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2025-02-11s390/bitops: Disable arch_test_bit() optimization for PROFILE_ALL_BRANCHESHeiko Carstens
With PROFILE_ALL_BRANCHES enabled gcc sometimes fails to handle __builtin_constant_p() correctly: In function 'arch_test_bit', inlined from 'node_state' at include/linux/nodemask.h:423:9, inlined from 'warn_if_node_offline' at include/linux/gfp.h:252:2, inlined from '__alloc_pages_node_noprof' at include/linux/gfp.h:267:2, inlined from 'alloc_pages_node_noprof' at include/linux/gfp.h:296:9, inlined from 'vm_area_alloc_pages.constprop' at mm/vmalloc.c:3591:11: >> arch/s390/include/asm/bitops.h:60:17: warning: 'asm' operand 2 probably does not match constraints 60 | asm volatile( | ^~~ >> arch/s390/include/asm/bitops.h:60:17: error: impossible constraint in 'asm' Therefore disable the optimization for this case. This is similar to commit 63678eecec57 ("s390/preempt: disable __preempt_count_add() optimization for PROFILE_ALL_BRANCHES") Fixes: b2bc1b1a77c0 ("s390/bitops: Provide optimized arch_test_bit()") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202502091912.xL2xTCGw-lkp@intel.com/ Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2025-02-05s390/net: Remove LCS driverAswin Karuvally
The original Open Systems Adapter (OSA) was introduced by IBM in the mid-90s. These were then superseded by OSA-Express in 1999 which used Queued Direct IO to greatly improve throughput. The newer cards retained the older, slower non-QDIO (OSE) modes for compatibility with older systems. In Linux, the lcs driver was responsible for cards operating in the older OSE mode and the qeth driver was introduced to allow the OSA-Express cards to operate in the newer QDIO (OSD) mode. For an S390 machine from 1998 or later, there is no reason to use the OSE mode and lcs driver as all OSA cards since 1999 provide the faster OSD mode. As a result, it's been years since we have heard of a customer configuration involving the lcs driver. This patch removes the lcs driver. The technology it supports has been obsolete for past 25+ years and is irrelevant for current use cases. Reviewed-by: Alexandra Winter <wintera@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com> Signed-off-by: Aswin Karuvally <aswin@linux.ibm.com> Signed-off-by: Alexandra Winter <wintera@linux.ibm.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20250204103135.1619097-1-wintera@linux.ibm.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-04Merge tag 'kvm-s390-next-6.14-2' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD - some selftest fixes - move some kvm-related functions from mm into kvm - remove all usage of page->index and page->lru from kvm - fixes and cleanups for vsie
2025-01-31KVM: s390: remove the last user of page->indexClaudio Imbrenda
Shadow page tables use page->index to keep the g2 address of the guest page table being shadowed. Instead of keeping the information in page->index, split the address and smear it over the 16-bit softbits areas of 4 PGSTEs. This removes the last s390 user of page->index. Reviewed-by: Steffen Eiden <seiden@linux.ibm.com> Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Link: https://lore.kernel.org/r/20250123144627.312456-16-imbrenda@linux.ibm.com Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20250123144627.312456-16-imbrenda@linux.ibm.com>
2025-01-31KVM: s390: move PGSTE softbitsClaudio Imbrenda
Move the softbits in the PGSTEs to the other usable area. This leaves the 16-bit block of usable bits free, which will be used in the next patch for something else. Reviewed-by: Steffen Eiden <seiden@linux.ibm.com> Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Link: https://lore.kernel.org/r/20250123144627.312456-15-imbrenda@linux.ibm.com Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20250123144627.312456-15-imbrenda@linux.ibm.com>
2025-01-31KVM: s390: move gmap_shadow_pgt_lookup() into kvmClaudio Imbrenda
Move gmap_shadow_pgt_lookup() from mm/gmap.c into kvm/gaccess.c . Reviewed-by: Steffen Eiden <seiden@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Link: https://lore.kernel.org/r/20250123144627.312456-13-imbrenda@linux.ibm.com Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20250123144627.312456-13-imbrenda@linux.ibm.com>
2025-01-31KVM: s390: stop using lists to keep track of used dat tablesClaudio Imbrenda
Until now, every dat table allocated to map a guest was put in a linked list. The page->lru field of struct page was used to keep track of which pages were being used, and when the gmap is torn down, the list was walked and all pages freed. This patch gets rid of the usage of page->lru. Page tables are now freed by recursively walking the dat table tree. Since s390_unlist_old_asce() becomes useless now, remove it. Acked-by: Steffen Eiden <seiden@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Link: https://lore.kernel.org/r/20250123144627.312456-12-imbrenda@linux.ibm.com Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20250123144627.312456-12-imbrenda@linux.ibm.com>
