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2024-11-18Merge tag 'arm64-upstream' of ↵Linus Torvalds1-0/+30
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: - Support for running Linux in a protected VM under the Arm Confidential Compute Architecture (CCA) - Guarded Control Stack user-space support. Current patches follow the x86 ABI of implicitly creating a shadow stack on clone(). Subsequent patches (already on the list) will add support for clone3() allowing finer-grained control of the shadow stack size and placement from libc - AT_HWCAP3 support (not running out of HWCAP2 bits yet but we are getting close with the upcoming dpISA support) - Other arch features: - In-kernel use of the memcpy instructions, FEAT_MOPS (previously only exposed to user; uaccess support not merged yet) - MTE: hugetlbfs support and the corresponding kselftests - Optimise CRC32 using the PMULL instructions - Support for FEAT_HAFT enabling ARCH_HAS_NONLEAF_PMD_YOUNG - Optimise the kernel TLB flushing to use the range operations - POE/pkey (permission overlays): further cleanups after bringing the signal handler in line with the x86 behaviour for 6.12 - arm64 perf updates: - Support for the NXP i.MX91 PMU in the existing IMX driver - Support for Ampere SoCs in the Designware PCIe PMU driver - Support for Marvell's 'PEM' PCIe PMU present in the 'Odyssey' SoC - Support for Samsung's 'Mongoose' CPU PMU - Support for PMUv3.9 finer-grained userspace counter access control - Switch back to platform_driver::remove() now that it returns 'void' - Add some missing events for the CXL PMU driver - Miscellaneous arm64 fixes/cleanups: - Page table accessors cleanup: type updates, drop unused macros, reorganise arch_make_huge_pte() and clean up pte_mkcont(), sanity check addresses before runtime P4D/PUD folding - Command line override for ID_AA64MMFR0_EL1.ECV (advertising the FEAT_ECV for the generic timers) allowing Linux to boot with firmware deployments that don't set SCTLR_EL3.ECVEn - ACPI/arm64: tighten the check for the array of platform timer structures and adjust the error handling procedure in gtdt_parse_timer_block() - Optimise the cache flush for the uprobes xol slot (skip if no change) and other uprobes/kprobes cleanups - Fix the context switching of tpidrro_el0 when kpti is enabled - Dynamic shadow call stack fixes - Sysreg updates - Various arm64 kselftest improvements * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (168 commits) arm64: tls: Fix context-switching of tpidrro_el0 when kpti is enabled kselftest/arm64: Try harder to generate different keys during PAC tests kselftest/arm64: Don't leak pipe fds in pac.exec_sign_all() arm64/ptrace: Clarify documentation of VL configuration via ptrace kselftest/arm64: Corrupt P0 in the irritator when testing SSVE acpi/arm64: remove unnecessary cast arm64/mm: Change protval as 'pteval_t' in map_range() kselftest/arm64: Fix missing printf() argument in gcs/gcs-stress.c kselftest/arm64: Add FPMR coverage to fp-ptrace kselftest/arm64: Expand the set of ZA writes fp-ptrace does kselftets/arm64: Use flag bits for features in fp-ptrace assembler code kselftest/arm64: Enable build of PAC tests with LLVM=1 kselftest/arm64: Check that SVCR is 0 in signal handlers selftests/mm: Fix unused function warning for aarch64_write_signal_pkey() kselftest/arm64: Fix printf() compiler warnings in the arm64 syscall-abi.c tests kselftest/arm64: Fix printf() warning in the arm64 MTE prctl() test kselftest/arm64: Fix printf() compiler warnings in the arm64 fp tests kselftest/arm64: Fix build with stricter assemblers arm64/scs: Drop unused prototype __pi_scs_patch_vmlinux() arm64/scs: Deal with 64-bit relative offsets in FDE frames ...
2024-11-03fdget(), trivial conversionsAl Viro1-10/+5
fdget() is the first thing done in scope, all matching fdput() are immediately followed by leaving the scope. Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-10-04prctl: arch-agnostic prctl for shadow stackMark Brown1-0/+30
Three architectures (x86, aarch64, riscv) have announced support for shadow stacks with fairly similar functionality. While x86 is using arch_prctl() to control the functionality neither arm64 nor riscv uses that interface so this patch adds arch-agnostic prctl() support to get and set status of shadow stacks and lock the current configuation to prevent further changes, with support for turning on and off individual subfeatures so applications can limit their exposure to features that they do not need. The features are: - PR_SHADOW_STACK_ENABLE: Tracking and enforcement of shadow stacks, including allocation of a shadow stack if one is not already allocated. - PR_SHADOW_STACK_WRITE: Writes to specific addresses in the shadow stack. - PR_SHADOW_STACK_PUSH: Push additional values onto the shadow stack. These features are expected to be inherited by new threads and cleared on exec(), unknown features should be rejected for enable but accepted for locking (in order to allow for future proofing). This is based on a patch originally written by Deepak Gupta but modified fairly heavily, support for indirect landing pads is removed, additional modes added and the locking interface reworked. The set status prctl() is also reworked to just set flags, if setting/reading the shadow stack pointer is required this could be a separate prctl. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Yury Khrustalev <yury.khrustalev@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Deepak Gupta <debug@rivosinc.com> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-4-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-09-23Merge tag 'pull-stable-struct_fd' of ↵Linus Torvalds1-5/+5
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull 'struct fd' updates from Al Viro: "Just the 'struct fd' layout change, with conversion to accessor helpers" * tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: add struct fd constructors, get rid of __to_fd() struct fd: representation change introduce fd_file(), convert all accessors to it.
