diff --git a/Documentation/locking/seqlock.rst b/Documentation/locking/seqlock.rst index 366dd368d90a..62c5ad98c11c 100644 --- a/Documentation/locking/seqlock.rst +++ b/Documentation/locking/seqlock.rst @@ -87,6 +87,58 @@ Read path:: } while (read_seqcount_retry(&foo_seqcount, seq)); +.. _seqcount_locktype_t: + +Sequence counters with associated locks (``seqcount_LOCKTYPE_t``) +----------------------------------------------------------------- + +As discussed at :ref:`seqcount_t`, sequence count write side critical +sections must be serialized and non-preemptible. This variant of +sequence counters associate the lock used for writer serialization at +initialization time, which enables lockdep to validate that the write +side critical sections are properly serialized. + +This lock association is a NOOP if lockdep is disabled and has neither +storage nor runtime overhead. If lockdep is enabled, the lock pointer is +stored in struct seqcount and lockdep's "lock is held" assertions are +injected at the beginning of the write side critical section to validate +that it is properly protected. + +For lock types which do not implicitly disable preemption, preemption +protection is enforced in the write side function. + +The following sequence counters with associated locks are defined: + + - ``seqcount_spinlock_t`` + - ``seqcount_raw_spinlock_t`` + - ``seqcount_rwlock_t`` + - ``seqcount_mutex_t`` + - ``seqcount_ww_mutex_t`` + +The plain seqcount read and write APIs branch out to the specific +seqcount_LOCKTYPE_t implementation at compile-time. This avoids kernel +API explosion per each new seqcount LOCKTYPE. + +Initialization (replace "LOCKTYPE" with one of the supported locks):: + + /* dynamic */ + seqcount_LOCKTYPE_t foo_seqcount; + seqcount_LOCKTYPE_init(&foo_seqcount, &lock); + + /* static */ + static seqcount_LOCKTYPE_t foo_seqcount = + SEQCNT_LOCKTYPE_ZERO(foo_seqcount, &lock); + + /* C99 struct init */ + struct { + .seq = SEQCNT_LOCKTYPE_ZERO(foo.seq, &lock), + } foo; + +Write path: same as in :ref:`seqcount_t`, while running from a context +with the associated LOCKTYPE lock acquired. + +Read path: same as in :ref:`seqcount_t`. + .. _seqlock_t: Sequential locks (``seqlock_t``) diff --git a/arch/ia64/include/asm/smp.h b/arch/ia64/include/asm/smp.h index 7847ae40a181..aa92234c0142 100644 --- a/arch/ia64/include/asm/smp.h +++ b/arch/ia64/include/asm/smp.h @@ -18,7 +18,6 @@ #include #include -#include #include #include #include @@ -44,11 +43,6 @@ ia64_get_lid (void) #ifdef CONFIG_SMP -#define XTP_OFFSET 0x1e0008 - -#define SMP_IRQ_REDIRECTION (1 << 0) -#define SMP_IPI_REDIRECTION (1 << 1) - #define raw_smp_processor_id() (current_thread_info()->cpu) extern struct smp_boot_data { @@ -62,7 +56,6 @@ extern cpumask_t cpu_core_map[NR_CPUS]; DECLARE_PER_CPU_SHARED_ALIGNED(cpumask_t, cpu_sibling_map); extern int smp_num_siblings; extern void __iomem *ipi_base_addr; -extern unsigned char smp_int_redirect; extern volatile int ia64_cpu_to_sapicid[]; #define cpu_physical_id(i) ia64_cpu_to_sapicid[i] @@ -84,34 +77,6 @@ cpu_logical_id (int cpuid) return i; } -/* - * XTP control functions: - * min_xtp : route all interrupts to this CPU - * normal_xtp: nominal XTP value - * max_xtp : never deliver interrupts to this CPU. - */ - -static inline void -min_xtp (void) -{ - if (smp_int_redirect & SMP_IRQ_REDIRECTION) - writeb(0x00, ipi_base_addr + XTP_OFFSET); /* XTP to min */ -} - -static inline void -normal_xtp (void) -{ - if (smp_int_redirect & SMP_IRQ_REDIRECTION) - writeb(0x08, ipi_base_addr + XTP_OFFSET); /* XTP normal */ -} - -static inline void -max_xtp (void) -{ - if (smp_int_redirect & SMP_IRQ_REDIRECTION) - writeb(0x0f, ipi_base_addr + XTP_OFFSET); /* Set XTP to max */ -} - /* Upping and downing of CPUs */ extern int __cpu_disable (void); extern void __cpu_die (unsigned int cpu); diff --git a/arch/ia64/include/asm/xtp.h b/arch/ia64/include/asm/xtp.h new file mode 100644 index 000000000000..5bf1d70ad860 --- /dev/null +++ b/arch/ia64/include/asm/xtp.h @@ -0,0 +1,46 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_IA64_XTP_H +#define _ASM_IA64_XTP_H + +#include + +#ifdef CONFIG_SMP + +#define XTP_OFFSET 0x1e0008 + +#define SMP_IRQ_REDIRECTION (1 << 0) +#define SMP_IPI_REDIRECTION (1 << 1) + +extern unsigned char smp_int_redirect; + +/* + * XTP control functions: + * min_xtp : route all interrupts to this CPU + * normal_xtp: nominal XTP value + * max_xtp : never deliver interrupts to this CPU. + */ + +static inline void +min_xtp (void) +{ + if (smp_int_redirect & SMP_IRQ_REDIRECTION) + writeb(0x00, ipi_base_addr + XTP_OFFSET); /* XTP to min */ +} + +static inline void +normal_xtp (void) +{ + if (smp_int_redirect & SMP_IRQ_REDIRECTION) + writeb(0x08, ipi_base_addr + XTP_OFFSET); /* XTP normal */ +} + +static inline void +max_xtp (void) +{ + if (smp_int_redirect & SMP_IRQ_REDIRECTION) + writeb(0x0f, ipi_base_addr + XTP_OFFSET); /* Set XTP to max */ +} + +#endif /* CONFIG_SMP */ + +#endif /* _ASM_IA64_XTP_Hy */ diff --git a/arch/ia64/kernel/iosapic.c b/arch/ia64/kernel/iosapic.c index fad4db20ce65..35adcf89035a 100644 --- a/arch/ia64/kernel/iosapic.c +++ b/arch/ia64/kernel/iosapic.c @@ -95,6 +95,7 @@ #include #include #include +#include #undef DEBUG_INTERRUPT_ROUTING diff --git a/arch/ia64/kernel/irq.c b/arch/ia64/kernel/irq.c index 0a8e5e585edc..ecef17c7c35b 100644 --- a/arch/ia64/kernel/irq.c +++ b/arch/ia64/kernel/irq.c @@ -25,6 +25,7 @@ #include #include +#include /* * 'what should we do if we get a hw irq event on an illegal vector'. diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c index 36eba4ba6543..f19cb97c0098 100644 --- a/arch/ia64/kernel/process.c +++ b/arch/ia64/kernel/process.c @@ -47,6 +47,7 @@ #include #include #include +#include #include "entry.h" diff --git a/arch/ia64/kernel/sal.c b/arch/ia64/kernel/sal.c index c455ece977ad..e4f0705c0282 100644 --- a/arch/ia64/kernel/sal.c +++ b/arch/ia64/kernel/sal.c @@ -18,6 +18,7 @@ #include #include #include +#include __cacheline_aligned DEFINE_SPINLOCK(sal_lock); unsigned long sal_platform_features; diff --git a/arch/ia64/kernel/setup.c b/arch/ia64/kernel/setup.c index d2d440fe855b..dd595fbd8006 100644 --- a/arch/ia64/kernel/setup.c +++ b/arch/ia64/kernel/setup.c @@ -65,6 +65,7 @@ #include #include #include +#include #if defined(CONFIG_SMP) && (IA64_CPU_SIZE > PAGE_SIZE) # error "struct cpuinfo_ia64 too big!" diff --git a/arch/ia64/kernel/smp.c b/arch/ia64/kernel/smp.c index 0e2742003121..7b7b64eb3129 100644 --- a/arch/ia64/kernel/smp.c +++ b/arch/ia64/kernel/smp.c @@ -45,6 +45,7 @@ #include #include #include +#include /* * Note: alignment of 4 entries/cacheline was empirically determined diff --git a/arch/parisc/include/asm/timex.h b/arch/parisc/include/asm/timex.h index 45537cd4d1d3..06b510f8172e 100644 --- a/arch/parisc/include/asm/timex.h +++ b/arch/parisc/include/asm/timex.h @@ -7,6 +7,7 @@ #ifndef _ASMPARISC_TIMEX_H #define _ASMPARISC_TIMEX_H +#include #define CLOCK_TICK_RATE 1193180 /* Underlying HZ */ diff --git a/arch/sh/include/asm/io.h b/arch/sh/include/asm/io.h index 26f0f9b4658b..ec587b583822 100644 --- a/arch/sh/include/asm/io.h +++ b/arch/sh/include/asm/io.h @@ -17,6 +17,7 @@ #include #include #include +#include #include #include diff --git a/arch/sh/kernel/machvec.c b/arch/sh/kernel/machvec.c index beadbbdb4486..76bd8955d4fe 100644 --- a/arch/sh/kernel/machvec.c +++ b/arch/sh/kernel/machvec.c @@ -15,6 +15,7 @@ #include #include #include +#include #define MV_NAME_SIZE 32 diff --git a/arch/sparc/include/asm/timer_64.h b/arch/sparc/include/asm/timer_64.h index c7e4fb601a57..dcfad4613e18 100644 --- a/arch/sparc/include/asm/timer_64.h +++ b/arch/sparc/include/asm/timer_64.h @@ -7,6 +7,7 @@ #ifndef _SPARC64_TIMER_H #define _SPARC64_TIMER_H +#include #include #include diff --git a/arch/sparc/include/asm/vvar.h b/arch/sparc/include/asm/vvar.h index 0289503d1cb0..6eaf5cfcaae1 100644 --- a/arch/sparc/include/asm/vvar.h +++ b/arch/sparc/include/asm/vvar.h @@ -6,7 +6,8 @@ #define _ASM_SPARC_VVAR_DATA_H #include -#include +#include +#include #include #include diff --git a/arch/sparc/kernel/vdso.c b/arch/sparc/kernel/vdso.c index 58880662b271..0e27437eb97b 100644 --- a/arch/sparc/kernel/vdso.c +++ b/arch/sparc/kernel/vdso.c @@ -7,7 +7,6 @@ * a different vsyscall implementation for Linux/IA32 and for the name. */ -#include #include #include diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h index b9527a54db99..0f0dd645b594 100644 --- a/arch/x86/include/asm/fixmap.h +++ b/arch/x86/include/asm/fixmap.h @@ -26,9 +26,9 @@ #ifndef __ASSEMBLY__ #include -#include #include #include +#include #ifdef CONFIG_X86_32 #include #include diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h index e15f364efbcc..c0538f82c9a2 100644 --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h @@ -5,16 +5,6 @@ #include #include -/* - * We need the APIC definitions automatically as part of 'smp.h' - */ -#ifdef CONFIG_X86_LOCAL_APIC -# include -# include -# ifdef CONFIG_X86_IO_APIC -# include -# endif -#endif #include #include diff --git a/arch/x86/include/asm/tsc.h b/arch/x86/include/asm/tsc.h index b7b2624fba86..01a300a9700b 100644 --- a/arch/x86/include/asm/tsc.h +++ b/arch/x86/include/asm/tsc.h @@ -6,6 +6,7 @@ #define _ASM_X86_TSC_H #include +#include /* * Standard way to access the cycle counter. diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index ccf726cc87b7..5f943b938167 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -46,6 +46,7 @@ #include #include #include +#include #include #include #include diff --git a/arch/x86/kernel/apic/apic_noop.c b/arch/x86/kernel/apic/apic_noop.c index 98c9bb75d185..780c702969b7 100644 --- a/arch/x86/kernel/apic/apic_noop.c +++ b/arch/x86/kernel/apic/apic_noop.c @@ -10,6 +10,7 @@ * like self-ipi, etc... */ #include +#include #include diff --git a/arch/x86/kernel/apic/bigsmp_32.c b/arch/x86/kernel/apic/bigsmp_32.c index 38b5b51d42f6..98d015a4405a 100644 --- a/arch/x86/kernel/apic/bigsmp_32.c +++ b/arch/x86/kernel/apic/bigsmp_32.c @@ -9,6 +9,7 @@ #include #include +#include #include "local.h" diff --git a/arch/x86/kernel/apic/hw_nmi.c b/arch/x86/kernel/apic/hw_nmi.c index d1fc62a67320..34a992e275ef 100644 --- a/arch/x86/kernel/apic/hw_nmi.c +++ b/arch/x86/kernel/apic/hw_nmi.c @@ -9,6 +9,7 @@ * Bits copied from original nmi.c file * */ +#include #include #include diff --git a/arch/x86/kernel/apic/ipi.c b/arch/x86/kernel/apic/ipi.c index 6ca0f91372fd..387154e39e08 100644 --- a/arch/x86/kernel/apic/ipi.c +++ b/arch/x86/kernel/apic/ipi.c @@ -2,6 +2,7 @@ #include #include +#include #include "local.h" diff --git a/arch/x86/kernel/apic/local.h b/arch/x86/kernel/apic/local.h index 04797f05ce94..a997d849509a 100644 --- a/arch/x86/kernel/apic/local.h +++ b/arch/x86/kernel/apic/local.h @@ -10,6 +10,7 @@ #include +#include #include /* APIC flat 64 */ diff --git a/arch/x86/kernel/apic/probe_32.c b/arch/x86/kernel/apic/probe_32.c index 67b33d67002f..7bda71def557 100644 --- a/arch/x86/kernel/apic/probe_32.c +++ b/arch/x86/kernel/apic/probe_32.c @@ -10,6 +10,7 @@ #include #include +#include #include #include diff --git a/arch/x86/kernel/apic/probe_64.c b/arch/x86/kernel/apic/probe_64.c index 29f0e0984557..bd3835d6b535 100644 --- a/arch/x86/kernel/apic/probe_64.c +++ b/arch/x86/kernel/apic/probe_64.c @@ -8,6 +8,7 @@ * Martin Bligh, Andi Kleen, James Bottomley, John Stultz, and * James Cleverdon. */ +#include #include #include "local.h" diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index d4806eac9325..dcc3d943c68f 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 965474d78cef..c5d6f17d9b9d 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -45,6 +45,7 @@ #include #include #include +#include #include #include #include diff --git a/arch/x86/kernel/cpu/hygon.c b/arch/x86/kernel/cpu/hygon.c index 4e28c1fc8749..ac6c30e5801d 100644 --- a/arch/x86/kernel/cpu/hygon.c +++ b/arch/x86/kernel/cpu/hygon.c @@ -10,6 +10,7 @@ #include #include +#include #include #include #include diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index b6b7b38dff5f..59a1e3ce3f14 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -23,6 +23,7 @@ #include #include #include +#include #ifdef CONFIG_X86_64 #include diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c index 8d85e00bb40a..a0e8fc7d85f1 100644 --- a/arch/x86/kernel/devicetree.c +++ b/arch/x86/kernel/devicetree.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include #include diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c index dd73135d7cee..beb1bada1b0a 100644 --- a/arch/x86/kernel/irqinit.c +++ b/arch/x86/kernel/irqinit.c @@ -22,6 +22,8 @@ #include #include #include +#include +#include #include #include #include diff --git a/arch/x86/kernel/jailhouse.c b/arch/x86/kernel/jailhouse.c index 6eb8b50ea07e..4eb8f2d19a87 100644 --- a/arch/x86/kernel/jailhouse.c +++ b/arch/x86/kernel/jailhouse.c @@ -13,6 +13,8 @@ #include #include #include +#include +#include #include #include #include diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c index c27b82b62c8b..411af4aa7b51 100644 --- a/arch/x86/kernel/mpparse.c +++ b/arch/x86/kernel/mpparse.c @@ -19,6 +19,8 @@ #include #include +#include +#include #include #include #include diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index b9a68d8e06d8..3511736fbc74 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -25,6 +25,7 @@ #include #include +#include #include #include #include diff --git a/arch/x86/kernel/topology.c b/arch/x86/kernel/topology.c index b8810ebbc8ae..0a2ec801b63f 100644 --- a/arch/x86/kernel/topology.c +++ b/arch/x86/kernel/topology.c @@ -31,6 +31,7 @@ #include #include #include +#include #include static DEFINE_PER_CPU(struct x86_cpu, cpu_devices); diff --git a/arch/x86/kernel/tsc_msr.c b/arch/x86/kernel/tsc_msr.c index 4fec6f3a1858..46c72f2ec32f 100644 --- a/arch/x86/kernel/tsc_msr.c +++ b/arch/x86/kernel/tsc_msr.c @@ -7,6 +7,7 @@ */ #include +#include #include #include diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c index 4cb958419fb0..7c055259de3a 100644 --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -52,6 +52,7 @@ #include #include #include +#include #include "mm_internal.h" diff --git a/arch/x86/xen/apic.c b/arch/x86/xen/apic.c index 5e53bfbe5823..1aff4ae65655 100644 --- a/arch/x86/xen/apic.c +++ b/arch/x86/xen/apic.c @@ -1,8 +1,10 @@ // SPDX-License-Identifier: GPL-2.0 #include +#include #include #include +#include #include #include diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c index 3e89b0067ff0..9e87ab010c82 100644 --- a/arch/x86/xen/enlighten_hvm.c +++ b/arch/x86/xen/enlighten_hvm.c @@ -11,6 +11,7 @@ #include #include +#include #include #include #include diff --git a/arch/x86/xen/smp_hvm.c b/arch/x86/xen/smp_hvm.c index f8d39440b292..f5e7db4f82ab 100644 --- a/arch/x86/xen/smp_hvm.c +++ b/arch/x86/xen/smp_hvm.c @@ -1,4 +1,5 @@ // SPDX-License-Identifier: GPL-2.0 +#include #include #include