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2022-02-10Merge tag 'audit-pr-20220209' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit Pull audit fix from Paul Moore: "Another audit fix, this time a single rather small but important fix for an oops/page-fault caused by improperly accessing userspace memory" * tag 'audit-pr-20220209' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit: audit: don't deref the syscall args when checking the openat2 open_how::flags
2022-02-10genirq: Kill irq_chip::parent_deviceMarc Zyngier
Now that noone is using irq_chip::parent_device in the tree, get rid of it. Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Bartosz Golaszewski <brgl@bgdev.pl> Link: https://lore.kernel.org/r/20220201120310.878267-13-maz@kernel.org
2022-02-09Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski
Daniel Borkmann says: ==================== pull-request: bpf-next 2022-02-09 We've added 126 non-merge commits during the last 16 day(s) which contain a total of 201 files changed, 4049 insertions(+), 2215 deletions(-). The main changes are: 1) Add custom BPF allocator for JITs that pack multiple programs into a huge page to reduce iTLB pressure, from Song Liu. 2) Add __user tagging support in vmlinux BTF and utilize it from BPF verifier when generating loads, from Yonghong Song. 3) Add per-socket fast path check guarding from cgroup/BPF overhead when used by only some sockets, from Pavel Begunkov. 4) Continued libbpf deprecation work of APIs/features and removal of their usage from samples, selftests, libbpf & bpftool, from Andrii Nakryiko and various others. 5) Improve BPF instruction set documentation by adding byte swap instructions and cleaning up load/store section, from Christoph Hellwig. 6) Switch BPF preload infra to light skeleton and remove libbpf dependency from it, from Alexei Starovoitov. 7) Fix architecture-agnostic macros in libbpf for accessing syscall arguments from BPF progs for non-x86 architectures, from Ilya Leoshkevich. 8) Rework port members in struct bpf_sk_lookup and struct bpf_sock to be of 16-bit field with anonymous zero padding, from Jakub Sitnicki. 9) Add new bpf_copy_from_user_task() helper to read memory from a different task than current. Add ability to create sleepable BPF iterator progs, from Kenny Yu. 10) Implement XSK batching for ice's zero-copy driver used by AF_XDP and utilize TX batching API from XSK buffer pool, from Maciej Fijalkowski. 11) Generate temporary netns names for BPF selftests to avoid naming collisions, from Hangbin Liu. 12) Implement bpf_core_types_are_compat() with limited recursion for in-kernel usage, from Matteo Croce. 13) Simplify pahole version detection and finally enable CONFIG_DEBUG_INFO_DWARF5 to be selected with CONFIG_DEBUG_INFO_BTF, from Nathan Chancellor. 14) Misc minor fixes to libbpf and selftests from various folks. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (126 commits) selftests/bpf: Cover 4-byte load from remote_port in bpf_sk_lookup bpf: Make remote_port field in struct bpf_sk_lookup 16-bit wide libbpf: Fix compilation warning due to mismatched printf format selftests/bpf: Test BPF_KPROBE_SYSCALL macro libbpf: Add BPF_KPROBE_SYSCALL macro libbpf: Fix accessing the first syscall argument on s390 libbpf: Fix accessing the first syscall argument on arm64 libbpf: Allow overriding PT_REGS_PARM1{_CORE}_SYSCALL selftests/bpf: Skip test_bpf_syscall_macro's syscall_arg1 on arm64 and s390 libbpf: Fix accessing syscall arguments on riscv libbpf: Fix riscv register names libbpf: Fix accessing syscall arguments on powerpc selftests/bpf: Use PT_REGS_SYSCALL_REGS in bpf_syscall_macro libbpf: Add PT_REGS_SYSCALL_REGS macro selftests/bpf: Fix an endianness issue in bpf_syscall_macro test bpf: Fix bpf_prog_pack build HPAGE_PMD_SIZE bpf: Fix leftover header->pages in sparc and powerpc code. libbpf: Fix signedness bug in btf_dump_array_data() selftests/bpf: Do not export subtest as standalone test bpf, x86_64: Fail gracefully on bpf_jit_binary_pack_finalize failures ... ==================== Link: https://lore.kernel.org/r/20220209210050.8425-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-09audit: don't deref the syscall args when checking the openat2 open_how::flagsPaul Moore
As reported by Jeff, dereferencing the openat2 syscall argument in audit_match_perm() to obtain the open_how::flags can result in an oops/page-fault. This patch fixes this by using the open_how struct that we store in the audit_context with audit_openat2_how(). Independent of this patch, Richard Guy Briggs posted a similar patch to the audit mailing list roughly 40 minutes after this patch was posted. Cc: stable@vger.kernel.org Fixes: 1c30e3af8a79 ("audit: add support for the openat2 syscall") Reported-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-02-09genirq: Allow the PM device to originate from irq domainMarc Zyngier
As a preparation to moving the reference to the device used for runtime power management, add a new 'dev' field to the irqdomain structure for that exact purpose. The irq_chip_pm_{get,put}() helpers are made aware of the dual location via a new private helper. No functional change intended. Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Tony Lindgren <tony@atomide.com> Acked-by: Bartosz Golaszewski <brgl@bgdev.pl> Link: https://lore.kernel.org/r/20220201120310.878267-2-maz@kernel.org
2022-02-08bpf: Fix bpf_prog_pack build HPAGE_PMD_SIZESong Liu