2024-09-19Merge tag 'sched-core-2024-09-19' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: - Implement the SCHED_DEADLINE server infrastructure - Daniel Bristot de Oliveira's last major contribution to the kernel: "SCHED_DEADLINE servers can help fixing starvation issues of low priority tasks (e.g., SCHED_OTHER) when higher priority tasks monopolize CPU cycles. Today we have RT Throttling; DEADLINE servers should be able to replace and improve that." (Daniel Bristot de Oliveira, Peter Zijlstra, Joel Fernandes, Youssef Esmat, Huang Shijie) - Preparatory changes for sched_ext integration: - Use set_next_task(.first) where required - Fix up set_next_task() implementations - Clean up DL server vs. core sched - Split up put_prev_task_balance() - Rework pick_next_task() - Combine the last put_prev_task() and the first set_next_task() - Rework dl_server - Add put_prev_task(.next) (Peter Zijlstra, with a fix by Tejun Heo) - Complete the EEVDF transition and refine EEVDF scheduling: - Implement delayed dequeue - Allow shorter slices to wakeup-preempt - Use sched_attr::sched_runtime to set request/slice suggestion - Document the new feature flags - Remove unused and duplicate-functionality fields - Simplify & unify pick_next_task_fair() - Misc debuggability enhancements (Peter Zijlstra, with fixes/cleanups by Dietmar Eggemann, Valentin Schneider and Chuyi Zhou) - Initialize the vruntime of a new task when it is first enqueued, resulting in significant decrease in latency of newly woken tasks (Zhang Qiao) - Introduce SM_IDLE and an idle re-entry fast-path in __schedule() (K Prateek Nayak, Peter Zijlstra) - Clean up and clarify the usage of Clean up usage of rt_task() (Qais Yousef) - Preempt SCHED_IDLE entities in strict cgroup hierarchies (Tianchen Ding) - Clarify the documentation of time units for deadline scheduler parameters (Christian Loehle) - Remove the HZ_BW chicken-bit feature flag introduced a year ago, the original change seems to be working fine (Phil Auld) - Misc fixes and cleanups (Chen Yu, Dan Carpenter, Huang Shijie, Peilin He, Qais Yousefm and Vincent Guittot) * tag 'sched-core-2024-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits) sched/cpufreq: Use NSEC_PER_MSEC for deadline task cpufreq/cppc: Use NSEC_PER_MSEC for deadline task sched/deadline: Clarify nanoseconds in uapi sched/deadline: Convert schedtool example to chrt sched/debug: Fix the runnable tasks output sched: Fix sched_delayed vs sched_core kernel/sched: Fix util_est accounting for DELAY_DEQUEUE kthread: Fix task state in kthread worker if being frozen sched/pelt: Use rq_clock_task() for hw_pressure sched/fair: Move effective_cpu_util() and effective_cpu_util() in fair.c sched/core: Introduce SM_IDLE and an idle re-entry fast-path in __schedule() sched: Add put_prev_task(.next) sched: Rework dl_server sched: Combine the last put_prev_task() and the first set_next_task() sched: Rework pick_next_task() sched: Split up put_prev_task_balance() sched: Clean up DL server vs core sched sched: Fixup set_next_task() implementations sched: Use set_next_task(.first) where required sched/fair: Properly deactivate sched_delayed task upon class change ...
2024-08-23hrtimer: Use and report correct timerslack values for realtime tasksFelix Moessbauer1-0/+2
The timerslack_ns setting is used to specify how much the hardware timers should be delayed, to potentially dispatch multiple timers in a single interrupt. This is a performance optimization. Timers of realtime tasks (having a realtime scheduling policy) should not be delayed. This logic was inconsitently applied to the hrtimers, leading to delays of realtime tasks which used timed waits for events (e.g. condition variables). Due to the downstream override of the slack for rt tasks, the procfs reported incorrect (non-zero) timerslack_ns values. This is changed by setting the timer_slack_ns task attribute to 0 for all tasks with a rt policy. By that, downstream users do not need to specially handle rt tasks (w.r.t. the slack), and the procfs entry shows the correct value of "0". Setting non-zero slack values (either via procfs or PR_SET_TIMERSLACK) on tasks with a rt policy is ignored, as stated in "man 2 PR_SET_TIMERSLACK": Timer slack is not applied to threads that are scheduled under a real-time scheduling policy (see sched_setscheduler(2)). The special handling of timerslack on rt tasks in downstream users is removed as well. Signed-off-by: Felix Moessbauer <felix.moessbauer@siemens.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20240814121032.368444-2-felix.moessbauer@siemens.com
2024-08-12introduce fd_file(), convert all accessors to it.Al Viro1-5/+5
For any changes of struct fd representation we need to turn existing accesses to fields into calls of wrappers. Accesses to struct fd::flags are very few (3 in linux/file.h, 1 in net/socket.c, 3 in fs/overlayfs/file.c and 3 more in explicit initializers). Those can be dealt with in the commit converting to new layout; accesses to struct fd::file are too many for that. This commit converts (almost) all of f.file to fd_file(f). It's not entirely mechanical ('file' is used as a member name more than just in struct fd) and it does not even attempt to distinguish the uses in pointer context from those in boolean context; the latter will be eventually turned into a separate helper (fd_empty()). NOTE: mass conversion to fd_empty(), tempting as it might be, is a bad idea; better do that piecewise in commit that convert from fdget...() to CLASS(...). [conflicts in fs/fhandle.c, kernel/bpf/syscall.c, mm/memcontrol.c caught by git; fs/stat.c one got caught by git grep] [fs/xattr.c conflict] Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-05-22Merge tag 'riscv-for-linus-6.10-mw1' of ↵Linus Torvalds1-0/+6
