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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
"Along with the usual shower of singleton patches, notable patch series
in this pull request are:
- "Align kvrealloc() with krealloc()" from Danilo Krummrich. Adds
consistency to the APIs and behaviour of these two core allocation
functions. This also simplifies/enables Rustification.
- "Some cleanups for shmem" from Baolin Wang. No functional changes -
mode code reuse, better function naming, logic simplifications.
- "mm: some small page fault cleanups" from Josef Bacik. No
functional changes - code cleanups only.
- "Various memory tiering fixes" from Zi Yan. A small fix and a
little cleanup.
- "mm/swap: remove boilerplate" from Yu Zhao. Code cleanups and
simplifications and .text shrinkage.
- "Kernel stack usage histogram" from Pasha Tatashin and Shakeel
Butt. This is a feature, it adds new feilds to /proc/vmstat such as
$ grep kstack /proc/vmstat
kstack_1k 3
kstack_2k 188
kstack_4k 11391
kstack_8k 243
kstack_16k 0
which tells us that 11391 processes used 4k of stack while none at
all used 16k. Useful for some system tuning things, but
partivularly useful for "the dynamic kernel stack project".
- "kmemleak: support for percpu memory leak detect" from Pavel
Tikhomirov. Teaches kmemleak to detect leaksage of percpu memory.
- "mm: memcg: page counters optimizations" from Roman Gushchin. "3
independent small optimizations of page counters".
- "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from
David Hildenbrand. Improves PTE/PMD splitlock detection, makes
powerpc/8xx work correctly by design rather than by accident.
- "mm: remove arch_make_page_accessible()" from David Hildenbrand.
Some folio conversions which make arch_make_page_accessible()
unneeded.
- "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David
Finkel. Cleans up and fixes our handling of the resetting of the
cgroup/process peak-memory-use detector.
- "Make core VMA operations internal and testable" from Lorenzo
Stoakes. Rationalizaion and encapsulation of the VMA manipulation
APIs. With a view to better enable testing of the VMA functions,
even from a userspace-only harness.
- "mm: zswap: fixes for global shrinker" from Takero Funaki. Fix
issues in the zswap global shrinker, resulting in improved
performance.
- "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao. Fill
in some missing info in /proc/zoneinfo.
- "mm: replace follow_page() by folio_walk" from David Hildenbrand.
Code cleanups and rationalizations (conversion to folio_walk())
resulting in the removal of follow_page().
- "improving dynamic zswap shrinker protection scheme" from Nhat
Pham. Some tuning to improve zswap's dynamic shrinker. Significant
reductions in swapin and improvements in performance are shown.
- "mm: Fix several issues with unaccepted memory" from Kirill
Shutemov. Improvements to the new unaccepted memory feature,
- "mm/mprotect: Fix dax puds" from Peter Xu. Implements mprotect on
DAX PUDs. This was missing, although nobody seems to have notied
yet.
- "Introduce a store type enum for the Maple tree" from Sidhartha
Kumar. Cleanups and modest performance improvements for the maple
tree library code.
- "memcg: further decouple v1 code from v2" from Shakeel Butt. Move
more cgroup v1 remnants away from the v2 memcg code.
- "memcg: initiate deprecation of v1 features" from Shakeel Butt.
Adds various warnings telling users that memcg v1 features are
deprecated.
- "mm: swap: mTHP swap allocator base on swap cluster order" from
Chris Li. Greatly improves the success rate of the mTHP swap
allocation.
- "mm: introduce numa_memblks" from Mike Rapoport. Moves various
disparate per-arch implementations of numa_memblk code into generic
code.
- "mm: batch free swaps for zap_pte_range()" from Barry Song. Greatly
improves the performance of munmap() of swap-filled ptes.
- "support large folio swap-out and swap-in for shmem" from Baolin
Wang. With this series we no longer split shmem large folios into
simgle-page folios when swapping out shmem.
- "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao. Nice
performance improvements and code reductions for gigantic folios.
- "support shmem mTHP collapse" from Baolin Wang. Adds support for
khugepaged's collapsing of shmem mTHP folios.
- "mm: Optimize mseal checks" from Pedro Falcato. Fixes an mprotect()
performance regression due to the addition of mseal().
- "Increase the number of bits available in page_type" from Matthew
Wilcox. Increases the number of bits available in page_type!
- "Simplify the page flags a little" from Matthew Wilcox. Many legacy
page flags are now folio flags, so the page-based flags and their
accessors/mutators can be removed.
- "mm: store zero pages to be swapped out in a bitmap" from Usama
Arif. An optimization which permits us to avoid writing/reading
zero-filled zswap pages to backing store.
- "Avoid MAP_FIXED gap exposure" from Liam Howlett. Fixes a race
window which occurs when a MAP_FIXED operqtion is occurring during
an unrelated vma tree walk.
- "mm: remove vma_merge()" from Lorenzo Stoakes. Major rotorooting of
the vma_merge() functionality, making ot cleaner, more testable and
better tested.
- "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.
Minor fixups of DAMON selftests and kunit tests.
- "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.
Code cleanups and folio conversions.
- "Shmem mTHP controls and stats improvements" from Ryan Roberts.
Cleanups for shmem controls and stats.
- "mm: count the number of anonymous THPs per size" from Barry Song.
Expose additional anon THP stats to userspace for improved tuning.
- "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more
folio conversions and removal of now-unused page-based APIs.
- "replace per-quota region priorities histogram buffer with
per-context one" from SeongJae Park. DAMON histogram
rationalization.