Fix build with CONFIG_TRANSPARENT_HUGEPAGE=n with BPF_PROG_PACK_SIZE as PAGE_SIZE. Fixes: 57631054fae6 ("bpf: Introduce bpf_prog_pack allocator") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220208220509.4180389-3-song@kernel.org
2022-02-08tracing: Fix tp_printk option related with tp_printk_stop_on_bootJaeSang Yoo
The kernel parameter "tp_printk_stop_on_boot" starts with "tp_printk" which is the same as another kernel parameter "tp_printk". If "tp_printk" setup is called before the "tp_printk_stop_on_boot", it will override the latter and keep it from being set. This is similar to other kernel parameter issues, such as: Commit 745a600cf1a6 ("um: console: Ignore console= option") or init/do_mounts.c:45 (setup function of "ro" kernel param) Fix it by checking for a "_" right after the "tp_printk" and if that exists do not process the parameter. Link: https://lkml.kernel.org/r/20220208195421.969326-1-jsyoo5b@gmail.com Signed-off-by: JaeSang Yoo <jsyoo5b@gmail.com> [ Fixed up change log and added space after if condition ] Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-08rcu-tasks: Set ->percpu_enqueue_shift to zero upon contentionPaul E. McKenney
Currently, call_rcu_tasks_generic() sets ->percpu_enqueue_shift to order_base_2(nr_cpu_ids) upon encountering sufficient contention. This does not shift to use of non-CPU-0 callback queues as intended, but rather continues using only CPU 0's queue. Although this does provide some decrease in contention due to spreading work over multiple locks, it is not the dramatic decrease that was intended. This commit therefore makes call_rcu_tasks_generic() set ->percpu_enqueue_shift to 0. Reported-by: Neeraj Upadhyay <quic_neeraju@quicinc.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-08rcu-tasks: Use order_base_2() instead of ilog2()Paul E. McKenney
The ilog2() function can be used to generate a shift count, but it will generate the same count for a power of two as for one greater than a power of two. This results in shift counts that are larger than necessary for systems with a power-of-two number of CPUs because the CPUs are numbered from zero, so that the maximum CPU number is one less than that power of two. This commit therefore substitutes order_base_2(), which appears to have been designed for exactly this use case. Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-08rcu: Create and use an rcu_rdp_cpu_online()Paul E. McKenney
The pattern "rdp->grpmask & rcu_rnp_online_cpus(rnp)" occurs frequently in RCU code in order to determine whether rdp->cpu is online from an RCU perspective. This commit therefore creates an rcu_rdp_cpu_online() function to replace it. [ paulmck: Apply kernel test robot unused-variable feedback. ] Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-08rcu: Make rcu_barrier() no longer block CPU-hotplug operationsPaul E. McKenney
This commit removes the cpus_read_lock() and cpus_read_unlock() calls from rcu_barrier(), thus allowing CPUs to come and go during the course of rcu_barrier() execution. Posting of the ->barrier_head callbacks does synchronize with portions of RCU's CPU-hotplug notifiers, but these locks are held for short time periods on both sides. Thus, full CPU-hotplug operations could both start and finish during the execution of a given rcu_barrier() invocation. Additional synchronization is provided by a global ->barrier_lock. Since the ->barrier_lock is only used during rcu_barrier() execution and during onlining/offlining a CPU, the contention for this lock should be low. It might be tempting to make use of a per-CPU lock just on general principles, but straightforward attempts to do this have the problems shown below. Initial state: 3 CPUs present, CPU 0 and CPU1 do not have any callback and CPU2 has callbacks. 1. CPU0 calls rcu_barrier(). 2. CPU1 starts offlining for CPU2. CPU1 calls rcutree_migrate_callbacks(). rcu_barrier_entrain() is called from rcutree_migrate_callbacks(), with CPU2's rdp->barrier_lock. It does not entrain ->barrier_head for CPU2, as rcu_barrier() on CPU0 hasn't started the barrier sequence (by calling rcu_seq_start(&rcu_state.barrier_sequence)) yet. 3. CPU0 starts new barrier sequence. It iterates over CPU0 and CPU1, after acquiring their per-cpu ->barrier_lock and finds 0 segcblist length. It updates ->barrier_seq_snap for CPU0 and CPU1 and continues loop iteration to CPU2. for_each_possible_cpu(cpu) { raw_spin_lock_irqsave(&rdp->barrier_lock, flags); if (!rcu_segcblist_n_cbs(&rdp->cblist)) { WRITE_ONCE(rdp->barrier_seq_snap, gseq); raw_spin_unlock_irqrestore(&rdp->barrier_lock, flags); rcu_barrier_trace(TPS("NQ"), cpu, rcu_state.barrier_sequence); continue; } 4. rcutree_migrate_callbacks() completes execution on CPU1. Segcblist len for CPU2 becomes 0. 5. The loop iteration on CPU0, checks rcu_segcblist_n_cbs(&rdp->cblist) for CPU2 and completes the loop iteration after setting ->barrier_seq_snap. 6. As there isn't any ->barrier_head callback entrained; at this point, rcu_barrier() in CPU0 returns. 7. The callbacks, which migrated from CPU2 to CPU1, execute. Straightforward per-CPU locking is also subject to the following race condition noted by Boqun Feng: 1. CPU0 calls rcu_barrier(), starting a new barrier sequence by invoking rcu_seq_start() and init_completion(), but does not yet initialize rcu_state.barrier_cpu_count. 2. CPU1 starts offlining for CPU2, calling rcutree_migrate_callbacks(), which in turn calls rcu_barrier_entrain() holding CPU2's. rdp->barrier_lock. It then entrains ->barrier_head for CPU2 and atomically increments rcu_state.barrier_cpu_count, which is unfortunately not yet initialized to the value 2. 