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V updates from Palmer Dabbelt: - Add byte/half-word compare-and-exchange, emulated via LR/SC loops - Support for Rust - Support for Zihintpause in hwprobe - Add PR_RISCV_SET_ICACHE_FLUSH_CTX prctl() - Support lockless lockrefs * tag 'riscv-for-linus-6.10-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (42 commits) riscv: defconfig: Enable CONFIG_CLK_SOPHGO_CV1800 riscv: select ARCH_HAS_FAST_MULTIPLIER riscv: mm: still create swiotlb buffer for kmalloc() bouncing if required riscv: Annotate pgtable_l{4,5}_enabled with __ro_after_init riscv: Remove redundant CONFIG_64BIT from pgtable_l{4,5}_enabled riscv: mm: Always use an ASID to flush mm contexts riscv: mm: Preserve global TLB entries when switching contexts riscv: mm: Make asid_bits a local variable riscv: mm: Use a fixed layout for the MM context ID riscv: mm: Introduce cntx2asid/cntx2version helper macros riscv: Avoid TLB flush loops when affected by SiFive CIP-1200 riscv: Apply SiFive CIP-1200 workaround to single-ASID sfence.vma riscv: mm: Combine the SMP and UP TLB flush code riscv: Only send remote fences when some other CPU is online riscv: mm: Broadcast kernel TLB flushes only when needed riscv: Use IPIs for remote cache/TLB flushes by default riscv: Factor out page table TLB synchronization riscv: Flush the instruction cache during SMP bringup riscv: hwprobe: export Zihintpause ISA extension riscv: misaligned: remove CONFIG_RISCV_M_MODE specific code ...
2024-05-06powerpc/dexcr: Add DEXCR prctl interfaceBenjamin Gray1-0/+16
Now that we track a DEXCR on a per-task basis, individual tasks are free to configure it as they like. The interface is a pair of getter/setter prctl's that work on a single aspect at a time (multiple aspects at once is more difficult if there are different rules applied for each aspect, now or in future). The getter shows the current state of the process config, and the setter allows setting/clearing the aspect. Signed-off-by: Benjamin Gray <bgray@linux.ibm.com> [mpe: Account for PR_RISCV_SET_ICACHE_FLUSH_CTX, shrink some longs lines] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20240417112325.728010-5-bgray@linux.ibm.com
2024-04-30Merge patch series "riscv: Create and document PR_RISCV_SET_ICACHE_FLUSH_CTX ↵Palmer Dabbelt1-0/+6
prctl" Charlie Jenkins <charlie@rivosinc.com> says: Improve the performance of icache flushing by creating a new prctl flag PR_RISCV_SET_ICACHE_FLUSH_CTX. The interface is left generic to allow for future expansions such as with the proposed J extension [1]. Documentation is also provided to explain the use case. Patch sent to add PR_RISCV_SET_ICACHE_FLUSH_CTX to man-pages [2]. [1] https://github.com/riscv/riscv-j-extension [2] https://lore.kernel.org/linux-man/20240124-fencei_prctl-v1-1-0bddafcef331@rivosinc.com * b4-shazam-merge: cpumask: Add assign cpu documentation: Document PR_RISCV_SET_ICACHE_FLUSH_CTX prctl riscv: Include riscv_set_icache_flush_ctx prctl riscv: Remove unnecessary irqflags processor.h include Link: https://lore.kernel.org/r/20240312-fencei-v13-0-4b6bdc2bbf32@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-04-18riscv: Include riscv_set_icache_flush_ctx prctlCharlie Jenkins1-0/+6
Support new prctl with key PR_RISCV_SET_ICACHE_FLUSH_CTX to enable optimization of cross modifying code. This prctl enables userspace code to use icache flushing instructions such as fence.i with the guarantee that the icache will continue to be clean after thread migration. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Samuel Holland <samuel.holland@sifive.com> Link: https://lore.kernel.org/r/20240312-fencei-v13-2-4b6bdc2bbf32@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-03-26prctl: generalize PR_SET_MDWE support check to be per-archZev Weiss1-2/+5
Patch series "ARM: prctl: Reject PR_SET_MDWE where not supported". I noticed after a recent kernel update that my ARM926 system started segfaulting on any execve() after calling prctl(PR_SET_MDWE). After some investigation it appears that ARMv5 is incapable of providing the appropriate protections for MDWE, since any readable memory is also implicitly executable. The prctl_set_mdwe() function already had some special-case logic added disabling it on PARISC (commit 793838138c15, "prctl: Disable prctl(PR_SET_MDWE) on parisc"); this patch series (1) generalizes that check to use an arch_*() function, and (2) adds a corresponding override for ARM to disable MDWE on pre-ARMv6 CPUs. With the series applied, prctl(PR_SET_MDWE) is rejected on ARMv5 and subsequent execve() calls (as well as mmap(PROT_READ|PROT_WRITE)) can succeed instead of unconditionally failing; on ARMv6 the prctl works as it did previously. [0] https://lore.kernel.org/all/2023112456-linked-nape-bf19@gregkh/ This patch (of 2): There exist systems other than PARISC where MDWE may not be feasible to support; rather than cluttering up the generic code with additional arch-specific logic let's add a generic function for checking MDWE support and allow each arch to override it as needed. Link: https://lkml.kernel.org/r/20240227013546.15769-4-zev@bewilderbeest.net Link: