kernel.git/arch/s390/include, branch linux-6.10.y

s390/ftrace: Avoid calling unwinder in ftrace_return_address()

2024-10-04T14:33:47Z

commit a84dd0d8ae24bdc6da341187fc4c1a0adfce2ccc upstream. ftrace_return_address() is called extremely often from performance-critical code paths when debugging features like CONFIG_TRACE_IRQFLAGS are enabled. For example, with debug_defconfig, ftrace selftests on my LPAR currently execute ftrace_return_address() as follows: ftrace_return_address(0) - 0 times (common code uses __builtin_return_address(0) instead) ftrace_return_address(1) - 2,986,805,401 times (with this patch applied) ftrace_return_address(2) - 140 times ftrace_return_address(>2) - 0 times The use of __builtin_return_address(n) was replaced by return_address() with an unwinder call by commit cae74ba8c295 ("s390/ftrace: Use unwinder instead of __builtin_return_address()") because __builtin_return_address(n) simply walks the stack backchain and doesn't check for reaching the stack top. For shallow stacks with fewer than "n" frames, this results in reads at low addresses and random memory accesses. While calling the fully functional unwinder "works", it is very slow for this purpose. Moreover, potentially following stack switches and walking past IRQ context is simply wrong thing to do for ftrace_return_address(). Reimplement return_address() to essentially be __builtin_return_address(n) with checks for reaching the stack top. Since the ftrace_return_address(n) argument is always a constant, keep the implementation in the header, allowing both GCC and Clang to unroll the loop and optimize it to the bare minimum. Fixes: cae74ba8c295 ("s390/ftrace: Use unwinder instead of __builtin_return_address()") Cc: stable@vger.kernel.org Reported-by: Sumanth Korikkar Reviewed-by: Heiko Carstens Acked-by: Sumanth Korikkar Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

s390/boot: Fix KASLR base offset off by __START_KERNEL bytes

2024-08-29T15:36:06Z

[ Upstream commit 1642285e511c2a40b14e87a41aa8feace6123036 ] Symbol offsets to the KASLR base do not match symbol address in the vmlinux image. That is the result of setting the KASLR base to the beginning of .text section as result of an optimization. Revert that optimization and allocate virtual memory for the whole kernel image including __START_KERNEL bytes as per the linker script. That allows keeping the semantics of the KASLR base offset in sync with other architectures. Rename __START_KERNEL to TEXT_OFFSET, since it represents the offset of the .text section within the kernel image, rather than a virtual address. Still skip mapping TEXT_OFFSET bytes to save memory on pgtables and provoke exceptions in case an attempt to access this area is made, as no kernel symbol may reside there. In case CONFIG_KASAN is enabled the location counter might exceed the value of TEXT_OFFSET, while the decompressor linker script forcefully resets it to TEXT_OFFSET, which leads to a sections overlap link failure. Use MAX() expression to avoid that. Reported-by: Omar Sandoval Closes: https://lore.kernel.org/linux-s390/ZnS8dycxhtXBZVky@telecaster.dhcp.thefacebook.com/ Fixes: 56b1069c40c7 ("s390/boot: Rework deployment of the kernel image") Signed-off-by: Alexander Gordeev Acked-by: Vasily Gorbik Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin

s390/uv: Panic for set and remove shared access UVC errors

2024-08-29T15:35:44Z

[ Upstream commit cff59d8631e1409ffdd22d9d717e15810181b32c ] The return value uv_set_shared() and uv_remove_shared() (which are wrappers around the share() function) is not always checked. The system integrity of a protected guest depends on the Share and Unshare UVCs being successful. This means that any caller that fails to check the return value will compromise the security of the protected guest. No code path that would lead to such violation of the security guarantees is currently exercised, since all the areas that are shared never get unshared during the lifetime of the system. This might change and become an issue in the future. The Share and Unshare UVCs can only fail in case of hypervisor misbehaviour (either a bug or malicious behaviour). In such cases there is no reasonable way forward, and the system needs to panic. This patch replaces the return at the end of the share() function with a panic, to guarantee system integrity. Fixes: 5abb9351dfd9 ("s390/uv: introduce guest side ultravisor code") Signed-off-by: Claudio Imbrenda Reviewed-by: Christian Borntraeger Reviewed-by: Steffen Eiden Reviewed-by: Janosch Frank Link: https://lore.kernel.org/r/20240801112548.85303-1-imbrenda@linux.ibm.com Message-ID: <20240801112548.85303-1-imbrenda@linux.ibm.com> [frankja@linux.ibm.com: Fixed up patch subject] Signed-off-by: Janosch Frank Signed-off-by: Sasha Levin

Merge tag 'kvm-s390-master-6.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

2024-07-05T08:45:53Z

KVM: s390: Fix z16 support The z16 support might fail with the lpswey instruction. Provide a handler.

