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2022-02-22cgroup: clarify cgroup_css_set_fork()Christian Brauner
With recent fixes for the permission checking when moving a task into a cgroup using a file descriptor to a cgroup's cgroup.procs file and calling write() it seems a good idea to clarify CLONE_INTO_CGROUP permission checking with a comment. Cc: Tejun Heo <tj@kernel.org> Cc: <cgroups@vger.kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2022-02-21random: clear fast pool, crng, and batches in cpuhp bring upJason A. Donenfeld
For the irq randomness fast pool, rather than having to use expensive atomics, which were visibly the most expensive thing in the entire irq handler, simply take care of the extreme edge case of resetting count to zero in the cpuhp online handler, just after workqueues have been reenabled. This simplifies the code a bit and lets us use vanilla variables rather than atomics, and performance should be improved. As well, very early on when the CPU comes up, while interrupts are still disabled, we clear out the per-cpu crng and its batches, so that it always starts with fresh randomness. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Sultan Alsawaf <sultan@kerneltoast.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21printk: make suppress_panic_printk staticJiapeng Chong
This symbol is not used outside of printk.c, so marks it static. Fix the following sparse warning: kernel/printk/printk.c:100:19: warning: symbol 'suppress_panic_printk' was not declared. Should it be static? Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Reviewed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220216031957.9761-1-jiapeng.chong@linux.alibaba.com
2022-02-21printk: Set console_set_on_cmdline=1 when __add_preferred_console() is ↵Andre Kalb
called with user_specified == true In case of using console="" or console=null set console_set_on_cmdline=1 to disable "stdout-path" node from DT. We basically need to set it every time when __add_preferred_console() is called with parameter 'user_specified' set. Therefore we can move setting it into a helper function that is called from __add_preferred_console(). Suggested-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Andre Kalb <andre.kalb@sma.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/YgzU4ho8l6XapyG2@pc6682
2022-02-21Merge tag 'v5.17-rc5' into sched/core, to resolve conflictsIngo Molnar
New conflicts in sched/core due to the following upstream fixes: 44585f7bc0cb ("psi: fix "defined but not used" warnings when CONFIG_PROC_FS=n") a06247c6804f ("psi: Fix uaf issue when psi trigger is destroyed while being polled") Conflicts: include/linux/psi_types.h kernel/sched/psi.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
2022-02-21Merge tag 'irq-api-2022-02-21' into irq/coreThomas Gleixner
Merge the generic_handle_irq_safe() API back into irq/core.
2022-02-21genirq: Provide generic_handle_irq_safe()Sebastian Andrzej Siewior
Provide generic_handle_irq_safe() which can used from any context. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Reviewed-by: Oleksandr Natalenko <oleksandr@natalenko.name> Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Link: https://lore.kernel.org/r/20220211181500.1856198-2-bigeasy@linutronix.de
2022-02-21x86/speculation: Include unprivileged eBPF status in Spectre v2 mitigation ↵Josh Poimboeuf
reporting With unprivileged eBPF enabled, eIBRS (without retpoline) is vulnerable to Spectre v2 BHB-based attacks. When both are enabled, print a warning message and report it in the 'spectre_v2' sysfs vulnerabilities file. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2022-02-20Merge tag 'locking_urgent_for_v5.17_rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fix from Borislav Petkov: "Fix a NULL ptr dereference when dumping lockdep chains through /proc/lockdep_chains" * tag 'locking_urgent_for_v5.17_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: lockdep: Correct lock_classes index mapping
2022-02-20Merge tag 'sched_urgent_for_v5.17_rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fix from Borislav Petkov: "Fix task exposure order when forking tasks" * tag 'sched_urgent_for_v5.17_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched: Fix yet more sched_fork() races
2022-02-20Merge tag 'pidfd.v5.17-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux Pull pidfd fix from Christian Brauner: "This fixes a problem reported by lockdep when installing a pidfd via fd_install() with siglock and the tasklisk write lock held in copy_process() when calling clone()/clone3() with CLONE_PIDFD. Originally a pidfd was created prior to holding any of these locks but this required a call to ksys_close(). So quite some time ago in 6fd2fe494b17 ("copy_process(): don't use ksys_close() on cleanups") we switched to a get_unused_fd_flags() + fd_install() model. As part of that we moved fd_install() as late as possible. This was done for two main reasons. First, because we needed to ensure that we call fd_install() past the point of no return as once that's called the fd is live in the task's file table. Second, because we tried to ensure that the fd is visible in /proc/<pid>/fd/<pidfd> right when the task is visible. This fix moves the fd_install() to an even later point which means that a task will be visible in proc while the pidfd isn't yet under /proc/<pid>/fd/<pidfd>. While this is a user visible change it's very unlikely that this will have any impact. Nobody should be relying on that and if they do we need to come up with something better but again, it's doubtful this is relevant" * tag 'pidfd.v5.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: copy_process(): Move fd_install() out of sighand->siglock critical section