https://lkml.kernel.org/r/20240227013546.15769-5-zev@bewilderbeest.net Signed-off-by: Zev Weiss <zev@bewilderbeest.net> Acked-by: Helge Deller <deller@gmx.de> [parisc] Cc: Borislav Petkov <bp@alien8.de> Cc: David Hildenbrand <david@redhat.com> Cc: Florent Revest <revest@chromium.org> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Kees Cook <keescook@chromium.org> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ondrej Mosnacek <omosnace@redhat.com> Cc: Rick Edgecombe <rick.p.edgecombe@intel.com> Cc: Russell King (Oracle) <linux@armlinux.org.uk> Cc: Sam James <sam@gentoo.org> Cc: Stefan Roesch <shr@devkernel.io> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: Yin Fengwei <fengwei.yin@intel.com> Cc: <stable@vger.kernel.org> [6.3+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-07getrusage: use sig->stats_lock rather than lock_task_sighand()Oleg Nesterov1-3/+13
lock_task_sighand() can trigger a hard lockup. If NR_CPUS threads call getrusage() at the same time and the process has NR_THREADS, spin_lock_irq will spin with irqs disabled O(NR_CPUS * NR_THREADS) time. Change getrusage() to use sig->stats_lock, it was specifically designed for this type of use. This way it runs lockless in the likely case. TODO: - Change do_task_stat() to use sig->stats_lock too, then we can remove spin_lock_irq(siglock) in wait_task_zombie(). - Turn sig->stats_lock into seqcount_rwlock_t, this way the readers in the slow mode won't exclude each other. See https://lore.kernel.org/all/20230913154907.GA26210@redhat.com/ - stats_lock has to disable irqs because ->siglock can be taken in irq context, it would be very nice to change __exit_signal() to avoid the siglock->stats_lock dependency. Link: https://lkml.kernel.org/r/20240122155053.GA26214@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Dylan Hatch <dylanbhatch@google.com> Tested-by: Dylan Hatch <dylanbhatch@google.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-07getrusage: move thread_group_cputime_adjusted() outside of lock_task_sighand()Oleg Nesterov1-15/+19
Patch series "getrusage: use sig->stats_lock", v2. This patch (of 2): thread_group_cputime() does its own locking, we can safely shift thread_group_cputime_adjusted() which does another for_each_thread loop outside of ->siglock protected section. This is also preparation for the next patch which changes getrusage() to use stats_lock instead of siglock, thread_group_cputime() takes the same lock. With the current implementation recursive read_seqbegin_or_lock() is fine, thread_group_cputime() can't enter the slow mode if the caller holds stats_lock, yet this looks more safe and better performance-wise. Link: https://lkml.kernel.org/r/20240122155023.GA26169@redhat.com Link: https://lkml.kernel.org/r/20240122155050.GA26205@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Dylan Hatch <dylanbhatch@google.com> Tested-by: Dylan Hatch <dylanbhatch@google.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-11-18prctl: Disable prctl(PR_SET_MDWE) on pariscHelge Deller1-0/+4
systemd-254 tries to use prctl(PR_SET_MDWE) for it's MemoryDenyWriteExecute functionality, but fails on parisc which still needs executable stacks in certain combinations of gcc/glibc/kernel. Disable prctl(PR_SET_MDWE) by returning -EINVAL for now on parisc, until userspace has catched up. Signed-off-by: Helge Deller <deller@gmx.de> Co-developed-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Sam James <sam@gentoo.org> Closes: https://github.com/systemd/systemd/issues/29775 Tested-by: Sam James <sam@gentoo.org> Link: https://lore.kernel.org/all/875y2jro9a.fsf@gentoo.org/ Cc: <stable@vger.kernel.org> # v6.3+
2023-11-02Merge tag 'mm-nonmm-stable-2023-11-02-14-08' of ↵Linus Torvalds1-21/+20
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: "As usual, lots of singleton and doubleton patches all over the tree and there's little I can say which isn't in the individual changelogs. The lengthier patch series are - 'kdump: use generic functions to simplify crashkernel reservation in arch', from Baoquan He. This is mainly cleanups and consolidation of the 'crashkernel=' kernel parameter handling - After much discussion, David Laight's 'minmax: Relax type checks in min() and max()' is here. Hopefully reduces some typecasting and the use of min_t() and max_t() - A group of patches from Oleg Nesterov which clean up and slightly fix our handling of reads from /proc/PID/task/... and which remove task_struct.thread_group" * tag 'mm-nonmm-stable-2023-11-02-14-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (64 commits) scripts/gdb/vmalloc: disable on no-MMU scripts/gdb: fix usage of MOD_TEXT not defined when CONFIG_MODULES=n .mailmap: add address mapping for Tomeu Vizoso mailmap: update email address for Claudiu Beznea tools/testing/selftests/mm/run_vmtests.sh: lower the ptrace permissions .mailmap: map Benjamin Poirier's address scripts/gdb: add lx_current support for riscv ocfs2: fix a spelling typo in comment proc: test ProtectionKey in proc-empty-vm test proc: fix proc-empty-vm test with vsyscall fs/proc/base.c: remove unneeded semicolon do_io_accounting: use sig->stats_lock do_io_accounting: use __for_each_thread() ocfs2: replace BUG_ON() at ocfs2_num_free_extents() with ocfs2_error() ocfs2: fix a typo in a comment scripts/show_delta: add __main__ judgement before main code treewide: mark stuff as __ro_after_init fs: ocfs2: check status values proc: test /proc/${pid}/statm compiler.h: move __is_constexpr() to compiler.h ...