KVM: s390: fix LPSWEY handling

2024-07-01T12:31:15Z

in rare cases, e.g. for injecting a machine check we do intercept all load PSW instructions via ICTL_LPSW. With facility 193 a new variant LPSWEY was added. KVM needs to handle that as well. Fixes: a3efa8429266 ("KVM: s390: gen_facilities: allow facilities 165, 193, 194 and 196") Reported-by: Marc Hartmayer Reviewed-by: Sven Schnelle Reviewed-by: Claudio Imbrenda Signed-off-by: Christian Borntraeger Message-ID: <20240628163547.2314-1-borntraeger@linux.ibm.com>

randomize_kstack: Remove non-functional per-arch entropy filtering

2024-06-28T15:54:56Z

An unintended consequence of commit 9c573cd31343 ("randomize_kstack: Improve entropy diffusion") was that the per-architecture entropy size filtering reduced how many bits were being added to the mix, rather than how many bits were being used during the offsetting. All architectures fell back to the existing default of 0x3FF (10 bits), which will consume at most 1KiB of stack space. It seems that this is working just fine, so let's avoid the confusion and update everything to use the default. The prior intent of the per-architecture limits were: arm64: capped at 0x1FF (9 bits), 5 bits effective powerpc: uncapped (10 bits), 6 or 7 bits effective riscv: uncapped (10 bits), 6 bits effective x86: capped at 0xFF (8 bits), 5 (x86_64) or 6 (ia32) bits effective s390: capped at 0xFF (8 bits), undocumented effective entropy Current discussion has led to just dropping the original per-architecture filters. The additional entropy appears to be safe for arm64, x86, and s390. Quoting Arnd, "There is no point pretending that 15.75KB is somehow safe to use while 15.00KB is not." Co-developed-by: Yuntao Liu Signed-off-by: Yuntao Liu Fixes: 9c573cd31343 ("randomize_kstack: Improve entropy diffusion") Link: https://lore.kernel.org/r/20240617133721.377540-1-liuyuntao12@huawei.com Reviewed-by: Arnd Bergmann Acked-by: Mark Rutland Acked-by: Heiko Carstens # s390 Link: https://lore.kernel.org/r/20240619214711.work.953-kees@kernel.org Signed-off-by: Kees Cook

Merge tag 's390-6.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2024-05-21T19:09:36Z

