From: Joe Perches <joe@perches.com>
To: "Heinrich Schuchardt" <xypron.glpk@gmx.de>,
"Alex Deucher" <alexander.deucher@amd.com>,
"Christian König" <christian.koenig@amd.com>
Cc: David Airlie <airlied@linux.ie>,
dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/1] drm/radeon: avoid NULL dereference, si_get_vce_clock_voltage
Date: Sun, 21 Aug 2016 14:06:02 -0700 [thread overview]
Message-ID: <1471813562.3746.23.camel@perches.com> (raw)
In-Reply-To: <1471812743-5095-1-git-send-email-xypron.glpk@gmx.de>
On Sun, 2016-08-21 at 22:52 +0200, Heinrich Schuchardt wrote:
> It does not make sense to check if table is NULL
> and afterwards to dereference it without
> considering the result.
This makes no sense.
> The inconsistency was indicated by cppcheck.
Perhaps this is a defect in cppcheck?
> An actual NULL pointer dereference was not observed.
[]
> diff --git a/drivers/gpu/drm/radeon/si_dpm.c b/drivers/gpu/drm/radeon/si_dpm.c
[]
> @@ -2962,7 +2962,7 @@ static int si_get_vce_clock_voltage(struct radeon_device *rdev,
> &rdev->pm.dpm.dyn_state.vce_clock_voltage_dependency_table;
>
> if (((evclk == 0) && (ecclk == 0)) ||
> - (table && (table->count == 0))) {
Here table is only dereferenced if table is non-null
> + table == NULL || table->count == 0) {
> *voltage = 0;
> return 0;
> }
Perhaps the unnecessary parentheses can be reduce though.
if ((evclk == 0 && ecclk == 0) || (table && table->count == 0)) {
next prev parent reply other threads:[~2016-08-21 21:06 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-21 20:52 [PATCH 1/1] drm/radeon: avoid NULL dereference, si_get_vce_clock_voltage Heinrich Schuchardt
2016-08-21 21:06 ` Joe Perches [this message]
2016-08-21 21:20 ` Heinrich Schuchardt
2016-08-21 21:31 ` Joe Perches
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