diff --git a/arch/x86/xen/smp_pv.c b/arch/x86/xen/smp_pv.c index 9ea598dcc132..47c8f4b444c9 100644 --- a/arch/x86/xen/smp_pv.c +++ b/arch/x86/xen/smp_pv.c @@ -29,6 +29,7 @@ #include #include #include +#include #include #include diff --git a/arch/x86/xen/suspend_pv.c b/arch/x86/xen/suspend_pv.c index 8303b58c79a9..cae9660f4c67 100644 --- a/arch/x86/xen/suspend_pv.c +++ b/arch/x86/xen/suspend_pv.c @@ -1,11 +1,11 @@ // SPDX-License-Identifier: GPL-2.0 #include -#include - #include #include +#include + #include "xen-ops.h" void xen_pv_pre_suspend(void) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 521c29b8ae29..413e0b5c8e6b 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -406,7 +406,7 @@ struct ioc { enum ioc_running running; atomic64_t vtime_rate; - seqcount_t period_seqcount; + seqcount_spinlock_t period_seqcount; u32 period_at; /* wallclock starttime */ u64 period_at_vtime; /* vtime starttime */ @@ -873,7 +873,6 @@ static void ioc_now(struct ioc *ioc, struct ioc_now *now) static void ioc_start_period(struct ioc *ioc, struct ioc_now *now) { - lockdep_assert_held(&ioc->lock); WARN_ON_ONCE(ioc->running != IOC_RUNNING); write_seqcount_begin(&ioc->period_seqcount); @@ -2001,7 +2000,7 @@ static int blk_iocost_init(struct request_queue *q) ioc->running = IOC_IDLE; atomic64_set(&ioc->vtime_rate, VTIME_PER_USEC); - seqcount_init(&ioc->period_seqcount); + seqcount_spinlock_init(&ioc->period_seqcount, &ioc->lock); ioc->period_at = ktime_to_us(ktime_get()); atomic64_set(&ioc->cur_period, 0); atomic_set(&ioc->hweight_gen, 0); diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c index 07f5273207e7..434a3314fb0e 100644 --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -52,12 +52,6 @@ DEFINE_WD_CLASS(reservation_ww_class); EXPORT_SYMBOL(reservation_ww_class); -struct lock_class_key reservation_seqcount_class; -EXPORT_SYMBOL(reservation_seqcount_class); - -const char reservation_seqcount_string[] = "reservation_seqcount"; -EXPORT_SYMBOL(reservation_seqcount_string); - /** * dma_resv_list_alloc - allocate fence list * @shared_max: number of fences we need space for @@ -143,9 +137,8 @@ subsys_initcall(dma_resv_lockdep); void dma_resv_init(struct dma_resv *obj) { ww_mutex_init(&obj->lock, &reservation_ww_class); + seqcount_ww_mutex_init(&obj->seq, &obj->lock); - __seqcount_init(&obj->seq, reservation_seqcount_string, - &reservation_seqcount_class); RCU_INIT_POINTER(obj->fence, NULL); RCU_INIT_POINTER(obj->fence_excl, NULL); } @@ -275,7 +268,6 @@ void dma_resv_add_shared_fence(struct dma_resv *obj, struct dma_fence *fence) fobj = dma_resv_get_list(obj); count = fobj->shared_count; - preempt_disable(); write_seqcount_begin(&obj->seq); for (i = 0; i < count; ++i) { @@ -297,7 +289,6 @@ replace: smp_store_mb(fobj->shared_count, count); write_seqcount_end(&obj->seq); - preempt_enable(); dma_fence_put(old); } EXPORT_SYMBOL(dma_resv_add_shared_fence); @@ -324,14 +315,12 @@ void dma_resv_add_excl_fence(struct dma_resv *obj, struct dma_fence *fence) if (fence) dma_fence_get(fence); - preempt_disable(); write_seqcount_begin(&obj->seq); /* write_seqcount_begin provides the necessary memory barrier */ RCU_INIT_POINTER(obj->fence_excl, fence); if (old) old->shared_count = 0; write_seqcount_end(&obj->seq); - preempt_enable(); /* inplace update, no shared fences */ while (i--) @@ -409,13 +398,11 @@ retry: src_list = dma_resv_get_list(dst); old = dma_resv_get_excl(dst); - preempt_disable(); write_seqcount_begin(&dst->seq); /* write_seqcount_begin provides the necessary memory barrier */ RCU_INIT_POINTER(dst->fence_excl, new); RCU_INIT_POINTER(dst->fence, dst_list); write_seqcount_end(&dst->seq); - preempt_enable(); dma_resv_list_free(src_list); dma_fence_put(old); diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c index e5a5ba869eb4..a58af513c952 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c @@ -258,11 +258,9 @@ static int amdgpu_amdkfd_remove_eviction_fence(struct amdgpu_bo *bo, new->shared_count = k; /* Install the new fence list, seqcount provides the barriers */ - preempt_disable(); write_seqcount_begin(&resv->seq); RCU_INIT_POINTER(resv->fence, new); write_seqcount_end(&resv->seq); - preempt_enable(); /* Drop the references to the removed fences or move them to ef_list */ for (i = j, k = 0; i < old->shared_count; ++i) { diff --git a/drivers/iommu/intel/irq_remapping.c b/drivers/iommu/intel/irq_remapping.c index aa096b333a99..23583b0e66a5 100644 --- a/drivers/iommu/intel/irq_remapping.c +++ b/drivers/iommu/intel/irq_remapping.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index fb8d1fb14088..ef0fd4830803 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -7019,7 +7019,7 @@ static struct r5conf *setup_conf(struct mddev *mddev) } else goto abort; spin_lock_init(&conf->device_lock); - seqcount_init(&conf->gen_lock); + seqcount_spinlock_init(&conf->gen_lock, &conf->device_lock); mutex_init(&conf->cache_size_mutex); init_waitqueue_head(&conf->wait_for_quiescent); init_waitqueue_head(&conf->wait_for_stripe); diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h index 7fb3b26a181a..16fc29472f5c 100644 --- a/drivers/md/raid5.h +++ b/drivers/md/raid5.h @@ -582,7 +582,7 @@ struct r5conf { int prev_chunk_sectors; int prev_algo; short generation; /* increments with every reshape */ - seqcount_t gen_lock; /* lock against generation changes */ + seqcount_spinlock_t gen_lock; /* lock against generation changes */ unsigned long reshape_checkpoint; /* Time we last updated * metadata */ long long min_offset_diff; /* minimum difference between diff --git a/fs/dcache.c b/fs/dcache.c index 361ea7ab30ea..ea0485861d93 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1746,7 +1746,7 @@ static struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name) dentry->d_lockref.count = 1; dentry->d_flags = 0; spin_lock_init(&dentry->d_lock); - seqcount_init(&dentry->d_seq); + seqcount_spinlock_init(&dentry->d_seq, &dentry->d_lock); dentry->d_inode = NULL; dentry->d_parent = dentry; dentry->d_sb = sb; diff --git a/fs/fs_struct.c b/fs/fs_struct.c index ca639ed967b7..04b3f5b9c629 100644 --- a/fs/fs_struct.c +++ b/fs/fs_struct.c @@ -117,7 +117,7 @@ struct fs_struct *copy_fs_struct(struct fs_struct *old) fs->users = 1; fs->in_exec = 0; spin_lock_init(&fs->lock); - seqcount_init(&fs->seq); + seqcount_spinlock_init(&fs->seq, &fs->lock); fs->umask = old->umask; spin_lock(&old->lock); @@ -163,6 +163,6 @@ EXPORT_SYMBOL(current_umask); struct fs_struct init_fs = { .users = 1, .lock = __SPIN_LOCK_UNLOCKED(init_fs.lock), - .seq = SEQCNT_ZERO(init_fs.seq), + .seq = SEQCNT_SPINLOCK_ZERO(init_fs.seq, &init_fs.lock), .umask = 0022, }; diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h index 2b7f6dcd2eb8..210e590e1f71 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h @@ -117,7 +117,7 @@ struct nfs4_state_owner { unsigned long so_flags; struct list_head so_states; struct nfs_seqid_counter so_seqid; - seqcount_t so_reclaim_seqcount; + seqcount_spinlock_t so_reclaim_seqcount; struct mutex so_delegreturn_mutex; }; diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index a8dc25ce48bb..b1dba24918f8 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -509,7 +509,7 @@ nfs4_alloc_state_owner(struct nfs_server *server, nfs4_init_seqid_counter(&sp->so_seqid); atomic_set(&sp->so_count, 1); INIT_LIST_HEAD(&sp->so_lru); - seqcount_init(&sp->so_reclaim_seqcount); + seqcount_spinlock_init(&sp->so_reclaim_seqcount, &sp->so_lock); mutex_init(&sp->so_delegreturn_mutex); return