2022-02-20Merge branch 'ucount-rlimit-fixes-for-v5.17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull ucounts fixes from Eric Biederman: "Michal Koutný recently found some bugs in the enforcement of RLIMIT_NPROC in the recent ucount rlimit implementation. In this set of patches I have developed a very conservative approach changing only what is necessary to fix the bugs that I can see clearly. Cleanups and anything that is making the code more consistent can follow after we have the code working as it has historically. The problem is not so much inconsistencies (although those exist) but that it is very difficult to figure out what the code should be doing in the case of RLIMIT_NPROC. All other rlimits are only enforced where the resource is acquired (allocated). RLIMIT_NPROC by necessity needs to be enforced in an additional location, and our current implementation stumbled it's way into that implementation" * 'ucount-rlimit-fixes-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: ucounts: Handle wrapping in is_ucounts_overlimit ucounts: Move RLIMIT_NPROC handling after set_user ucounts: Base set_cred_ucounts changes on the real user ucounts: Enforce RLIMIT_NPROC not RLIMIT_NPROC+1 rlimit: Fix RLIMIT_NPROC enforcement failure caused by capability calls in set_user
2022-02-19bpf: Initialize ret to 0 inside btf_populate_kfunc_set()Souptick Joarder (HPE)
Kernel test robot reported below error -> kernel/bpf/btf.c:6718 btf_populate_kfunc_set() error: uninitialized symbol 'ret'. Initialize ret to 0. Fixes: dee872e124e8 ("bpf: Populate kfunc BTF ID sets in struct btf") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Souptick Joarder (HPE) <jrdr.linux@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/bpf/20220219163915.125770-1-jrdr.linux@gmail.com
2022-02-19sched/preempt: Add PREEMPT_DYNAMIC using static keysMark Rutland
Where an architecture selects HAVE_STATIC_CALL but not HAVE_STATIC_CALL_INLINE, each static call has an out-of-line trampoline which will either branch to a callee or return to the caller. On such architectures, a number of constraints can conspire to make those trampolines more complicated and potentially less useful than we'd like. For example: * Hardware and software control flow integrity schemes can require the addition of "landing pad" instructions (e.g. `BTI` for arm64), which will also be present at the "real" callee. * Limited branch ranges can require that trampolines generate or load an address into a register and perform an indirect branch (or at least have a slow path that does so). This loses some of the benefits of having a direct branch. * Interaction with SW CFI schemes can be complicated and fragile, e.g. requiring that we can recognise idiomatic codegen and remove indirections understand, at least until clang proves more helpful mechanisms for dealing with this. For PREEMPT_DYNAMIC, we don't need the full power of static calls, as we really only need to enable/disable specific preemption functions. We can achieve the same effect without a number of the pain points above by using static keys to fold early returns into the preemption functions themselves rather than in an out-of-line trampoline, effectively inlining the trampoline into the start of the function. For arm64, this results in good code generation. For example, the dynamic_cond_resched() wrapper looks as follows when enabled. When disabled, the first `B` is replaced with a `NOP`, resulting in an early return. | <dynamic_cond_resched>: | bti c | b <dynamic_cond_resched+0x10> // or `nop` | mov w0, #0x0 | ret | mrs x0, sp_el0 | ldr x0, [x0, #8] | cbnz x0, <dynamic_cond_resched+0x8> | paciasp | stp x29, x30, [sp, #-16]! | mov x29, sp | bl <preempt_schedule_common> | mov w0, #0x1 | ldp x29, x30, [sp], #16 | autiasp | ret ... compared to the regular form of the function: | <__cond_resched>: | bti c | mrs x0, sp_el0 | ldr x1, [x0, #8] | cbz x1, <__cond_resched+0x18> | mov w0, #0x0 | ret | paciasp | stp x29, x30, [sp, #-16]! | mov x29, sp | bl <preempt_schedule_common> | mov w0, #0x1 | ldp x29, x30, [sp], #16 | autiasp | ret Any architecture which implements static keys should be able to use this to implement PREEMPT_DYNAMIC with similar cost to non-inlined static calls. Since this is likely to have greater overhead than (inlined) static calls, PREEMPT_DYNAMIC is only defaulted to enabled when HAVE_PREEMPT_DYNAMIC_CALL is selected. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20220214165216.2231574-6-mark.rutland@arm.com
2022-02-19sched/preempt: Decouple HAVE_PREEMPT_DYNAMIC from GENERIC_ENTRYMark Rutland
Now that the enabled/disabled states for the preemption functions are declared alongside their definitions, the core PREEMPT_DYNAMIC logic is no longer tied to GENERIC_ENTRY, and can safely be selected so long as an architecture provides enabled/disabled states for irqentry_exit_cond_resched(). Make it possible to select HAVE_PREEMPT_DYNAMIC without GENERIC_ENTRY. For existing users of HAVE_PREEMPT_DYNAMIC there should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20220214165216.2231574-5-mark.rutland@arm.com
2022-02-19sched/preempt: Simplify irqentry_exit_cond_resched() callersMark Rutland
Currently callers of irqentry_exit_cond_resched() need to be aware of whether the function should be indirected via a static call, leading to ugly ifdeffery in callers. Save them the hassle with a static inline wrapper that does the right thing. The raw_irqentry_exit_cond_resched() will also be useful in subsequent patches which will add conditional wrappers for preemption functions. Note: in arch/x86/entry/common.c, xen_pv_evtchn_do_upcall() always calls irqentry_exit_cond_resched() directly, even when PREEMPT_DYNAMIC is in use. I believe this is a latent bug (which this patch corrects), but I'm not entirely certain this wasn't deliberate. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20220214165216.2231574-4-mark.rutland@arm.com