3. The just-entrained RCU callback is invoked. It atomically decrements rcu_state.barrier_cpu_count and sees that it is now zero. This callback therefore invokes complete(). 4. CPU0 continues executing rcu_barrier(), but is not blocked by its call to wait_for_completion(). This results in rcu_barrier() returning before all pre-existing callbacks have been invoked, which is a bug. Therefore, synchronization is provided by rcu_state.barrier_lock, which is also held across the initialization sequence, especially the rcu_seq_start() and the atomic_set() that sets rcu_state.barrier_cpu_count to the value 2. In addition, this lock is held when entraining the rcu_barrier() callback, when deciding whether or not a CPU has callbacks that rcu_barrier() must wait on, when setting the ->qsmaskinitnext for incoming CPUs, and when migrating callbacks from a CPU that is going offline. Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Co-developed-by: Neeraj Upadhyay <quic_neeraju@quicinc.com> Signed-off-by: Neeraj Upadhyay <quic_neeraju@quicinc.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-08rcu: Rework rcu_barrier() and callback-migration logicPaul E. McKenney
This commit reworks rcu_barrier() and callback-migration logic to permit allowing rcu_barrier() to run concurrently with CPU-hotplug operations. The key trick is for callback migration to check to see if an rcu_barrier() is in flight, and, if so, enqueue the ->barrier_head callback on its behalf. This commit adds synchronization with RCU's CPU-hotplug notifiers. Taken together, this will permit a later commit to remove the cpus_read_lock() and cpus_read_unlock() calls from rcu_barrier(). [ paulmck: Updated per kbuild test robot feedback. ] [ paulmck: Updated per reviews session with Neeraj, Frederic, Uladzislau, and Boqun. ] Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-08rcu: Refactor rcu_barrier() empty-list handlingPaul E. McKenney
This commit saves a few lines by checking first for an empty callback list. If the callback list is empty, then that CPU is taken care of, regardless of its online or nocb state. Also simplify tracing accordingly and fold a few lines together. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-08rcu: Kill rnp->ofl_seq and use only rcu_state.ofl_lock for exclusionDavid Woodhouse
If we allow architectures to bring APs online in parallel, then we end up requiring rcu_cpu_starting() to be reentrant. But currently, the manipulation of rnp->ofl_seq is not thread-safe. However, rnp->ofl_seq is also fairly much pointless anyway since both rcu_cpu_starting() and rcu_report_dead() hold rcu_state.ofl_lock for fairly much the whole time that rnp->ofl_seq is set to an odd number to indicate that an operation is in progress. So drop rnp->ofl_seq completely, and use only rcu_state.ofl_lock. This has a couple of minor complexities: lockdep will complain when we take rcu_state.ofl_lock, and currently accepts the 'excuse' of having an odd value in rnp->ofl_seq. So switch it to an arch_spinlock_t to avoid that false positive complaint. Since we're killing rnp->ofl_seq of course that 'excuse' has to be changed too, so make it check for arch_spin_is_locked(rcu_state.ofl_lock). There's no arch_spin_lock_irqsave() so we have to manually save and restore local interrupts around the locking. At Paul's request based on Neeraj's analysis, make rcu_gp_init not just wait but *exclude* any CPU online/offline activity, which was fairly much true already by virtue of it holding rcu_state.ofl_lock. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-07bpf: Introduce bpf_jit_binary_pack_[alloc|finalize|free]Song Liu
This is the jit binary allocator built on top of bpf_prog_pack. bpf_prog_pack allocates RO memory, which cannot be used directly by the JIT engine. Therefore, a temporary rw buffer is allocated for the JIT engine. Once JIT is done, bpf_jit_binary_pack_finalize is used to copy the program to the RO memory. bpf_jit_binary_pack_alloc reserves 16 bytes of extra space for illegal instructions, which is small than the 128 bytes space reserved by bpf_jit_binary_alloc. This change is necessary for bpf_jit_binary_hdr to find the correct header. Also, flag use_bpf_prog_pack is added to differentiate a program allocated by bpf_jit_binary_pack_alloc. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220204185742.271030-9-song@kernel.org
2022-02-07bpf: Introduce bpf_prog_pack allocatorSong Liu
Most BPF programs are small, but they consume a page each. For systems with busy traffic and many BPF programs, this could add significant pressure to instruction TLB. High iTLB pressure usually causes slow down for the whole system, which includes visible performance degradation for production workloads. Introduce bpf_prog_pack allocator to pack multiple BPF programs in a huge page. The memory is then allocated in 64 byte chunks. Memory allocated by bpf_prog_pack allocator is RO protected after initial allocation. To write to it, the user (jit engine) need to use text poke API. Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220204185742.271030-8-song@kernel.org
2022-02-07bpf: Introduce bpf_arch_text_copySong Liu
This will be used to copy JITed text to RO protected module memory. On x86, bpf_arch_text_copy is implemented with text_poke_copy. bpf_arch_text_copy returns pointer to dst on success, and ERR_PTR(errno) on errors. Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220204185742.271030-7-song@kernel.org
2022-02-07bpf: Use prog->jited_len in bpf_prog_ksym_set_addr()Song Liu
