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authorLinus Torvalds <torvalds@linux-foundation.org>2020-08-30 21:43:50 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2020-08-30 21:43:50 +0300
commitb69bea8a657b681442765b06be92a2607b1bd875 (patch)
tree8dcecaf4e5eff737500b73d402b4ef81c1b5368c /include
parent3edd8db2d53fe6c96ad66248bb1479ae62807268 (diff)
parenteb1f00237aca2e368b93db79303f8433d1976d10 (diff)
downloadlinux-b69bea8a657b681442765b06be92a2607b1bd875.tar.xz
Merge tag 'locking-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Thomas Gleixner: "A set of fixes for lockdep, tracing and RCU: - Prevent recursion by using raw_cpu_* operations - Fixup the interrupt state in the cpu idle code to be consistent - Push rcu_idle_enter/exit() invocations deeper into the idle path so that the lock operations are inside the RCU watching sections - Move trace_cpu_idle() into generic code so it's called before RCU goes idle. - Handle raw_local_irq* vs. local_irq* operations correctly - Move the tracepoints out from under the lockdep recursion handling which turned out to be fragile and inconsistent" * tag 'locking-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: lockdep,trace: Expose tracepoints lockdep: Only trace IRQ edges mips: Implement arch_irqs_disabled() arm64: Implement arch_irqs_disabled() nds32: Implement arch_irqs_disabled() locking/lockdep: Cleanup x86/entry: Remove unused THUNKs cpuidle: Move trace_cpu_idle() into generic code cpuidle: Make CPUIDLE_FLAG_TLB_FLUSHED generic sched,idle,rcu: Push rcu_idle deeper into the idle path cpuidle: Fixup IRQ state lockdep: Use raw_cpu_*() for per-cpu variables
Diffstat (limited to 'include')
-rw-r--r--include/linux/cpuidle.h13
-rw-r--r--include/linux/irqflags.h73
-rw-r--r--include/linux/lockdep.h18
-rw-r--r--include/linux/mmu_context.h5
4 files changed, 64 insertions, 45 deletions
diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index b65909ae4e20..75895e6363b8 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -75,12 +75,13 @@ struct cpuidle_state {
};
/* Idle State Flags */
-#define CPUIDLE_FLAG_NONE (0x00)
-#define CPUIDLE_FLAG_POLLING BIT(0) /* polling state */
-#define CPUIDLE_FLAG_COUPLED BIT(1) /* state applies to multiple cpus */
-#define CPUIDLE_FLAG_TIMER_STOP BIT(2) /* timer is stopped on this state */
-#define CPUIDLE_FLAG_UNUSABLE BIT(3) /* avoid using this state */
-#define CPUIDLE_FLAG_OFF BIT(4) /* disable this state by default */
+#define CPUIDLE_FLAG_NONE (0x00)
+#define CPUIDLE_FLAG_POLLING BIT(0) /* polling state */
+#define CPUIDLE_FLAG_COUPLED BIT(1) /* state applies to multiple cpus */
+#define CPUIDLE_FLAG_TIMER_STOP BIT(2) /* timer is stopped on this state */
+#define CPUIDLE_FLAG_UNUSABLE BIT(3) /* avoid using this state */
+#define CPUIDLE_FLAG_OFF BIT(4) /* disable this state by default */
+#define CPUIDLE_FLAG_TLB_FLUSHED BIT(5) /* idle-state flushes TLBs */
struct cpuidle_device_kobj;
struct cpuidle_state_kobj;
diff --git a/include/linux/irqflags.h b/include/linux/irqflags.h
index bd5c55755447..3ed4e8771b64 100644
--- a/include/linux/irqflags.h
+++ b/include/linux/irqflags.h
@@ -49,17 +49,18 @@ struct irqtrace_events {
DECLARE_PER_CPU(int, hardirqs_enabled);
DECLARE_PER_CPU(int, hardirq_context);
- extern void trace_hardirqs_on_prepare(void);
- extern void trace_hardirqs_off_finish(void);
- extern void trace_hardirqs_on(void);
- extern void trace_hardirqs_off(void);
-# define lockdep_hardirq_context() (this_cpu_read(hardirq_context))
+extern void trace_hardirqs_on_prepare(void);
+extern void trace_hardirqs_off_finish(void);
+extern void trace_hardirqs_on(void);
+extern void trace_hardirqs_off(void);
+
+# define lockdep_hardirq_context() (raw_cpu_read(hardirq_context))
# define lockdep_softirq_context(p) ((p)->softirq_context)
# define lockdep_hardirqs_enabled() (this_cpu_read(hardirqs_enabled))
# define lockdep_softirqs_enabled(p) ((p)->softirqs_enabled)
# define lockdep_hardirq_enter() \
do { \
- if (this_cpu_inc_return(hardirq_context) == 1) \
+ if (__this_cpu_inc_return(hardirq_context) == 1)\
current->hardirq_threaded = 0; \
} while (0)
# define lockdep_hardirq_threaded() \
@@ -68,7 +69,7 @@ do { \
} while (0)
# define lockdep_hardirq_exit() \
do { \
- this_cpu_dec(hardirq_context); \
+ __this_cpu_dec(hardirq_context); \
} while (0)
# define lockdep_softirq_enter() \
do { \
@@ -120,17 +121,17 @@ do { \
#else
# define trace_hardirqs_on_prepare() do { } while (0)
# define trace_hardirqs_off_finish() do { } while (0)
-# define trace_hardirqs_on() do { } while (0)
-# define trace_hardirqs_off() do { } while (0)
-# define lockdep_hardirq_context() 0
-# define lockdep_softirq_context(p) 0
-# define lockdep_hardirqs_enabled() 0
-# define lockdep_softirqs_enabled(p) 0
-# define lockdep_hardirq_enter() do { } while (0)
-# define lockdep_hardirq_threaded() do { } while (0)
-# define lockdep_hardirq_exit() do { } while (0)
-# define lockdep_softirq_enter() do { } while (0)
-# define lockdep_softirq_exit() do { } while (0)
+# define trace_hardirqs_on() do { } while (0)
+# define trace_hardirqs_off() do { } while (0)
+# define lockdep_hardirq_context() 0
+# define lockdep_softirq_context(p) 0
+# define lockdep_hardirqs_enabled() 0
+# define lockdep_softirqs_enabled(p) 0
+# define lockdep_hardirq_enter() do { } while (0)
+# define lockdep_hardirq_threaded() do { } while (0)
+# define lockdep_hardirq_exit() do { } while (0)
+# define lockdep_softirq_enter() do { } while (0)
+# define lockdep_softirq_exit() do { } while (0)
# define lockdep_hrtimer_enter(__hrtimer) false
# define lockdep_hrtimer_exit(__context) do { } while (0)
# define lockdep_posixtimer_enter() do { } while (0)
@@ -181,26 +182,33 @@ do { \
* if !TRACE_IRQFLAGS.
