Apr 12 09:44 perf.data.2023041209442259
-rw------- 1 root root 606438 Apr 12 09:44 perf.data.2023041209442514
-rw------- 1 root root 82246 Apr 12 09:44 perf.data.2023041209442760
-rw------- 1 root root 82342 Apr 12 09:44 perf.data.2023041209443003
# perf script -i perf.data.2023041209442259 | head -n 5
perf 232 [000] 66.846217: sched:sched_switch: prev_comm=perf prev_pid=232 prev_prio=120 prev_state=D ==> next_comm=perf next_pid=234 next_prio=120
perf 234 [000] 66.846449: sched:sched_switch: prev_comm=perf prev_pid=234 prev_prio=120 prev_state=S ==> next_comm=perf next_pid=232 next_prio=120
perf 232 [000] 66.846546: sched:sched_switch: prev_comm=perf prev_pid=232 prev_prio=120 prev_state=R ==> next_comm=perf next_pid=234 next_prio=120
perf 234 [000] 66.846606: sched:sched_switch: prev_comm=perf prev_pid=234 prev_prio=120 prev_state=S ==> next_comm=perf next_pid=232 next_prio=120
perf 232 [000] 66.846646: sched:sched_switch: prev_comm=perf prev_pid=232 prev_prio=120 prev_state=R ==> next_comm=perf next_pid=234 next_prio=120
[1] Link: https://lore.kernel.org/oe-lkp/202304250929.efef2caa-yujie.liu@intel.com
Fixes: bb447c27a467 ("perf/core: Set data->sample_flags in perf_prepare_sample()")
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20230425103217.130600-1-yangjihong1@huawei.com
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Ingo Molnar:
- Add Intel Granite Rapids support
- Add uncore events for Intel SPR IMC PMU
- Fix perf IRQ throttling bug
* tag 'perf-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel/uncore: Add events for Intel SPR IMC PMU
perf/core: Fix hardlockup failure caused by perf throttle
perf/x86/cstate: Add Granite Rapids support
perf/x86/msr: Add Granite Rapids
perf/x86/intel: Add Granite Rapids
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of
switching from a user process to a kernel thread.
- More folio conversions from Kefeng Wang, Zhang Peng and Pankaj
Raghav.
- zsmalloc performance improvements from Sergey Senozhatsky.
- Yue Zhao has found and fixed some data race issues around the
alteration of memcg userspace tunables.
- VFS rationalizations from Christoph Hellwig:
- removal of most of the callers of write_one_page()
- make __filemap_get_folio()'s return value more useful
- Luis Chamberlain has changed tmpfs so it no longer requires swap
backing. Use `mount -o noswap'.
- Qi Zheng has made the slab shrinkers operate locklessly, providing
some scalability benefits.
- Keith Busch has improved dmapool's performance, making part of its
operations O(1) rather than O(n).
- Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd,
permitting userspace to wr-protect anon memory unpopulated ptes.
- Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive
rather than exclusive, and has fixed a bunch of errors which were
caused by its unintuitive meaning.
- Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature,
which causes minor faults to install a write-protected pte.
- Vlastimil Babka has done some maintenance work on vma_merge():
cleanups to the kernel code and improvements to our userspace test
harness.
- Cleanups to do_fault_around() by Lorenzo Stoakes.
- Mike Rapoport has moved a lot of initialization code out of various
mm/ files and into mm/mm_init.c.
- Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for
DRM, but DRM doesn't use it any more.
- Lorenzo has also coverted read_kcore() and vread() to use iterators
and has thereby removed the use of bounce buffers in some cases.
- Lorenzo has also contributed further cleanups of vma_merge().
- Chaitanya Prakash provides some fixes to the mmap selftesting code.
- Matthew Wilcox changes xfs and afs so they no longer take sleeping
locks in ->map_page(), a step towards RCUification of pagefaults.
- Suren Baghdasaryan has improved mmap_lock scalability by switching to
per-VMA locking.
- Frederic Weisbecker has reworked the percpu cache draining so that it
no longer causes latency glitches on cpu isolated workloads.
- Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig
logic.
- Liu Shixin has changed zswap's initialization so we no longer waste a
chunk of memory if zswap is not being used.
- Yosry Ahmed has improved the performance of memcg statistics
flushing.
- David Stevens has fixed several issues involving khugepaged,
userfaultfd and shmem.
- Christoph Hellwig has provided some cleanup work to zram's IO-related
code paths.
- David Hildenbrand has fixed up some issues in the selftest code's
testing of our pte state changing.
- Pankaj Raghav has made page_endio() unneeded and has removed it.
- Peter Xu contributed some rationalizations of the userfaultfd
selftests.
- Yosry Ahmed has fixed an issue around memcg's page recalim
accounting.
- Chaitanya Prakash has fixed some arm-related issues in the
selftests/mm code.
- Longlong Xia has improved the way in which KSM handles hwpoisoned
pages.
- Peter Xu fixes a few issues with uffd-wp at fork() time.
- Stefan Roesch has changed KSM so that it may now be used on a
per-process and per-cgroup basis.
* tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits)
mm,unmap: avoid flushing TLB in batch if PTE is inaccessible
shmem: restrict noswap option to initial user namespace
mm/khugepaged: fix conflicting mods to collapse_file()
sparse: remove unnecessary 0 values from rc
mm: move 'mmap_min_addr' logic from callers into vm_unmapped_area()
hugetlb: pte_alloc_huge() to replace huge pte_alloc_map()
maple_tree: fix allocation in mas_sparse_area()
mm: do not increment pgfault stats when page fault handler retries
zsmalloc: allow only one active pool compaction context
selftests/mm: add new selftests for KSM
mm: add new KSM process and sysfs knobs
mm: add new api to enable ksm per process
mm: shrinkers: fix debugfs file permissions
mm: don't check VMA write permissions if the PTE/PMD indicates write permissions
migrate_pages_batch: fix statistics for longterm pin retry
userfaultfd: use helper function range_in_vma()
lib/show_mem.c: use for_each_populated_zone() simplify code
mm: correct arg in reclaim_pages()/reclaim_clean_pages_from_list()
fs/buffer: convert create_page_buffers to folio_create_buffers
fs/buffer: add folio_create_empty_buffers helper
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux
Pull module updates from Luis Chamberlain:
"The summary of the changes for this pull requests is:
- Song Liu's new struct module_memory replacement
- Nick Alcock's MODULE_LICENSE() removal for non-modules
- My cleanups and enhancements to reduce the areas where we vmalloc
module memory for duplicates, and the respective debug code which
proves the remaining vmalloc pressure comes from userspace.
Most of the changes have been in linux-next for quite some time except
the minor fixes I made to check if a module was already loaded prior
to allocating the final module memory with vmalloc and the respective
debug code it introduces to help clarify the issue. Although the
functional change is small it is rather safe as it can only *help*
reduce vmalloc space for duplicates and is confirmed to fix a bootup
issue with over 400 CPUs with KASAN enabled. I don't expect stable
kernels to pick up that fix as the cleanups would have also had to
have been picked up. Folks on larger CPU systems with modules will
want to just upgrade if vmalloc space has been an issue on bootup.
Given the size of this request, here's some more elaborate details:
The functional change change in this pull request is the very first
patch from Song Liu which replaces the 'struct module_layout' with a
new 'struct module_memory'. The old data structure tried to put
together all types of supported module memory types in one data
structure, the new one abstracts the differences in memory types in a
module to allow each one to provide their own set of details. This
paves the way in the future so we can deal with them in a cleaner way.
If you look at changes they also provide a nice cleanup of how we
handle these different memory areas in a module. This change has been
in linux-next since before the merge window opened for v6.3 so to
provide more than a full kernel cycle of testing. It's a good thing as
quite a bit of fixes have been found for it.
Jason Baron then made dynamic debug a first class citizen module user
by using module notifier callbacks to allocate / remove module
specific dynamic debug information.