2023-10-06mm: add a NO_INHERIT flag to the PR_SET_MDWE prctlFlorent Revest1-6/+26
This extends the current PR_SET_MDWE prctl arg with a bit to indicate that the process doesn't want MDWE protection to propagate to children. To implement this no-inherit mode, the tag in current->mm->flags must be absent from MMF_INIT_MASK. This means that the encoding for "MDWE but without inherit" is different in the prctl than in the mm flags. This leads to a bit of bit-mangling in the prctl implementation. Link: https://lkml.kernel.org/r/20230828150858.393570-6-revest@chromium.org Signed-off-by: Florent Revest <revest@chromium.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Alexey Izbyshev <izbyshev@ispras.ru> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Ayush Jain <ayush.jain3@amd.com> Cc: David Hildenbrand <david@redhat.com> Cc: Greg Thelen <gthelen@google.com> Cc: Joey Gouly <joey.gouly@arm.com> Cc: KP Singh <kpsingh@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Szabolcs Nagy <Szabolcs.Nagy@arm.com> Cc: Topi Miettinen <toiwoton@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04getrusage: use __for_each_thread()Oleg Nesterov1-3/+1
do/while_each_thread should be avoided when possible. Plus this change allows to avoid lock_task_sighand(), we can use rcu and/or sig->stats_lock instead. Link: https://lkml.kernel.org/r/20230909172629.GA20454@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04getrusage: add the "signal_struct *sig" local variableOleg Nesterov1-18/+19
No functional changes, cleanup/preparation. Link: https://lkml.kernel.org/r/20230909172554.GA20441@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-07-17prctl: move PR_GET_AUXV out of PR_MCE_KILLMiguel Ojeda1-5/+5
Somehow PR_GET_AUXV got added into PR_MCE_KILL's switch when the patch was applied [1]. Thus move it out of the switch, to the place the patch added it. In the recently released v6.4 kernel some user could, in principle, be already using this feature by mapping the right page and passing the PR_GET_AUXV constant as a pointer: prctl(PR_MCE_KILL, PR_GET_AUXV, ...) So this does change the behavior for users. We could keep the bug since the other subcases in PR_MCE_KILL (PR_MCE_KILL_CLEAR and PR_MCE_KILL_SET) do not overlap. However, v6.4 may be recent enough (2 weeks old) that moving the lines (rather than just adding a new case) does not break anybody? Moreover, the documentation in man-pages was just committed today [2]. Link: https://lkml.kernel.org/r/20230708233344.361854-1-ojeda@kernel.org Fixes: ddc65971bb67 ("prctl: add PR_GET_AUXV to copy auxv to userspace") Link: https://lore.kernel.org/all/d81864a7f7f43bca6afa2a09fc2e850e4050ab42.1680611394.git.josh@joshtriplett.org/ [1] Link: https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/commit/?id=8cf0c06bfd3c2b219b044d4151c96f0da50af9ad [2] Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-08riscv: Add prctl controls for userspace vector managementAndy Chiu1-0/+12
This patch add two riscv-specific prctls, to allow usespace control the use of vector unit: * PR_RISCV_V_SET_CONTROL: control the permission to use Vector at next, or all following execve for a thread. Turning off a thread's Vector live is not possible since libraries may have registered ifunc that may execute Vector instructions. * PR_RISCV_V_GET_CONTROL: get the same permission setting for the current thread, and the setting for following execve(s). Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Greentime Hu <greentime.hu@sifive.com> Reviewed-by: Vincent Chen <vincent.chen@sifive.com> Link: https://lore.kernel.org/r/20230605110724.21391-22-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-05-02mm/ksm: unmerge and clear VM_MERGEABLE when setting PR_SET_MEMORY_MERGE=0David Hildenbrand1-9/+3
Patch series "mm/ksm: improve PR_SET_MEMORY_MERGE=0 handling and cleanup disabling KSM", v2. (1) Make PR_SET_MEMORY_MERGE=0 unmerge pages like setting MADV_UNMERGEABLE does, (2) add a selftest for it and (3) factor out disabling of KSM from s390/gmap code. This patch (of 3): Let's unmerge any KSM pages when setting PR_SET_MEMORY_MERGE=0, and clear the VM_MERGEABLE flag from all VMAs -- just like KSM would. Of course, only do that if we previously set PR_SET_MEMORY_MERGE=1. Link: https://lkml.kernel.org/r/20230422205420.30372-1-david@redhat.com Link: https://lkml.kernel.org/r/20230422205420.30372-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Stefan Roesch <shr@devkernel.io> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Rik van Riel <riel@surriel.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-21mm: add new api to enable ksm per processStefan Roesch1-0/+27
Patch series "mm: process/cgroup ksm support", v9. So far KSM can only be enabled by calling madvise for memory regions. To be able to use KSM for more workloads, KSM needs to have the ability to be enabled / disabled at the process / cgroup level. Use case 1: The madvise call is not available in the programming language. An example for this are programs with forked workloads using a garbage collected language without pointers. In such a language madvise cannot be made available. In addition the addresses of objects get moved around as they are garbage collected. KSM sharing needs to be enabled "from the outside" for these type of workloads. Use case 2: The same interpreter can also be used for workloads where KSM brings no benefit or even has overhead. We'd like to be able to enable KSM on a workload by workload basis. Use case 3: With the madvise call sharing opportunities are only enabled for the current process: it is a workload-local decision. A considerable number of sharing opportunities may exist across multiple workloads or jobs (if they are part of the same security domain). Only a higler level entity like a job scheduler or container can know for certain if its running one or more instances of a job. That job scheduler however doesn't have the necessary internal workload knowledge to make targeted madvise calls. Security concerns: In previous discussions security concerns have been brought up. The problem is that an individual workload does not have the knowledge about what else is running on a machine. Therefore it has to be very conservative in what memory areas