Using prog->jited_len is simpler and more accurate than current estimation (header + header->size). Also, fix missing prog->jited_len with multi function program. This hasn't been a real issue before this. Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220204185742.271030-5-song@kernel.org
2022-02-07bpf: Use size instead of pages in bpf_binary_headerSong Liu
This is necessary to charge sub page memory for the BPF program. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220204185742.271030-4-song@kernel.org
2022-02-07bpf: Use bytes instead of pages for bpf_jit_[charge|uncharge]_modmemSong Liu
This enables sub-page memory charge and allocation. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220204185742.271030-3-song@kernel.org
2022-02-07PM: s2idle: ACPI: Fix wakeup interrupts handlingRafael J. Wysocki
After commit e3728b50cd9b ("ACPI: PM: s2idle: Avoid possible race related to the EC GPE") wakeup interrupts occurring immediately after the one discarded by acpi_s2idle_wake() may be missed. Moreover, if the SCI triggers again immediately after the rearming in acpi_s2idle_wake(), that wakeup may be missed too. The problem is that pm_system_irq_wakeup() only calls pm_system_wakeup() when pm_wakeup_irq is 0, but that's not the case any more after the interrupt causing acpi_s2idle_wake() to run until pm_wakeup_irq is cleared by the pm_wakeup_clear() call in s2idle_loop(). However, there may be wakeup interrupts occurring in that time frame and if that happens, they will be missed. To address that issue first move the clearing of pm_wakeup_irq to the point at which it is known that the interrupt causing acpi_s2idle_wake() to tun will be discarded, before rearming the SCI for wakeup. Moreover, because that only reduces the size of the time window in which the issue may manifest itself, allow pm_system_irq_wakeup() to register two second wakeup interrupts in a row and, when discarding the first one, replace it with the second one. [Of course, this assumes that only one wakeup interrupt can be discarded in one go, but currently that is the case and I am not aware of any plans to change that.] Fixes: e3728b50cd9b ("ACPI: PM: s2idle: Avoid possible race related to the EC GPE") Cc: 5.4+ <stable@vger.kernel.org> # 5.4+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-02-07livepatch: Fix build failure on 32 bits processorsChristophe Leroy
Trying to build livepatch on powerpc/32 results in: kernel/livepatch/core.c: In function 'klp_resolve_symbols': kernel/livepatch/core.c:221:23: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] 221 | sym = (Elf64_Sym *)sechdrs[symndx].sh_addr + ELF_R_SYM(relas[i].r_info); | ^ kernel/livepatch/core.c:221:21: error: assignment to 'Elf32_Sym *' {aka 'struct elf32_sym *'} from incompatible pointer type 'Elf64_Sym *' {aka 'struct elf64_sym *'} [-Werror=incompatible-pointer-types] 221 | sym = (Elf64_Sym *)sechdrs[symndx].sh_addr + ELF_R_SYM(relas[i].r_info); | ^ kernel/livepatch/core.c: In function 'klp_apply_section_relocs': kernel/livepatch/core.c:312:35: error: passing argument 1 of 'klp_resolve_symbols' from incompatible pointer type [-Werror=incompatible-pointer-types] 312 | ret = klp_resolve_symbols(sechdrs, strtab, symndx, sec, sec_objname); | ^~~~~~~ | | | Elf32_Shdr * {aka struct elf32_shdr *} kernel/livepatch/core.c:193:44: note: expected 'Elf64_Shdr *' {aka 'struct elf64_shdr *'} but argument is of type 'Elf32_Shdr *' {aka 'struct elf32_shdr *'} 193 | static int klp_resolve_symbols(Elf64_Shdr *sechdrs, const char *strtab, | ~~~~~~~~~~~~^~~~~~~ Fix it by using the right types instead of forcing 64 bits types. Fixes: 7c8e2bdd5f0d ("livepatch: Apply vmlinux-specific KLP relocations early") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Petr Mladek <pmladek@suse.com> Acked-by: Joe Lawrence <joe.lawrence@redhat.com> Acked-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5288e11b018a762ea3351cc8fb2d4f15093a4457.1640017960.git.christophe.leroy@csgroup.eu
2022-02-06perf: Fix list corruption in perf_cgroup_switch()Song Liu
There's list corruption on cgrp_cpuctx_list. This happens on the following path: perf_cgroup_switch: list_for_each_entry(cgrp_cpuctx_list) cpu_ctx_sched_in ctx_sched_in ctx_pinned_sched_in merge_sched_in perf_cgroup_event_disable: remove the event from the list Use list_for_each_entry_safe() to allow removing an entry during iteration. Fixes: 058fe1c0440e ("perf/core: Make cgroup switch visit only cpuctxs with cgroup events") Signed-off-by: Song Liu <song@kernel.org> Reviewed-by: Rik van Riel <riel@surriel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220204004057.2961252-1-song@kernel.org
2022-02-06sched/fair: Fix fault in reweight_entityTadeusz Struk
Syzbot found a GPF in reweight_entity. This has been bisected to commit 4ef0c5c6b5ba ("kernel/sched: Fix sched_fork() access an invalid sched_task_group") There is a race between sched_post_fork() and setpriority(PRIO_PGRP) within a thread group that causes a null-ptr-deref in reweight_entity() in CFS. The scenario is that the main process spawns number of new threads, which then call setpriority(PRIO_PGRP, 0, -20), wait, and exit. For each of the new threads the copy_process() gets invoked, which adds the new task_struct and calls sched_post_fork() for it. In the above scenario there is a possibility that setpriority(PRIO_PGRP) and set_one_prio() will be called for a thread in the group that is just being created by copy_process(), and for which the sched_post_fork() has not been executed yet. This will trigger a null pointer dereference in reweight_entity(), as it will try to access the run queue pointer, which hasn't been set. Before the mentioned change the cfs_rq pointer for the task has been set in sched_fork(), which is called much earlier in copy_process(), before the new task is added to the thread_group. Now it is done in the sched_post_fork(), which is called after that. To fix the issue the remove the update_load param from the update_load param() function and call reweight_task() only if the task flag doesn't have the TASK_NEW flag set. Fixes: 4ef0c5c6b5ba ("kernel/sched: Fix sched_fork() access an invalid sched_task_group") Reported-by: syzbot+af7a719bc92395ee41b3@syzkaller.appspotmail.com Signed-off-by: Tadeusz Struk <tadeusz.struk@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20220203161846.1160750-1-tadeusz.struk@linaro.org
