kernel/linux.git/init, branch v6.6.23

modules: wait do_free_init correctly

2024-03-26T22:19:55+00:00

[ Upstream commit 8f8cd6c0a43ed637e620bbe45a8d0e0c2f4d5130 ] The synchronization here is to ensure the ordering of freeing of a module init so that it happens before W+X checking. It is worth noting it is not that the freeing was not happening, it is just that our sanity checkers raced against the permission checkers which assume init memory is already gone. Commit 1a7b7d922081 ("modules: Use vmalloc special flag") moved calling do_free_init() into a global workqueue instead of relying on it being called through call_rcu(..., do_free_init), which used to allowed us call do_free_init() asynchronously after the end of a subsequent grace period. The move to a global workqueue broke the gaurantees for code which needed to be sure the do_free_init() would complete with rcu_barrier(). To fix this callers which used to rely on rcu_barrier() must now instead use flush_work(&init_free_wq). Without this fix, we still could encounter false positive reports in W+X checking since the rcu_barrier() here can not ensure the ordering now. Even worse, the rcu_barrier() can introduce significant delay. Eric Chanudet reported that the rcu_barrier introduces ~0.1s delay on a PREEMPT_RT kernel. [ 0.291444] Freeing unused kernel memory: 5568K [ 0.402442] Run /sbin/init as init process With this fix, the above delay can be eliminated. Link: https://lkml.kernel.org/r/20240227023546.2490667-1-changbin.du@huawei.com Fixes: 1a7b7d922081 ("modules: Use vmalloc special flag") Signed-off-by: Changbin Du Tested-by: Eric Chanudet Acked-by: Luis Chamberlain Cc: Xiaoyi Su Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

update workarounds for gcc "asm goto" issue

2024-02-23T08:24:47+00:00

commit 68fb3ca0e408e00db1c3f8fccdfa19e274c033be upstream. In commit 4356e9f841f7 ("work around gcc bugs with 'asm goto' with outputs") I did the gcc workaround unconditionally, because the cause of the bad code generation wasn't entirely clear. In the meantime, Jakub Jelinek debugged the issue, and has come up with a fix in gcc [2], which also got backported to the still maintained branches of gcc-11, gcc-12 and gcc-13. Note that while the fix technically wasn't in the original gcc-14 branch, Jakub says: "while it is true that no GCC 14 snapshots until today (or whenever the fix will be committed) have the fix, for GCC trunk it is up to the distros to use the latest snapshot if they use it at all and would allow better testing of the kernel code without the workaround, so that if there are other issues they won't be discovered years later. Most userland code doesn't actually use asm goto with outputs..." so we will consider gcc-14 to be fixed - if somebody is using gcc snapshots of the gcc-14 before the fix, they should upgrade. Note that while the bug goes back to gcc-11, in practice other gcc changes seem to have effectively hidden it since gcc-12.1 as per a bisect by Jakub. So even a gcc-14 snapshot without the fix likely doesn't show actual problems. Also, make the default 'asm_goto_output()' macro mark the asm as volatile by hand, because of an unrelated gcc issue [1] where it doesn't match the documented behavior ("asm goto is always volatile"). Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103979 [1] Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113921 [2] Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/ Requested-by: Jakub Jelinek Cc: Uros Bizjak Cc: Nick Desaulniers Cc: Sean Christopherson Cc: Andrew Pinski Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