can be shared or not. However, if the system is dedicated to running multiple jobs within the same security domain, its the job scheduler that has the knowledge that sharing can be safely enabled and is even desirable. Performance: Experiments with using UKSM have shown a capacity increase of around 20%. Here are the metrics from an instagram workload (taken from a machine with 64GB main memory): full_scans: 445 general_profit: 20158298048 max_page_sharing: 256 merge_across_nodes: 1 pages_shared: 129547 pages_sharing: 5119146 pages_to_scan: 4000 pages_unshared: 1760924 pages_volatile: 10761341 run: 1 sleep_millisecs: 20 stable_node_chains: 167 stable_node_chains_prune_millisecs: 2000 stable_node_dups: 2751 use_zero_pages: 0 zero_pages_sharing: 0 After the service is running for 30 minutes to an hour, 4 to 5 million shared pages are common for this workload when using KSM. Detailed changes: 1. New options for prctl system command This patch series adds two new options to the prctl system call. The first one allows to enable KSM at the process level and the second one to query the setting. The setting will be inherited by child processes. With the above setting, KSM can be enabled for the seed process of a cgroup and all processes in the cgroup will inherit the setting. 2. Changes to KSM processing When KSM is enabled at the process level, the KSM code will iterate over all the VMA's and enable KSM for the eligible VMA's. When forking a process that has KSM enabled, the setting will be inherited by the new child process. 3. Add general_profit metric The general_profit metric of KSM is specified in the documentation, but not calculated. This adds the general profit metric to /sys/kernel/debug/mm/ksm. 4. Add more metrics to ksm_stat This adds the process profit metric to /proc/<pid>/ksm_stat. 5. Add more tests to ksm_tests and ksm_functional_tests This adds an option to specify the merge type to the ksm_tests. This allows to test madvise and prctl KSM. It also adds a two new tests to ksm_functional_tests: one to test the new prctl options and the other one is a fork test to verify that the KSM process setting is inherited by client processes. This patch (of 3): So far KSM can only be enabled by calling madvise for memory regions. To be able to use KSM for more workloads, KSM needs to have the ability to be enabled / disabled at the process / cgroup level. 1. New options for prctl system command This patch series adds two new options to the prctl system call. The first one allows to enable KSM at the process level and the second one to query the setting. The setting will be inherited by child processes. With the above setting, KSM can be enabled for the seed process of a cgroup and all processes in the cgroup will inherit the setting. 2. Changes to KSM processing When KSM is enabled at the process level, the KSM code will iterate over all the VMA's and enable KSM for the eligible VMA's. When forking a process that has KSM enabled, the setting will be inherited by the new child process. 1) Introduce new MMF_VM_MERGE_ANY flag This introduces the new flag MMF_VM_MERGE_ANY flag. When this flag is set, kernel samepage merging (ksm) gets enabled for all vma's of a process. 2) Setting VM_MERGEABLE on VMA creation When a VMA is created, if the MMF_VM_MERGE_ANY flag is set, the VM_MERGEABLE flag will be set for this VMA. 3) support disabling of ksm for a process This adds the ability to disable ksm for a process if ksm has been enabled for the process with prctl. 4) add new prctl option to get and set ksm for a process This adds two new options to the prctl system call - enable ksm for all vmas of a process (if the vmas support it). - query if ksm has been enabled for a process. 3. Disabling MMF_VM_MERGE_ANY for storage keys in s390 In the s390 architecture when storage keys are used, the MMF_VM_MERGE_ANY will be disabled. Link: https://lkml.kernel.org/r/20230418051342.1919757-1-shr@devkernel.io Link: https://lkml.kernel.org/r/20230418051342.1919757-2-shr@devkernel.io Signed-off-by: Stefan Roesch <shr@devkernel.io> Acked-by: David Hildenbrand <david@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Rik van Riel <riel@surriel.com> Cc: Bagas Sanjaya <bagasdotme@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18prctl: add PR_GET_AUXV to copy auxv to userspaceJosh Triplett1-0/+15
If a library wants to get information from auxv (for instance, AT_HWCAP/AT_HWCAP2), it has a few options, none of them perfectly reliable or ideal: - Be main or the pre-main startup code, and grub through the stack above main. Doesn't work for a library. - Call libc getauxval. Not ideal for libraries that are trying to be libc-independent and/or don't otherwise require anything from other libraries. - Open and read /proc/self/auxv. Doesn't work for libraries that may run in arbitrarily constrained environments that may not have /proc mounted (e.g. libraries that might be used by an init program or a container setup tool). - Assume you're on the main thread and still on the original stack, and try to walk the stack upwards, hoping to find auxv. Extremely bad idea. - Ask the caller to pass auxv in for you. Not ideal for a user-friendly library, and then your caller may have the same problem. Add a prctl that copies current->mm->saved_auxv to a userspace buffer. Link: https://lkml.kernel.org/r/d81864a7f7f43bca6afa2a09fc2e850e4050ab42.1680611394.git.josh@joshtriplett.org Signed-off-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18kernel/sys.c: fix and improve control flow in __sys_setres[ug]id()Ondrej Mosnacek1-29/+40
