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From: "Pavel Machek" <pavel@ucw.cz>
To: "Chen-Yu Tsai (Moxa)" <wens@csie.org>
Cc: nobuhiro1.iwamatsu@toshiba.co.jp, pavel@denx.de,
	cip-dev@lists.cip-project.org, JohnsonCH.Chen@moxa.com
Subject: Re: [cip-dev] [PATCH 4.4.y-cip 17/23] PM / OPP: Fix NULL pointer dereference crash when disabling OPPs
Date: Tue, 14 Jul 2020 19:37:19 +0200	[thread overview]
Message-ID: <20200714173719.GB18210@amd> (raw)
In-Reply-To: <20200708154554.26450-18-wens@csie.org>


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Hi!

On Wed 2020-07-08 23:45:48, Chen-Yu Tsai (Moxa) wrote:
> From: Jon Hunter <jonathanh@nvidia.com>
> 
> commit 78ecc56247f0ec2bc0cf6f2f2af69e98d99767bc upstream.
> 
> Commit 7d34d56ef334 (PM / OPP: Disable OPPs that aren't supported by
> the regulator) causes a crash to happen on Tegra124 Jetson TK1 when
> using the DFLL clock source for the CPU.  The DFLL manages the voltage
> itself and so there is no regulator specified for the OPPs and so we
> get a crash when we try to dereference the regulator pointer.  Fix
> this by checking to see if the regulator IS_ERR_OR_NULL before
> dereferencing it.
> 
> Fixes: 7d34d56ef334 (PM / OPP: Disable OPPs that aren't supported by

So this one should be close to the patch it fixes, or maybe squashed
together.

Best regards,
								Pavel

> diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
> index 91b4cc261d84a..067379f931662 100644
> --- a/drivers/base/power/opp/core.c
> +++ b/drivers/base/power/opp/core.c
> @@ -975,7 +975,7 @@ static bool _opp_supported_by_regulators(struct dev_pm_opp *opp,
>  {
>  	struct regulator *reg = dev_opp->regulator;
>  
> -	if (!IS_ERR(reg) &&
> +	if (!IS_ERR_OR_NULL(reg) &&
>  	    !regulator_is_supported_voltage(reg, opp->u_volt_min,
>  					    opp->u_volt_max)) {
>  		pr_warn("%s: OPP minuV: %lu maxuV: %lu, not supported by regulator\n",