- "Docs/damon: update GitHub repo URLs and maintainer-profile" from
SeongJae Park. DAMON documentation updates.
- "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and
improve related doc and warn" from Jason Wang: fixes usage of page
allocator __GFP_NOFAIL and GFP_ATOMIC flags.
- "mm: split underused THPs" from Yu Zhao. Improve THP=always policy.
This was overprovisioning THPs in sparsely accessed memory areas.
- "zram: introduce custom comp backends API" frm Sergey Senozhatsky.
Add support for zram run-time compression algorithm tuning.
- "mm: Care about shadow stack guard gap when getting an unmapped
area" from Mark Brown. Fix up the various arch_get_unmapped_area()
implementations to better respect guard areas.
- "Improve mem_cgroup_iter()" from Kinsey Ho. Improve the reliability
of mem_cgroup_iter() and various code cleanups.
- "mm: Support huge pfnmaps" from Peter Xu. Extends the usage of huge
pfnmap support.
- "resource: Fix region_intersects() vs add_memory_driver_managed()"
from Huang Ying. Fix a bug in region_intersects() for systems with
CXL memory.
- "mm: hwpoison: two more poison recovery" from Kefeng Wang. Teaches
a couple more code paths to correctly recover from the encountering
of poisoned memry.
- "mm: enable large folios swap-in support" from Barry Song. Support
the swapin of mTHP memory into appropriately-sized folios, rather
than into single-page folios"
* tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (416 commits)
zram: free secondary algorithms names
uprobes: turn xol_area->pages[2] into xol_area->page
uprobes: introduce the global struct vm_special_mapping xol_mapping
Revert "uprobes: use vm_special_mapping close() functionality"
mm: support large folios swap-in for sync io devices
mm: add nr argument in mem_cgroup_swapin_uncharge_swap() helper to support large folios
mm: fix swap_read_folio_zeromap() for large folios with partial zeromap
mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries
set_memory: add __must_check to generic stubs
mm/vma: return the exact errno in vms_gather_munmap_vmas()
memcg: cleanup with !CONFIG_MEMCG_V1
mm/show_mem.c: report alloc tags in human readable units
mm: support poison recovery from copy_present_page()
mm: support poison recovery from do_cow_fault()
resource, kunit: add test case for region_intersects()
resource: make alloc_free_mem_region() works for iomem_resource
mm: z3fold: deprecate CONFIG_Z3FOLD
vfio/pci: implement huge_fault support
mm/arm64: support large pfn mappings
mm/x86: support large pfn mappings
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
- cpuset isolation improvements
- cpuset cgroup1 support is split into its own file behind the new
config option CONFIG_CPUSET_V1. This makes it the second controller
which makes cgroup1 support optional after memcg
- Handling of unavailable v1 controller handling improved during
cgroup1 mount operations
- union_find applied to cpuset. It makes code simpler and more
efficient
- Reduce spurious events in pids.events
- Cleanups and other misc changes
- Contains a merge of cgroup/for-6.11-fixes to receive cpuset fixes
that further changes build upon
* tag 'cgroup-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (34 commits)
cgroup: Do not report unavailable v1 controllers in /proc/cgroups
cgroup: Disallow mounting v1 hierarchies without controller implementation
cgroup/cpuset: Expose cpuset filesystem with cpuset v1 only
cgroup/cpuset: Move cpu.h include to cpuset-internal.h
cgroup/cpuset: add sefltest for cpuset v1
cgroup/cpuset: guard cpuset-v1 code under CONFIG_CPUSETS_V1
cgroup/cpuset: rename functions shared between v1 and v2
cgroup/cpuset: move v1 interfaces to cpuset-v1.c
cgroup/cpuset: move validate_change_legacy to cpuset-v1.c
cgroup/cpuset: move legacy hotplug update to cpuset-v1.c
cgroup/cpuset: add callback_lock helper
cgroup/cpuset: move memory_spread to cpuset-v1.c
cgroup/cpuset: move relax_domain_level to cpuset-v1.c
cgroup/cpuset: move memory_pressure to cpuset-v1.c
cgroup/cpuset: move common code to cpuset-internal.h
cgroup/cpuset: introduce cpuset-v1.c
selftest/cgroup: Make test_cpuset_prs.sh deal with pre-isolated CPUs
cgroup/cpuset: Account for boot time isolated CPUs
cgroup/cpuset: remove use_parent_ecpus of cpuset
cgroup/cpuset: remove fetch_xcpus
...
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Rust does not yet have support for software tags. Prevent RUST from
being selected if KASAN_SW_TAGS is enabled.
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20240820194910.187826-3-mmaurer@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
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Make it possible to use the Control Flow Integrity (CFI) sanitizer when
Rust is enabled. Enabling CFI with Rust requires that CFI is configured
to normalize integer types so that all integer types of the same size
and signedness are compatible under CFI.
Rust and C use the same LLVM backend for code generation, so Rust KCFI
is compatible with the KCFI used in the kernel for C. In the case of
FineIBT, CFI also depends on -Zpatchable-function-entry for rewriting
the function prologue, so we set that flag for Rust as well. The flag
for FineIBT requires rustc 1.80.0 or later, so include a Kconfig
requirement for that.
Enabling Rust will select CFI_ICALL_NORMALIZE_INTEGERS because the flag
is required to use Rust with CFI. Using select rather than `depends on`
avoids the case where Rust is not visible in menuconfig due to
CFI_ICALL_NORMALIZE_INTEGERS not being enabled. One disadvantage of
select is that RUST must `depends on` all of the things that
CFI_ICALL_NORMALIZE_INTEGERS depends on to avoid invalid configurations.