2025-01-31KVM: s390: move some gmap shadowing functions away from mm/gmap.cClaudio Imbrenda
Move some gmap shadowing functions from mm/gmap.c to kvm/kvm-s390.c and the newly created kvm/gmap-vsie.c This is a step toward removing gmap from mm. Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Link: https://lore.kernel.org/r/20250123144627.312456-10-imbrenda@linux.ibm.com Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20250123144627.312456-10-imbrenda@linux.ibm.com>
2025-01-31KVM: s390: get rid of gmap_translate()Claudio Imbrenda
Add gpa_to_hva(), which uses memslots, and use it to replace all uses of gmap_translate(). Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Link: https://lore.kernel.org/r/20250123144627.312456-9-imbrenda@linux.ibm.com Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20250123144627.312456-9-imbrenda@linux.ibm.com>
2025-01-31KVM: s390: get rid of gmap_fault()Claudio Imbrenda
All gmap page faults are already handled in kvm by the function kvm_s390_handle_dat_fault(); only few users of gmap_fault remained, all within kvm. Convert those calls to use kvm_s390_handle_dat_fault() instead. Remove gmap_fault() entirely since it has no more users. Acked-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Link: https://lore.kernel.org/r/20250123144627.312456-8-imbrenda@linux.ibm.com Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20250123144627.312456-8-imbrenda@linux.ibm.com>
2025-01-31KVM: s390: move pv gmap functions into kvmClaudio Imbrenda
Move gmap related functions from kernel/uv into kvm. Create a new file to collect gmap-related functions. Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> [fixed unpack_one(), thanks mhartmay@linux.ibm.com] Link: https://lore.kernel.org/r/20250123144627.312456-6-imbrenda@linux.ibm.com Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20250123144627.312456-6-imbrenda@linux.ibm.com>
2025-01-31KVM: s390: fake memslot for ucontrol VMsClaudio Imbrenda
Create a fake memslot for ucontrol VMs. The fake memslot identity-maps userspace. Now memslots will always be present, and ucontrol is not a special case anymore. Suggested-by: Sean Christopherson <seanjc@google.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20250123144627.312456-4-imbrenda@linux.ibm.com Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20250123144627.312456-4-imbrenda@linux.ibm.com>
2025-01-31KVM: s390: vsie: stop using "struct page" for vsie pageDavid Hildenbrand
Now that we no longer use page->index and the page refcount explicitly, let's avoid messing with "struct page" completely. Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Tested-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Message-ID: <20250107154344.1003072-5-david@redhat.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
2025-01-30Merge tag 's390-6.14-3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 fixes from Alexander Gordeev: - Architecutre-specific ftrace recursion trylock tests were removed in favour of the generic function_graph_enter(), but s390 got missed. Remove this test for s390 as well. - Add ftrace_get_symaddr() for s390, which returns the symbol address from ftrace 'ip' parameter * tag 's390-6.14-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/tracing: Define ftrace_get_symaddr() for s390 s390/fgraph: Fix to remove ftrace_test_recursion_trylock()
2025-01-30Merge tag 's390-6.14-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull more s390 updates from Alexander Gordeev: - The rework that uncoupled physical and virtual address spaces inadvertently prevented KASAN shadow mappings from using large pages. Restore large page mappings for KASAN shadows - Add decompressor routine physmem_alloc() that may fail, unlike physmem_alloc_or_die(). This allows callers to implement fallback paths - Allow falling back from large pages to smaller pages (1MB or 4KB) if the allocation of 2GB pages in the decompressor can not be fulfilled - Add to the decompressor boot print support of "%%" format string, width and padding hadnling, length modifiers and decimal conversion specifiers - Add to the decompressor message severity levels similar to kernel ones. Support command-line options that control console output verbosity - Replaces boot_printk() calls with appropriate loglevel- specific helpers such as boot_emerg(), boot_warn(), and boot_debug(). - Collect all boot messages into a ring buffer independent of the current log level. This is particularly useful for early crash analysis - If 'earlyprintk' command line parameter is not specified, store decompressor boot messages in a ring buffer to be printed later by the kernel, once the console driver is registered - Add 'bootdebug' command line parameter to enable printing of decompressor debug messages when needed. That parameters allows message suppressing and filtering - Dump boot messages on a decompressor crash, but only if 'bootdebug' command line parameter is enabled - When CONFIG_PRINTK_TIME is enabled, add timestamps