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From: Michal Simek <monstr@monstr.eu>
To: Mark Rutland <mark.rutland@arm.com>, 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,
	mattst88@gmail.com, mingo@redhat.com, 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: Re: [PATCH v4 07/10] microblaze: snapshot thread flags
Date: Wed, 25 Aug 2021 11:03:17 +0200	[thread overview]
Message-ID: <d62b4ccf-505d-e8e2-1195-48327ba4a4eb@monstr.eu> (raw)
In-Reply-To: <20210803095428.17009-8-mark.rutland@arm.com>



On 8/3/21 11:54 AM, 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, 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>
> Cc: Michal Simek <monstr@monstr.eu>
> ---
>  arch/microblaze/kernel/signal.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/microblaze/kernel/signal.c b/arch/microblaze/kernel/signal.c
> index fc61eb0eb8dd..23e8a9336a29 100644
> --- a/arch/microblaze/kernel/signal.c
> +++ b/arch/microblaze/kernel/signal.c
> @@ -283,7 +283,7 @@ static void do_signal(struct pt_regs *regs, int in_syscall)
>  #ifdef DEBUG_SIG
>  	pr_info("do signal: %p %d\n", regs, in_syscall);
>  	pr_info("do signal2: %lx %lx %ld [%lx]\n", regs->pc, regs->r1,
> -			regs->r12, current_thread_info()->flags);
> +			regs->r12, read_thread_flags());
>  #endif
>  
>  	if (get_signal(&ksig)) {
> 

Tested-by: Michal Simek <michal.simek@xilinx.com>

Thanks,
Michal


-- 
Michal Simek, Ing. (M.Eng), OpenPGP -> KeyID: FE3D1F91
w: www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel - Xilinx Microblaze
Maintainer of Linux kernel - Xilinx Zynq ARM and ZynqMP ARM64 SoCs
U-Boot custodian - Xilinx Microblaze/Zynq/ZynqMP/Versal SoCs


  reply	other threads:[~2021-08-25  9:03 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 " 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 [this message]
2021-08-03  9:54 ` [PATCH v4 08/10] openrisc: " Mark Rutland
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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