From: "Heiko Stübner" <heiko@sntech.de>
To: Yizhuo <yzhai003@ucr.edu>
Cc: csong@cs.ucr.edu, zhiyunq@cs.ucr.edu,
linux-kernel@vger.kernel.org,
Kishon Vijay Abraham I <kishon@ti.com>,
linux-rockchip@lists.infradead.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] phy: Variable "caldone" in function rockchip_emmc_phy_power() could be uninitialized
Date: Tue, 12 Feb 2019 11:47:31 +0100 [thread overview]
Message-ID: <1884796.YtlDmFZGdE@diego> (raw)
In-Reply-To: <20190206014733.21094-1-yzhai003@ucr.edu>
Am Mittwoch, 6. Februar 2019, 02:47:33 CET schrieb Yizhuo:
> In function rockchip_emmc_phy_power(), local variable "caldone"
> could be uninitialized if function regmap_read() returns -EINVAL.
> However, it will be used directly in the later context, which
> is potentially unsafe.
>
> Signed-off-by: Yizhuo <yzhai003@ucr.edu>
> ---
> drivers/phy/rockchip/phy-rockchip-emmc.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/phy/rockchip/phy-rockchip-emmc.c
> b/drivers/phy/rockchip/phy-rockchip-emmc.c index f1b24f18e9b2..ca921ae08309
> 100644
> --- a/drivers/phy/rockchip/phy-rockchip-emmc.c
> +++ b/drivers/phy/rockchip/phy-rockchip-emmc.c
> @@ -85,11 +85,12 @@ struct rockchip_emmc_phy {
> static int rockchip_emmc_phy_power(struct phy *phy, bool on_off)
> {
> struct rockchip_emmc_phy *rk_phy = phy_get_drvdata(phy);
> - unsigned int caldone;
> + unsigned int caldone = 0;
hmm, this may hide actual uninitialized uses in the future?
With the added error handling below, there shouldn't be a case
where caldone might be used uninitialized still?
Heiko
> unsigned int dllrdy;
> unsigned int freqsel = PHYCTRL_FREQSEL_200M;
> unsigned long rate;
> unsigned long timeout;
> + int err;
>
> /*
> * Keep phyctrl_pdb and phyctrl_endll low to allow
> @@ -164,9 +165,14 @@ static int rockchip_emmc_phy_power(struct phy *phy,
> bool on_off) * wait 5us for calpad busy trimming
> */
> udelay(5);
> - regmap_read(rk_phy->reg_base,
> + err = regmap_read(rk_phy->reg_base,
> rk_phy->reg_offset + GRF_EMMCPHY_STATUS,
> &caldone);
> + if (err) {
> + pr_err("Failed to read status.\n");
> + return err;
> + }
> +
> caldone = (caldone >> PHYCTRL_CALDONE_SHIFT) & PHYCTRL_CALDONE_MASK;
> if (caldone != PHYCTRL_CALDONE_DONE) {
> pr_err("rockchip_emmc_phy_power: caldone timeout.\n");
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prev parent reply other threads:[~2019-02-12 10:47 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-06 1:47 [PATCH] phy: Variable "caldone" in function rockchip_emmc_phy_power() could be uninitialized Yizhuo
2019-02-12 10:47 ` Heiko Stübner [this message]
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