Nick Alcock has done quite a bit of work cross-tree to remove module
license tags from things which cannot possibly be module at my request
so to:
a) help him with his longer term tooling goals which require a
deterministic evaluation if a piece a symbol code could ever be
part of a module or not. But quite recently it is has been made
clear that tooling is not the only one that would benefit.
Disambiguating symbols also helps efforts such as live patching,
kprobes and BPF, but for other reasons and R&D on this area is
active with no clear solution in sight.
b) help us inch closer to the now generally accepted long term goal
of automating all the MODULE_LICENSE() tags from SPDX license tags
In so far as a) is concerned, although module license tags are a no-op
for non-modules, tools which would want create a mapping of possible
modules can only rely on the module license tag after the commit
8b41fc4454e ("kbuild: create modules.builtin without
Makefile.modbuiltin or tristate.conf").
Nick has been working on this *for years* and AFAICT I was the only
one to suggest two alternatives to this approach for tooling. The
complexity in one of my suggested approaches lies in that we'd need a
possible-obj-m and a could-be-module which would check if the object
being built is part of any kconfig build which could ever lead to it
being part of a module, and if so define a new define
-DPOSSIBLE_MODULE [0].
A more obvious yet theoretical approach I've suggested would be to
have a tristate in kconfig imply the same new -DPOSSIBLE_MODULE as
well but that means getting kconfig symbol names mapping to modules
always, and I don't think that's the case today. I am not aware of
Nick or anyone exploring either of these options. Quite recently Josh
Poimboeuf has pointed out that live patching, kprobes and BPF would
benefit from resolving some part of the disambiguation as well but for
other reasons. The function granularity KASLR (fgkaslr) patches were
mentioned but Joe Lawrence has clarified this effort has been dropped
with no clear solution in sight [1].
In the meantime removing module license tags from code which could
never be modules is welcomed for both objectives mentioned above. Some
developers have also welcomed these changes as it has helped clarify
when a module was never possible and they forgot to clean this up, and
so you'll see quite a bit of Nick's patches in other pull requests for
this merge window. I just picked up the stragglers after rc3. LWN has
good coverage on the motivation behind this work [2] and the typical
cross-tree issues he ran into along the way. The only concrete blocker
issue he ran into was that we should not remove the MODULE_LICENSE()
tags from files which have no SPDX tags yet, even if they can never be
modules. Nick ended up giving up on his efforts due to having to do
this vetting and backlash he ran into from folks who really did *not
understand* the core of the issue nor were providing any alternative /
guidance. I've gone through his changes and dropped the patches which
dropped the module license tags where an SPDX license tag was missing,
it only consisted of 11 drivers. To see if a pull request deals with a
file which lacks SPDX tags you can just use:
./scripts/spdxcheck.py -f \
$(git diff --name-only commid-id | xargs echo)
You'll see a core module file in this pull request for the above, but
that's not related to his changes. WE just need to add the SPDX
license tag for the kernel/module/kmod.c file in the future but it
demonstrates the effectiveness of the script.
Most of Nick's changes were spread out through different trees, and I
just picked up the slack after rc3 for the last kernel was out. Those
changes have been in linux-next for over two weeks.
The cleanups, debug code I added and final fix I added for modules
were motivated by David Hildenbrand's report of boot failing on a
systems with over 400 CPUs when KASAN was enabled due to running out
of virtual memory space. Although the functional change only consists
of 3 lines in the patch "module: avoid allocation if module is already
present and ready", proving that this was the best we can do on the
modules side took quite a bit of effort and new debug code.
The initial cleanups I did on the modules side of things has been in
linux-next since around rc3 of the last kernel, the actual final fix
for and debug code however have only been in linux-next for about a
week or so but I think it is worth getting that code in for this merge
window as it does help fix / prove / evaluate the issues reported with
larger number of CPUs. Userspace is not yet fixed as it is taking a
bit of time for folks to understand the crux of the issue and find a
proper resolution. Worst come to worst, I have a kludge-of-concept [3]
of how to make kernel_read*() calls for modules unique / converge
them, but I'm currently inclined to |