2022-02-06Merge tag 'perf_urgent_for_v5.17_rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Borislav Petkov: - Intel/PT: filters could crash the kernel - Intel: default disable the PMU for SMM, some new-ish EFI firmware has started using CPL3 and the PMU CPL filters don't discriminate against SMM, meaning that CPL3 (userspace only) events now also count EFI/SMM cycles. - Fixup for perf_event_attr::sig_data * tag 'perf_urgent_for_v5.17_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel/pt: Fix crash with stop filters in single-range mode perf: uapi: Document perf_event_attr::sig_data truncation on 32 bit architectures selftests/perf_events: Test modification of perf_event_attr::sig_data perf: Copy perf_event_attr::sig_data on modification x86/perf: Default set FREEZE_ON_SMI for all
2022-02-04bpf: Implement bpf_core_types_are_compat().Matteo Croce
Adopt libbpf's bpf_core_types_are_compat() for kernel duty by adding explicit recursion limit of 2 which is enough to handle 2 levels of function prototypes. Signed-off-by: Matteo Croce <mcroce@microsoft.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220204005519.60361-2-mcroce@linux.microsoft.com
2022-02-04cpufreq: schedutil: Use to_gov_attr_set() to get the gov_attr_setKevin Hao
The to_gov_attr_set() has been moved to the cpufreq.h, so use it to get the gov_attr_set. Signed-off-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-02-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-03gcc-plugins/stackleak: Use noinstr in favor of notraceKees Cook
While the stackleak plugin was already using notrace, objtool is now a bit more picky. Update the notrace uses to noinstr. Silences the following objtool warnings when building with: CONFIG_DEBUG_ENTRY=y CONFIG_STACK_VALIDATION=y CONFIG_VMLINUX_VALIDATION=y CONFIG_GCC_PLUGIN_STACKLEAK=y vmlinux.o: warning: objtool: do_syscall_64()+0x9: call to stackleak_track_stack() leaves .noinstr.text section vmlinux.o: warning: objtool: do_int80_syscall_32()+0x9: call to stackleak_track_stack() leaves .noinstr.text section vmlinux.o: warning: objtool: exc_general_protection()+0x22: call to stackleak_track_stack() leaves .noinstr.text section vmlinux.o: warning: objtool: fixup_bad_iret()+0x20: call to stackleak_track_stack() leaves .noinstr.text section vmlinux.o: warning: objtool: do_machine_check()+0x27: call to stackleak_track_stack() leaves .noinstr.text section vmlinux.o: warning: objtool: .text+0x5346e: call to stackleak_erase() leaves .noinstr.text section vmlinux.o: warning: objtool: .entry.text+0x143: call to stackleak_erase() leaves .noinstr.text section vmlinux.o: warning: objtool: .entry.text+0x10eb: call to stackleak_erase() leaves .noinstr.text section vmlinux.o: warning: objtool: .entry.text+0x17f9: call to stackleak_erase() leaves .noinstr.text section Note that the plugin's addition of calls to stackleak_track_stack() from noinstr functions is expected to be safe, as it isn't runtime instrumentation and is self-contained. Cc: Alexander Popov <alex.popov@linux.com> Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-02-03Merge tag 'net-5.17-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Jakub Kicinski: "Including fixes from bpf, netfilter, and ieee802154. Current release - regressions: - Partially revert "net/smc: Add netlink net namespace support", fix uABI breakage - netfilter: - nft_ct: fix use after free when attaching zone template - nft_byteorder: track register operations Previous releases - regressions: - ipheth: fix EOVERFLOW in ipheth_rcvbulk_callback - phy: qca8081: fix speeds lower than 2.5Gb/s - sched: fix use-after-free in tc_new_tfilter() Previous releases - always broken: - tcp: fix mem under-charging with zerocopy sendmsg() - tcp: add missing tcp_skb_can_collapse() test in tcp_shift_skb_data() - neigh: do not trigger immediate probes on NUD_FAILED from neigh_managed_work, avoid a deadlock - bpf: use VM_MAP instead of VM_ALLOC for ringbuf, avoid KASAN false-positives - netfilter: nft_reject_bridge: fix for missing reply from prerouting - smc: forward wakeup to smc socket waitqueue after fallback - ieee802154: - return meaningful error codes from the netlink helpers - mcr20a: fix lifs/sifs periods - at86rf230, ca8210: stop leaking skbs on error paths - macsec: add missing un-offload call for NETDEV_UNREGISTER of parent - ax25: add refcount in ax25_dev to avoid UAF bugs - eth: mlx5e: - fix SFP module EEPROM query - fix broken SKB allocation in HW-GRO - IPsec offload: fix tunnel mode crypto for non-TCP/UDP flows - eth: amd-xgbe: - fix skb data length underflow - ensure reset of the tx_timer_active flag, avoid Tx timeouts - eth: stmmac: fix runtime pm use in stmmac_dvr_remove() - eth: e1000e: handshake with CSME starts from Alder Lake platforms" * tag 'net-5.