2022-02-19sched/preempt: Refactor sched_dynamic_update()Mark Rutland
Currently sched_dynamic_update needs to open-code the enabled/disabled function names for each preemption model it supports, when in practice this is a boolean enabled/disabled state for each function. Make this clearer and avoid repetition by defining the enabled/disabled states at the function definition, and using helper macros to perform the static_call_update(). Where x86 currently overrides the enabled function, it is made to provide both the enabled and disabled states for consistency, with defaults provided by the core code otherwise. In subsequent patches this will allow us to support PREEMPT_DYNAMIC without static calls. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20220214165216.2231574-3-mark.rutland@arm.com
2022-02-19sched/preempt: Move PREEMPT_DYNAMIC logic laterMark Rutland
The PREEMPT_DYNAMIC logic in kernel/sched/core.c patches static calls for a bunch of preemption functions. While most are defined prior to this, the definition of cond_resched() is later in the file, and so we only have its declarations from include/linux/sched.h. In subsequent patches we'd like to define some macros alongside the definition of each of the preemption functions, which we can use within sched_dynamic_update(). For this to be possible, the PREEMPT_DYNAMIC logic needs to be placed after the various preemption functions. As a preparatory step, this patch moves the PREEMPT_DYNAMIC logic after the various preemption functions, with no other changes -- this is purely a move. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20220214165216.2231574-2-mark.rutland@arm.com
2022-02-19sched: Fix yet more sched_fork() racesPeter Zijlstra
Where commit 4ef0c5c6b5ba ("kernel/sched: Fix sched_fork() access an invalid sched_task_group") fixed a fork race vs cgroup, it opened up a race vs syscalls by not placing the task on the runqueue before it gets exposed through the pidhash. Commit 13765de8148f ("sched/fair: Fix fault in reweight_entity") is trying to fix a single instance of this, instead fix the whole class of issues, effectively reverting this commit. Fixes: 4ef0c5c6b5ba ("kernel/sched: Fix sched_fork() access an invalid sched_task_group") Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Tadeusz Struk <tadeusz.struk@linaro.org> Tested-by: Zhang Qiao <zhangqiao22@huawei.com> Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Link: https://lkml.kernel.org/r/YgoeCbwj5mbCR0qA@hirez.programming.kicks-ass.net
2022-02-18bpf: Call maybe_wait_bpf_programs() only once from generic_map_delete_batch()Eric Dumazet
As stated in the comment found in maybe_wait_bpf_programs(), the synchronize_rcu() barrier is only needed before returning to userspace, not after each deletion in the batch. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/bpf/20220218181801.2971275-1-eric.dumazet@gmail.com
2022-02-18KVM: x86: allow defining return-0 static callsPaolo Bonzini
A few vendor callbacks are only used by VMX, but they return an integer or bool value. Introduce KVM_X86_OP_OPTIONAL_RET0 for them: if a func is NULL in struct kvm_x86_ops, it will be changed to __static_call_return0 when updating static calls. Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-17Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski
Daniel Borkmann says: ==================== bpf-next 2022-02-17 We've added 29 non-merge commits during the last 8 day(s) which contain a total of 34 files changed, 1502 insertions(+), 524 deletions(-). The main changes are: 1) Add BTFGen support to bpftool which allows to use CO-RE in kernels without BTF info, from Mauricio Vásquez, Rafael David Tinoco, Lorenzo Fontana and Leonardo Di Donato. (Details: https://lpc.events/event/11/contributions/948/) 2) Prepare light skeleton to be used in both kernel module and user space and convert bpf_preload.ko to use light skeleton, from Alexei Starovoitov. 3) Rework bpftool's versioning scheme and align with libbpf's version number; also add linked libbpf version info to "bpftool version", from Quentin Monnet. 4) Add minimal C++ specific additions to bpftool's skeleton codegen to facilitate use of C skeletons in C++ applications, from Andrii Nakryiko. 5) Add BPF verifier sanity check whether relative offset on kfunc calls overflows desc->imm and reject the BPF program if the case, from Hou Tao. 6) Fix libbpf to use a dynamically allocated buffer for netlink messages to avoid receiving truncated messages on some archs, from Toke Høiland-Jørgensen. 7) Various follow-up fixes to the JIT bpf_prog_pack allocator, from Song Liu. 8) Various BPF selftest and vmtest.sh fixes, from Yucong Sun. 9) Fix bpftool pretty print handling on dumping map keys/values when no BTF is available, from Jiri Olsa and Yinjun Zhang. 10) Extend XDP frags selftest to check for invalid length, from Lorenzo Bianconi. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (29 commits) bpf: bpf_prog_pack: Set proper size before freeing ro_header selftests/bpf: Fix crash in core_reloc when bpftool btfgen fails selftests/bpf: Fix vmtest.sh to launch smp vm. libbpf: Fix memleak in libbpf_netlink_recv() bpftool: Fix C++ additions to skeleton bpftool: Fix pretty print dump for maps without BTF loaded selftests/bpf: Test "bpftool gen min_core_btf" bpftool: Gen min_core_btf explanation and examples bpftool: Implement btfgen_get_btf() bpftool: Implement "gen min_core_btf" logic bpftool: Add gen min_core_btf command libbpf: Expose bpf_core_{add,free}_cands() to bpftool libbpf: Split bpf_core_apply_relo() bpf: Reject kfunc calls that overflow insn->imm selftests/bpf: Add Skeleton templated wrapper as an example bpftool: Add C++-specific open/load/etc skeleton wrappers selftests/bpf: Fix GCC11 compiler warnings in -O2 mode bpftool: Fix the error when lookup in no-btf maps libbpf: Use dynamically allocated buffer when receiving netlink messages libbpf: Fix libbpf.map inheritance chain for LIBBPF_0.7.0 ... ==================== Link: https://lore.kernel.org/r/20220217232027.29831-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-17bpf: bpf_prog_pack: Set proper size before freeing ro_headerSong Liu