to boot messages in the same format as regular printk() - Dump physical memory tracking information on boot: online ranges, reserved areas and vmem allocations - Dump virtual memory layout and randomization details - Improve decompression error reporting and dump the message ring buffer in case the boot failed and system halted - Add an exception handler which handles exceptions when FPU control register is attempted to be set to an invalid value. Remove '.fixup' section as result of this change - Use 'A', 'O', and 'R' inline assembly format flags, which allows recent Clang compilers to generate better FPU code - Rework uaccess code so it reads better and generates more efficient code - Cleanup futex inline assembly code - Disable KMSAN instrumention for futex inline assemblies, which contain dereferenced user pointers. Otherwise, shadows for the user pointers would be accessed - PFs which are not initially configured but in standby create only a single-function PCI domain. If they are configured later on, sibling PFs and their child VFs will not be added to their PCI domain breaking SR-IOV expectations. Fix that by allowing initially configured but in standby PFs create multi-function PCI domains - Add '-std=gnu11' to decompressor and purgatory CFLAGS to avoid compile errors caused by kernel's own definitions of 'bool', 'false', and 'true' conflicting with the C23 reserved keywords - Fix sclp subsystem failure when a sclp console is not present - Fix misuse of non-NULL terminated strings in vmlogrdr driver - Various other small improvements, cleanups and fixes * tag 's390-6.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (53 commits) s390/vmlogrdr: Use array instead of string initializer s390/vmlogrdr: Use internal_name for error messages s390/sclp: Initialize sclp subsystem via arch_cpu_finalize_init() s390/tools: Use array instead of string initializer s390/vmem: Fix null-pointer-arithmetic warning in vmem_map_init() s390: Add '-std=gnu11' to decompressor and purgatory CFLAGS s390/bitops: Use correct constraint for arch_test_bit() inline assembly s390/pci: Fix SR-IOV for PFs initially in standby s390/futex: Avoid KMSAN instrumention for user pointers s390/uaccess: Rename get_put_user_noinstr_attributes to uaccess_kmsan_or_inline s390/futex: Cleanup futex_atomic_cmpxchg_inatomic() s390/futex: Generate futex atomic op functions s390/uaccess: Remove INLINE_COPY_FROM_USER and INLINE_COPY_TO_USER s390/uaccess: Use asm goto for put_user()/get_user() s390/uaccess: Remove usage of the oac specifier s390/uaccess: Replace EX_TABLE_UA_LOAD_MEM exception handling s390/uaccess: Cleanup noinstr __put_user()/__get_user() inline assembly constraints s390/uaccess: Remove __put_user_fn()/__get_user_fn() wrappers s390/uaccess: Move put_user() / __put_user() close to put_user() asm code s390/uaccess: Use asm goto for __mvc_kernel_nofault() ...
2025-01-29s390/tracing: Define ftrace_get_symaddr() for s390Masami Hiramatsu (Google)
Add ftrace_get_symaddr() for s390, which returns the symbol address from ftrace's 'ip' parameter. Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/173807818869.1854334.15474589105952793986.stgit@devnote2 Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-28s390/sclp: Initialize sclp subsystem via arch_cpu_finalize_init()Heiko Carstens
With the switch to GENERIC_CPU_DEVICES an early call to the sclp subsystem was added to smp_prepare_cpus(). This will usually succeed since the sclp subsystem is implicitly initialized early enough if an sclp based console is present. If no such console is present the initialization happens with an arch_initcall(); in such cases calls to the sclp subsystem will fail. For CPU detection this means that the fallback sigp loop will be used permanently to detect CPUs instead of the preferred READ_CPU_INFO sclp request. Fix this by adding an explicit early sclp_init() call via arch_cpu_finalize_init(). Reported-by: Sheshu Ramanandan <sheshu.ramanandan@ibm.com> Fixes: 4a39f12e753d ("s390/smp: Switch to GENERIC_CPU_DEVICES") Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26Merge tag 'mm-stable-2025-01-26-14-59' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "The various patchsets are summarized below. Plus of course many indivudual patches which are described in their changelogs. - "Allocate and free frozen pages" from Matthew Wilcox reorganizes the page allocator so we end up with the ability to allocate and free zero-refcount pages. So that callers (ie, slab) can avoid a refcount inc & dec - "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to use large folios other than PMD-sized ones - "Fix mm/rodata_test" from Petr Tesarik performs some maintenance and fixes for this small built-in kernel selftest - "mas_anode_descend() related cleanup" from Wei Yang tidies up part of the mapletree code - "mm: fix format issues and param types" from Keren Sun implements a few minor code cleanups - "simplify split calculation" from Wei Yang provides a few fixes and a test for the mapletree