Alice has been using KCFI on her phone for several months, so it is
reasonably well tested on arm64.
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Gatlin Newhouse <gatlin.newhouse@gmail.com>
Acked-by: Kees Cook <kees@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240801-kcfi-v2-2-c93caed3d121@google.com
[ Replaced `!FINEIBT` requirement with `!CALL_PADDING` to prevent
a build error on older Rust compilers. Fixed typo. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
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Add all of the flags that are needed to support the shadow call stack
(SCS) sanitizer with Rust, and updates Kconfig to allow only
configurations that work.
The -Zfixed-x18 flag is required to use SCS on arm64, and requires rustc
version 1.80.0 or greater. This restriction is reflected in Kconfig.
When CONFIG_DYNAMIC_SCS is enabled, the build will be configured to
include unwind tables in the build artifacts. Dynamic SCS uses the
unwind tables at boot to find all places that need to be patched. The
-Cforce-unwind-tables=y flag ensures that unwind tables are available
for Rust code.
In non-dynamic mode, the -Zsanitizer=shadow-call-stack flag is what
enables the SCS sanitizer. Using this flag requires rustc version 1.82.0
or greater on the targets used by Rust in the kernel. This restriction
is reflected in Kconfig.
It is possible to avoid the requirement of rustc 1.80.0 by using
-Ctarget-feature=+reserve-x18 instead of -Zfixed-x18. However, this flag
emits a warning during the build, so this patch does not add support for
using it and instead requires 1.80.0 or greater.
The dependency is placed on `select HAVE_RUST` to avoid a situation
where enabling Rust silently turns off the sanitizer. Instead, turning
on the sanitizer results in Rust being disabled. We generally do not
want changes to CONFIG_RUST to result in any mitigations being changed
or turned off.
At the time of writing, rustc 1.82.0 only exists via the nightly release
channel. There is a chance that the -Zsanitizer=shadow-call-stack flag
will end up needing 1.83.0 instead, but I think it is small.
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240829-shadow-call-stack-v7-1-2f62a4432abf@google.com
[ Fixed indentation using spaces. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
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Re-run Kconfig if we detect the Rust compiler has changed via the version
text, like it is done for C.
Unlike C, and unlike `RUSTC_VERSION`, the `RUSTC_VERSION_TEXT` is kept
under `depends on RUST`, since it should not be needed unless `RUST`
is enabled.
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20240902165535.1101978-3-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
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Now that we support several Rust versions, introduce
`CONFIG_RUSTC_VERSION` so that it can be used in Kconfig to enable and
disable configuration options based on the `rustc` version.
The approach taken resembles `pahole`'s -- see commit 613fe1692377
("kbuild: Add CONFIG_PAHOLE_VERSION"), i.e. a simple version parsing
without trying to identify several kinds of compilers, since so far
there is only one (`rustc`).
However, unlike `pahole`'s, we also print a zero if executing failed for
any reason, rather than checking if the command is found and executable
(which still leaves things like a file that exists and is executable,
but e.g. is built for another platform [1]). An equivalent approach to
the one here was also submitted for `pahole` [2].
Link: https://lore.kernel.org/rust-for-linux/CANiq72=4vX_tJMJLE6e+bg7ZECHkS-AQpm8GBzuK75G1EB7+Nw@mail.gmail.com/ [1]
Link: https://lore.kernel.org/linux-kbuild/20240728125527.690726-1-ojeda@kernel.org/ [2]
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20240902165535.1101978-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
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Pull bpf/master to receive baebe9aaba1e ("bpf: allow passing struct
bpf_iter_<type> as kfunc arguments") and related changes in preparation for
the DSQ iterator patchset.
Signed-off-by: Tejun Heo <tj@kernel.org>
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Add sched_ext_ops operations to init/exit cgroups, and track task migrations
and config changes. A BPF scheduler may not implement or implement only
subset of cgroup features. The implemented features can be indicated using
%SCX_OPS_HAS_CGOUP_* flags. If cgroup configuration makes use of features
that are not implemented, a warning is triggered.
While a BPF scheduler is being enabled and disabled, relevant cgroup
operations are locked out using scx_cgroup_rwsem. This avoids situations
like task prep taking place while the task is being moved across cgroups,
making things easier for BPF schedulers.
v7: - cgroup interface file visibility toggling is dropped in favor just
warning messages. Dynamically changing interface visiblity caused more
confusion than helping.
v6: - Updated to reflect the removal of SCX_KF_SLEEPABLE.
- Updated to use CONFIG_GROUP_SCHED_WEIGHT and fixes for
!CONFIG_FAIR_GROUP_SCHED && CONFIG_EXT_GROUP_SCHED.
v5: - Flipped the locking order between scx_cgroup_rwsem and
cpus_read_lock() to avoid locking order conflict w/ cpuset. Better
documentation around locking.
- sched_move_task() takes an early exit if the source and destination
are identical. This triggered the warning in scx_cgroup_can_attach()
as it left p->scx.cgrp_moving_from uncleared. Updated the cgroup
migration path so that ops.cgroup_prep_move() is skipped for identity
migrations so that its invocations always match ops.cgroup_move()
one-to-one.
v4: - Example schedulers moved into their own patches.
- Fix build failure when !CONFIG_CGROUP_SCHED, reported by Andrea Righi.
v3: - Make scx_example_pair switch all tasks by default.
- Convert to BPF inline iterators.