bpf_prog_pack_free() uses header->size to decide whether the header should be freed with module_memfree() or the bpf_prog_pack logic. However, in kvmalloc() failure path of bpf_jit_binary_pack_alloc(), header->size is not set yet. As a result, bpf_prog_pack_free() may treat a slice of a pack as a standalone kvmalloc'd header and call module_memfree() on the whole pack. This in turn causes use-after-free by other users of the pack. Fix this by setting ro_header->size before freeing ro_header. Fixes: 33c9805860e5 ("bpf: Introduce bpf_jit_binary_pack_[alloc|finalize|free]") Reported-by: syzbot+2f649ec6d2eea1495a8f@syzkaller.appspotmail.com Reported-by: syzbot+ecb1e7e51c52f68f7481@syzkaller.appspotmail.com Reported-by: syzbot+87f65c75f4a72db05445@syzkaller.appspotmail.com Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220217183001.1876034-1-song@kernel.org
2022-02-17Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Fast path bpf marge for some -next work. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-17Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfJakub Kicinski
Alexei Starovoitov says: ==================== pull-request: bpf 2022-02-17 We've added 8 non-merge commits during the last 7 day(s) which contain a total of 8 files changed, 119 insertions(+), 15 deletions(-). The main changes are: 1) Add schedule points in map batch ops, from Eric. 2) Fix bpf_msg_push_data with len 0, from Felix. 3) Fix crash due to incorrect copy_map_value, from Kumar. 4) Fix crash due to out of bounds access into reg2btf_ids, from Kumar. 5) Fix a bpf_timer initialization issue with clang, from Yonghong. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: bpf: Add schedule points in batch ops bpf: Fix crash due to out of bounds access into reg2btf_ids. selftests: bpf: Check bpf_msg_push_data return value bpf: Fix a bpf_timer initialization issue bpf: Emit bpf_timer in vmlinux BTF selftests/bpf: Add test for bpf_timer overwriting crash bpf: Fix crash due to incorrect copy_map_value bpf: Do not try bpf_msg_push_data with len 0 ==================== Link: https://lore.kernel.org/r/20220217190000.37925-1-alexei.starovoitov@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-17Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-17bpf: Add schedule points in batch opsEric Dumazet
syzbot reported various soft lockups caused by bpf batch operations. INFO: task kworker/1:1:27 blocked for more than 140 seconds. INFO: task hung in rcu_barrier Nothing prevents batch ops to process huge amount of data, we need to add schedule points in them. Note that maybe_wait_bpf_programs(map) calls from generic_map_delete_batch() can be factorized by moving the call after the loop. This will be done later in -next tree once we get this fix merged, unless there is strong opinion doing this optimization sooner. Fixes: aa2e93b8e58e ("bpf: Add generic support for update and delete batch ops") Fixes: cb4d03ab499d ("bpf: Add generic support for lookup batch op") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Stanislav Fomichev <sdf@google.com> Acked-by: Brian Vazquez <brianvv@google.com> Link: https://lore.kernel.org/bpf/20220217181902.808742-1-eric.dumazet@gmail.com
2022-02-17mm/munlock: rmap call mlock_vma_page() munlock_vma_page()Hugh Dickins
Add vma argument to mlock_vma_page() and munlock_vma_page(), make them inline functions which check (vma->vm_flags & VM_LOCKED) before calling mlock_page() and munlock_page() in mm/mlock.c. Add bool compound to mlock_vma_page() and munlock_vma_page(): this is because we have understandable difficulty in accounting pte maps of THPs, and if passed a PageHead page, mlock_page() and munlock_page() cannot tell whether it's a pmd map to be counted or a pte map to be ignored. Add vma arg to page_add_file_rmap() and page_remove_rmap(), like the others, and use that to call mlock_vma_page() at the end of the page adds, and munlock_vma_page() at the end of page_remove_rmap() (end or beginning? unimportant, but end was easier for assertions in testing). No page lock is required (although almost all adds happen to hold it): delete the "Serialize with page migration" BUG_ON(!PageLocked(page))s. Certainly page lock did serialize with page migration, but I'm having difficulty explaining why that was ever important. Mlock accounting on THPs has been hard to define, differed between anon and file, involved PageDoubleMap in some places and not others, required clear_page_mlock() at some points. Keep it simple now: just count the pmds and ignore the ptes, there is no reason for ptes to undo pmd mlocks. page_add_new_anon_rmap() callers unchanged: they have long been calling lru_cache_add_inactive_or_unevictable(), which does its own VM_LOCKED handling (it also checks for not VM_SPECIAL: I think that's overcautious, and inconsistent with other checks, that mmap_region() already prevents VM_LOCKED on VM_SPECIAL; but haven't quite convinced myself to change it). Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-02-17ucounts: Handle wrapping in is_ucounts_overlimitEric W. Biederman