code - "mm/vma: make more mmap logic userland testable" from Lorenzo Stoakes continues the work of moving vma-related code into the (relatively) new mm/vma.c - "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David Hildenbrand cleans up and rationalizes handling of gfp flags in the page allocator - "readahead: Reintroduce fix for improper RA window sizing" from Jan Kara is a second attempt at fixing a readahead window sizing issue. It should reduce the amount of unnecessary reading - "synchronously scan and reclaim empty user PTE pages" from Qi Zheng addresses an issue where "huge" amounts of pte pagetables are accumulated: https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/ Qi's series addresses this windup by synchronously freeing PTE memory within the context of madvise(MADV_DONTNEED) - "selftest/mm: Remove warnings found by adding compiler flags" from Muhammad Usama Anjum fixes some build warnings in the selftests code when optional compiler warnings are enabled - "mm: don't use __GFP_HARDWALL when migrating remote pages" from David Hildenbrand tightens the allocator's observance of __GFP_HARDWALL - "pkeys kselftests improvements" from Kevin Brodsky implements various fixes and cleanups in the MM selftests code, mainly pertaining to the pkeys tests - "mm/damon: add sample modules" from SeongJae Park enhances DAMON to estimate application working set size - "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn provides some cleanups to memcg's hugetlb charging logic - "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song removes the global swap cgroup lock. A speedup of 10% for a tmpfs-based kernel build was demonstrated - "zram: split page type read/write handling" from Sergey Senozhatsky has several fixes and cleaups for zram in the area of zram_write_page(). A watchdog softlockup warning was eliminated - "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin Brodsky cleans up the pagetable destructor implementations. A rare use-after-free race is fixed - "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes simplifies and cleans up the debugging code in the VMA merging logic - "Account page tables at all levels" from Kevin Brodsky cleans up and regularizes the pagetable ctor/dtor handling. This results in improvements in accounting accuracy - "mm/damon: replace most damon_callback usages in sysfs with new core functions" from SeongJae Park cleans up and generalizes DAMON's sysfs file interface logic - "mm/damon: enable page level properties based monitoring" from SeongJae Park increases the amount of information which is presented in response to DAMOS actions - "mm/damon: remove DAMON debugfs interface" from SeongJae Park removes DAMON's long-deprecated debugfs interfaces. Thus the migration to sysfs is completed - "mm/hugetlb: Refactor hugetlb allocation resv accounting" from Peter Xu cleans up and generalizes the hugetlb reservation accounting - "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino removes a never-used feature of the alloc_pages_bulk() interface - "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park extends DAMOS filters to support not only exclusion (rejecting), but also inclusion (allowing) behavior - "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi introduces a new memory descriptor for zswap.zpool that currently overlaps with struct page for now. This is part of the effort to reduce the size of struct page and to enable dynamic allocation of memory descriptors - "mm, swap: rework of swap allocator locks" from Kairui Song redoes and simplifies the swap allocator locking. A speedup of 400% was demonstrated for one workload. As was a 35% reduction for kernel build time with swap-on-zram - "mm: update mips to use do_mmap(), make mmap_region() internal" from Lorenzo Stoakes reworks MIPS's use of mmap_region() so that mmap_region() can be made MM-internal - "mm/mglru: performance optimizations" from Yu Zhao fixes a few MGLRU regressions and otherwise improves MGLRU performance - "Docs/mm/damon: add tuning guide and misc updates" from SeongJae Park updates DAMON documentation - "Cleanup for memfd_create()" from Isaac Manjarres does that thing - "mm: hugetlb+THP folio and migration cleanups" from David Hildenbrand provides various cleanups in the areas of hugetlb folios, THP folios and migration - "Uncached buffered IO" from Jens Axboe implements the new RWF_DONTCACHE flag which provides synchronous dropbehind for pagecache reading and writing. To permite userspace to address issues with massive buildup of useless pagecache when reading/writing fast devices - "selftests/mm: virtual_address_range: Reduce memory" from Thomas Weißschuh fixes and optimizes some of the MM selftests" * tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits) mm/compaction: fix UBSAN shift-out-of-bounds warning s390/mm: add missing ctor/dtor on page table upgrade kasan: sw_tags: use str_on_off() helper in kasan_init_sw_tags() tools: add VM_WARN_ON_VMG definition mm/damon/core: use