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (69 commits) ax25: fix reference count leaks of ax25_dev net: stmmac: ensure PTP time register reads are consistent net: ipa: request IPA register values be retained dt-bindings: net: qcom,ipa: add optional qcom,qmp property tools/resolve_btfids: Do not print any commands when building silently bpf: Use VM_MAP instead of VM_ALLOC for ringbuf net, neigh: Do not trigger immediate probes on NUD_FAILED from neigh_managed_work tcp: add missing tcp_skb_can_collapse() test in tcp_shift_skb_data() net: sparx5: do not refer to skb after passing it on Partially revert "net/smc: Add netlink net namespace support" net/mlx5e: Avoid field-overflowing memcpy() net/mlx5e: Use struct_group() for memcpy() region net/mlx5e: Avoid implicit modify hdr for decap drop rule net/mlx5e: IPsec: Fix tunnel mode crypto offload for non TCP/UDP traffic net/mlx5e: IPsec: Fix crypto offload for non TCP/UDP encapsulated traffic net/mlx5e: Don't treat small ceil values as unlimited in HTB offload net/mlx5: E-Switch, Fix uninitialized variable modact net/mlx5e: Fix handling of wrong devices during bond netevent net/mlx5e: Fix broken SKB allocation in HW-GRO net/mlx5e: Fix wrong calculation of header index in HW_GRO ...
2022-02-03Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfJakub Kicinski
Daniel Borkmann says: ==================== pull-request: bpf 2022-02-03 We've added 6 non-merge commits during the last 10 day(s) which contain a total of 7 files changed, 11 insertions(+), 236 deletions(-). The main changes are: 1) Fix BPF ringbuf to allocate its area with VM_MAP instead of VM_ALLOC flag which otherwise trips over KASAN, from Hou Tao. 2) Fix unresolved symbol warning in resolve_btfids due to LSM callback rename, from Alexei Starovoitov. 3) Fix a possible race in inc_misses_counter() when IRQ would trigger during counter update, from He Fengqing. 4) Fix tooling infra for cross-building with clang upon probing whether gcc provides the standard libraries, from Jean-Philippe Brucker. 5) Fix silent mode build for resolve_btfids, from Nathan Chancellor. 6) Drop unneeded and outdated lirc.h header copy from tooling infra as BPF does not require it anymore, from Sean Young. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: tools/resolve_btfids: Do not print any commands when building silently bpf: Use VM_MAP instead of VM_ALLOC for ringbuf tools: Ignore errors from `which' when searching a GCC toolchain tools headers UAPI: remove stale lirc.h bpf: Fix possible race in inc_misses_counter bpf: Fix renaming task_getsecid_subj->current_getsecid_subj. ==================== Link: https://lore.kernel.org/r/20220203155815.25689-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-03bpf: Fix a btf decl_tag bug when tagging a functionYonghong Song
syzbot reported a btf decl_tag bug with stack trace below: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 0 PID: 3592 Comm: syz-executor914 Not tainted 5.16.0-syzkaller-11424-gb7892f7d5cb2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:btf_type_vlen include/linux/btf.h:231 [inline] RIP: 0010:btf_decl_tag_resolve+0x83e/0xaa0 kernel/bpf/btf.c:3910 ... Call Trace: <TASK> btf_resolve+0x251/0x1020 kernel/bpf/btf.c:4198 btf_check_all_types kernel/bpf/btf.c:4239 [inline] btf_parse_type_sec kernel/bpf/btf.c:4280 [inline] btf_parse kernel/bpf/btf.c:4513 [inline] btf_new_fd+0x19fe/0x2370 kernel/bpf/btf.c:6047 bpf_btf_load kernel/bpf/syscall.c:4039 [inline] __sys_bpf+0x1cbb/0x5970 kernel/bpf/syscall.c:4679 __do_sys_bpf kernel/bpf/syscall.c:4738 [inline] __se_sys_bpf kernel/bpf/syscall.c:4736 [inline] __x64_sys_bpf+0x75/0xb0 kernel/bpf/syscall.c:4736 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae The kasan error is triggered with an illegal BTF like below: type 0: void type 1: int type 2: decl_tag to func type 3 type 3: func to func_proto type 8 The total number of types is 4 and the type 3 is illegal since its func_proto type is out of range. Currently, the target type of decl_tag can be struct/union, var or func. Both struct/union and var implemented their own 'resolve' callback functions and hence handled properly in kernel. But func type doesn't have 'resolve' callback function. When btf_decl_tag_resolve() tries to check func type, it tries to get vlen of its func_proto type, which triggered the above kasan error. To fix the issue, btf_decl_tag_resolve() needs to do btf_func_check() before trying to accessing func_proto type. In the current implementation, func type is checked with btf_func_check() in the main checking function btf_check_all_types(). To fix the above kasan issue, let us implement 'resolve' callback func type properly. The 'resolve' callback will be also called in btf_check_all_types() for func types. Fixes: b5ea834dde6b ("bpf: Support for new btf kind BTF_KIND_TAG") Reported-by: syzbot+53619be9444215e785ed@syzkaller.appspotmail.com Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20220203191727.741862-1-yhs@fb.com
2022-02-03printk: Fix incorrect __user type in proc_dointvec_minmax_sysadmin()Mickaël Salaün