While examining is_ucounts_overlimit and reading the various messages I realized that is_ucounts_overlimit fails to deal with counts that may have wrapped. Being wrapped should be a transitory state for counts and they should never be wrapped for long, but it can happen so handle it. Cc: stable@vger.kernel.org Fixes: 21d1c5e386bc ("Reimplement RLIMIT_NPROC on top of ucounts") Link: https://lkml.kernel.org/r/20220216155832.680775-5-ebiederm@xmission.com Reviewed-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-02-17ucounts: Move RLIMIT_NPROC handling after set_userEric W. Biederman
During set*id() which cred->ucounts to charge the the current process to is not known until after set_cred_ucounts. So move the RLIMIT_NPROC checking into a new helper flag_nproc_exceeded and call flag_nproc_exceeded after set_cred_ucounts. This is very much an arbitrary subset of the places where we currently change the RLIMIT_NPROC accounting, designed to preserve the existing logic. Fixing the existing logic will be the subject of another series of changes. Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20220216155832.680775-4-ebiederm@xmission.com Fixes: 21d1c5e386bc ("Reimplement RLIMIT_NPROC on top of ucounts") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-02-17ucounts: Base set_cred_ucounts changes on the real userEric W. Biederman
Michal Koutný <mkoutny@suse.com> wrote: > Tasks are associated to multiple users at once. Historically and as per > setrlimit(2) RLIMIT_NPROC is enforce based on real user ID. > > The commit 21d1c5e386bc ("Reimplement RLIMIT_NPROC on top of ucounts") > made the accounting structure "indexed" by euid and hence potentially > account tasks differently. > > The effective user ID may be different e.g. for setuid programs but > those are exec'd into already existing task (i.e. below limit), so > different accounting is moot. > > Some special setresuid(2) users may notice the difference, justifying > this fix. I looked at cred->ucount and it is only used for rlimit operations that were previously stored in cred->user. Making the fact cred->ucount can refer to a different user from cred->user a bug, affecting all uses of cred->ulimit not just RLIMIT_NPROC. Fix set_cred_ucounts to always use the real uid not the effective uid. Further simplify set_cred_ucounts by noticing that set_cred_ucounts somehow retained a draft version of the check to see if alloc_ucounts was needed that checks the new->user and new->user_ns against the current_real_cred(). Remove that draft version of the check. All that matters for setting the cred->ucounts are the user_ns and uid fields in the cred. Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20220207121800.5079-4-mkoutny@suse.com Link: https://lkml.kernel.org/r/20220216155832.680775-3-ebiederm@xmission.com Reported-by: Michal Koutný <mkoutny@suse.com> Reviewed-by: Michal Koutný <mkoutny@suse.com> Fixes: 21d1c5e386bc ("Reimplement RLIMIT_NPROC on top of ucounts") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-02-17ucounts: Enforce RLIMIT_NPROC not RLIMIT_NPROC+1Eric W. Biederman
Michal Koutný <mkoutny@suse.com> wrote: > It was reported that v5.14 behaves differently when enforcing > RLIMIT_NPROC limit, namely, it allows one more task than previously. > This is consequence of the commit 21d1c5e386bc ("Reimplement > RLIMIT_NPROC on top of ucounts") that missed the sharpness of > equality in the forking path. This can be fixed either by fixing the test or by moving the increment to be before the test. Fix it my moving copy_creds which contains the increment before is_ucounts_overlimit. In the case of CLONE_NEWUSER the ucounts in the task_cred changes. The function is_ucounts_overlimit needs to use the final version of the ucounts for the new process. Which means moving the is_ucounts_overlimit test after copy_creds is necessary. Both the test in fork and the test in set_user were semantically changed when the code moved to ucounts. The change of the test in fork was bad because it was before the increment. The test in set_user was wrong and the change to ucounts fixed it. So this fix only restores the old behavior in one lcation not two. Link: https://lkml.kernel.org/r/20220204181144.24462-1-mkoutny@suse.com Link: https://lkml.kernel.org/r/20220216155832.680775-2-ebiederm@xmission.com Cc: stable@vger.kernel.org Reported-by: Michal Koutný <mkoutny@suse.com> Reviewed-by: Michal Koutný <mkoutny@suse.com> Fixes: 21d1c5e386bc ("Reimplement RLIMIT_NPROC on top of ucounts") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-02-17rlimit: Fix RLIMIT_NPROC enforcement failure caused by capability calls in ↵Eric W. Biederman