Linux Security Modules (LSMs) that implement the "capable" hook will usually emit an access denial message to the audit log whenever they "block" the current task from using the given capability based on their security policy. The occurrence of a denial is used as an indication that the given task has attempted an operation that requires the given access permission, so the callers of functions that perform LSM permission checks must take care to avoid calling them too early (before it is decided if the permission is actually needed to perform the requested operation). The __sys_setres[ug]id() functions violate this convention by first calling ns_capable_setid() and only then checking if the operation requires the capability or not. It means that any caller that has the capability granted by DAC (task's capability set) but not by MAC (LSMs) will generate a "denied" audit record, even if is doing an operation for which the capability is not required. Fix this by reordering the checks such that ns_capable_setid() is checked last and -EPERM is returned immediately if it returns false. While there, also do two small optimizations: * move the capability check before prepare_creds() and * bail out early in case of a no-op. Link: https://lkml.kernel.org/r/20230217162154.837549-1-omosnace@redhat.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-23Merge tag 'mm-stable-2023-02-20-13-37' of ↵Linus Torvalds1-0/+33
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Daniel Verkamp has contributed a memfd series ("mm/memfd: add F_SEAL_EXEC") which permits the setting of the memfd execute bit at memfd creation time, with the option of sealing the state of the X bit. - Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset() thread-safe for pmd unshare") which addresses a rare race condition related to PMD unsharing. - Several folioification patch serieses from Matthew Wilcox, Vishal Moola, Sidhartha Kumar and Lorenzo Stoakes - Johannes Weiner has a series ("mm: push down lock_page_memcg()") which does perform some memcg maintenance and cleanup work. - SeongJae Park has added DAMOS filtering to DAMON, with the series "mm/damon/core: implement damos filter". These filters provide users with finer-grained control over DAMOS's actions. SeongJae has also done some DAMON cleanup work. - Kairui Song adds a series ("Clean up and fixes for swap"). - Vernon Yang contributed the series "Clean up and refinement for maple tree". - Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It adds to MGLRU an LRU of memcgs, to improve the scalability of global reclaim. - David Hildenbrand has added some userfaultfd cleanup work in the series "mm: uffd-wp + change_protection() cleanups". - Christoph Hellwig has removed the generic_writepages() library function in the series "remove generic_writepages". - Baolin Wang has performed some maintenance on the compaction code in his series "Some small improvements for compaction". - Sidhartha Kumar is doing some maintenance work on struct page in his series "Get rid of tail page fields". - David Hildenbrand contributed some cleanup, bugfixing and generalization of pte management and of pte debugging in his series "mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap PTEs". - Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation flag in the series "Discard __GFP_ATOMIC". - Sergey Senozhatsky has improved zsmalloc's memory utilization with his series "zsmalloc: make zspage chain size configurable". - Joey Gouly has added prctl() support for prohibiting the creation of writeable+executable mappings. The previous BPF-based approach had shortcomings. See "mm: In-kernel support for memory-deny-write-execute (MDWE)". - Waiman Long did some kmemleak cleanup and bugfixing in the series "mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF". - T.J. Alumbaugh has contributed some MGLRU cleanup work in his series "mm: multi-gen LRU: improve". - Jiaqi Yan has provided some enhancements to our memory error statistics reporting, mainly by presenting the statistics on a per-node basis. See the series "Introduce per NUMA node memory error statistics". - Mel Gorman has a second and hopefully final shot at fixing a CPU-hog regression in compaction via his series "Fix excessive CPU usage during compaction". - Christoph Hellwig does some vmalloc maintenance work in the series "cleanup vfree and vunmap". - Christoph Hellwig has removed block_device_operations.rw_page() in ths series "remove ->rw_page". - We get some maple_tree improvements and cleanups in Liam Howlett's series "VMA tree type safety and remove __vma_adjust()". - Suren Baghdasaryan has done some work on the maintainability of our vm_flags handling in the series "introduce vm_flags modifier functions". - Some pagemap cleanup and generalization work in Mike Rapoport's series "mm, arch: add generic implementation of pfn_valid() for FLATMEM" and "fixups for generic implementation of pfn_valid()" - Baoquan He has done some work to make /proc/vmallocinfo and /proc/kcore better represent the real state of things in his series "mm/vmalloc.c: allow vread() to read out vm_map_ram areas". - Jason Gunthorpe rationalized the GUP system's interface to the rest of the kernel in the series "Simplify the external interface for GUP". - SeongJae Park wishes to migrate people from DAMON's debugfs interface over to its sysfs interface. To support this, we'll temporarily be printing warnings when people use the debugfs interface. See the series "mm/damon: deprecate DAMON debugfs interface". - Andrey Konovalov provided the accurately named "lib/stackdepot: fixes and clean-ups" series. - Huang Ying has provided a dramatic reduction in migration's TLB flush IPI rates with the series "migrate_pages(): batch TLB flushing". - Arnd Bergmann has some objtool fixups in "objtool warning fixes". * tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (505 commits) include/linux/migrate.h: remove unneeded externs mm/memory_hotplug: cleanup return value handing in do_migrate_range() mm/uffd: fix comment in handling pte markers mm: change to return bool for isolate_movable_page() mm: hugetlb: change to return bool for isolate_hugetlb() mm: change to return bool for isolate_lru_page() mm: change to return bool for folio_isolate_lru() objtool: add UACCESS exceptions for __tsan_volatile_read/write kmsan: disable ftrace in kmsan core code kasan: mark addr_has_metadata __always_inline mm: memcontrol: rename memcg_kmem_enabled() sh: initialize max_mapnr m68k/nommu: add missing definition of ARCH_PFN_OFFSET mm: percpu: fix incorrect size in pcpu_obj_full_size() maple_tree: reduce stack usage with gcc-9 and earlier mm: page_alloc: call panic() when memoryless node allocation fails mm: multi-gen LRU: avoid futile retries migrate_pages: move THP/hugetlb migration support check to simplify code migrate_pages: batch flushing TLB migrate_pages: share more code between _unmap and _move ...