str_high_low() helper in damos_wmark_wait_us() seqlock: add missing parameter documentation for raw_seqcount_try_begin() mm/page-writeback: consolidate wb_thresh bumping logic into __wb_calc_thresh mm/page_alloc: remove the incorrect and misleading comment zram: remove zcomp_stream_put() from write_incompressible_page() mm: separate move/undo parts from migrate_pages_batch() mm/kfence: use str_write_read() helper in get_access_type() selftests/mm/mkdirty: fix memory leak in test_uffdio_copy() kasan: hw_tags: Use str_on_off() helper in kasan_init_hw_tags() selftests/mm: virtual_address_range: avoid reading from VM_IO mappings selftests/mm: vm_util: split up /proc/self/smaps parsing selftests/mm: virtual_address_range: unmap chunks after validation selftests/mm: virtual_address_range: mmap() without PROT_WRITE selftests/memfd/memfd_test: fix possible NULL pointer dereference mm: add FGP_DONTCACHE folio creation flag mm: call filemap_fdatawrite_range_kick() after IOCB_DONTCACHE issue ...
2025-01-26s390/bitops: Use correct constraint for arch_test_bit() inline assemblyHeiko Carstens
Use the "Q" instead of "R" constraint to correctly reflect the instruction format of the tm instruction: the first operand is a memory reference without index register and short displacement. The "R" constraint indicates a memory reference with index register instead. This may lead to compile errors like: arch/s390/include/asm/bitops.h: Assembler messages: arch/s390/include/asm/bitops.h:60: Error: operand 1: syntax error; missing ')' after base register arch/s390/include/asm/bitops.h:60: Error: operand 2: syntax error; ')' not allowed here arch/s390/include/asm/bitops.h:60: Error: junk at end of line: `,4' Reported-by: Nathan Chancellor <nathan@kernel.org> Closes: https://lore.kernel.org/r/20250122-s390-fix-std-for-gcc-15-v1-1-8b00cadee083@kernel.org Fixes: b2bc1b1a77c0 ("s390/bitops: Provide optimized arch_test_bit()") Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390/futex: Avoid KMSAN instrumention for user pointersHeiko Carstens
Similar to commit eb6efdfeaeca ("s390/uaccess: add KMSAN support to put_user() and get_user()") disable KMSAN instrumention for futex inline assemblies, which contain dereferenced user pointers. With KMSAN instrumentation this would lead to accesses of shadows for user pointers, which should not happen. Handle the futex operations like they copy a value (old) from user space to kernel space. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390/uaccess: Rename get_put_user_noinstr_attributes to uaccess_kmsan_or_inlineHeiko Carstens
Rename get_put_user_noinstr_attributes to a more generic uaccess_kmsan_or_inline name. This allows to use it for other non put_user()/get_user() uaccess functions withour causing confusion. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390/futex: Cleanup futex_atomic_cmpxchg_inatomic()Heiko Carstens
Cleanup the futex_atomic_cmpxchg_inatomic() inline assembly to make it a bit more readable. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390/futex: Generate futex atomic op functionsHeiko Carstens
Cleanup the futex atomic op inline assembly and generate a function for each futex atomic op. This makes the code hopefully a bit more readable. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390/uaccess: Remove INLINE_COPY_FROM_USER and INLINE_COPY_TO_USERHeiko Carstens
The s390 implementations of raw_copy_from_user() and raw_copy_to_user() are never inlined. However INLINE_COPY_FROM_USER and INLINE_COPY_TO_USER are still set. This leads to the odd situation that only the error handling (memset to zero of the not copied bytes) of copy_from_user() is inlined, while the actual fast path code is out-of-line. This would make sense if raw_copy_from_user() and raw_copy_to_user() were implemented in assembler files, where inlining is not possible. But the current s390 setup does not make any sense. Address this by moving the raw uaccess copy inline assemblies to the uaccess header file, and remove INLINE_COPY_FROM_USER and INLINE_COPY_TO_USER definitions. This way the uaccess code, but now including error handling, is still out-of-line with the common code _copy_from_user() and _copy_to_user() variants, which inline the raw uaccess functions via _inline_copy_from_user() and _inline_copy_to_user(). This reduces the size of the kernel image by ~17kb. (defconfig, gcc 14.2.0) Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390/uaccess: Use asm goto for put_user()/get_user()Heiko Carstens
Use asm goto if available for put_user() and get_user(). This generates slightly better code. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390/uaccess: Remove usage of the oac specifierHeiko Carstens
Remove usage of the operand access control specifier for put_user() and get_user() (again). Instead hardcode the specifier for both inline assemblies. This saves one instruction. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390/uaccess: Replace EX_TABLE_UA_LOAD_MEM exception handlingHeiko Carstens