set_user Solar Designer <solar@openwall.com> wrote: > I'm not aware of anyone actually running into this issue and reporting > it. The systems that I personally know use suexec along with rlimits > still run older/distro kernels, so would not yet be affected. > > So my mention was based on my understanding of how suexec works, and > code review. Specifically, Apache httpd has the setting RLimitNPROC, > which makes it set RLIMIT_NPROC: > > https://httpd.apache.org/docs/2.4/mod/core.html#rlimitnproc > > The above documentation for it includes: > > "This applies to processes forked from Apache httpd children servicing > requests, not the Apache httpd children themselves. This includes CGI > scripts and SSI exec commands, but not any processes forked from the > Apache httpd parent, such as piped logs." > > In code, there are: > > ./modules/generators/mod_cgid.c: ( (cgid_req.limits.limit_nproc_set) && ((rc = apr_procattr_limit_set(procattr, APR_LIMIT_NPROC, > ./modules/generators/mod_cgi.c: ((rc = apr_procattr_limit_set(procattr, APR_LIMIT_NPROC, > ./modules/filters/mod_ext_filter.c: rv = apr_procattr_limit_set(procattr, APR_LIMIT_NPROC, conf->limit_nproc); > > For example, in mod_cgi.c this is in run_cgi_child(). > > I think this means an httpd child sets RLIMIT_NPROC shortly before it > execs suexec, which is a SUID root program. suexec then switches to the > target user and execs the CGI script. > > Before 2863643fb8b9, the setuid() in suexec would set the flag, and the > target user's process count would be checked against RLIMIT_NPROC on > execve(). After 2863643fb8b9, the setuid() in suexec wouldn't set the > flag because setuid() is (naturally) called when the process is still > running as root (thus, has those limits bypass capabilities), and > accordingly execve() would not check the target user's process count > against RLIMIT_NPROC. In commit 2863643fb8b9 ("set_user: add capability check when rlimit(RLIMIT_NPROC) exceeds") capable calls were added to set_user to make it more consistent with fork. Unfortunately because of call site differences those capable calls were checking the credentials of the user before set*id() instead of after set*id(). This breaks enforcement of RLIMIT_NPROC for applications that set the rlimit and then call set*id() while holding a full set of capabilities. The capabilities are only changed in the new credential in security_task_fix_setuid(). The code in apache suexec appears to follow this pattern. Commit 909cc4ae86f3 ("[PATCH] Fix two bugs with process limits (RLIMIT_NPROC)") where this check was added describes the targes of this capability check as: 2/ When a root-owned process (e.g. cgiwrap) sets up process limits and then calls setuid, the setuid should fail if the user would then be running more than rlim_cur[RLIMIT_NPROC] processes, but it doesn't. This patch adds an appropriate test. With this patch, and per-user process limit imposed in cgiwrap really works. So the original use case of this check also appears to match the broken pattern. Restore the enforcement of RLIMIT_NPROC by removing the bad capable checks added in set_user. This unfortunately restores the inconsistent state the code has been in for the last 11 years, but dealing with the inconsistencies looks like a larger problem. Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20210907213042.GA22626@openwall.com/ Link: https://lkml.kernel.org/r/20220212221412.GA29214@openwall.com Link: https://lkml.kernel.org/r/20220216155832.680775-1-ebiederm@xmission.com Fixes: 2863643fb8b9 ("set_user: add capability check when rlimit(RLIMIT_NPROC) exceeds") History-Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git Reviewed-by: Solar Designer <solar@openwall.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-02-16module: fix building with sysfs disabledDmitry Torokhov
Sysfs support might be disabled so we need to guard the code that instantiates "compression" attribute with an #ifdef. Fixes: b1ae6dc41eaa ("module: add in-kernel support for decompressing") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-02-16bpf: Fix crash due to out of bounds access into reg2btf_ids.Kumar Kartikeya Dwivedi
When commit e6ac2450d6de ("bpf: Support bpf program calling kernel function") added kfunc support, it defined reg2btf_ids as a cheap way to translate the verifier reg type to the appropriate btf_vmlinux BTF ID, however commit c25b2ae13603 ("bpf: Replace PTR_TO_XXX_OR_NULL with PTR_TO_XXX | PTR_MAYBE_NULL") moved the __BPF_REG_TYPE_MAX from the last member of bpf_reg_type enum to after the base register types, and defined other variants using type flag composition. However, now, the direct usage of reg->type to index into reg2btf_ids may no longer fall into __BPF_REG_TYPE_MAX range, and hence lead to out of bounds access and kernel crash on dereference of bad pointer. Fixes: c25b2ae13603 ("bpf: Replace PTR_TO_XXX_OR_NULL with PTR_TO_XXX | PTR_MAYBE_NULL") Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220216201943.624869-1-memxor@gmail.com
2022-02-16PM: hibernate: fix load_image_and_restore() error pathYe Bin
As 'swsusp_check' open 'hib_resume_bdev', if call 'create_basic_memory_bitmaps' failed, we need to close 'hib_resume_bdev' in 'load_image_and_restore' function. Signed-off-by: Ye Bin <yebin10@huawei.com> [ rjw: Subject ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-02-16libbpf: Split bpf_core_apply_relo()Mauricio Vásquez
BTFGen needs to run the core relocation logic in order to understand what are the types involved in a given relocation. Currently bpf_core_apply_relo() calculates and **applies** a relocation to an instruction. Having both operations in the same function makes it difficult to only calculate the relocation without patching the instruction. This commit splits that logic in two different phases: (1) calculate the relocation and (2) patch the instruction. For the first phase bpf_core_apply_relo() is renamed to bpf_core_calc_relo_insn() who is now only on charge of calculating the relocation, the second phase uses the already existing bpf_core_patch_insn(). bpf_object__relocate_core() uses both of them and the BTFGen will use only bpf_core_calc_relo_insn(). Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io> Signed-off-by: Rafael David Tinoco <rafael.tinoco@aquasec.com> Signed-off-by: Lorenzo Fontana <lorenzo.fontana@elastic.co> Signed-off-by: Leonardo Di Donato <leonardo.didonato@elastic.co> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220215225856.671072-2-mauricio@kinvolk.io