rootfs: Fix support for rootfstype= when root= is given

2024-01-25T23:35:46+00:00

commit 21528c69a0d8483f7c6345b1a0bc8d8975e9a172 upstream. Documentation/filesystems/ramfs-rootfs-initramfs.rst states: If CONFIG_TMPFS is enabled, rootfs will use tmpfs instead of ramfs by default. To force ramfs, add "rootfstype=ramfs" to the kernel command line. This currently does not work when root= is provided since then saved_root_name contains a string and rootfstype= is ignored. Therefore, ramfs is currently always chosen when root= is provided. The current behavior for rootfs's filesystem is: root= | rootfstype= | chosen rootfs filesystem ------------+-------------+-------------------------- unspecified | unspecified | tmpfs unspecified | tmpfs | tmpfs unspecified | ramfs | ramfs provided | ignored | ramfs rootfstype= should be respected regardless whether root= is given, as shown below: root= | rootfstype= | chosen rootfs filesystem ------------+-------------+-------------------------- unspecified | unspecified | tmpfs (as before) unspecified | tmpfs | tmpfs (as before) unspecified | ramfs | ramfs (as before) provided | unspecified | ramfs (compatibility with before) provided | tmpfs | tmpfs (new) provided | ramfs | ramfs (new) This table represents the new behavior. Fixes: 6e19eded3684 ("initmpfs: use initramfs if rootfstype= or root= specified") Cc: Signed-off-by: Rob Landley Link: https://lore.kernel.org/lkml/8244c75f-445e-b15b-9dbf-266e7ca666e2@landley.net/ Reviewed-and-Tested-by: Mimi Zohar Signed-off-by: Stefan Berger Link: https://lore.kernel.org/r/20231120011248.396012-1-stefanb@linux.ibm.com Signed-off-by: Greg Kroah-Hartman

proc: sysctl: prevent aliased sysctls from getting passed to init

2023-11-28T17:19:57+00:00

commit 8001f49394e353f035306a45bcf504f06fca6355 upstream. The code that checks for unknown boot options is unaware of the sysctl alias facility, which maps bootparams to sysctl values. If a user sets an old value that has a valid alias, a message about an invalid parameter will be printed during boot, and the parameter will get passed to init. Fix by checking for the existence of aliased parameters in the unknown boot parameter code. If an alias exists, don't return an error or pass the value to init. Signed-off-by: Krister Johansen Cc: stable@vger.kernel.org Fixes: 0a477e1ae21b ("kernel/sysctl: support handling command line aliases") Signed-off-by: Luis Chamberlain Signed-off-by: Greg Kroah-Hartman

x86/retpoline: Make sure there are no unconverted return thunks due to KCSAN

2023-11-28T17:19:36+00:00

[ Upstream commit 2d7ce49f58dc95495b3e22e45d2be7de909b2c63 ] Enabling CONFIG_KCSAN leads to unconverted, default return thunks to remain after patching. As David Kaplan describes in his debugging of the issue, it is caused by a couple of KCSAN-generated constructors which aren't processed by objtool: "When KCSAN is enabled, GCC generates lots of constructor functions named _sub_I_00099_0 which call __tsan_init and then return. The returns in these are generally annotated normally by objtool and fixed up at runtime. But objtool runs on vmlinux.o and vmlinux.o does not include a couple of object files that are in vmlinux, like init/version-timestamp.o and .vmlinux.export.o, both of which contain _sub_I_00099_0 functions. As a result, the returns in these functions are not annotated, and the panic occurs when we call one of them in do_ctors and it uses the default return thunk. This difference can be seen by counting the number of these functions in the object files: $ objdump -d vmlinux.o|grep -c "<_sub_I_00099_0>:" 2601 $ objdump -d vmlinux|grep -c "<_sub_I_00099_0>:" 2603 If these functions are only run during kernel boot, there is no speculation concern." Fix it by disabling KCSAN on version-timestamp.o and .vmlinux.export.o so the extra functions don't get generated. KASAN and GCOV are already disabled for those files. [ bp: Massage commit message. ] Closes: https://lore.kernel.org/lkml/20231016214810.GA3942238@dev-arch.thelio-3990X/ Reported-by: Nathan Chancellor Signed-off-by: Josh Poimboeuf Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Nick Desaulniers Acked-by: Marco Elver Tested-by: Nathan Chancellor Link: https://lore.kernel.org/r/20231017165946.v4i2d4exyqwqq3bx@treble Signed-off-by: Sasha Levin

