Messages in this thread | | | Date | Fri, 11 Jun 2021 04:14:45 +0900 | From | Stafford Horne <> | Subject | Re: [RFC PATCH 08/10] openrisc: snapshot thread flags |
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On Wed, Jun 09, 2021 at 01:19:59PM +0100, Mark Rutland wrote: > Some thread flags can be set remotely, and so even when IRQs are > disabled, the flags can change under our feet. Generally this is > unlikely to cause a problem in practice, but it is somewhat unsound, and > KCSAN will legitimately warn that there is a data race. > > To avoid such issues, we should snapshot the flags prior to using them. > Let's use the new helpers to do so on openrisc. > > Signed-off-by: Mark Rutland <mark.rutland@arm.com> > Cc: Jonas Bonn <jonas@southpole.se> > Cc: Stafford Horne <shorne@gmail.com> > Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> > --- > arch/openrisc/kernel/signal.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/openrisc/kernel/signal.c b/arch/openrisc/kernel/signal.c > index 1ebcff271096..a730a914c2b4 100644 > --- a/arch/openrisc/kernel/signal.c > +++ b/arch/openrisc/kernel/signal.c > @@ -315,7 +315,7 @@ do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall) > } > } > local_irq_disable(); > - thread_flags = current_thread_info()->flags; > + thread_flags = read_thread_flags(); > } while (thread_flags & _TIF_WORK_MASK); > return 0; > }
This looks good to me. As per patch 01/10 this adds a READ_ONCE around the original flags read.
Acked-by: Stafford Horne <shorne@gmail.com>
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