2022-02-16locking/lockdep: Iterate lock_classes directly when reading lockdep filesWaiman Long
When dumping lock_classes information via /proc/lockdep, we can't take the lockdep lock as the lock hold time is indeterminate. Iterating over all_lock_classes without holding lock can be dangerous as there is a slight chance that it may branch off to other lists leading to infinite loop or even access invalid memory if changes are made to all_lock_classes list in parallel. To avoid this problem, iteration of lock classes is now done directly on the lock_classes array itself. The lock_classes_in_use bitmap is checked to see if the lock class is being used. To avoid iterating the full array all the times, a new max_lock_class_idx value is added to track the maximum lock_class index that is currently being used. We can theoretically take the lockdep lock for iterating all_lock_classes when other lockdep files (lockdep_stats and lock_stat) are accessed as the lock hold time will be shorter for them. For consistency, they are also modified to iterate the lock_classes array directly. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220211035526.1329503-2-longman@redhat.com
2022-02-16sched/isolation: Split housekeeping cpumask per isolation featuresFrederic Weisbecker
To prepare for supporting each housekeeping feature toward cpuset, split the global housekeeping cpumask per HK_TYPE_* entry. This will later allow, for example, to runtime modify the cpulist passed through "isolcpus=", "nohz_full=" and "rcu_nocbs=" kernel boot parameters. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Juri Lelli <juri.lelli@redhat.com> Reviewed-by: Phil Auld <pauld@redhat.com> Link: https://lore.kernel.org/r/20220207155910.527133-9-frederic@kernel.org
2022-02-16sched/isolation: Fix housekeeping_mask memory leakFrederic Weisbecker
If "nohz_full=" or "isolcpus=nohz" are called with CONFIG_NO_HZ_FULL=n, housekeeping_mask doesn't get freed despite it being unused if housekeeping_setup() is called for the first time. Check this scenario first to fix this, so that no useless allocation is performed. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Juri Lelli <juri.lelli@redhat.com> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Phil Auld <pauld@redhat.com> Link: https://lore.kernel.org/r/20220207155910.527133-8-frederic@kernel.org
2022-02-16sched/isolation: Consolidate error handlingFrederic Weisbecker
Centralize the mask freeing and return value for the error path. This makes potential leaks more visible. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Juri Lelli <juri.lelli@redhat.com> Reviewed-by: Phil Auld <pauld@redhat.com> Link: https://lore.kernel.org/r/20220207155910.527133-7-frederic@kernel.org
2022-02-16sched/isolation: Consolidate check for housekeeping minimum serviceFrederic Weisbecker
There can be two subsequent calls to housekeeping_setup() due to "nohz_full=" and "isolcpus=" that can mix up. The two passes each have their own way to deal with an empty housekeeping set of CPUs. Consolidate this part and remove the awful "tmp" based naming. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Juri Lelli <juri.lelli@redhat.com> Reviewed-by: Phil Auld <pauld@redhat.com> Link: https://lore.kernel.org/r/20220207155910.527133-6-frederic@kernel.org
2022-02-16sched/isolation: Use single feature type while referring to housekeeping cpumaskFrederic Weisbecker
Refer to housekeeping APIs using single feature types instead of flags. This prevents from passing multiple isolation features at once to housekeeping interfaces, which soon won't be possible anymore as each isolation features will have their own cpumask. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Juri Lelli <juri.lelli@redhat.com> Reviewed-by: Phil Auld <pauld@redhat.com> Link: https://lore.kernel.org/r/20220207155910.527133-5-frederic@kernel.org
2022-02-16workqueue: Decouple HK_FLAG_WQ and HK_FLAG_DOMAIN cpumask fetchFrederic Weisbecker
To prepare for supporting each feature of the housekeeping cpumask toward cpuset, prepare each of the HK_FLAG_* entries to move to their own cpumask with enforcing to fetch them individually. The new constraint is that multiple HK_FLAG_* entries can't be mixed together anymore in a single call to housekeeping cpumask(). This will later allow, for example, to runtime modify the cpulist passed through "isolcpus=", "nohz_full=" and "rcu_nocbs=" kernel boot parameters. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Juri Lelli <juri.lelli@redhat.com> Reviewed-by: Phil Auld <pauld@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20220207155910.527133-3-frederic@kernel.org
2022-02-16psi: fix possible trigger missing in the windowZhaoyang Huang
When a new threshold breaching stall happens after a psi event was generated and within the window duration, the new event is not generated because the events are rate-limited to one per window. If after that no new stall is recorded then the event will not be generated even after rate-limiting duration has passed. This is happening because with no new stall, window_update will not be called even though threshold was previously breached. To fix this, record threshold breaching occurrence and generate the event once window duration is passed. Suggested-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Suren Baghdasaryan <surenb@google.com> Link: https://lore.kernel.org/r/1643093818-19835-1-git-send-email-huangzhaoyang@gmail.com
2022-02-16sched/numa: Avoid migrating task to CPU-less nodeHuang Ying