The move of proc_dointvec_minmax_sysadmin() from kernel/sysctl.c to kernel/printk/sysctl.c introduced an incorrect __user attribute to the buffer argument. I spotted this change in [1] as well as the kernel test robot. Revert this change to please sparse: kernel/printk/sysctl.c:20:51: warning: incorrect type in argument 3 (different address spaces) kernel/printk/sysctl.c:20:51: expected void * kernel/printk/sysctl.c:20:51: got void [noderef] __user *buffer Fixes: faaa357a55e0 ("printk: move printk sysctl to printk/sysctl.c") Link: https://lore.kernel.org/r/20220104155024.48023-2-mic@digikod.net [1] Reported-by: kernel test robot <lkp@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: John Ogness <john.ogness@linutronix.de> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Xiaoming Ni <nixiaoming@huawei.com> Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com> Link: https://lore.kernel.org/r/20220203145029.272640-1-mic@digikod.net Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-02-03Revert "module, async: async_synchronize_full() on module init iff async is ↵Igor Pylypiv
used" This reverts commit 774a1221e862b343388347bac9b318767336b20b. We need to finish all async code before the module init sequence is done. In the reverted commit the PF_USED_ASYNC flag was added to mark a thread that called async_schedule(). Then the PF_USED_ASYNC flag was used to determine whether or not async_synchronize_full() needs to be invoked. This works when modprobe thread is calling async_schedule(), but it does not work if module dispatches init code to a worker thread which then calls async_schedule(). For example, PCI driver probing is invoked from a worker thread based on a node where device is attached: if (cpu < nr_cpu_ids) error = work_on_cpu(cpu, local_pci_probe, &ddi); else error = local_pci_probe(&ddi); We end up in a situation where a worker thread gets the PF_USED_ASYNC flag set instead of the modprobe thread. As a result, async_synchronize_full() is not invoked and modprobe completes without waiting for the async code to finish. The issue was discovered while loading the pm80xx driver: (scsi_mod.scan=async) modprobe pm80xx worker ... do_init_module() ... pci_call_probe() work_on_cpu(local_pci_probe) local_pci_probe() pm8001_pci_probe() scsi_scan_host() async_schedule() worker->flags |= PF_USED_ASYNC; ... < return from worker > ... if (current->flags & PF_USED_ASYNC) <--- false async_synchronize_full(); Commit 21c3c5d28007 ("block: don't request module during elevator init") fixed the deadlock issue which the reverted commit 774a1221e862 ("module, async: async_synchronize_full() on module init iff async is used") tried to fix. Since commit 0fdff3ec6d87 ("async, kmod: warn on synchronous request_module() from async workers") synchronous module loading from async is not allowed. Given that the original deadlock issue is fixed and it is no longer allowed to call synchronous request_module() from async we can remove PF_USED_ASYNC flag to make module init consistently invoke async_synchronize_full() unless async module probe is requested. Signed-off-by: Igor Pylypiv <ipylypiv@google.com> Reviewed-by: Changyuan Lyu <changyuanl@google.com> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-02-03Merge branch 'for-5.17-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: - Eric's fix for a long standing cgroup1 permission issue where it only checks for uid 0 instead of CAP which inadvertently allows unprivileged userns roots to modify release_agent userhelper - Fixes for the fallout from Waiman's recent cpuset work * 'for-5.17-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup/cpuset: Fix "suspicious RCU usage" lockdep warning cgroup-v1: Require capabilities to set release_agent cpuset: Fix the bug that subpart_cpus updated wrongly in update_cpumask() cgroup/cpuset: Make child cpusets restrict parents on v1 hierarchy
2022-02-03cgroup/cpuset: Fix "suspicious RCU usage" lockdep warningWaiman Long
It was found that a "suspicious RCU usage" lockdep warning was issued with the rcu_read_lock() call in update_sibling_cpumasks(). It is because the update_cpumasks_hier() function may sleep. So we have to release the RCU lock, call update_cpumasks_hier() and reacquire it afterward. Also add a percpu_rwsem_assert_held() in update_sibling_cpumasks() instead of stating that in the comment. Fixes: 4716909cc5c5 ("cpuset: Track cpusets that use parent's effective_cpus") Signed-off-by: Waiman Long <longman@redhat.com> Tested-by: Phil Auld <pauld@redhat.com> Reviewed-by: Phil Auld <pauld@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2022-02-02bpf: Use VM_MAP instead of VM_ALLOC for ringbufHou Tao
After commit 2fd3fb0be1d1 ("kasan, vmalloc: unpoison VM_ALLOC pages after mapping"), non-VM_ALLOC mappings will be marked as accessible in __get_vm_area_node() when KASAN is enabled. But now the flag for ringbuf area is VM_ALLOC, so KASAN will complain out-of-bound access after vmap() returns. Because the ringbuf area is created by mapping allocated pages, so use VM_MAP instead. After the change, info in /proc/vmallocinfo also changes from [start]-[end] 24576 ringbuf_map_alloc+0x171/0x290 vmalloc user to [start]-[end] 24576 ringbuf_map_alloc+0x171/0x290 vmap user Fixes: 457f44363a88 ("bpf: Implement BPF ring buffer and verifier support for it") Reported-by: syzbot+5ad567a418794b9b5983@syzkaller.appspotmail.com Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220202060158.6260-1-houtao1@huawei.com
2022-02-02genirq, softirq: Use in_hardirq() instead of in_irq()Changbin Du
Replace the obsolete and ambiguos macro in_irq() with the new macro in_hardirq(). Signed-off-by: Changbin Du <changbin.du@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20220128110727.5110-1-changbin.du@gmail.com
2022-02-02block: check that there is a plug in blk_flush_plugChristoph Hellwig