Remove EX_TABLE_UA_LOAD_MEM exception handling and replace it with EX_TABLE_UA_FAULT. Open code the return code check, and also open code setting of the destination to zero in case of an error. In almost all cases the compiler is able to optimize the open coded checks away, since all users of get_users() must check the return code, and are not supposed to use the result in case of an error. In addition this allows to change the get_user() inline assembly so that the "Q" constraint can be used for the destination, instead of only an "a" constraint. This generates slightly better code. Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390/uaccess: Cleanup noinstr __put_user()/__get_user() inline assembly ↵Heiko Carstens
constraints Remove superfluous underscores, brackets, and early clobber to make the code a bit more readable. Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390/uaccess: Remove __put_user_fn()/__get_user_fn() wrappersHeiko Carstens
The __put_user_fn() and __get_user_fn() wrappers are leftovers from the time where the kernel was compiled with or without mvcos support plus they were later used to workaround the problems that came with asm register constructs. Both reasons do not exist anymore, therefore remove the wrappers and shorten the code. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390/uaccess: Move put_user() / __put_user() close to put_user() asm codeHeiko Carstens
Keep put_user() and get_user() code separated. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390/uaccess: Use asm goto for __mvc_kernel_nofault()Heiko Carstens
Use asm goto for __mvc_kernel_nofault() if available. This generates slightly better code, since the error checking happens implicitly with the goto (aka exception) and the good path comes without any checks and branches. Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390/uaccess: Implement __get_kernel_nofault()/__put_kernel_nofault() with mvcHeiko Carstens
Use the mvc instruction in order to implement __get_kernel_nofault() and __put_kernel_nofault(). Both functions have a source and destination address where the code is supposed to read from and write to. Use the mvc instruction to copy from source to destination instead of lg/stg like instructions. This generates slightly better code. Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390/extable: Rename EX_TABLE_UA_STORE to EX_TABLE_UA_FAULTHeiko Carstens
Rename EX_TABLE_UA_STORE to a more generic EX_TABLE_UA_FAULT name. This allows to use the extable type also for uaccess inline assemblies which read from userspace, without causing confusion. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390/fpu: Use CONFIG_CC_HAS_ASM_AOR_FORMAT_FLAGS instead of CONFIG_CC_IS_CLANGHeiko Carstens
Use the more precise CONFIG_CC_HAS_ASM_AOR_FORMAT_FLAGS to tell if the compiler has support for the A, O, and R inline assembly format flags. This allows recent Clang compilers to generate better code. Move code around so the good (aka better) case at the top of each ifdef construct. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390: Rename GCC_ASM_FLAG_OUTPUT_BROKEN to CC_ASM_FLAG_OUTPUT_BROKENHeiko Carstens
Config options which can be used to check for compiler bugs and features have the compiler independent CC prefix in order to avoid duplicating and having to check config options for multiple compilers. Therefore rename the config option accordingly. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390/fpu: Add fpc exception handler / remove fixup section againHeiko Carstens
The fixup section was added again by mistake when test_fp_ctl() was removed. The reason for the removal of the fixup section is described in commit 484a8ed8b7d1 ("s390/extable: add dedicated uaccess handler"). Remove it again for the same reason. Add an exception handler which handles exceptions when the floating point control register is attempted to be set to invalid values. The exception handler sets the floating point control register to zero and continues execution at the specified address. The new sfpc inline assembly is open-coded to make back porting a bit easier. Fixes: 702644249d3e ("s390/fpu: get rid of test_fp_ctl()") Cc: stable@vger.kernel.org Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390: Optimize __pa/__va when RANDOMIZE_IDENTITY_BASE is offVasily Gorbik
Use a zero identity base when CONFIG_RANDOMIZE_IDENTITY_BASE is off, slightly optimizing __pa/__va calculations. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390/boot: Add physmem tracking debug supportVasily Gorbik
Introduce boot_debug() calls to track memory detection, online ranges, reserved areas, and allocations (except for VMEM allocations, which are too frequent). Instead introduce dump_physmem_reserved() function which prints out full memory tracking information. This helps in debugging early boot memory handling. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390/boot: Add timestamps to early boot messagesVasily Gorbik
