From: Mark Rutland <mark.rutland@arm.com>
To: linux-kernel@vger.kernel.org
Cc: benh@kernel.crashing.org, boqun.feng@gmail.com, bp@alien8.de,
catalin.marinas@arm.com, dvyukov@google.com, elver@google.com,
ink@jurassic.park.msu.ru, jonas@southpole.se,
juri.lelli@redhat.com, linux@armlinux.org.uk, luto@kernel.org,
mark.rutland@arm.com, mattst88@gmail.com, mingo@redhat.com,
monstr@monstr.eu, mpe@ellerman.id.au, paulmck@kernel.org,
paulus@samba.org, peterz@infradead.org, rth@twiddle.net,
shorne@gmail.com, stefan.kristiansson@saunalahti.fi,
tglx@linutronix.de, vincent.guittot@linaro.org, will@kernel.org
Subject: [PATCH v4 08/10] openrisc: snapshot thread flags
Date: Tue, 3 Aug 2021 10:54:26 +0100 [thread overview]
Message-ID: <20210803095428.17009-9-mark.rutland@arm.com> (raw)
In-Reply-To: <20210803095428.17009-1-mark.rutland@arm.com>
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, a snapshot of the flags has to be taken prior to
using them. Some places already use READ_ONCE() for that, others do not.
Convert them all to the new flag accessor helpers.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Stafford Horne <shorne@gmail.com>
Cc: Jonas Bonn <jonas@southpole.se>
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;
}
--
2.11.0
next prev parent reply other threads:[~2021-08-03 9:56 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-03 9:54 [PATCH v4 00/10] thread_info: use helpers to snapshot thread flags Mark Rutland
2021-08-03 9:54 ` [PATCH v4 01/10] thread_info: add " Mark Rutland
2021-08-03 9:54 ` [PATCH v4 02/10] entry: " Mark Rutland
2021-08-03 9:54 ` [PATCH v4 03/10] sched: " Mark Rutland
2021-08-03 9:54 ` [PATCH v4 04/10] alpha: " Mark Rutland
2021-08-03 9:54 ` [PATCH v4 05/10] arm: " Mark Rutland
2021-08-03 9:54 ` [PATCH v4 06/10] arm64: " Mark Rutland
2021-08-03 9:54 ` [PATCH v4 07/10] microblaze: " Mark Rutland
2021-08-25 9:03 ` Michal Simek
2021-08-03 9:54 ` Mark Rutland [this message]
2021-08-03 9:54 ` [PATCH v4 09/10] powerpc: " Mark Rutland
2021-08-03 9:54 ` [PATCH v4 10/10] x86: " Mark Rutland
2021-08-03 16:01 ` [PATCH v4 00/10] thread_info: use helpers to " Paul E. McKenney
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