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Date:   Mon, 10 May 2021 14:05:54 +0200
From:   Pavel Machek <pavel@denx.de>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        Shixin Liu <liushixin2@huawei.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        Sasha Levin <sashal@kernel.org>
Subject: Re: [PATCH 5.10 104/299] crypto: stm32/hash - Fix PM reference leak
 on stm32-hash.c
Message-ID: <20210510120554.GB3547@duo.ucw.cz>
References: <20210510102004.821838356@linuxfoundation.org>
 <20210510102008.377102138@linuxfoundation.org>
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Hi!

> pm_runtime_get_sync will increment pm usage counter even it failed.
> Forgetting to putting operation will result in reference leak here.
> Fix it by replacing it with pm_runtime_resume_and_get to keep usage
> counter balanced.

I believe we need to enforce "patches need to be tested" rule at least
against robots.

Code was correct in 3/4 instances, this introduces bugs. Yes, last one
needs fixing.

Best regards,
								Pavel

> +++ b/drivers/crypto/stm32/stm32-hash.c
> @@ -812,7 +812,7 @@ static void stm32_hash_finish_req(struct ahash_reques=
t *req, int err)
>  static int stm32_hash_hw_init(struct stm32_hash_dev *hdev,
>  			      struct stm32_hash_request_ctx *rctx)
>  {
> -	pm_runtime_get_sync(hdev->dev);
> +	pm_runtime_resume_and_get(hdev->dev);
> =20
>  	if (!(HASH_FLAGS_INIT & hdev->flags)) {
>  		stm32_hash_write(hdev, HASH_CR, HASH_CR_INIT);
> @@ -961,7 +961,7 @@ static int stm32_hash_export(struct ahash_request *re=
q, void *out)
>  	u32 *preg;
>  	unsigned int i;
> =20
> -	pm_runtime_get_sync(hdev->dev);
> +	pm_runtime_resume_and_get(hdev->dev);
> =20
>  	while ((stm32_hash_read(hdev, HASH_SR) & HASH_SR_BUSY))
>  		cpu_relax();
> @@ -999,7 +999,7 @@ static int stm32_hash_import(struct ahash_request *re=
q, const void *in)
> =20
>  	preg =3D rctx->hw_context;
> =20
> -	pm_runtime_get_sync(hdev->dev);
> +	pm_runtime_resume_and_get(hdev->dev);
> =20
>  	stm32_hash_write(hdev, HASH_IMR, *preg++);
>  	stm32_hash_write(hdev, HASH_STR, *preg++);

--=20
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany

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