Rename blk_flush_plug to __blk_flush_plug and add a wrapper that includes the NULL check instead of open coding that check everywhere. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20220127070549.1377856-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-02block: remove blk_needs_flush_plugChristoph Hellwig
blk_needs_flush_plug fails to account for the cb_list, which needs flushing as well. Remove it and just check if there is a plug instead of poking into the internals of the plug structure. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220127070549.1377856-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-02block: pass a block_device and opf to bio_allocChristoph Hellwig
Pass the block_device and operation that we plan to use this bio for to bio_alloc to optimize the assignment. NULL/0 can be passed, both for the passthrough case on a raw request_queue and to temporarily avoid refactoring some nasty code. Also move the gfp_mask argument after the nr_vecs argument for a much more logical calling convention matching what most of the kernel does. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20220124091107.642561-18-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-02block: remove genhd.hChristoph Hellwig
There is no good reason to keep genhd.h separate from the main blkdev.h header that includes it. So fold the contents of genhd.h into blkdev.h and remove genhd.h entirely. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20220124093913.742411-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-02perf/core: Allow kernel address filter when not filtering the kernelAdrian Hunter
The so-called 'kernel' address filter can also be useful for filtering fixed addresses in user space. Allow that. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220131072453.2839535-6-adrian.hunter@intel.com
2022-02-02perf/core: Fix address filter parser for multiple filtersAdrian Hunter
Reset appropriate variables in the parser loop between parsing separate filters, so that they do not interfere with parsing the next filter. Fixes: 375637bc524952 ("perf/core: Introduce address range filtering") Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220131072453.2839535-4-adrian.hunter@intel.com
2022-02-02perf: Copy perf_event_attr::sig_data on modificationMarco Elver
The intent has always been that perf_event_attr::sig_data should also be modifiable along with PERF_EVENT_IOC_MODIFY_ATTRIBUTES, because it is observable by user space if SIGTRAP on events is requested. Currently only PERF_TYPE_BREAKPOINT is modifiable, and explicitly copies relevant breakpoint-related attributes in hw_breakpoint_copy_attr(). This misses copying perf_event_attr::sig_data. Since sig_data is not specific to PERF_TYPE_BREAKPOINT, introduce a helper to copy generic event-type-independent attributes on modification. Fixes: 97ba62b27867 ("perf: Add support for SIGTRAP on perf events") Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Link: https://lore.kernel.org/r/20220131103407.1971678-1-elver@google.com
2022-02-02sched: move autogroup sysctls into its own fileZhen Ni
move autogroup sysctls to autogroup.c and use the new register_sysctl_init() to register the sysctl interface. Signed-off-by: Zhen Ni <nizhen@uniontech.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220128095025.8745-1-nizhen@uniontech.com
2022-02-02rseq: Remove broken uapi field layout on 32-bit little endianMathieu Desnoyers
The rseq rseq_cs.ptr.{ptr32,padding} uapi endianness handling is entirely wrong on 32-bit little endian: a preprocessor logic mistake wrongly uses the big endian field layout on 32-bit little endian architectures. Fortunately, those ptr32 accessors were never used within the kernel, and only meant as a convenience for user-space. Remove those and replace the whole rseq_cs union by a __u64 type, as this is the only thing really needed to express the ABI. Document how 32-bit architectures are meant to interact with this field. Fixes: ec9c82e03a74 ("rseq: uapi: Declare rseq_cs field as union, update includes") Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220127152720.25898-1-mathieu.desnoyers@efficios.com
2022-02-01clocksource: Add a Kconfig option for WATCHDOG_MAX_SKEWWaiman Long
A watchdog maximum skew of 100us may still be too small for some systems or archs. It may also be too small when some kernel debug config options are enabled. So add a new Kconfig option CLOCKSOURCE_WATCHDOG_MAX_SKEW_US to allow kernel builders to have more control on the threshold for marking clocksource as unstable. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01rcutorture: Enable limited callback-flooding tests of SRCUPaul E. McKenney
This commit allows up to 50,000 callbacks worth of callback-flooding tests of SRCU. The goal of this change is to exercise Tree SRCU's ability to transition from SRCU_SIZE_SMALL to SRCU_SIZE_BIG triggered by callback-queue-time lock contention. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01torture: Wake up kthreads after storing task_struct pointerPaul E. McKenney
Currently, _torture_create_kthread() uses kthread_run() to create torture-test kthreads, which means that the resulting task_struct pointer is stored after the newly created kthread has been marked runnable. This in turn can cause spurious failure of checks for code being run by a particular kthread. This commit therefore changes _torture_create_kthread() to use kthread_create(), then to do an explicit wake_up_process() after the task_struct pointer has been stored. Reported-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Neeraj Upadhyay <quic_neeraju@quicinc.com> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>