- scx_bpf_task_cgroup() is added to determine the current cgroup from
CPU controller's POV. This allows BPF schedulers to accurately track
CPU cgroup membership.
- scx_example_flatcg added. This demonstrates flattened hierarchy
implementation of CPU cgroup control and shows significant performance
improvement when cgroups which are nested multiple levels are under
competition.
v2: - Build fixes for different CONFIG combinations.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: David Vernet <dvernet@meta.com>
Acked-by: Josh Don <joshdon@google.com>
Acked-by: Hao Luo <haoluo@google.com>
Acked-by: Barret Rhoden <brho@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Andrea Righi <andrea.righi@canonical.com>
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sched_ext will soon add cgroup cpu.weigh support. The cgroup interface code
is currently gated behind CONFIG_FAIR_GROUP_SCHED. As the fair class and/or
SCX may implement the feature, put the interface code behind the new
CONFIG_CGROUP_SCHED_WEIGHT which is selected by CONFIG_FAIR_GROUP_SCHED.
This allows either sched class to enable the itnerface code without ading
more complex CONFIG tests.
When !CONFIG_FAIR_GROUP_SCHED, a dummy version of sched_group_set_shares()
is added to support later CONFIG_CGROUP_SCHED_WEIGHT &&
!CONFIG_FAIR_GROUP_SCHED builds.
No functional changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
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Use LZMA2 options that match the arch-specific alignment of instructions.
This change reduces compressed kernel size 0-2 % depending on the arch.
On 1-byte-aligned x86 it makes no difference and on 4-byte-aligned archs
it helps the most.
Use the ARM-Thumb filter for ARM-Thumb2 kernels. This reduces compressed
kernel size about 5 %.[1] Previously such kernels were compressed using
the ARM filter which didn't do anything useful with ARM-Thumb2 code.
Add BCJ filter support for ARM64 and RISC-V. Compared to unfiltered XZ or
plain LZMA, the compressed kernel size is reduced about 5 % on ARM64 and 7
% on RISC-V. A new enough version of the xz tool is required: 5.4.0 for
ARM64 and 5.6.0 for RISC-V. With an old xz version, a message is printed
to standard error and the kernel is compressed without the filter.
Update lib/decompress_unxz.c to match the changes to xz_wrap.sh.
Update the CONFIG_KERNEL_XZ help text in init/Kconfig:
- Add the RISC-V and ARM64 filters.
- Clarify that the PowerPC filter is for big endian only.
- Omit IA-64.
Link: https://lore.kernel.org/lkml/1637379771-39449-1-git-send-email-zhongjubin@huawei.com/ [1]
Link: https://lkml.kernel.org/r/20240721133633.47721-15-lasse.collin@tukaani.org
Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Reviewed-by: Sam James <sam@gentoo.org>
Cc: Simon Glass <sjg@chromium.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Jubin Zhong <zhongjubin@huawei.com>
Cc: Jules Maselbas <jmaselbas@zdiv.net>
Cc: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Joel Stanley <joel@jms.id.au>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Rui Li <me@lirui.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Fix typo in Kconfig help
Link: https://lkml.kernel.org/r/78656.1720853990@turing-police
Fixes: e93d4166b40a ("mm: memcg: put cgroup v1-specific code under a config option")
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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This patch introduces CONFIG_CPUSETS_V1 and guard cpuset-v1 code under
CONFIG_CPUSETS_V1. The default value of CONFIG_CPUSETS_V1 is N, so that
user who adopted v2 don't have 'pay' for cpuset v1.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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If GCOV is enabled and this option is set, it enables code coverage
profiling of the io_uring subsystem. Only use this for test purposes,
as it will impact the runtime performance.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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When enabling Rust in the kernel, we only need to block on the
RANDSTRUCT feature and GCC plugin. The rest of the GCC plugins
are reasonably safe to enable.
[ Originally (years ago) we only had this restriction, but we ended up
restricting also the rest of the GCC plugins 1) to be on the safe side,
2) since compiler plugin support could be going away in the kernel and
3) since mixed builds are best effort so far; so I asked Neal about
his experience enabling the other plugins -- Neal says:
When I originally wrote this patch two years ago to get things
working, Fedora used all the GCC plugins, so I was trying to get GCC +
Rust to work while minimizing the delta on build differences. This was
the combination that worked. We've been carrying this patch in the
Asahi tree for a year now. And while Fedora does not currently have
GCC plugins enabled because it caused issues with some third-party
modules (I think it was the NVIDIA driver, but I'm not sure), it was
around long enough for me to know with some confidence that it was
fine this way.
- Miguel ]
Signed-off-by: Neal Gompa <neal@gompa.dev>
Link: https://lore.kernel.org/r/20240731125615.3368813-1-neal@gompa.dev
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
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Pull rust fixes from Miguel Ojeda:
- Fix '-Os' Rust 1.80.0+ builds adding more intrinsics (also tweaked in
upstream Rust for the upcoming 1.82.0).
- Fix support for the latest version of rust-analyzer due to a change
on rust-analyzer config file semantics (considered a fix since most
developers use the latest version of the tool, which is the only one
actually supported by upstream). I am discussing stability of the
config file with upstream -- they may be able to start versioning it.
- Fix GCC 14 builds due to '-fmin-function-alignment' not skipped for
libclang (bindgen).
- A couple Kconfig fixes around '{RUSTC,BINDGEN}_VERSION_TEXT' to
suppress error messages in a foreign architecture chroot and to use a
proper default format.
- Clean 'rust-analyzer' target warning due to missing recursive make
invocation mark.