Merge tag 'wq-for-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

2023-09-01T23:06:32+00:00

Pull workqueue updates from Tejun Heo: - Unbound workqueues now support more flexible affinity scopes. The default behavior is to soft-affine according to last level cache boundaries. A work item queued from a given LLC is executed by a worker running on the same LLC but the worker may be moved across cache boundaries as the scheduler sees fit. On machines which multiple L3 caches, which are becoming more popular along with chiplet designs, this improves cache locality while not harming work conservation too much. Unbound workqueues are now also a lot more flexible in terms of execution affinity. Differeing levels of affinity scopes are supported and both the default and per-workqueue affinity settings can be modified dynamically. This should help working around amny of sub-optimal behaviors observed recently with asymmetric ARM CPUs. This involved signficant restructuring of workqueue code. Nothing was reported yet but there's some risk of subtle regressions. Should keep an eye out. - Rescuer workers now has more identifiable comms. - workqueue.unbound_cpus added so that CPUs which can be used by workqueue can be constrained early during boot. - Now that all the in-tree users have been flushed out, trigger warning if system-wide workqueues are flushed. * tag 'wq-for-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (31 commits) workqueue: fix data race with the pwq->stats[] increment workqueue: Rename rescuer kworker workqueue: Make default affinity_scope dynamically updatable workqueue: Add "Affinity Scopes and Performance" section to documentation workqueue: Implement non-strict affinity scope for unbound workqueues workqueue: Add workqueue_attrs->__pod_cpumask workqueue: Factor out need_more_worker() check and worker wake-up workqueue: Factor out work to worker assignment and collision handling workqueue: Add multiple affinity scopes and interface to select them workqueue: Modularize wq_pod_type initialization workqueue: Add tools/workqueue/wq_dump.py which prints out workqueue configuration workqueue: Generalize unbound CPU pods workqueue: Factor out clearing of workqueue-only attrs fields workqueue: Factor out actual cpumask calculation to reduce subtlety in wq_update_pod() workqueue: Initialize unbound CPU pods later in the boot workqueue: Move wq_pod_init() below workqueue_init() workqueue: Rename NUMA related names to use pod instead workqueue: Rename workqueue_attrs->no_numa to ->ordered workqueue: Make unbound workqueues to use per-cpu pool_workqueues workqueue: Call wq_update_unbound_numa() on all CPUs in NUMA node on CPU hotplug ...

Merge tag 'mm-nonmm-stable-2023-08-28-22-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2023-08-29T21:53:51+00:00

Pull non-MM updates from Andrew Morton: - An extensive rework of kexec and crash Kconfig from Eric DeVolder ("refactor Kconfig to consolidate KEXEC and CRASH options") - kernel.h slimming work from Andy Shevchenko ("kernel.h: Split out a couple of macros to args.h") - gdb feature work from Kuan-Ying Lee ("Add GDB memory helper commands") - vsprintf inclusion rationalization from Andy Shevchenko ("lib/vsprintf: Rework header inclusions") - Switch the handling of kdump from a udev scheme to in-kernel handling, by Eric DeVolder ("crash: Kernel handling of CPU and memory hot un/plug") - Many singleton patches to various parts of the tree * tag 'mm-nonmm-stable-2023-08-28-22-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (81 commits) document while_each_thread(), change first_tid() to use for_each_thread() drivers/char/mem.c: shrink character device's devlist[] array x86/crash: optimize CPU changes crash: change crash_prepare_elf64_headers() to for_each_possible_cpu() crash: hotplug support for kexec_load() x86/crash: add x86 crash hotplug support crash: memory and CPU hotplug sysfs attributes kexec: exclude elfcorehdr from the segment digest crash: add generic infrastructure for crash hotplug support crash: move a few code bits to setup support of crash hotplug kstrtox: consistently use _tolower() kill do_each_thread() nilfs2: fix WARNING in mark_buffer_dirty due to discarded buffer reuse scripts/bloat-o-meter: count weak symbol sizes treewide: drop CONFIG_EMBEDDED lockdep: fix static memory detection even more lib/vsprintf: declare no_hash_pointers in sprintf.h lib/vsprintf: split out sprintf() and friends kernel/fork: stop playing lockless games for exe_file replacement adfs: delete unused "union adfs_dirtail" definition ...

