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From:   Denis Arefev <arefev@swemel.ru>
To:     Evan Quan <evan.quan@amd.com>
Cc:     Alex Deucher <alexander.deucher@amd.com>,
        =?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@amd.com>,
        "Pan, Xinhui" <Xinhui.Pan@amd.com>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>, amd-gfx@lists.freedesktop.org,
        dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
        lvc-project@linuxtesting.org, trufanov@swemel.ru, vfh@swemel.ru
Subject: 
Date:   Tue, 22 Nov 2022 16:07:46 +0300
Message-Id: <20221122130746.24432-1-arefev@swemel.ru>
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Date: Tue, 22 Nov 2022 15:51:44 +0300
Subject: [PATCH] powerplay: hwmgr: added result check

The return value of the 'div64_s64'
function called in ppevvmath.h:371
was not checked.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Denis Arefev <arefev@swemel.ru>
---
 drivers/gpu/drm/amd/pm/powerplay/hwmgr/ppevvmath.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/ppevvmath.h b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/ppevvmath.h
index dac29fe6cfc6..82aa7130d143 100644
--- a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/ppevvmath.h
+++ b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/ppevvmath.h
@@ -357,6 +357,7 @@ static fInt fDivide (fInt X, fInt Y)
 {
 	fInt fZERO, fQuotient;
 	int64_t longlongX, longlongY;
+	int64_t result;
 
 	fZERO = ConvertToFraction(0);
 
@@ -367,10 +368,11 @@ static fInt fDivide (fInt X, fInt Y)
 	longlongY = (int64_t)Y.full;
 
 	longlongX = longlongX << 16; /*Q(16,16) -> Q(32,32) */
+	longlongY = longlongY << 16;
 
-	div64_s64(longlongX, longlongY); /*Q(32,32) divided by Q(16,16) = Q(16,16) Back to original format */
+	result = div64_s64(longlongX, longlongY);
 
-	fQuotient.full = (int)longlongX;
+	fQuotient = ConvertToFraction((int)result);
 	return fQuotient;
 }
 
-- 
2.25.1