sp; } diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 6e264dded46e..0e4a3837da52 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -61,7 +61,7 @@ struct userfaultfd_ctx { /* waitqueue head for events */ wait_queue_head_t event_wqh; /* a refile sequence protected by fault_pending_wqh lock */ - struct seqcount refile_seq; + seqcount_spinlock_t refile_seq; /* pseudo fd refcounting */ refcount_t refcount; /* userfaultfd syscall flags */ @@ -1961,7 +1961,7 @@ static void init_once_userfaultfd_ctx(void *mem) init_waitqueue_head(&ctx->fault_wqh); init_waitqueue_head(&ctx->event_wqh); init_waitqueue_head(&ctx->fd_wqh); - seqcount_init(&ctx->refile_seq); + seqcount_spinlock_init(&ctx->refile_seq, &ctx->fault_pending_wqh.lock); } SYSCALL_DEFINE1(userfaultfd, int, flags) diff --git a/include/linux/dcache.h b/include/linux/dcache.h index a81f0c3cf352..65d975bf9390 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -89,7 +89,7 @@ extern struct dentry_stat_t dentry_stat; struct dentry { /* RCU lookup touched fields */ unsigned int d_flags; /* protected by d_lock */ - seqcount_t d_seq; /* per dentry seqlock */ + seqcount_spinlock_t d_seq; /* per dentry seqlock */ struct hlist_bl_node d_hash; /* lookup hash list */ struct dentry *d_parent; /* parent directory */ struct qstr d_name; diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h index ee50d10f052b..d44a77e8a7e3 100644 --- a/include/linux/dma-resv.h +++ b/include/linux/dma-resv.h @@ -46,8 +46,6 @@ #include extern struct ww_class reservation_ww_class; -extern struct lock_class_key reservation_seqcount_class; -extern const char reservation_seqcount_string[]; /** * struct dma_resv_list - a list of shared fences @@ -71,7 +69,7 @@ struct dma_resv_list { */ struct dma_resv { struct ww_mutex lock; - seqcount_t seq; + seqcount_ww_mutex_t seq; struct dma_fence __rcu *fence_excl; struct dma_resv_list __rcu *fence; diff --git a/include/linux/dynamic_queue_limits.h b/include/linux/dynamic_queue_limits.h index 99fc06f0afc1..407c2f281b64 100644 --- a/include/linux/dynamic_queue_limits.h +++ b/include/linux/dynamic_queue_limits.h @@ -38,6 +38,8 @@ #ifdef __KERNEL__ +#include + struct dql { /* Fields accessed in enqueue path (dql_queued) */ unsigned int num_queued; /* Total ever queued */ diff --git a/include/linux/fs_struct.h b/include/linux/fs_struct.h index cf1015abfbf2..783b48dedb72 100644 --- a/include/linux/fs_struct.h +++ b/include/linux/fs_struct.h @@ -9,7 +9,7 @@ struct fs_struct { int users; spinlock_t lock; - seqcount_t seq; + seqcount_spinlock_t seq; int umask; int in_exec; struct path root, pwd; diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 15c8ac313678..107cedd7019a 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -17,6 +17,7 @@ #include #include #include +#include #include #include @@ -159,7 +160,7 @@ struct hrtimer_clock_base { struct hrtimer_cpu_base *cpu_base; unsigned int index; clockid_t clockid; - seqcount_t seq; + seqcount_raw_spinlock_t seq; struct hrtimer *running; struct timerqueue_head active; ktime_t (*get_time)(void); diff --git a/include/linux/ktime.h b/include/linux/ktime.h index 42d2e6ac35f2..a12b5523cc18 100644 --- a/include/linux/ktime.h +++ b/include/linux/ktime.h @@ -23,6 +23,7 @@ #include #include +#include /* Nanosecond scalar representation for kernel time values */ typedef s64 ktime_t; diff --git a/include/linux/kvm_irqfd.h b/include/linux/kvm_irqfd.h index dc1da020305b..dac047abdba7 100644 --- a/include/linux/kvm_irqfd.h +++ b/include/linux/kvm_irqfd.h @@ -42,7 +42,7 @@ struct kvm_kernel_irqfd { wait_queue_entry_t wait; /* Update side is protected by irqfds.lock */ struct kvm_kernel_irq_routing_entry irq_entry; - seqcount_t irq_entry_sc; + seqcount_spinlock_t irq_entry_sc; /* Used for level IRQ fast-path */ int gsi; struct work_struct inject; diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 39a35699d0d6..62a382d1845b 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -11,6 +11,7 @@ #define __LINUX_LOCKDEP_H #include +#include #include struct task_struct; diff --git a/include/linux/mutex.h b/include/linux/mutex.h index ae197cc00cc8..dcd185cbfe79 100644 --- a/include/linux/mutex.h +++ b/include/linux/mutex.h @@ -65,6 +65,17 @@ struct mutex { #endif }; +struct ww_class; +struct ww_acquire_ctx; + +struct ww_mutex { + struct mutex base; + struct ww_acquire_ctx *ctx; +#ifdef CONFIG_DEBUG_MUTEXES + struct ww_class *ww_class; +#endif +}; + /* * This is the control structure for tasks blocked on mutex, * which resides on the blocked task's kernel stack: diff --git a/include/linux/sched.h b/include/linux/sched.h index 52bcc9f48e17..53ddc02e2e79 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -32,6 +32,7 @@ #include #include #include +#include #include /* task_struct member predeclarations (sorted alphabetically): */ @@ -1049,7 +1050,7 @@ struct task_struct { /* Protected by ->alloc_lock: */ nodemask_t mems_allowed; /* Seqence number to catch updates: */ - seqcount_t mems_allowed_seq; + seqcount_spinlock_t mems_allowed_seq; int cpuset_mem_spread_rotor; int cpuset_slab_spread_rotor; #endif diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h index 54bc20496392..962d9768945f 100644 --- a/include/linux/seqlock.h +++ b/include/linux/seqlock.h @@ -10,13 +10,16 @@ * * Copyrights: * - Based on x86_64 vsyscall gettimeofday: Keith Owens, Andrea Arcangeli + * - Sequence counters with associated locks, (C) 2020 Linutronix GmbH */ -#include -#include -#include #include #include +#include +#include +#include +#include + #include /* @@ -48,6 +51,10 @@ * This mechanism can't be used if the protected data contains pointers, * as the writer can invalidate a pointer that a reader is following. * + * If the write serialization mechanism is one of the common kernel + * locking primitives, use a sequence counter with associated lock + * (seqcount_LOCKTYPE_t) instead. + * * If it's desired to automatically handle the sequence counter writer * serialization and non-preemptibility requirements, use a sequential * lock (seqlock_t) instead. @@ -72,17 +79,18 @@ static inline void __seqcount_init(seqcount_t *s, const char *name, } #ifdef CONFIG_DEBUG_LOCK_ALLOC -# define SEQCOUNT_DEP_MAP_INIT(lockname) \ - .dep_map = { .name = #lockname } \ + +# define SEQCOUNT_DEP_MAP_INIT(lockname) \ + .dep_map = { .name = #lockname } /** * seqcount_init() - runtime initializer for seqcount_t * @s: Pointer to the seqcount_t instance */ -# define seqcount_init(s) \ - do { \ - static struct lock_class_key __key; \ - __seqcount_init((s), #s, &__key); \ +# define seqcount_init(s) \ + do { \ + static struct lock_class_key __key; \ + __seqcount_init((s), #s, &__key); \ } while (0) static inline void seqcount_lockdep_reader_access(const seqcount_t *s) @@ -108,9 +116,143 @@ static inline void seqcount_lockdep_reader_access(const seqcount_t *s) */ #define SEQCNT_ZERO(name) { .sequence = 0, SEQCOUNT_DEP_MAP_INIT(name) } +/* + * Sequence counters with associated locks (seqcount_LOCKTYPE_t) + * + * A sequence counter which associates the lock used for writer + * serialization at initialization time. This enables lockdep to validate + * that the write side critical section is properly serialized. + * + * For associated locks which do not implicitly disable preemption, + * preemption protection is enforced in the write side function. + * + * Lockdep is never used in any for the raw write variants. + * + * See Documentation/locking/seqlock.rst + */ + +#ifdef CONFIG_LOCKDEP +#define __SEQ_LOCK(expr) expr +#else +#define __SEQ_LOCK(expr) +#endif + +/** + * typedef seqcount_LOCKNAME_t - sequence counter with LOCKTYPR associated + * @seqcount: The real sequence counter + * @lock: Pointer to the associated spinlock + * + * A plain sequence counter with external writer synchronization by a + * spinlock. The spinlock is associated to the sequence count in the + * static initializer or init function. This enables lockdep to validate + * that the write side critical section is properly serialized. + */ + +/** + * seqcount_LOCKNAME_init() - runtime initializer for seqcount_LOCKNAME_t + * @s: Pointer to the seqcount_LOCKNAME_t instance + * @lock: Pointer to the associated LOCKTYPE + */ + +/* + * SEQCOUNT_LOCKTYPE() - Instantiate seqcount_LOCKNAME_t and helpers + * @locktype: actual typename + * @lockname: name + * @preemptible: preemptibility of above locktype + * @lockmember: argument for lockdep_assert_held() + */ +#define SEQCOUNT_LOCKTYPE(locktype, lockname, preemptible, lockmember) \ +typedef struct seqcount_##lockname { \ + seqcount_t seqcount; \ + __SEQ_LOCK(locktype *lock); \ +} seqcount_##lockname##_t; \ + \ +static __always_inline void \ +seqcount_##lockname##_init(seqcount_##lockname##_t *s, locktype *lock) \ +{ \ + seqcount_init(&s->seqcount); \ + __SEQ_LOCK(s->lock = lock); \ +} \ + \ +static __always_inline seqcount_t * \ +__seqcount_##lockname##_ptr(seqcount_##lockname##_t *s) \ +{ \ + return &s->seqcount; \ +} \ + \ +static __always_inline bool \ +__seqcount_##lockname##_preemptible(seqcount_##lockname##_t *s) \ +{ \ + return preemptible; \ +} \ + \ +static __always_inline void \ +__seqcount_##lockname##_assert(seqcount_##lockname##_t *s) \ +{ \ + __SEQ_LOCK(lockdep_assert_held(lockmember)); \ +} + +/* + * __seqprop() for seqcount_t + */ + +static inline seqcount_t *__seqcount_ptr(seqcount_t *s) +{ + return s; +} + +static inline bool __seqcount_preemptible(seqcount_t *s) +{ + return false; +} + +static inline void __seqcount_assert(seqcount_t *s) +{ + lockdep_assert_preemption_disabled(); +} + +SEQCOUNT_LOCKTYPE(raw_spinlock_t, raw_spinlock, false, s->lock) +SEQCOUNT_LOCKTYPE(spinlock_t, spinlock, false, s->lock) +SEQCOUNT_LOCKTYPE(rwlock_t, rwlock, false, s->lock) +SEQCOUNT_LOCKTYPE(struct mutex, mutex, true, s->lock) +SEQCOUNT_LOCKTYPE(struct ww_mutex, ww_mutex, true, &s->lock->base) + +/** + * SEQCNT_LOCKNAME_ZERO - static initializer for seqcount_LOCKNAME_t + * @name: Name of the seqcount_LOCKNAME_t instance + * @lock: Pointer to the associated LOCKTYPE + */ + +#define SEQCOUNT_LOCKTYPE_ZERO(seq_name, assoc_lock) { \ + .seqcount = SEQCNT_ZERO(seq_name.seqcount), \ + __SEQ_LOCK(.lock = (assoc_lock)) \ +} + +#define SEQCNT_SPINLOCK_ZERO(name, lock) SEQCOUNT_LOCKTYPE_ZERO(name, lock) +#define SEQCNT_RAW_SPINLOCK_ZERO(name, lock) SEQCOUNT_LOCKTYPE_ZERO(name, lock) +#define SEQCNT_RWLOCK_ZERO(name, lock) SEQCOUNT_LOCKTYPE_ZERO(name, lock) +#define SEQCNT_MUTEX_ZERO(name, lock) SEQCOUNT_LOCKTYPE_ZERO(name, lock) +#define SEQCNT_WW_MUTEX_ZERO(name, lock) SEQCOUNT_LOCKTYPE_ZERO(name, lock) + + +#define __seqprop_case(s, lockname, prop) \ + seqcount_##lockname##_t: __seqcount_##lockname##_##prop((void *)(s)) + +#define __seqprop(s, prop) _Generic(*(s), \ + seqcount_t: __seqcount_##prop((void *)(s)), \ + __seqprop_case((s), raw_spinlock, prop), \ + __seqprop_case((s), spinlock, prop), \ + __seqprop_case((s), rwlock, prop), \ + __seqprop_case((s), mutex, prop), \ + __seqprop_case((s), ww_mutex, prop)) + +#define __seqcount_ptr(s) __seqprop(s, ptr) +#define __seqcount_lock_preemptible(s) __seqprop(s, preemptible) +#define __seqcount_assert_lock_held(s) __seqprop(s, assert) + /** * __read_seqcount_begin() - begin a seqcount_t read section w/o barrier - * @s: Pointer to seqcount_t + * @s: Pointer to seqcount_t or any of the seqcount_locktype_t variants * * __read_seqcount_begin is like read_seqcount_begin, but has no smp_rmb() * barrier. Callers should ensure that smp_rmb() or equivalent ordering is @@ -122,7 +264,10 @@ static inline void seqcount_lockdep_reader_access(const seqcount_t *s) * * Return: count to be passed to read_seqcount_retry() */ -static inline unsigned __read_seqcount_begin(const seqcount_t *s) +#define __read_seqcount_begin(s) \ + __read_seqcount_t_begin(__seqcount_ptr(s)) + +static inline unsigned __read_seqcount_t_begin(const seqcount_t *s) { unsigned ret; @@ -138,32 +283,38 @@ repeat: /** * raw_read_seqcount_begin() - begin a seqcount_t read section w/o lockdep - * @s: Pointer to seqcount_t + * @s: Pointer to seqcount_t or any of the seqcount_locktype_t variants * * Return: count to be passed to read_seqcount_retry() */ -static inline unsigned raw_read_seqcount_begin(const seqcount_t *s) +#define raw_read_seqcount_begin(s) \ + raw_read_seqcount_t_begin(__seqcount_ptr(s)) + +static inline unsigned raw_read_seqcount_t_begin(const seqcount_t *s) { - unsigned ret = __read_seqcount_begin(s); + unsigned ret = __read_seqcount_t_begin(s); smp_rmb(); return ret; } /** * read_seqcount_begin() - begin a seqcount_t read critical section - * @s: Pointer to seqcount_t + * @s: Pointer to seqcount_t or any of the seqcount_locktype_t variants * * Return: count to be passed to read_seqcount_retry() */ -static inline unsigned read_seqcount_begin(const seqcount_t *s) +#define read_seqcount_begin(s) \ + read_seqcount_t_begin(__seqcount_ptr(s)) + +static inline unsigned read_seqcount_t_begin(const seqcount_t *s) { seqcount_lockdep_reader_access(s); - return raw_read_seqcount_begin(s); + return raw_read_seqcount_t_begin(s); } /** * raw_read_seqcount() - read the raw seqcount_t counter value - * @s: Pointer to seqcount_t + * @s: Pointer to seqcount_t or any of the seqcount_locktype_t variants * * raw_read_seqcount opens a read critical section of the given * seqcount_t, without any lockdep checking, and without checking or @@ -172,7 +323,10 @@ static inline unsigned read_seqcount_begin(const seqcount_t *s) * * Return: count to be passed to read_seqcount_retry() */ -static inline unsigned raw_read_seqcount(const seqcount_t *s) +#define raw_read_seqcount(s) \ + raw_read_seqcount_t(__seqcount_ptr(s)) + +static inline unsigned raw_read_seqcount_t(const seqcount_t *s) { unsigned ret = READ_ONCE(s->sequence); smp_rmb(); @@ -183,7 +337,7 @@ static inline unsigned raw_read_seqcount(const seqcount_t *s) /** * raw_seqcount_begin() - begin a seqcount_t read critical section w/o * lockdep and w/o counter stabilization - * @s: Pointer to seqcount_t + * @s: Pointer to seqcount_t or any of the seqcount_locktype_t variants * * raw_seqcount_begin opens a read critical section of the given * seqcount_t. Unlike read_seqcount_begin(), this function will not wait @@ -197,18 +351,21 @@ static inline unsigned raw_read_seqcount(const seqcount_t *s) * * Return: count to be passed to read_seqcount_retry() */ -static inline unsigned raw_seqcount_begin(const seqcount_t *s) +#define raw_seqcount_begin(s) \ + raw_seqcount_t_begin(__seqcount_ptr(s)) + +static inline unsigned raw_seqcount_t_begin(const seqcount_t *s) { /* * If the counter is odd, let read_seqcount_retry() fail * by decrementing the counter. */ - return raw_read_seqcount(s) & ~1; + return raw_read_seqcount_t(s) & ~1; } /** * __read_seqcount_retry() - end a seqcount_t read section w/o barrier - * @s: Pointer to seqcount_t + * @s: Pointer to seqcount_t or any of the seqcount_locktype_t variants * @start: count, from read_seqcount_begin() * * __read_seqcount_retry is like read_seqcount_retry, but has no smp_rmb() @@ -221,7 +378,10 @@ static inline unsigned raw_seqcount_begin(const seqcount_t *s) * * Return: true if a read section retry is required, else false */ -static inline int __read_seqcount_retry(const seqcount_t *s, unsigned start) +#define __read_seqcount_retry(s, start) \ + __read_seqcount_t_retry(__seqcount_ptr(s), start) + +static inline int __read_seqcount_t_retry(const seqcount_t *s, unsigned start) { kcsan_atomic_next(0); return unlikely(READ_ONCE(s->sequence) != start); @@ -229,7 +389,7 @@ static inline int __read_seqcount_retry(const seqcount_t *s, unsigned start) /** * read_seqcount_retry() - end a seqcount_t read critical section - * @s: Pointer to seqcount_t + * @s: Pointer to seqcount_t or any of the seqcount_locktype_t variants * @start: count, from read_seqcount_begin() * * read_seqcount_retry closes the read critical section of given @@ -238,17 +398,28 @@ static inline int __read_seqcount_retry(const seqcount_t *s, unsigned start) * * Return: true if a read section retry is required, else false */ -static inline int read_seqcount_retry(const seqcount_t *s, unsigned start) +#define read_seqcount_retry(s, start) \ + read_seqcount_t_retry(__seqcount_ptr(s), start) + +static inline int read_seqcount_t_retry(const seqcount_t *s, unsigned start) { smp_rmb(); - return __read_seqcount_retry(s, start); + return __read_seqcount_t_retry(s, start); } /** * raw_write_seqcount_begin() - start a seqcount_t write section w/o lockdep - * @s: Pointer to seqcount_t + * @s: Pointer to seqcount_t or any of the seqcount_locktype_t variants */ -static inline void raw_write_seqcount_begin(seqcount_t *s) +#define raw_write_seqcount_begin(s) \ +do { \ + if (__seqcount_lock_preemptible(s)) \ + preempt_disable(); \ + \ + raw_write_seqcount_t_begin(__seqcount_ptr(s)); \ +} while (0) + +static inline void raw_write_seqcount_t_begin(seqcount_t *s) { kcsan_nestable_atomic_begin(); s->sequence++; @@ -257,49 +428,50 @@ static inline void raw_write_seqcount_begin(seqcount_t *s) /** * raw_write_seqcount_end() - end a seqcount_t write section w/o lockdep - * @s: Pointer to seqcount_t + * @s: Pointer to seqcount_t or any of the seqcount_locktype_t variants */ -static inline void raw_write_seqcount_end(seqcount_t *s) +#define raw_write_seqcount_end(s) \ +do { \ + raw_write_seqcount_t_end(__seqcount_ptr(s)); \ + \ + if (__seqcount_lock_preemptible(s)) \ + preempt_enable(); \ +} while (0) + +static inline void raw_write_seqcount_t_end(seqcount_t *s) { smp_wmb(); s->sequence++; kcsan_nestable_atomic_end(); } -static inline void __write_seqcount_begin_nested(seqcount_t *s, int subclass) -{ - raw_write_seqcount_begin(s); - seqcount_acquire(&s->dep_map, subclass, 0, _RET_IP_); -} - /** * write_seqcount_begin_nested() - start a seqcount_t write section with * custom lockdep nesting level - * @s: Pointer to seqcount_t + * @s: Pointer to seqcount_t or any of the seqcount_locktype_t variants * @subclass: lockdep nesting level * * See Documentation/locking/lockdep-design.rst */ -static inline void write_seqcount_begin_nested(seqcount_t *s, int subclass) -{ - lockdep_assert_preemption_disabled(); - __write_seqcount_begin_nested(s, subclass); -} +#define write_seqcount_begin_nested(s, subclass) \ +do { \ + __seqcount_assert_lock_held(s); \ + \ + if (__seqcount_lock_preemptible(s)) \ + preempt_disable(); \ + \ + write_seqcount_t_begin_nested(__seqcount_ptr(s), subclass); \ +} while (0) -/* - * A write_seqcount_begin() variant w/o lockdep non-preemptibility checks. - * - * Use for internal seqlock.h code where it's known that preemption is - * already disabled. For example, seqlock_t write side functions. - */ -static inline void __write_seqcount_begin(seqcount_t *s) +static inline void write_seqcount_t_begin_nested(seqcount_t *s, int subclass) { - __write_seqcount_begin_nested(s, 0); + raw_write_seqcount_t_begin(s); + seqcount_acquire(&s->dep_map, subclass, 0, _RET_IP_); } /** * write_seqcount_begin() - start a seqcount_t write side critical section - * @s: Pointer to seqcount_t + * @s: Pointer to seqcount_t or any of the seqcount_locktype_t variants * * write_seqcount_begin opens a write side critical section of the given * seqcount_t. @@ -308,26 +480,44 @@ static inline void __write_seqcount_begin(seqcount_t *s) * non-preemptible. If readers can be invoked from hardirq or softirq * context, interrupts or bottom halves must be respectively disabled. */ -static inline void write_seqcount_begin(seqcount_t *s) +#define write_seqcount_begin(s) \ +do { \ + __seqcount_assert_lock_held(s); \ + \ + if (__seqcount_lock_preemptible(s)) \ + preempt_disable(); \ + \ + write_seqcount_t_begin(__seqcount_ptr(s)); \ +} while (0) + +static inline void write_seqcount_t_begin(seqcount_t *s) { - write_seqcount_begin_nested(s, 0); + write_seqcount_t_begin_nested(s, 0); } /** * write_seqcount_end() - end a seqcount_t write side critical section - * @s: Pointer to seqcount_t + * @s: Pointer to seqcount_t or any of the seqcount_locktype_t variants * * The write section must've been opened with write_seqcount_begin(). */ -static inline void write_seqcount_end(seqcount_t *s) +#define write_seqcount_end(s) \ +do { \ + write_seqcount_t_end(__seqcount_ptr(s)); \ + \ + if (__seqcount_lock_preemptible(s)) \ + preempt_enable(); \ +} while (0) + +static inline void write_seqcount_t_end(seqcount_t *s) { seqcount_release(&s->dep_map, _RET_IP_); - raw_write_seqcount_end(s); + raw_write_seqcount_t_end(s); } /** * raw_write_seqcount_barrier() - do a seqcount_t write barrier - * @s: Pointer to seqcount_t + * @s: Pointer to seqcount_t or any of the seqcount_locktype_t variants * * This can be used to provide an ordering guarantee instead of the usual * consistency guarantee. It is one wmb cheaper, because it can collapse @@ -366,7 +556,10 @@ static inline void write_seqcount_end(seqcount_t *s) * WRITE_ONCE(X, false); * } */ -static inline void raw_write_seqcount_barrier(seqcount_t *s) +#define raw_write_seqcount_barrier(s) \ + raw_write_seqcount_t_barrier(__seqcount_ptr(s)) + +static inline void raw_write_seqcount_t_barrier(seqcount_t *s) { kcsan_nestable_atomic_begin(); s->sequence++; @@ -378,12 +571,15 @@ static inline void raw_write_seqcount_barrier(seqcount_t *s) /** * write_seqcount_invalidate() - invalidate in-progress seqcount_t read * side operations - * @s: Pointer to seqcount_t + * @s: Pointer to seqcount_t or any of the seqcount_locktype_t variants * * After write_seqcount_invalidate, no seqcount_t read side operations * will complete successfully and see data older than this. */ -static inline void write_seqcount_invalidate(seqcount_t *s) +#define write_seqcount_invalidate(s) \ + write_seqcount_t_invalidate(__seqcount_ptr(s)) + +static inline void write_seqcount_t_invalidate(seqcount_t *s) { smp_wmb(); kcsan_nestable_atomic_begin(); @@ -393,7 +589,7 @@ static inline void write_seqcount_invalidate(seqcount_t *s) /** * raw_read_seqcount_latch() - pick even/odd seqcount_t latch data copy - * @s: Pointer to seqcount_t + * @s: Pointer to seqcount_t or any of the seqcount_locktype_t variants * * Use seqcount_t latching to switch between two storage places protected * by a sequence counter. Doing so allows having interruptible, preemptible, @@ -406,7 +602,10 @@ static inline void write_seqcount_invalidate(seqcount_t *s) * picking which data copy to read. The full counter value