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

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  reply	other threads:[~2020-07-14 17:37 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-08 15:45 [cip-dev] [PATCH 4.4.y-cip 00/23] PM / OPP v2 & cpufreq backports part 2 Chen-Yu Tsai (Moxa)
2020-07-08 15:45 ` [cip-dev] [PATCH 4.4.y-cip 01/23] PM / OPP: get/put regulators from OPP core Chen-Yu Tsai (Moxa)
2020-07-08 15:45 ` [cip-dev] [PATCH 4.4.y-cip 02/23] PM / OPP: Disable OPPs that aren't supported by the regulator Chen-Yu Tsai (Moxa)
2020-07-08 15:45 ` [cip-dev] [PATCH 4.4.y-cip 03/23] PM / OPP: Introduce dev_pm_opp_get_max_volt_latency() Chen-Yu Tsai (Moxa)
2020-07-08 15:45 ` [cip-dev] [PATCH 4.4.y-cip 04/23] PM / OPP: Introduce dev_pm_opp_get_max_transition_latency() Chen-Yu Tsai (Moxa)
2020-07-08 15:45 ` [cip-dev] [PATCH 4.4.y-cip 05/23] PM / OPP: Parse clock-latency and voltage-tolerance for v1 bindings Chen-Yu Tsai (Moxa)
2020-07-09  4:38   ` Nobuhiro Iwamatsu
2020-07-08 15:45 ` [cip-dev] [PATCH 4.4.y-cip 06/23] PM / OPP: Manage device clk Chen-Yu Tsai (Moxa)
2020-07-14 17:44   ` Pavel Machek
2020-07-14 17:57   ` Pavel Machek
2020-07-08 15:45 ` [cip-dev] [PATCH 4.4.y-cip 07/23] PM / OPP: Add dev_pm_opp_set_rate() Chen-Yu Tsai (Moxa)
2020-07-08 15:45 ` [cip-dev] [PATCH 4.4.y-cip 08/23] cpufreq: dt: Convert few pr_debug/err() calls to dev_dbg/err() Chen-Yu Tsai (Moxa)
2020-07-08 15:45 ` [cip-dev] [PATCH 4.4.y-cip 09/23] cpufreq: dt: Rename 'need_update' to 'opp_v1' Chen-Yu Tsai (Moxa)
2020-07-08 15:45 ` [cip-dev] [PATCH 4.4.y-cip 10/23] cpufreq: dt: OPP layers handles clock-latency for V1 bindings as well Chen-Yu Tsai (Moxa)
2020-07-08 15:45 ` [cip-dev] [PATCH 4.4.y-cip 11/23] cpufreq: dt: Pass regulator name to the OPP core Chen-Yu Tsai (Moxa)
2020-07-08 15:45 ` [cip-dev] [PATCH 4.4.y-cip 12/23] cpufreq: dt: Unsupported OPPs are already disabled Chen-Yu Tsai (Moxa)
2020-07-08 15:45 ` [cip-dev] [PATCH 4.4.y-cip 13/23] cpufreq: dt: Reuse dev_pm_opp_get_max_transition_latency() Chen-Yu Tsai (Moxa)
2020-07-08 15:45 ` [cip-dev] [PATCH 4.4.y-cip 14/23] cpufreq: dt: Use dev_pm_opp_set_rate() to switch frequency Chen-Yu Tsai (Moxa)
2020-07-08 15:45 ` [cip-dev] [PATCH 4.4.y-cip 15/23] cpufreq: dt: No need to fetch voltage-tolerance Chen-Yu Tsai (Moxa)
2020-07-08 15:45 ` [cip-dev] [PATCH 4.4.y-cip 16/23] cpufreq: dt: No need to allocate resources anymore Chen-Yu Tsai (Moxa)
2020-07-08 15:45 ` [cip-dev] [PATCH 4.4.y-cip 17/23] PM / OPP: Fix NULL pointer dereference crash when disabling OPPs Chen-Yu Tsai (Moxa)
2020-07-14 17:37   ` Pavel Machek [this message]
2020-07-08 15:45 ` [cip-dev] [PATCH 4.4.y-cip 18/23] PM / OPP: Initialize regulator pointer to an error value Chen-Yu Tsai (Moxa)
2020-07-14 17:38   ` Pavel Machek
2020-07-08 15:45 ` [cip-dev] [PATCH 4.4.y-cip 19/23] PM / OPP: Fix incorrect comments Chen-Yu Tsai (Moxa)
2020-07-08 15:45 ` [cip-dev] [PATCH 4.4.y-cip 20/23] PM / OPP: Rename structures for clarity Chen-Yu Tsai (Moxa)
2020-07-08 15:45 ` [cip-dev] [PATCH 4.4.y-cip 21/23] cpufreq: dt: Drop stale comment Chen-Yu Tsai (Moxa)
2020-07-08 15:45 ` [cip-dev] [PATCH 4.4.y-cip 22/23] PM / OPP: Remove useless check Chen-Yu Tsai (Moxa)
2020-07-14 17:41   ` Pavel Machek
2020-07-08 15:45 ` [cip-dev] [PATCH 4.4.y-cip 23/23] PM / OPP: Update voltage in case freq == old_freq Chen-Yu Tsai (Moxa)
2020-07-09  4:48 ` [cip-dev] [PATCH 4.4.y-cip 00/23] PM / OPP v2 & cpufreq backports part 2 Nobuhiro Iwamatsu
2020-07-14 17:33 ` Pavel Machek
2020-08-31  3:41   ` Chen-Yu Tsai (Moxa)
2020-09-02 21:50     ` Pavel Machek

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