Re: [PATCH 1/2] lockdep: improve current->(hard|soft)irqs_enabled synchronisation with actual irq state
From: Nicholas Piggin <npiggin@gmail.com>
Date: 2020-08-12 08:18:37
Also in:
linux-arch, lkml
Excerpts from peterz@infradead.org's message of August 7, 2020 9:11 pm:
What's wrong with something like this? AFAICT there's no reason to actually try and add IRQ tracing here, it's just a hand full of instructions at the most.
Because we may want to use that in other places as well, so it would be nice to have tracing. Hmm... also, I thought NMI context was free to call local_irq_save/restore anyway so the bug would still be there in those cases? Thanks, Nick
quoted hunk ↗ jump to hunk
---diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h index 3a0db7b0b46e..6be22c1838e2 100644 --- a/arch/powerpc/include/asm/hw_irq.h +++ b/arch/powerpc/include/asm/hw_irq.h@@ -196,33 +196,6 @@ static inline bool arch_irqs_disabled(void) arch_local_irq_restore(flags); \ } while(0) -#ifdef CONFIG_TRACE_IRQFLAGS -#define powerpc_local_irq_pmu_save(flags) \ - do { \ - raw_local_irq_pmu_save(flags); \ - trace_hardirqs_off(); \ - } while(0) -#define powerpc_local_irq_pmu_restore(flags) \ - do { \ - if (raw_irqs_disabled_flags(flags)) { \ - raw_local_irq_pmu_restore(flags); \ - trace_hardirqs_off(); \ - } else { \ - trace_hardirqs_on(); \ - raw_local_irq_pmu_restore(flags); \ - } \ - } while(0) -#else -#define powerpc_local_irq_pmu_save(flags) \ - do { \ - raw_local_irq_pmu_save(flags); \ - } while(0) -#define powerpc_local_irq_pmu_restore(flags) \ - do { \ - raw_local_irq_pmu_restore(flags); \ - } while (0) -#endif /* CONFIG_TRACE_IRQFLAGS */ - #endif /* CONFIG_PPC_BOOK3S */ #ifdef CONFIG_PPC_BOOK3Ediff --git a/arch/powerpc/include/asm/local.h b/arch/powerpc/include/asm/local.h index bc4bd19b7fc2..b357a35672b1 100644 --- a/arch/powerpc/include/asm/local.h +++ b/arch/powerpc/include/asm/local.h@@ -32,9 +32,9 @@ static __inline__ void local_##op(long i, local_t *l) \ { \ unsigned long flags; \ \ - powerpc_local_irq_pmu_save(flags); \ + raw_powerpc_local_irq_pmu_save(flags); \ l->v c_op i; \ - powerpc_local_irq_pmu_restore(flags); \ + raw_powerpc_local_irq_pmu_restore(flags); \ } #define LOCAL_OP_RETURN(op, c_op) \@@ -43,9 +43,9 @@ static __inline__ long local_##op##_return(long a, local_t *l) \ long t; \ unsigned long flags; \ \ - powerpc_local_irq_pmu_save(flags); \ + raw_powerpc_local_irq_pmu_save(flags); \ t = (l->v c_op a); \ - powerpc_local_irq_pmu_restore(flags); \ + raw_powerpc_local_irq_pmu_restore(flags); \ \ return t; \ }@@ -81,11 +81,11 @@ static __inline__ long local_cmpxchg(local_t *l, long o, long n) long t; unsigned long flags; - powerpc_local_irq_pmu_save(flags); + raw_powerpc_local_irq_pmu_save(flags); t = l->v; if (t == o) l->v = n; - powerpc_local_irq_pmu_restore(flags); + raw_powerpc_local_irq_pmu_restore(flags); return t; }@@ -95,10 +95,10 @@ static __inline__ long local_xchg(local_t *l, long n) long t; unsigned long flags; - powerpc_local_irq_pmu_save(flags); + raw_powerpc_local_irq_pmu_save(flags); t = l->v; l->v = n; - powerpc_local_irq_pmu_restore(flags); + raw_powerpc_local_irq_pmu_restore(flags); return t; }@@ -117,12 +117,12 @@ static __inline__ int local_add_unless(local_t *l, long a, long u) unsigned long flags; int ret = 0; - powerpc_local_irq_pmu_save(flags); + raw_powerpc_local_irq_pmu_save(flags); if (l->v != u) { l->v += a; ret = 1; } - powerpc_local_irq_pmu_restore(flags); + raw_powerpc_local_irq_pmu_restore(flags); return ret; }