Pull more s390 updates from Alexander Gordeev: - Switch read and write software bits for PUDs - Add missing hardware bits for PUDs and PMDs - Generate unwind information for C modules to fix GDB unwind error for vDSO functions - Create .build-id links for unstripped vDSO files to enable vDSO debugging with symbols - Use standard stack frame layout for vDSO generated stack frames to manually walk stack frames without DWARF information - Rework perf_callchain_user() and arch_stack_walk_user() functions to reduce code duplication - Skip first stack frame when walking user stack - Add basic checks to identify invalid instruction pointers when walking stack frames - Introduce and use struct stack_frame_vdso_wrapper within vDSO user wrapper code to automatically generate an asm-offset define. Also use STACK_FRAME_USER_OVERHEAD instead of STACK_FRAME_OVERHEAD to document that the code works with user space stack - Clear the backchain of the extra stack frame added by the vDSO user wrapper code. This allows the user stack walker to detect and skip the non-standard stack frame. Without this an incorrect instruction pointer would be added to stack traces. - Rewrite psw_idle() function in C to ease maintenance and further enhancements - Remove get_vtimer() function and use get_cpu_timer() instead - Mark psw variable in __load_psw_mask() as __unitialized to avoid superfluous clearing of PSW - Remove obsolete and superfluous comment about removed TIF_FPU flag - Replace memzero_explicit() and kfree() with kfree_sensitive() to fix warnings reported by Coccinelle - Wipe sensitive data and all copies of protected- or secure-keys from stack when an IOCTL fails - Both do_airq_interrupt() and do_io_interrupt() functions set CIF_NOHZ_DELAY flag. Move it in do_io_irq() to simplify the code - Provide iucv_alloc_device() and iucv_release_device() helpers, which can be used to deduplicate more or less identical IUCV device allocation and release code in four different drivers - Make use of iucv_alloc_device() and iucv_release_device() helpers to get rid of quite some code and also remove a cast to an incompatible function (clang W=1) - There is no user of iucv_root outside of the core IUCV code left. Therefore remove the EXPORT_SYMBOL - __apply_alternatives() contains a runtime check which verifies that the size of the to be patched code area is even. Convert this to a compile time check - Increase size of buffers for sending z/VM CP DIAGNOSE X'008' commands from 128 to 240 - Do not accept z/VM CP DIAGNOSE X'008' commands longer than maximally allowed - Use correct defines IPL_BP_NVME_LEN and IPL_BP0_NVME_LEN instead of IPL_BP_FCP_LEN and IPL_BP0_FCP_LEN ones to initialize NVMe reIPL block on 'scp_data' sysfs attribute update - Initialize the correct fields of the NVMe dump block, which were confused with FCP fields - Refactor macros for 'scp_data' (re-)IPL sysfs attribute to reduce code duplication - Introduce 'scp_data' sysfs attribute for dump IPL to allow tools such as dumpconf passing additional kernel command line parameters to a stand-alone dumper - Rework the CPACF query functions to use the correct RRE or RRF instruction formats and set instruction register fields correctly - Instead of calling BUG() at runtime force a link error during compile when a unsupported opcode is used with __cpacf_query() or __cpacf_check_opcode() functions - Fix a crash in ap_parse_bitmap_str() function on /sys/bus/ap/apmask or /sys/bus/ap/aqmask sysfs file update with a relative mask value - Fix "bindings complete" udev event which should be sent once all AP devices have been bound to device drivers and again when unbind/bind actions take place and all AP devices are bound again - Facility list alt_stfle_fac_list is nowhere used in the decompressor, therefore remove it there - Remove custom kprobes insn slot allocator in favour of the standard module_alloc() one, since kernel image and module areas are located within 4GB - Use kvcalloc() instead of kvmalloc_array() in zcrypt driver to avoid calling memset() with a large byte count and get rid of the sparse warning as result * tag 's390-6.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (39 commits) s390/zcrypt: Use kvcalloc() instead of kvmalloc_array() s390/kprobes: Remove custom insn slot allocator s390/boot: Remove alt_stfle_fac_list from decompressor s390/ap: Fix bind complete udev event sent after each AP bus scan s390/ap: Fix crash in AP internal function modify_bitmap() s390/cpacf: Make use of invalid opcode produce a link error s390/cpacf: Split and rework cpacf query functions s390/ipl: Introduce sysfs attribute 'scp_data' for dump ipl s390/ipl: Introduce macros for (re)ipl sysfs attribute 'scp_data' s390/ipl: Fix incorrect initialization of nvme dump block s390/ipl: Fix incorrect initialization of len fields in nvme reipl block s390/ipl: Do not accept z/VM CP diag X'008' cmds longer than max length s390/ipl: Fix size of vmcmd buffers for sending z/VM CP diag X'008' cmds s390/alternatives: Convert runtime sanity check into compile time check s390/iucv: Unexport iucv_root tty: hvc-iucv: Make use of iucv_alloc_device() s390/smsgiucv_app: Make use of iucv_alloc_device() s390/netiucv: Make use of iucv_alloc_device() s390/vmlogrdr: Make use of iucv_alloc_device() s390/iucv: Provide iucv_alloc_device() / iucv_release_device() ...