2023-02-02mm: implement memory-deny-write-execute as a prctlJoey Gouly1-0/+33
Patch series "mm: In-kernel support for memory-deny-write-execute (MDWE)", v2. The background to this is that systemd has a configuration option called MemoryDenyWriteExecute [2], implemented as a SECCOMP BPF filter. Its aim is to prevent a user task from inadvertently creating an executable mapping that is (or was) writeable. Since such BPF filter is stateless, it cannot detect mappings that were previously writeable but subsequently changed to read-only. Therefore the filter simply rejects any mprotect(PROT_EXEC). The side-effect is that on arm64 with BTI support (Branch Target Identification), the dynamic loader cannot change an ELF section from PROT_EXEC to PROT_EXEC|PROT_BTI using mprotect(). For libraries, it can resort to unmapping and re-mapping but for the main executable it does not have a file descriptor. The original bug report in the Red Hat bugzilla - [3] - and subsequent glibc workaround for libraries - [4]. This series adds in-kernel support for this feature as a prctl PR_SET_MDWE, that is inherited on fork(). The prctl denies PROT_WRITE | PROT_EXEC mappings. Like the systemd BPF filter it also denies adding PROT_EXEC to mappings. However unlike the BPF filter it only denies it if the mapping didn't previous have PROT_EXEC. This allows to PROT_EXEC -> PROT_EXEC | PROT_BTI with mprotect(), which is a problem with the BPF filter. This patch (of 2): The aim of such policy is to prevent a user task from creating an executable mapping that is also writeable. An example of mmap() returning -EACCESS if the policy is enabled: mmap(0, size, PROT_READ | PROT_WRITE | PROT_EXEC, flags, 0, 0); Similarly, mprotect() would return -EACCESS below: addr = mmap(0, size, PROT_READ | PROT_EXEC, flags, 0, 0); mprotect(addr, size, PROT_READ | PROT_WRITE | PROT_EXEC); The BPF filter that systemd MDWE uses is stateless, and disallows mprotect() with PROT_EXEC completely. This new prctl allows PROT_EXEC to be enabled if it was already PROT_EXEC, which allows the following case: addr = mmap(0, size, PROT_READ | PROT_EXEC, flags, 0, 0); mprotect(addr, size, PROT_READ | PROT_EXEC | PROT_BTI); where PROT_BTI enables branch tracking identification on arm64. Link: https://lkml.kernel.org/r/20230119160344.54358-1-joey.gouly@arm.com Link: https://lkml.kernel.org/r/20230119160344.54358-2-joey.gouly@arm.com Signed-off-by: Joey Gouly <joey.gouly@arm.com> Co-developed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jeremy Linton <jeremy.linton@arm.com> Cc: Kees Cook <keescook@chromium.org> Cc: Lennart Poettering <lennart@poettering.net> Cc: Mark Brown <broonie@kernel.org> Cc: nd <nd@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Szabolcs Nagy <szabolcs.nagy@arm.com> Cc: Topi Miettinen <toiwoton@gmail.com> Cc: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-21prlimit: do_prlimit needs to have a speculation checkGreg Kroah-Hartman1-0/+2
do_prlimit() adds the user-controlled resource value to a pointer that will subsequently be dereferenced. In order to help prevent this codepath from being used as a spectre "gadget" a barrier needs to be added after checking the range. Reported-by: Jordy Zomer <jordyzomer@google.com> Tested-by: Jordy Zomer <jordyzomer@google.com> Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-10Merge tag 'random-6.1-rc1-for-linus' of ↵Linus Torvalds1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/crng/random Pull random number generator updates from Jason Donenfeld: - Huawei reported that when they updated their kernel from 4.4 to something much newer, some userspace code they had broke, the culprit being the accidental removal of O_NONBLOCK from /dev/random way back in 5.6. It's been gone for over 2 years now and this is the first we've heard of it, but user