- Clean Clippy warning due to missing indentation in docs.
- Clean LLVM 19 build warning due to removed 3dnow feature upstream.
* tag 'rust-fixes-6.11' of https://github.com/Rust-for-Linux/linux:
rust: x86: remove `-3dnow{,a}` from target features
kbuild: rust-analyzer: mark `rust_is_available.sh` invocation as recursive
rust: add intrinsics to fix `-Os` builds
kbuild: rust: skip -fmin-function-alignment in bindgen flags
rust: Support latest version of `rust-analyzer`
rust: macros: indent list item in `module!`'s docs
rust: fix the default format for CONFIG_{RUSTC,BINDGEN}_VERSION_TEXT
rust: suppress error messages from CONFIG_{RUSTC,BINDGEN}_VERSION_TEXT
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When using the shadow call stack sanitizer, all code must be compiled
with the -ffixed-x18 flag, but this flag is not currently being passed
to Rust. This results in crashes that are extremely difficult to debug.
To ensure that nobody else has to go through the same debugging session
that I had to, prevent configurations that enable both SHADOW_CALL_STACK
and RUST.
It is rather common for people to backport 724a75ac9542 ("arm64: rust:
Enable Rust support for AArch64"), so I recommend applying this fix all
the way back to 6.1.
Cc: stable@vger.kernel.org # 6.1 and later
Fixes: 724a75ac9542 ("arm64: rust: Enable Rust support for AArch64")
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://lore.kernel.org/r/20240729-shadow-call-stack-v4-1-2a664b082ea4@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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Another oddity in these config entries is their default value can fall
back to 'n', which is a value for bool or tristate symbols.
The '|| echo n' is an incorrect workaround to avoid the syntax error.
This is not a big deal, as the entry is hidden by 'depends on RUST' in
situations where '$(RUSTC) --version' or '$(BINDGEN) --version' fails.
Anyway, it looks odd.
The default of a string type symbol should be a double-quoted string
literal. Turn it into an empty string when the version command fails.
Fixes: 2f7ab1267dc9 ("Kbuild: add Rust support")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20240727140302.1806011-2-masahiroy@kernel.org
[ Rebased on top of v6.11-rc1. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
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While this is a somewhat unusual case, I encountered odd error messages
when I ran Kconfig in a foreign architecture chroot.
$ make allmodconfig
sh: 1: rustc: not found
sh: 1: bindgen: not found
#
# configuration written to .config
#
The successful execution of 'command -v rustc' does not necessarily mean
that 'rustc --version' will succeed.
$ sh -c 'command -v rustc'
/home/masahiro/.cargo/bin/rustc
$ sh -c 'rustc --version'
sh: 1: rustc: not found
Here, 'rustc' is built for x86, and I ran it in an arm64 system.
The current code:
command -v $(RUSTC) >/dev/null 2>&1 && $(RUSTC) --version || echo n
can be turned into:
command -v $(RUSTC) >/dev/null 2>&1 && $(RUSTC) --version 2>/dev/null || echo n
However, I did not understand the necessity of 'command -v $(RUSTC)'.
I simplified it to:
$(RUSTC) --version 2>/dev/null || echo n
Fixes: 2f7ab1267dc9 ("Kbuild: add Rust support")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20240727140302.1806011-1-masahiroy@kernel.org
[ Rebased on top of v6.11-rc1. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
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Pull Rust updates from Miguel Ojeda:
"The highlight is the establishment of a minimum version for the Rust
toolchain, including 'rustc' (and bundled tools) and 'bindgen'.
The initial minimum will be the pinned version we currently have, i.e.
we are just widening the allowed versions. That covers three stable
Rust releases: 1.78.0, 1.79.0, 1.80.0 (getting released tomorrow),
plus beta, plus nightly.
This should already be enough for kernel developers in distributions
that provide recent Rust compiler versions routinely, such as Arch
Linux, Debian Unstable (outside the freeze period), Fedora Linux,
Gentoo Linux (especially the testing channel), Nix (unstable) and
openSUSE Slowroll and Tumbleweed.
In addition, the kernel is now being built-tested by Rust's pre-merge
CI. That is, every change that is attempting to land into the Rust
compiler is tested against the kernel, and it is merged only if it
passes. Similarly, the bindgen tool has agreed to build the kernel in
their CI too.
Thus, with the pre-merge CI in place, both projects hope to avoid
unintentional changes to Rust that break the kernel. This means that,
in general, apart from intentional changes on their side (that we will
need to workaround conditionally on our side), the upcoming Rust
compiler versions should generally work.
In addition, the Rust project has proposed getting the kernel into
stable Rust (at least solving the main blockers) as one of its three
flagship goals for 2024H2 [1].
I would like to thank Niko, Sid, Emilio et al. for their help
promoting the collaboration between Rust and the kernel.
Toolchain and infrastructure:
- Support several Rust toolchain versions.
- Support several bindgen versions.
- Remove 'cargo' requirement and simplify 'rusttest', thanks to
'alloc' having been dropped last cycle.
- Provide proper error reporting for the 'rust-analyzer' target.
'kernel' crate:
- Add 'uaccess' module with a safe userspace pointers abstraction.
- Add 'page' module with a 'struct page' abstraction.
- Support more complex generics in workqueue's 'impl_has_work!'
macro.
'macros' crate:
- Add 'firmware' field support to the 'module!' macro.
- Improve 'module!' macro documentation.
Documentation:
- Provide instructions on what packages should be installed to build
the kernel in some popular Linux distributions.