When CONFIG_PRINTK_TIME is enabled, add timestamps to boot messages in the same format as regular printk. Timestamps appear only with earlyprintk and are stored in the boot messages ring buffer, but are not propagated to main kernel messages (if earlyprintk is not enabled). This prevents double timestamps in the output. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390/boot: Add prefix filtering to bootdebug messagesVasily Gorbik
Enhance boot debugging by allowing the "bootdebug" kernel parameter to accept an optional comma-separated list of prefixes. Only debug messages starting with these prefixes will be printed during boot. For example: bootdebug=startup,vmem Not specifying a filter for the "bootdebug" parameter prints all debug messages. The `boot_fmt` macro can be defined to set a common prefix: #define boot_fmt(fmt) "startup: " fmt Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390/boot: Add bootdebug option to control debug messagesVasily Gorbik
Suppress decompressor debug messages by default, similar to regular kernel debug messages that require 'DEBUG' or 'dyndbg' to be enabled (depending on CONFIG_DYNAMIC_DEBUG). Introduce a 'bootdebug' option to enable printing these messages when needed. All messages are still stored in the boot ring buffer regardless. To enable boot debug messages: bootdebug debug Or combine with 'earlyprintk' to print them without delay: bootdebug debug earlyprintk Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390/boot: Defer boot messages when earlyprintk is not enabledVasily Gorbik
When earlyprintk is not specified, boot messages are only stored in a ring buffer to be printed later by printk when console driver is registered. Critical messages from boot_emerg() are always printed immediately, even without earlyprintk. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390/boot: Introduce ring buffer for boot messagesVasily Gorbik
Collect all boot messages into a ring buffer independent of the current log level. This allows to retain all boot-time messages, which is particularly useful for analyzing early crashes. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-25mm: introduce ctor/dtor at PGD levelKevin Brodsky
Following on from the introduction of P4D-level ctor/dtor, let's finish the job and introduce ctor/dtor at PGD level. The incurred improvement in page accounting is minimal - the main motivation is to create a single, generic place where construction/destruction hooks can be added for all page table pages. This patch should cover all architectures and all configurations where PGDs are one or more regular pages. This excludes any configuration where PGDs are allocated from a kmem_cache object. Link: https://lkml.kernel.org/r/20250103184415.2744423-7-kevin.brodsky@arm.com Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25mm: pgtable: introduce generic __tlb_remove_table()Qi Zheng
Several architectures (arm, arm64, riscv and x86) define exactly the same __tlb_remove_table(), just introduce generic __tlb_remove_table() to eliminate these duplications. The s390 __tlb_remove_table() is nearly the same, so also make s390 __tlb_remove_table() version generic. Link: https://lkml.kernel.org/r/ea372633d94f4d3f9f56a7ec5994bf050bf77e39.1736317725.git.zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com> Acked-by: Andreas Larsson <andreas@gaisler.com> [sparc] Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> [s390] Acked-by: Arnd Bergmann <arnd@arndb.de> [asm-generic] Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25s390: pgtable: consolidate PxD and PTE TLB free pathsQi Zheng
Call pagetable_dtor() for PMD|PUD|P4D tables just before ptdesc is freed - same as it is done for PTE tables. That allows consolidating TLB free paths for all table types. Link: https://lkml.kernel.org/r/ac69360a5f3350ebb2f63cd14b7b45316a130ee4.1736317725.git.zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25mm: pgtable: introduce pagetable_dtor()Qi Zheng
The pagetable_p*_dtor() are exactly the same except for the handling of ptlock. If we make ptlock_free() handle the case where ptdesc->ptl is NULL and remove VM_BUG_ON_PAGE() from pmd_ptlock_free(), we can unify pagetable_p*_dtor() into one function. Let's introduce pagetable_dtor() to do this. Later, pagetable_dtor() will be moved to tlb_remove_ptdesc(), so that ptlock and page table pages can be freed together (regardless of whether RCU is used). This prevents the use-after-free problem where the ptlock is freed immediately but the page table pages is freed later via RCU. Link: https://lkml.kernel.org/r/47f44fff9dc68d9d9e9a0d6c036df275f820598a.1736317725.git.zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Originally-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> [s390] Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25s390: pgtable: add statistics for PUD and P4D level page tableQi Zheng