*/
#ifdef CONFIG_TRACE_IRQFLAGS
-#define local_irq_enable() \
- do { trace_hardirqs_on(); raw_local_irq_enable(); } while (0)
-#define local_irq_disable() \
- do { raw_local_irq_disable(); trace_hardirqs_off(); } while (0)
+
+#define local_irq_enable() \
+ do { \
+ trace_hardirqs_on(); \
+ raw_local_irq_enable(); \
+ } while (0)
+
+#define local_irq_disable() \
+ do { \
+ bool was_disabled = raw_irqs_disabled();\
+ raw_local_irq_disable(); \
+ if (!was_disabled) \
+ trace_hardirqs_off(); \
+ } while (0)
+
#define local_irq_save(flags) \
do { \
raw_local_irq_save(flags); \
- trace_hardirqs_off(); \
+ if (!raw_irqs_disabled_flags(flags)) \
+ trace_hardirqs_off(); \
} while (0)
-
#define local_irq_restore(flags) \
do { \
- if (raw_irqs_disabled_flags(flags)) { \
- raw_local_irq_restore(flags); \
- trace_hardirqs_off(); \
- } else { \
+ if (!raw_irqs_disabled_flags(flags)) \
trace_hardirqs_on(); \
- raw_local_irq_restore(flags); \
- } \
+ raw_local_irq_restore(flags); \
} while (0)
#define safe_halt() \
@@ -214,10 +222,7 @@ do { \
#define local_irq_enable() do { raw_local_irq_enable(); } while (0)
#define local_irq_disable() do { raw_local_irq_disable(); } while (0)
-#define local_irq_save(flags) \
- do { \
- raw_local_irq_save(flags); \
- } while (0)
+#define local_irq_save(flags) do { raw_local_irq_save(flags); } while (0)
#define local_irq_restore(flags) do { raw_local_irq_restore(flags); } while (0)
#define safe_halt() do { raw_safe_halt(); } while (0)
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 62a382d1845b..6a584b3e5c74 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -535,19 +535,27 @@ do { \
DECLARE_PER_CPU(int, hardirqs_enabled);
DECLARE_PER_CPU(int, hardirq_context);
+/*
+ * The below lockdep_assert_*() macros use raw_cpu_read() to access the above
+ * per-cpu variables. This is required because this_cpu_read() will potentially
+ * call into preempt/irq-disable and that obviously isn't right. This is also
+ * correct because when IRQs are enabled, it doesn't matter if we accidentally
+ * read the value from our previous CPU.
+ */
+
#define lockdep_assert_irqs_enabled() \
do { \
- WARN_ON_ONCE(debug_locks && !this_cpu_read(hardirqs_enabled)); \
+ WARN_ON_ONCE(debug_locks && !raw_cpu_read(hardirqs_enabled)); \
} while (0)
#define lockdep_assert_irqs_disabled() \
do { \
- WARN_ON_ONCE(debug_locks && this_cpu_read(hardirqs_enabled)); \
+ WARN_ON_ONCE(debug_locks && raw_cpu_read(hardirqs_enabled)); \
} while (0)
#define lockdep_assert_in_irq() \
do { \
- WARN_ON_ONCE(debug_locks && !this_cpu_read(hardirq_context)); \
+ WARN_ON_ONCE(debug_locks && !raw_cpu_read(hardirq_context)); \
} while (0)
#define lockdep_assert_preemption_enabled() \
@@ -555,7 +563,7 @@ do { \
WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT) && \
debug_locks && \
(preempt_count() != 0 || \
- !this_cpu_read(hardirqs_enabled))); \
+ !raw_cpu_read(hardirqs_enabled))); \
} while (0)
#define lockdep_assert_preemption_disabled() \
@@ -563,7 +571,7 @@ do { \
WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT) && \
debug_locks && \
(preempt_count() == 0 && \
- this_cpu_read(hardirqs_enabled))); \
+ raw_cpu_read(hardirqs_enabled))); \
} while (0)
#else
diff --git a/include/linux/mmu_context.h b/include/linux/mmu_context.h
index c51a84132d7c..03dee12d2b61 100644
--- a/include/linux/mmu_context.h
+++ b/include/linux/mmu_context.h
@@ -3,10 +3,15 @@
#define _LINUX_MMU_CONTEXT_H
#include <asm/mmu_context.h>
+#include <asm/mmu.h>
/* Architectures that care about IRQ state in switch_mm can override this. */
#ifndef switch_mm_irqs_off
# define switch_mm_irqs_off switch_mm
#endif
+#ifndef leave_mm
+static inline void leave_mm(int cpu) { }
+#endif
+
#endif