- Introduce the new kernel.org LLVM+Rust toolchains.
- Explain '#[no_std]'.
And a few other small bits"
Link: https://rust-lang.github.io/rust-project-goals/2024h2/index.html#flagship-goals [1]
* tag 'rust-6.11' of https://github.com/Rust-for-Linux/linux: (26 commits)
docs: rust: quick-start: add section on Linux distributions
rust: warn about `bindgen` versions 0.66.0 and 0.66.1
rust: start supporting several `bindgen` versions
rust: work around `bindgen` 0.69.0 issue
rust: avoid assuming a particular `bindgen` build
rust: start supporting several compiler versions
rust: simplify Clippy warning flags set
rust: relax most deny-level lints to warnings
rust: allow `dead_code` for never constructed bindings
rust: init: simplify from `map_err` to `inspect_err`
rust: macros: indent list item in `paste!`'s docs
rust: add abstraction for `struct page`
rust: uaccess: add typed accessors for userspace pointers
uaccess: always export _copy_[from|to]_user with CONFIG_RUST
rust: uaccess: add userspace pointers
kbuild: rust-analyzer: improve comment documentation
kbuild: rust-analyzer: better error handling
docs: rust: no_std is used
rust: alloc: add __GFP_HIGHMEM flag
rust: alloc: fix typo in docs for GFP_NOWAIT
...
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git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- Remove tristate choice support from Kconfig
- Stop using the PROVIDE() directive in the linker script
- Reduce the number of links for the combination of CONFIG_KALLSYMS and
CONFIG_DEBUG_INFO_BTF
- Enable the warning for symbol reference to .exit.* sections by
default
- Fix warnings in RPM package builds
- Improve scripts/make_fit.py to generate a FIT image with separate
base DTB and overlays
- Improve choice value calculation in Kconfig
- Fix conditional prompt behavior in choice in Kconfig
- Remove support for the uncommon EMAIL environment variable in Debian
package builds
- Remove support for the uncommon "name <email>" form for the DEBEMAIL
environment variable
- Raise the minimum supported GNU Make version to 4.0
- Remove stale code for the absolute kallsyms
- Move header files commonly used for host programs to scripts/include/
- Introduce the pacman-pkg target to generate a pacman package used in
Arch Linux
- Clean up Kconfig
* tag 'kbuild-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (65 commits)
kbuild: doc: gcc to CC change
kallsyms: change sym_entry::percpu_absolute to bool type
kallsyms: unify seq and start_pos fields of struct sym_entry
kallsyms: add more original symbol type/name in comment lines
kallsyms: use \t instead of a tab in printf()
kallsyms: avoid repeated calculation of array size for markers
kbuild: add script and target to generate pacman package
modpost: use generic macros for hash table implementation
kbuild: move some helper headers from scripts/kconfig/ to scripts/include/
Makefile: add comment to discourage tools/* addition for kernel builds
kbuild: clean up scripts/remove-stale-files
kconfig: recursive checks drop file/lineno
kbuild: rpm-pkg: introduce a simple changelog section for kernel.spec
kallsyms: get rid of code for absolute kallsyms
kbuild: Create INSTALL_PATH directory if it does not exist
kbuild: Abort make on install failures
kconfig: remove 'e1' and 'e2' macros from expression deduplication
kconfig: remove SYMBOL_CHOICEVAL flag
kconfig: add const qualifiers to several function arguments
kconfig: call expr_eliminate_yn() at least once in expr_eliminate_dups()
...
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- In the series "mm: Avoid possible overflows in dirty throttling" Jan
Kara addresses a couple of issues in the writeback throttling code.
These fixes are also targetted at -stable kernels.
- Ryusuke Konishi's series "nilfs2: fix potential issues related to
reserved inodes" does that. This should actually be in the
mm-nonmm-stable tree, along with the many other nilfs2 patches. My
bad.
- More folio conversions from Kefeng Wang in the series "mm: convert to
folio_alloc_mpol()"
- Kemeng Shi has sent some cleanups to the writeback code in the series
"Add helper functions to remove repeated code and improve readability
of cgroup writeback"
- Kairui Song has made the swap code a little smaller and a little
faster in the series "mm/swap: clean up and optimize swap cache
index".
- In the series "mm/memory: cleanly support zeropage in
vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David
Hildenbrand has reworked the rather sketchy handling of the use of
the zeropage in MAP_SHARED mappings. I don't see any runtime effects
here - more a cleanup/understandability/maintainablity thing.
- Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling
of higher addresses, for aarch64. The (poorly named) series is
"Restructure va_high_addr_switch".
- The core TLB handling code gets some cleanups and possible slight
optimizations in Bang Li's series "Add update_mmu_tlb_range() to
simplify code".
- Jane Chu has improved the handling of our
fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in
the series "Enhance soft hwpoison handling and injection".
- Jeff Johnson has sent a billion patches everywhere to add
MODULE_DESCRIPTION() to everything. Some landed in this pull.
- In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang
has simplified migration's use of hardware-offload memory copying.
- Yosry Ahmed performs more folio API conversions in his series "mm:
zswap: trivial folio conversions".
- In the series "large folios swap-in: handle refault cases first",
Chuanhua Han inches us forward in the handling of large pages in the
swap code. This is a cleanup and optimization, working toward the end
objective of full support of large folio swapin/out.
- In the series "mm,swap: cleanup VMA based swap readahead window
calculation", Huang Ying has contributed some cleanups and a possible
fixlet to his VMA based swap readahead code.