Like PMD and PTE level page table, also add statistics for PUD and P4D page table. Link: https://lkml.kernel.org/r/4707dffce228ccec5c6662810566dd12b5741c4b.1736317725.git.zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-21Merge tag 'ftrace-v6.14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull ftrace updates from Steven Rostedt: - Have fprobes built on top of function graph infrastructure The fprobe logic is an optimized kprobe that uses ftrace to attach to functions when a probe is needed at the start or end of the function. The fprobe and kretprobe logic implements a similar method as the function graph tracer to trace the end of the function. That is to hijack the return address and jump to a trampoline to do the trace when the function exits. To do this, a shadow stack needs to be created to store the original return address. Fprobes and function graph do this slightly differently. Fprobes (and kretprobes) has slots per callsite that are reserved to save the return address. This is fine when just a few points are traced. But users of fprobes, such as BPF programs, are starting to add many more locations, and this method does not scale. The function graph tracer was created to trace all functions in the kernel. In order to do this, when function graph tracing is started, every task gets its own shadow stack to hold the return address that is going to be traced. The function graph tracer has been updated to allow multiple users to use its infrastructure. Now have fprobes be one of those users. This will also allow for the fprobe and kretprobe methods to trace the return address to become obsolete. With new technologies like CFI that need to know about these methods of hijacking the return address, going toward a solution that has only one method of doing this will make the kernel less complex. - Cleanup with guard() and free() helpers There were several places in the code that had a lot of "goto out" in the error paths to either unlock a lock or free some memory that was allocated. But this is error prone. Convert the code over to use the guard() and free() helpers that let the compiler unlock locks or free memory when the function exits. - Remove disabling of interrupts in the function graph tracer When function graph tracer was first introduced, it could race with interrupts and NMIs. To prevent that race, it would disable interrupts and not trace NMIs. But the code has changed to allow NMIs and also interrupts. This change was done a long time ago, but the disabling of interrupts was never removed. Remove the disabling of interrupts in the function graph tracer is it is not needed. This greatly improves its performance. - Allow the :mod: command to enable tracing module functions on the kernel command line. The function tracer already has a way to enable functions to be traced in modules by writing ":mod:<module>" into set_ftrace_filter. That will enable either all the functions for the module if it is loaded, or if it is not, it will cache that command, and when the module is loaded that matches <module>, its functions will be enabled. This also allows init functions to be traced. But currently events do not have that feature. Because enabling function tracing can be done very early at boot up (before scheduling is enabled), the commands that can be done when function tracing is started is limited. Having the ":mod:" command to trace module functions as they are loaded is very useful. Update the kernel command line function filtering to allow it. * tag 'ftrace-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (26 commits) ftrace: Implement :mod: cache filtering on kernel command line tracing: Adopt __free() and guard() for trace_fprobe.c bpf: Use ftrace_get_symaddr() for kprobe_multi probes ftrace: Add ftrace_get_symaddr to convert fentry_ip to symaddr Documentation: probes: Update fprobe on function-graph tracer selftests/ftrace: Add a test case for repeating register/unregister fprobe selftests: ftrace: Remove obsolate maxactive syntax check tracing/fprobe: Remove nr_maxactive from fprobe fprobe: Add fprobe_header encoding feature fprobe: Rewrite fprobe on function-graph tracer s390/tracing: Enable HAVE_FTRACE_GRAPH_FUNC ftrace: Add CONFIG_HAVE_FTRACE_GRAPH_FUNC bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS tracing: Add ftrace_fill_perf_regs() for perf event tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs fprobe: Use ftrace_regs in fprobe exit handler fprobe: Use ftrace_regs in fprobe entry handler fgraph: Pass ftrace_regs to retfunc fgraph: Replace fgraph_ret_regs with ftrace_regs ...
2025-01-15s390/futex: Fix FUTEX_OP_ANDN implementationHeiko Carstens
The futex operation FUTEX_OP_ANDN is supposed to implement *(int *)UADDR2 &= ~OPARG; The s390 implementation just implements an AND instead of ANDN. Add the missing bitwise not operation to oparg to fix this. This is broken since nearly 19 years, so it looks like user space is not making use of this operation. Fixes: 3363fbdd6fb4 ("[PATCH] s390: futex atomic operations") Cc: stable@vger.kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
generated by cgit (git 2.34.1) at 2025-07-15 21:34:20 +0000