From: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Subject: kcov: simplify interrupt check in_interrupt() semantics are confusing and wrong for most users as it also returns true when bh is disabled. Thus we open coded a proper check for interrupts in __sanitizer_cov_trace_pc() with a lengthy explanatory comment. Use the new in_task() predicate instead. Link: http://lkml.kernel.org/r/20170321091026.139655-1-dvyukov@xxxxxxxxxx Signed-off-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> Cc: James Morse <james.morse@xxxxxxx> Cc: Alexander Popov <alex.popov@xxxxxxxxx> Cc: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Cc: Hillf Danton <hillf.zj@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/kcov.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) diff -puN kernel/kcov.c~kcov-simplify-interrupt-check kernel/kcov.c --- a/kernel/kcov.c~kcov-simplify-interrupt-check +++ a/kernel/kcov.c @@ -60,15 +60,8 @@ void notrace __sanitizer_cov_trace_pc(vo /* * We are interested in code coverage as a function of a syscall inputs, * so we ignore code executed in interrupts. - * The checks for whether we are in an interrupt are open-coded, because - * 1. We can't use in_interrupt() here, since it also returns true - * when we are inside local_bh_disable() section. - * 2. We don't want to use (in_irq() | in_serving_softirq() | in_nmi()), - * since that leads to slower generated code (three separate tests, - * one for each of the flags). */ - if (!t || (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_OFFSET - | NMI_MASK))) + if (!t || !in_task()) return; mode = READ_ONCE(t->kcov_mode); if (mode == KCOV_MODE_TRACE) { _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