- In the series "add mTHP support for anonymous shmem" Baolin Wang has
taught anonymous shmem mappings to use multisize THP. By default this
is a no-op - users must opt in vis sysfs controls. Dramatic
improvements in pagefault latency are realized.
- David Hildenbrand has some cleanups to our remaining use of
page_mapcount() in the series "fs/proc: move page_mapcount() to
fs/proc/internal.h".
- David also has some highmem accounting cleanups in the series
"mm/highmem: don't track highmem pages manually".
- Build-time fixes and cleanups from John Hubbard in the series
"cleanups, fixes, and progress towards avoiding "make headers"".
- Cleanups and consolidation of the core pagemap handling from Barry
Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers
and utilize them".
- Lance Yang's series "Reclaim lazyfree THP without splitting" has
reduced the latency of the reclaim of pmd-mapped THPs under fairly
common circumstances. A 10x speedup is seen in a microbenchmark.
It does this by punting to aother CPU but I guess that's a win unless
all CPUs are pegged.
- hugetlb_cgroup cleanups from Xiu Jianfeng in the series
"mm/hugetlb_cgroup: rework on cftypes".
- Miaohe Lin's series "Some cleanups for memory-failure" does just that
thing.
- Someone other than SeongJae has developed a DAMON feature in Honggyu
Kim's series "DAMON based tiered memory management for CXL memory".
This adds DAMON features which may be used to help determine the
efficiency of our placement of CXL/PCIe attached DRAM.
- DAMON user API centralization and simplificatio work in SeongJae
Park's series "mm/damon: introduce DAMON parameters online commit
function".
- In the series "mm: page_type, zsmalloc and page_mapcount_reset()"
David Hildenbrand does some maintenance work on zsmalloc - partially
modernizing its use of pageframe fields.
- Kefeng Wang provides more folio conversions in the series "mm: remove
page_maybe_dma_pinned() and page_mkclean()".
- More cleanup from David Hildenbrand, this time in the series
"mm/memory_hotplug: use PageOffline() instead of PageReserved() for
!ZONE_DEVICE". It "enlightens memory hotplug more about PageOffline()
pages" and permits the removal of some virtio-mem hacks.
- Barry Song's series "mm: clarify folio_add_new_anon_rmap() and
__folio_add_anon_rmap()" is a cleanup to the anon folio handling in
preparation for mTHP (multisize THP) swapin.
- Kefeng Wang's series "mm: improve clear and copy user folio"
implements more folio conversions, this time in the area of large
folio userspace copying.
- The series "Docs/mm/damon/maintaier-profile: document a mailing tool
and community meetup series" tells people how to get better involved
with other DAMON developers. From SeongJae Park.
- A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does
that.
- David Hildenbrand sends along more cleanups, this time against the
migration code. The series is "mm/migrate: move NUMA hinting fault
folio isolation + checks under PTL".
- Jan Kara has found quite a lot of strangenesses and minor errors in
the readahead code. He addresses this in the series "mm: Fix various
readahead quirks".
- SeongJae Park's series "selftests/damon: test DAMOS tried regions and
{min,max}_nr_regions" adds features and addresses errors in DAMON's
self testing code.
- Gavin Shan has found a userspace-triggerable WARN in the pagecache
code. The series "mm/filemap: Limit page cache size to that supported
by xarray" addresses this. The series is marked cc:stable.
- Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations
and cleanup" cleans up and slightly optimizes KSM.
- Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of
code motion. The series (which also makes the memcg-v1 code
Kconfigurable) are "mm: memcg: separate legacy cgroup v1 code and put
under config option" and "mm: memcg: put cgroup v1-specific memcg
data under CONFIG_MEMCG_V1"
- Dan Schatzberg's series "Add swappiness argument to memory.reclaim"
adds an additional feature to this cgroup-v2 control file.
- The series "Userspace controls soft-offline pages" from Jiaqi Yan
permits userspace to stop the kernel's automatic treatment of
excessive correctable memory errors. In order to permit userspace to
monitor and handle this situation.
- Kefeng Wang's series "mm: migrate: support poison recover from
migrate folio" teaches the kernel to appropriately handle migration
from poisoned source folios rather than simply panicing.
- SeongJae Park's series "Docs/damon: minor fixups and improvements"
does those things.
- In the series "mm/zsmalloc: change back to per-size_class lock"
Chengming Zhou improves zsmalloc's scalability and memory
utilization.
- Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for
pinning memfd folios" makes the GUP code use FOLL_PIN rather than
bare refcount increments. So these paes can first be moved aside if
they reside in the movable zone or a CMA block.
- Andrii Nakryiko has added a binary ioctl()-based API to
/proc/pid/maps for much faster reading of vma information. The series
is "query VMAs from /proc/<pid>/maps".
- In the series "mm: introduce per-order mTHP split counters" Lance
Yang improves the kernel's presentation of developer information
related to multisize THP splitting.
- Michael Ellerman has developed the series "Reimplement huge pages
without hugepd on powerpc (8xx, e500, book3s/64)". This permits
userspace to use all available huge page sizes.
- In the series "revert unconditional slab and page allocator fault
injection calls" Vlastimil Babka removes a performance-affecting and
not very useful feature from slab fault injection.
* tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (411 commits)
mm/mglru: fix ineffective protection calculation
mm/zswap: fix a white space issue
mm/hugetlb: fix kernel NULL pointer dereference when migrating hugetlb folio
mm/hugetlb: fix possible recursive locking detected warning
mm/gup: clear the LRU flag of a page before adding to LRU batch
mm/numa_balancing: teach mpol_to_str about the balancing mode
mm: memcg1: convert charge move flags to unsigned long long
alloc_tag: fix page_ext_get/page_ext_put sequence during page splitting
lib: reuse page_ext_data() to obtain codetag_ref
lib: add missing newline character in the warning message
mm/mglru: fix overshooting shrinker memory
mm/mglru: fix div-by-zero in vmpressure_calc_level()
mm/kmemleak: replace strncpy() with strscpy()
mm, page_alloc: put should_fail_alloc_page() back behing CONFIG_FAIL_PAGE_ALLOC
mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLAB
mm: ignore data-race in __swap_writepage
hugetlbfs: ensure generic_hugetlb_get_unmapped_area() returns higher address than mmap_min_addr
mm: shmem: rename mTHP shmem counters
mm: swap_state: use folio_alloc_mpol() in __read_swap_cache_async()
mm/migrate: putback split folios when numa hint migration fails
...
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Commit cf8e8658100d ("arch: Remove Itanium (IA-64) architecture")
removed the last use of the absolute kallsyms.
Signed-off-by: Jann Horn <jannh@google.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/all/20240221202655.2423854-1-jannh@google.com/
[masahiroy@kernel.org: rebase the code and reword the commit description]
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
|
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Several versions of GCC mis-compile asm goto with outputs. We try to
workaround this, but our workaround is demonstrably incomplete and
liable to result in subtle bugs, especially on arm64 where get_user()
has recently been moved over to using asm goto with outputs.
From discussion(s) with Linus at:
https://lore.kernel.org/linux-arm-kernel/Zpfv2tnlQ-gOLGac@J2N7QTR9R3.cambridge.arm.com/
https://lore.kernel.org/linux-arm-kernel/ZpfxLrJAOF2YNqCk@J2N7QTR9R3.cambridge.arm.com/
... it sounds like the best thing to do for now is to remove the
workaround and make CC_HAS_ASM_GOTO_OUTPUT depend on working compiler
versions.
The issue was originally reported to GCC by Sean Christopherson:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113921
... and Jakub Jelinek fixed this for GCC 14, with the fix backported to
13.3.0, 12.4.0, and 11.5.0.
In the kernel, we tried to workaround broken compilers in commits:
4356e9f841f7 ("work around gcc bugs with 'asm goto' with outputs")
68fb3ca0e408 ("update workarounds for gcc "asm goto" issue")
... but the workaround of adding an empty asm("") after the asm volatile
goto(...) demonstrably does not always avoid the problem, as can be seen
in the following test case:
| #define asm_goto_output(x...) \
| do { asm volatile goto(x); asm (""); } while (0)
|
| #define __good_or_bad(__val, __key) \
| do { \
| __label__ __failed; \
| unsigned long __tmp; \
| asm_goto_output( \
| " cbnz %[key], %l[__failed]\n" \
| " mov %[val], #0x900d\n" \
| : [val] "=r" (__tmp) \
| : [key] "r" (__key) \
| : \
| : __failed); \
| (__val) = __tmp; \
| break; \
| __failed: \
| (__val) = 0xbad; \
| } while (0)
|
| unsigned long get_val(unsigned long key);
| unsigned long get_val(unsigned long key)
| {
| unsigned long val = 0xbad;
|
| __good_or_bad(val, key);
|
| return val;
| }
GCC 13.2.0 (at -O2) compiles this to:
| cbnz x0, .Lfailed
| mov x0, #0x900d
| .Lfailed:
| ret
GCC 14.1.0 (at -O2) compiles this to:
| cbnz x0, .Lfailed
| mov x0, #0x900d
| ret
| .Lfailed:
| mov x0, #0xbad
| ret
Note that GCC 13.2.0 erroneously omits the assignment to 'val' in the
error path (even though this does not depend on an output of the asm
goto). GCC 14.1.0 correctly retains the assignment.
This problem can be seen within the kernel with the following test case:
| #include <linux/uaccess.h>
| #include <linux/types.h>
|
| noinline unsigned long test_unsafe_get_user(unsigned long __user *ptr);
| noinline unsigned long test_unsafe_get_user(unsigned long __user *ptr)
| {
| unsigned long val;
|
| unsafe_get_user(val, ptr, Efault);
| return val;
|
| Efault:
| val = 0x900d;
| return val;
| }
GCC 13.2.0 (arm64 defconfig) compiles this to:
| and x0, x0, #0xff7fffffffffffff
| ldtr x0, [x0]
| .Lextable_fixup:
| ret
GCC 13.2.0 (x86_64 defconfig + MITIGATION_RETPOLINE=n) compiles this to:
| endbr64
| mov (%rdi),%rax
| .Lextable_fixup:
| ret
... omitting the assignment to 'val' in the error path, and leaving
garbage in the result register returned by the function (which happens
to contain the faulting address in the generated code).
GCC 14.1.0 (arm64 defconfig) compiles this to:
| and x0, x0, #0xff7fffffffffffff
| ldtr x0, [x0]
| ret
| .Lextable_fixup:
| mov x0, #0x900d // #36877
| ret
GCC 14.1.0 (x86_64 defconfig + MITIGATION_RETPOLINE=n) compiles this to:
| endbr64
| mov (%rdi),%rax
| ret
| .Lextable_fixup:
| mov $0x900d,%eax
| ret
... retaining the expected assignment to 'val' in the error path.
We don't have a complete and reasonable workaround. While placing empty
asm("") blocks after each goto label *might* be sufficient, we don't
kn |