Merge tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-05-19T16:21:03Z

Pull mm updates from Andrew Morton: "The usual shower of singleton fixes and minor series all over MM, documented (hopefully adequately) in the respective changelogs. Notable series include: - Lucas Stach has provided some page-mapping cleanup/consolidation/ maintainability work in the series "mm/treewide: Remove pXd_huge() API". - In the series "Allow migrate on protnone reference with MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's MPOL_PREFERRED_MANY mode, yielding almost doubled performance in one test. - In their series "Memory allocation profiling" Kent Overstreet and Suren Baghdasaryan have contributed a means of determining (via /proc/allocinfo) whereabouts in the kernel memory is being allocated: number of calls and amount of memory. - Matthew Wilcox has provided the series "Various significant MM patches" which does a number of rather unrelated things, but in largely similar code sites. - In his series "mm: page_alloc: freelist migratetype hygiene" Johannes Weiner has fixed the page allocator's handling of migratetype requests, with resulting improvements in compaction efficiency. - In the series "make the hugetlb migration strategy consistent" Baolin Wang has fixed a hugetlb migration issue, which should improve hugetlb allocation reliability. - Liu Shixin has hit an I/O meltdown caused by readahead in a memory-tight memcg. Addressed in the series "Fix I/O high when memory almost met memcg limit". - In the series "mm/filemap: optimize folio adding and splitting" Kairui Song has optimized pagecache insertion, yielding ~10% performance improvement in one test. - Baoquan He has cleaned up and consolidated the early zone initialization code in the series "mm/mm_init.c: refactor free_area_init_core()". - Baoquan has also redone some MM initializatio code in the series "mm/init: minor clean up and improvement". - MM helper cleanups from Christoph Hellwig in his series "remove follow_pfn". - More cleanups from Matthew Wilcox in the series "Various page->flags cleanups". - Vlastimil Babka has contributed maintainability improvements in the series "memcg_kmem hooks refactoring". - More folio conversions and cleanups in Matthew Wilcox's series: "Convert huge_zero_page to huge_zero_folio" "khugepaged folio conversions" "Remove page_idle and page_young wrappers" "Use folio APIs in procfs" "Clean up __folio_put()" "Some cleanups for memory-failure" "Remove page_mapping()" "More folio compat code removal" - David Hildenbrand chipped in with "fs/proc/task_mmu: convert hugetlb functions to work on folis". - Code consolidation and cleanup work related to GUP's handling of hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2". - Rick Edgecombe has developed some fixes to stack guard gaps in the series "Cover a guard gap corner case". - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the series "mm/ksm: fix ksm exec support for prctl". - Baolin Wang has implemented NUMA balancing for multi-size THPs. This is a simple first-cut implementation for now. The series is "support multi-size THP numa balancing". - Cleanups to vma handling helper functions from Matthew Wilcox in the series "Unify vma_address and vma_pgoff_address". - Some selftests maintenance work from Dev Jain in the series "selftests/mm: mremap_test: Optimizations and style fixes". - Improvements to the swapping of multi-size THPs from Ryan Roberts in the series "Swap-out mTHP without splitting". - Kefeng Wang has significantly optimized the handling of arm64's permission page faults in the series "arch/mm/fault: accelerate pagefault when badaccess" "mm: remove arch's private VM_FAULT_BADMAP/BADACCESS" - GUP cleanups from David Hildenbrand in "mm/gup: consistently call it GUP-fast". - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault path to use struct vm_fault". - selftests build fixes from John Hubbard in the series "Fix selftests/mm build without requiring "make headers"". - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the series "Improved Memory Tier Creation for CPUless NUMA Nodes". Fixes the initialization code so that migration between different memory types works as intended. - David Hildenbrand has improved follow_pte() and fixed an errant driver in the series "mm: follow_pte() improvements and acrn follow_pte() fixes". - David also did some cleanup work on large folio mapcounts in his series "mm: mapcount for large folios + page_mapcount() cleanups". - Folio conversions in KSM in Alex Shi's series "transfer page to folio in KSM". - Barry Song has added some sysfs stats for monitoring multi-size THP's in the series "mm: add per-order mTHP alloc and swpout counters". - Some zswap cleanups from Yosry Ahmed in the series "zswap same-filled and limit checking cleanups". - Matthew Wilcox has been looking at buffer_head code and found the documentation to be lacking. The series is "Improve buffer head documentation". - Multi-size THPs get more work, this time from Lance Yang. His series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free" optimizes the freeing of these things. - Kemeng Shi has added more userspace-visible writeback instrumentation in the series "Improve visibility of writeback". - Kemeng Shi then sent some maintenance work on top in the series "Fix and cleanups to page-writeback". - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in the series "Improve anon_vma scalability for anon VMAs". Intel's test bot reported an improbable 3x improvement in one test. - SeongJae Park adds some DAMON feature work in the series "mm/damon: add a DAMOS filter type for page granularity access recheck" "selftests/damon: add DAMOS quota goal test" - Also some maintenance work in the series "mm/damon/paddr: simplify page level access re-check for pageout" "mm/damon: misc fixes and improvements" - David Hildenbrand has disabled some known-to-fail selftests ni the series "selftests: mm: cow: flag vmsplice() hugetlb tests as XFAIL". - memcg metadata storage optimizations from Shakeel Butt in "memcg: reduce memory consumption by memcg stats". - DAX fixes and maintenance work from Vishal Verma in the series "dax/bus.c: Fixups for dax-bus locking"" * tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits) memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault selftests: cgroup: add tests to verify the zswap writeback path mm: memcg: make alloc_mem_cgroup_per_node_info() return bool mm/damon/core: fix return value from damos_wmark_metric_value mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED selftests: cgroup: remove redundant enabling of memory controller Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT Docs/mm/damon/design: use a list for supported filters Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file selftests/damon: classify tests for functionalities and regressions selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None' selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts selftests/damon/_damon_sysfs: check errors from nr_schemes file reads mm/damon/core: initialize ->esz_bp from damos_quota_init_priv() selftests/damon: add a test for DAMOS quota goal ...