must then be * checked with read_seqcount_retry(). */ -static inline int raw_read_seqcount_latch(seqcount_t *s) +#define raw_read_seqcount_latch(s) \ + raw_read_seqcount_t_latch(__seqcount_ptr(s)) + +static inline int raw_read_seqcount_t_latch(seqcount_t *s) { /* Pairs with the first smp_wmb() in raw_write_seqcount_latch() */ int seq = READ_ONCE(s->sequence); /* ^^^ */ @@ -415,7 +614,7 @@ static inline int raw_read_seqcount_latch(seqcount_t *s) /** * raw_write_seqcount_latch() - redirect readers to even/odd copy - * @s: Pointer to seqcount_t + * @s: Pointer to seqcount_t or any of the seqcount_locktype_t variants * * The latch technique is a multiversion concurrency control method that allows * queries during non-atomic modifications. If you can guarantee queries never @@ -494,7 +693,10 @@ static inline int raw_read_seqcount_latch(seqcount_t *s) * When data is a dynamic data structure; one should use regular RCU * patterns to manage the lifetimes of the objects within. */ -static inline void raw_write_seqcount_latch(seqcount_t *s) +#define raw_write_seqcount_latch(s) \ + raw_write_seqcount_t_latch(__seqcount_ptr(s)) + +static inline void raw_write_seqcount_t_latch(seqcount_t *s) { smp_wmb(); /* prior stores before incrementing "sequence" */ s->sequence++; @@ -516,20 +718,20 @@ typedef struct { spinlock_t lock; } seqlock_t; -#define __SEQLOCK_UNLOCKED(lockname) \ - { \ - .seqcount = SEQCNT_ZERO(lockname), \ - .lock = __SPIN_LOCK_UNLOCKED(lockname) \ +#define __SEQLOCK_UNLOCKED(lockname) \ + { \ + .seqcount = SEQCNT_ZERO(lockname), \ + .lock = __SPIN_LOCK_UNLOCKED(lockname) \ } /** * seqlock_init() - dynamic initializer for seqlock_t * @sl: Pointer to the seqlock_t instance */ -#define seqlock_init(sl) \ - do { \ - seqcount_init(&(sl)->seqcount); \ - spin_lock_init(&(sl)->lock); \ +#define seqlock_init(sl) \ + do { \ + seqcount_init(&(sl)->seqcount); \ + spin_lock_init(&(sl)->lock); \ } while (0) /** @@ -592,7 +794,7 @@ static inline unsigned read_seqretry(const seqlock_t *sl, unsigned start) static inline void write_seqlock(seqlock_t *sl) { spin_lock(&sl->lock); - __write_seqcount_begin(&sl->seqcount); + write_seqcount_t_begin(&sl->seqcount); } /** @@ -604,7 +806,7 @@ static inline void write_seqlock(seqlock_t *sl) */ static inline void write_sequnlock(seqlock_t *sl) { - write_seqcount_end(&sl->seqcount); + write_seqcount_t_end(&sl->seqcount); spin_unlock(&sl->lock); } @@ -618,7 +820,7 @@ static inline void write_sequnlock(seqlock_t *sl) static inline void write_seqlock_bh(seqlock_t *sl) { spin_lock_bh(&sl->lock); - __write_seqcount_begin(&sl->seqcount); + write_seqcount_t_begin(&sl->seqcount); } /** @@ -631,7 +833,7 @@ static inline void write_seqlock_bh(seqlock_t *sl) */ static inline void write_sequnlock_bh(seqlock_t *sl) { - write_seqcount_end(&sl->seqcount); + write_seqcount_t_end(&sl->seqcount); spin_unlock_bh(&sl->lock); } @@ -645,7 +847,7 @@ static inline void write_sequnlock_bh(seqlock_t *sl) static inline void write_seqlock_irq(seqlock_t *sl) { spin_lock_irq(&sl->lock); - __write_seqcount_begin(&sl->seqcount); + write_seqcount_t_begin(&sl->seqcount); } /** @@ -657,7 +859,7 @@ static inline void write_seqlock_irq(seqlock_t *sl) */ static inline void write_sequnlock_irq(seqlock_t *sl) { - write_seqcount_end(&sl->seqcount); + write_seqcount_t_end(&sl->seqcount); spin_unlock_irq(&sl->lock); } @@ -666,7 +868,7 @@ static inline unsigned long __write_seqlock_irqsave(seqlock_t *sl) unsigned long flags; spin_lock_irqsave(&sl->lock, flags); - __write_seqcount_begin(&sl->seqcount); + write_seqcount_t_begin(&sl->seqcount); return flags; } @@ -695,13 +897,13 @@ static inline unsigned long __write_seqlock_irqsave(seqlock_t *sl) static inline void write_sequnlock_irqrestore(seqlock_t *sl, unsigned long flags) { - write_seqcount_end(&sl->seqcount); + write_seqcount_t_end(&sl->seqcount); spin_unlock_irqrestore(&sl->lock, flags); } /** * read_seqlock_excl() - begin a seqlock_t locking reader section - * @sl: Pointer to seqlock_t + * @sl: Pointer to seqlock_t * * read_seqlock_excl opens a seqlock_t locking reader critical section. A * locking reader exclusively locks out *both* other writers *and* other diff --git a/include/linux/time.h b/include/linux/time.h index 4c325bf44ce0..b142cb5f5a53 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -3,7 +3,6 @@ #define _LINUX_TIME_H # include -# include # include # include diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h index 16c0ed6c50a7..219037f4c08d 100644 --- a/include/linux/videodev2.h +++ b/include/linux/videodev2.h @@ -57,6 +57,7 @@ #define __LINUX_VIDEODEV2_H #include /* need struct timeval */ +#include #include #endif /* __LINUX_VIDEODEV2_H */ diff --git a/include/linux/ww_mutex.h b/include/linux/ww_mutex.h index d7554252404c..850424e5d030 100644 --- a/include/linux/ww_mutex.h +++ b/include/linux/ww_mutex.h @@ -48,14 +48,6 @@ struct ww_acquire_ctx { #endif }; -struct ww_mutex { - struct mutex base; - struct ww_acquire_ctx *ctx; -#ifdef CONFIG_DEBUG_MUTEXES - struct ww_class *ww_class; -#endif -}; - #ifdef CONFIG_DEBUG_LOCK_ALLOC # define __WW_CLASS_MUTEX_INITIALIZER(lockname, class) \ , .ww_class = class diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h index c7bfddfc65b0..439379ca9ffa 100644 --- a/include/net/netfilter/nf_conntrack.h +++ b/include/net/netfilter/nf_conntrack.h @@ -298,7 +298,7 @@ int nf_conntrack_hash_resize(unsigned int hashsize); extern struct hlist_nulls_head *nf_conntrack_hash; extern unsigned int nf_conntrack_htable_size; -extern seqcount_t nf_conntrack_generation; +extern seqcount_spinlock_t nf_conntrack_generation; extern unsigned int nf_conntrack_max; /* must be called with rcu read lock held */ diff --git a/init/init_task.c b/init/init_task.c index a3eb3847e1f4..89024e8c4e95 100644 --- a/init/init_task.c +++ b/init/init_task.c @@ -154,7 +154,8 @@ struct task_struct init_task .trc_holdout_list = LIST_HEAD_INIT(init_task.trc_holdout_list), #endif #ifdef CONFIG_CPUSETS - .mems_allowed_seq = SEQCNT_ZERO(init_task.mems_allowed_seq), + .mems_allowed_seq = SEQCNT_SPINLOCK_ZERO(init_task.mems_allowed_seq, + &init_task.alloc_lock), #endif #ifdef CONFIG_RT_MUTEXES .pi_waiters = RB_ROOT_CACHED, diff --git a/kernel/fork.c b/kernel/fork.c index 35e9894d394c..4d32190861bd 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -2011,7 +2011,7 @@ static __latent_entropy struct task_struct *copy_process( #ifdef CONFIG_CPUSETS p->cpuset_mem_spread_rotor = NUMA_NO_NODE; p->cpuset_slab_spread_rotor = NUMA_NO_NODE; - seqcount_init(&p->mems_allowed_seq); + seqcount_spinlock_init(&p->mems_allowed_seq, &p->alloc_lock); #endif #ifdef CONFIG_TRACE_IRQFLAGS memset(&p->irqtrace, 0, sizeof(p->irqtrace)); diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c index 5525cd3ba0c8..02ef87f50df2 100644 --- a/kernel/locking/lockdep_proc.c +++ b/kernel/locking/lockdep_proc.c @@ -423,7 +423,7 @@ static void seq_lock_time(struct seq_file *m, struct lock_time *lt) seq_time(m, lt->min); seq_time(m, lt->max); seq_time(m, lt->total); - seq_time(m, lt->nr ? div_s64(lt->total, lt->nr) : 0); + seq_time(m, lt->nr ? div64_u64(lt->total, lt->nr) : 0); } static void seq_stats(struct seq_file *m, struct lock_stat_data *data) diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index d89da1c7e005..c4038511d5c9 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -135,7 +135,11 @@ static const int hrtimer_clock_to_base_table[MAX_CLOCKS] = { * timer->base->cpu_base */ static struct hrtimer_cpu_base migration_cpu_base = { - .clock_base = { { .cpu_base = &migration_cpu_base, }, }, + .clock_base = { { + .cpu_base = &migration_cpu_base, + .seq = SEQCNT_RAW_SPINLOCK_ZERO(migration_cpu_base.seq, + &migration_cpu_base.lock), + }, }, }; #define migration_base migration_cpu_base.clock_base[0] @@ -1998,8 +2002,11 @@ int hrtimers_prepare_cpu(unsigned int cpu) int i; for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { - cpu_base->clock_base[i].cpu_base = cpu_base; - timerqueue_init_head(&cpu_base->clock_base[i].active); + struct hrtimer_clock_base *clock_b = &cpu_base->clock_base[i]; + + clock_b->cpu_base = cpu_base; + seqcount_raw_spinlock_init(&clock_b->seq, &cpu_base->lock); + timerqueue_init_head(&clock_b->active); } cpu_base->cpu = cpu; diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 63a632f9896c..406306b33452 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -39,18 +39,19 @@ enum timekeeping_adv_mode { TK_ADV_FREQ }; +static DEFINE_RAW_SPINLOCK(timekeeper_lock); + /* * The most important data for readout fits into a single 64 byte * cache line. */ static struct { - seqcount_t seq; + seqcount_raw_spinlock_t seq; struct timekeeper timekeeper; } tk_core ____cacheline_aligned = { - .seq = SEQCNT_ZERO(tk_core.seq), + .seq = SEQCNT_RAW_SPINLOCK_ZERO(tk_core.seq, &timekeeper_lock), }; -static DEFINE_RAW_SPINLOCK(timekeeper_lock); static struct timekeeper shadow_timekeeper; /** @@ -63,7 +64,7 @@ static struct timekeeper shadow_timekeeper; * See @update_fast_timekeeper() below. */ struct tk_fast { - seqcount_t seq; + seqcount_raw_spinlock_t seq; struct tk_read_base base[2]; }; @@ -80,11 +81,13 @@ static struct clocksource dummy_clock = { }; static struct tk_fast tk_fast_mono ____cacheline_aligned = { + .seq = SEQCNT_RAW_SPINLOCK_ZERO(tk_fast_mono.seq, &timekeeper_lock), .base[0] = { .clock = &dummy_clock, }, .base[1] = { .clock = &dummy_clock, }, }; static struct tk_fast tk_fast_raw ____cacheline_aligned = { + .seq = SEQCNT_RAW_SPINLOCK_ZERO(tk_fast_raw.seq, &timekeeper_lock), .base[0] = { .clock = &dummy_clock, }, .base[1] = { .clock = &dummy_clock, }, }; @@ -157,7 +160,7 @@ static inline void tk_update_sleep_time(struct timekeeper *tk, ktime_t delta) * tk_clock_read - atomic clocksource read() helper * * This helper is necessary to use in the read paths because, while the - * seqlock ensures we don't return a bad value while structures are updated, + * seqcount ensures we don't return a bad value while structures are updated, * it doesn't protect from potential crashes. There is the possibility that * the tkr's clocksource may change between the read reference, and the * clock reference passed to the read function. This can cause crashes if @@ -222,10 +225,10 @@ static inline u64 timekeeping_get_delta(const struct tk_read_base *tkr) unsigned int seq; /* - * Since we're called holding a seqlock, the data may shift + * Since we're called holding a seqcount, the data may shift * under us while we're doing the calculation. This can cause * false positives, since we'd note a problem but throw the - * results away. So nest another seqlock here to atomically + * results away. So nest another seqcount here to atomically * grab the points we are checking with. */ do { @@ -486,7 +489,7 @@ EXPORT_SYMBOL_GPL(ktime_get_raw_fast_ns); * * To keep it NMI safe since we're accessing from tracing, we're not using a * separate timekeeper with updates to monotonic clock and boot offset - * protected with seqlocks. This has the following minor side effects: + * protected with seqcounts. This has the following minor side effects: * * (1) Its possible that a timestamp be taken after the boot offset is updated * but before the timekeeper is updated. If this happens, the new boot offset diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index e38b60fc183e..5b97d233f89b 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -180,7 +180,7 @@ EXPORT_SYMBOL_GPL(nf_conntrack_htable_size); unsigned int nf_conntrack_max __read_mostly; EXPORT_SYMBOL_GPL(nf_conntrack_max); -seqcount_t nf_conntrack_generation __read_mostly; +seqcount_spinlock_t nf_conntrack_generation __read_mostly; static unsigned int nf_conntrack_hash_rnd __read_mostly; static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple, @@ -2588,7 +2588,8 @@ int nf_conntrack_init_start(void) /* struct nf_ct_ext uses u8 to store offsets/size */ BUILD_BUG_ON(total_extension_size() > 255u); - seqcount_init(&nf_conntrack_generation); + seqcount_spinlock_init(&nf_conntrack_generation, + &nf_conntrack_locks_all_lock); for (i = 0; i < CONNTRACK_LOCKS; i++) spin_lock_init(&nf_conntrack_locks[i]); diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c index b6aad3fc46c3..4b2834fd17b2 100644 --- a/net/netfilter/nft_set_rbtree.c +++ b/net/netfilter/nft_set_rbtree.c @@ -18,7 +18,7 @@ struct nft_rbtree { struct rb_root root; rwlock_t lock; - seqcount_t count; + seqcount_rwlock_t count; struct delayed_work gc_work; }; @@ -523,7 +523,7 @@ static int nft_rbtree_init(const struct nft_set *set, struct nft_rbtree *priv = nft_set_priv(set); rwlock_init(&priv->lock); - seqcount_init(&priv->count); + seqcount_rwlock_init(&priv->count, &priv->lock); priv->root = RB_ROOT; INIT_DEFERRABLE_WORK(&priv->gc_work, nft_rbtree_gc); diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index 042ea9b40c7b..d5280fd6f9c1 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -122,7 +122,7 @@ struct xfrm_pol_inexact_bin { /* list containing '*:*' policies */ struct hlist_head hhead; - seqcount_t count; + seqcount_spinlock_t count; /* tree sorted by daddr/prefix */ struct rb_root root_d; @@ -155,7 +155,7 @@ static struct xfrm_policy_afinfo const __rcu *xfrm_policy_afinfo[AF_INET6 + 1] __read_mostly; static struct kmem_cache *xfrm_dst_cache __ro_after_init; -static __read_mostly seqcount_t xfrm_policy_hash_generation; +static __read_mostly seqcount_mutex_t xfrm_policy_hash_generation; static struct rhashtable xfrm_policy_inexact_table; static const struct rhashtable_params xfrm_pol_inexact_params; @@ -719,7 +719,7 @@ xfrm_policy_inexact_alloc_bin(const struct xfrm_policy *pol, u8 dir) INIT_HLIST_HEAD(&bin->hhead); bin->root_d = RB_ROOT; bin->root_s = RB_ROOT; - seqcount_init(&bin->count); + seqcount_spinlock_init(&bin->count, &net->xfrm.xfrm_policy_lock); prev = rhashtable_lookup_get_insert_key(&xfrm_policy_inexact_table, &bin->k, &bin->head, @@ -1899,7 +1899,7 @@ static int xfrm_policy_match(const struct xfrm_policy *pol, static struct xfrm_pol_inexact_node * xfrm_policy_lookup_inexact_addr(const struct rb_root *r, - seqcount_t *count, + seqcount_spinlock_t *count, const xfrm_address_t *addr, u16 family) { const struct rb_node *parent; @@ -4157,7 +4157,7 @@ void __init xfrm_init(void) { register_pernet_subsys(&xfrm_net_ops); xfrm_dev_init(); - seqcount_init(&xfrm_policy_hash_generation); + seqcount_mutex_init(&xfrm_policy_hash_generation, &hash_resize_mutex); xfrm_input_init(); #ifdef CONFIG_XFRM_ESPINTCP diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c index ef7ed916ad4a..d6408bb497dc 100644 --- a/virt/kvm/eventfd.c +++ b/virt/kvm/eventfd.c @@ -303,7 +303,7 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args) INIT_LIST_HEAD(&irqfd->list); INIT_WORK(&irqfd->inject, irqfd_inject); INIT_WORK(&irqfd->shutdown, irqfd_shutdown); - seqcount_init(&irqfd->irq_entry_sc); + seqcount_spinlock_init(&irqfd->irq_entry_sc, &kvm->irqfds.lock); f = fdget(args->fd); if (!f.file) {