Merge tag 'mm-stable-2023-08-28-18-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2023-08-29T21:25:26+00:00

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 ...

Merge tag 'sched-core-2023-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2023-08-28T23:43:39+00:00

Pull scheduler updates from Ingo Molnar: - The biggest change is introduction of a new iteration of the SCHED_FAIR interactivity code: the EEVDF ("Earliest Eligible Virtual Deadline First") scheduler EEVDF too is a virtual-time scheduler, with two parameters (weight and relative deadline), compared to CFS that had weight only. It completely reworks the base scheduler: placement, preemption, picking -- everything LWN.net, as usual, has a terrific writeup about EEVDF: https://lwn.net/Articles/925371/ Preemption (both tick and wakeup) is driven by testing against a fresh pick. Because the tree is now effectively an interval tree, and the selection is no longer the 'leftmost' task, over-scheduling is less of a problem. A lot of the CFS heuristics are removed or replaced by more natural latency-space parameters & constructs In terms of expected performance regressions: we will and can fix everything where a 'good' workload misbehaves with the new scheduler, but EEVDF inevitably changes workload scheduling in a binary fashion, hopefully for the better in the overwhelming majority of cases, but in some cases it won't, especially in adversarial loads that got lucky with the previous code, such as some variants of hackbench. We are trying hard to err on the side of fixing all performance regressions, but we expect some inevitable post-release iterations of that process - Improve load-balancing on hybrid x86 systems: enable cluster scheduling (again) - Improve & fix bandwidth-scheduling on nohz systems - Improve bandwidth-throttling - Use lock guards to simplify and de-goto-ify control flow - Misc improvements, cleanups and fixes * tag 'sched-core-2023-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits) sched/eevdf/doc: Modify the documented knob to base_slice_ns as well sched/eevdf: Curb wakeup-preemption sched: Simplify sched_core_cpu_{starting,deactivate}() sched: Simplify try_steal_cookie() sched: Simplify sched_tick_remote() sched: Simplify sched_exec() sched: Simplify ttwu() sched: Simplify wake_up_if_idle() sched: Simplify: migrate_swap_stop() sched: Simplify sysctl_sched_uclamp_handler() sched: Simplify get_nohz_timer_target() sched/rt: sysctl_sched_rr_timeslice show default timeslice after reset sched/rt: Fix sysctl_sched_rr_timeslice intial value sched/fair: Block nohz tick_stop when cfs bandwidth in use sched, cgroup: Restore meaning to hierarchical_quota MAINTAINERS: Add Peter explicitly to the psi section sched/psi: Select KERNFS as needed sched/topology: Align group flags when removing degenerate domain sched/fair: remove util_est boosting sched/fair: Propagate enqueue flags into place_entity() ...

treewide: drop CONFIG_EMBEDDED

2023-08-21T20:46:25+00:00

There is only one Kconfig user of CONFIG_EMBEDDED and it can be switched to EXPERT or "if !ARCH_MULTIPLATFORM" (suggested by Arnd). Link: https://lkml.kernel.org/r/20230816055010.31534-1-rdunlap@infradead.org Signed-off-by: Randy Dunlap Acked-by: Geert Uytterhoeven Acked-by: Arnd Bergmann Acked-by: Palmer Dabbelt [RISC-V] Acked-by: Greg Ungerer Acked-by: Jason A. Donenfeld Acked-by: Michael Ellerman [powerpc] Cc: Russell King Cc: Vineet Gupta Cc: Brian Cain Cc: Michal Simek Cc: Thomas Bogendoerfer Cc: Dinh Nguyen Cc: Jonas Bonn Cc: Stefan Kristiansson Cc: Stafford Horne Cc: Nicholas Piggin Cc: Christophe Leroy Cc: Paul Walmsley Cc: Albert Ou Cc: Yoshinori Sato Cc: Rich Felker Cc: John Paul Adrian Glaubitz Cc: Max Filippov Cc: Josh Triplett Cc: Masahiro Yamada Signed-off-by: Andrew Morton