In a typical memory tiering system, there's no CPU in slow (PMEM) NUMA nodes. But if the number of the hint page faults on a PMEM node is the max for a task, The current NUMA balancing policy may try to place the task on the PMEM node instead of DRAM node. This is unreasonable, because there's no CPU in PMEM NUMA nodes. To fix this, CPU-less nodes are ignored when searching the migration target node for a task in this patch. To test the patch, we run a workload that accesses more memory in PMEM node than memory in DRAM node. Without the patch, the PMEM node will be chosen as preferred node in task_numa_placement(). While the DRAM node will be chosen instead with the patch. Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220214121553.582248-2-ying.huang@intel.com
2022-02-16sched/numa: Fix NUMA topology for systems with CPU-less nodesHuang Ying
The NUMA topology parameters (sched_numa_topology_type, sched_domains_numa_levels, and sched_max_numa_distance, etc.) identified by scheduler may be wrong for systems with CPU-less nodes. For example, the ACPI SLIT of a system with CPU-less persistent memory (Intel Optane DCPMM) nodes is as follows, [000h 0000 4] Signature : "SLIT" [System Locality Information Table] [004h 0004 4] Table Length : 0000042C [008h 0008 1] Revision : 01 [009h 0009 1] Checksum : 59 [00Ah 0010 6] Oem ID : "XXXX" [010h 0016 8] Oem Table ID : "XXXXXXX" [018h 0024 4] Oem Revision : 00000001 [01Ch 0028 4] Asl Compiler ID : "INTL" [020h 0032 4] Asl Compiler Revision : 20091013 [024h 0036 8] Localities : 0000000000000004 [02Ch 0044 4] Locality 0 : 0A 15 11 1C [030h 0048 4] Locality 1 : 15 0A 1C 11 [034h 0052 4] Locality 2 : 11 1C 0A 1C [038h 0056 4] Locality 3 : 1C 11 1C 0A While the `numactl -H` output is as follows, available: 4 nodes (0-3) node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 node 0 size: 64136 MB node 0 free: 5981 MB node 1 cpus: 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 node 1 size: 64466 MB node 1 free: 10415 MB node 2 cpus: node 2 size: 253952 MB node 2 free: 253920 MB node 3 cpus: node 3 size: 253952 MB node 3 free: 253951 MB node distances: node 0 1 2 3 0: 10 21 17 28 1: 21 10 28 17 2: 17 28 10 28 3: 28 17 28 10 In this system, there are only 2 sockets. In each memory controller, both DRAM and PMEM DIMMs are installed. Although the physical NUMA topology is simple, the logical NUMA topology becomes a little complex. Because both the distance(0, 1) and distance (1, 3) are less than the distance (0, 3), it appears that node 1 sits between node 0 and node 3. And the whole system appears to be a glueless mesh NUMA topology type. But it's definitely not, there is even no CPU in node 3. This isn't a practical problem now yet. Because the PMEM nodes (node 2 and node 3 in example system) are offlined by default during system boot. So init_numa_topology_type() called during system boot will ignore them and set sched_numa_topology_type to NUMA_DIRECT. And init_numa_topology_type() is only called at runtime when a CPU of a never-onlined-before node gets plugged in. And there's no CPU in the PMEM nodes. But it appears better to fix this to make the code more robust. To test the potential problem. We have used a debug patch to call init_numa_topology_type() when the PMEM node is onlined (in __set_migration_target_nodes()). With that, the NUMA parameters identified by scheduler is as follows, sched_numa_topology_type: NUMA_GLUELESS_MESH sched_domains_numa_levels: 4 sched_max_numa_distance: 28 To fix the issue, the CPU-less nodes are ignored when the NUMA topology parameters are identified. Because a node may become CPU-less or not at run time because of CPU hotplug, the NUMA topology parameters need to be re-initialized at runtime for CPU hotplug too. With the patch, the NUMA parameters identified for the example system above is as follows, sched_numa_topology_type: NUMA_DIRECT sched_domains_numa_levels: 2 sched_max_numa_distance: 21 Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220214121553.582248-1-ying.huang@intel.com
2022-02-16sched: replace cpumask_weight with cpumask_empty where appropriateYury Norov
In some places, kernel/sched code calls cpumask_weight() to check if any bit of a given cpumask is set. We can do it more efficiently with cpumask_empty() because cpumask_empty() stops traversing the cpumask as soon as it finds first set bit, while cpumask_weight() counts all bits unconditionally. Signed-off-by: Yury Norov <yury.norov@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220210224933.379149-23-yury.norov@gmail.com
2022-02-16lkdtm: Really write into kernel text in WRITE_KERNChristophe Leroy
WRITE_KERN is supposed to overwrite some kernel text, namely do_overwritten() function. But at the time being it overwrites do_overwritten() function descriptor, not function text. Fix it by dereferencing the function descriptor to obtain function text pointer. Export dereference_function_descriptor() for when LKDTM is built as a module. And make do_overwritten() noinline so that it is really do_overwritten() which is called by lkdtm_WRITE_KERN(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/31e58eaffb5bc51c07d8d4891d1982100ade8cfc.1644928018.git.christophe.leroy@csgroup.eu
2022-02-16asm-generic: Refactor dereference_[kernel]_function_descriptor()Christophe Leroy
dereference_function_descriptor() and dereference_kernel_function_descriptor() are identical on the three architectures implementing them. Make them common and put them out-of-line in kernel/extable.c which is one of the users and has similar type of functions. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Helge Deller <deller@gmx.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/449db09b2eba57f4ab05f80102a67d8675bc8bcd.1644928018.git.christophe.leroy@csgroup.eu