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma

2024-05-18T20:04:15Z

Pull rdma updates from Jason Gunthorpe: "Aside from the usual things this has an arch update for __iowrite64_copy() used by the RDMA drivers. This API was intended to generate large 64 byte MemWr TLPs on PCI. These days most processors had done this by just repeating writel() in a loop. S390 and some new ARM64 designs require a special helper to get this to generate. - Small improvements and fixes for erdma, efa, hfi1, bnxt_re - Fix a UAF crash after module unload on leaking restrack entry - Continue adding full RDMA support in mana with support for EQs, GID's and CQs - Improvements to the mkey cache in mlx5 - DSCP traffic class support in hns and several bug fixes - Cap the maximum number of MADs in the receive queue to avoid OOM - Another batch of rxe bug fixes from large scale testing - __iowrite64_copy() optimizations for write combining MMIO memory - Remove NULL checks before dev_put/hold() - EFA support for receive with immediate - Fix a recent memleaking regression in a cma error path" * tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (70 commits) RDMA/cma: Fix kmemleak in rdma_core observed during blktests nvme/rdma use siw RDMA/IPoIB: Fix format truncation compilation errors bnxt_re: avoid shift undefined behavior in bnxt_qplib_alloc_init_hwq RDMA/efa: Support QP with unsolicited write w/ imm. receive IB/hfi1: Remove generic .ndo_get_stats64 IB/hfi1: Do not use custom stat allocator RDMA/hfi1: Use RMW accessors for changing LNKCTL2 RDMA/mana_ib: implement uapi for creation of rnic cq RDMA/mana_ib: boundary check before installing cq callbacks RDMA/mana_ib: introduce a helper to remove cq callbacks RDMA/mana_ib: create and destroy RNIC cqs RDMA/mana_ib: create EQs for RNIC CQs RDMA/core: Remove NULL check before dev_{put, hold} RDMA/ipoib: Remove NULL check before dev_{put, hold} RDMA/mlx5: Remove NULL check before dev_{put, hold} RDMA/mlx5: Track DCT, DCI and REG_UMR QPs as diver_detail resources. RDMA/core: Add an option to display driver-specific QPs in the rdmatool RDMA/efa: Add shutdown notifier RDMA/mana_ib: Fix missing ret value IB/mlx5: Use __iowrite64_copy() for write combining stores ...

s390/cpacf: Make use of invalid opcode produce a link error

2024-05-16T08:17:11Z

Instead of calling BUG() at runtime introduce and use a prototype for a non-existing function to produce a link error during compile when a not supported opcode is used with the __cpacf_query() or __cpacf_check_opcode() inline functions. Suggested-by: Heiko Carstens Signed-off-by: Harald Freudenberger Reviewed-by: Holger Dengler Reviewed-by: Juergen Christ Cc: stable@vger.kernel.org Signed-off-by: Heiko Carstens