[PATCH] drm/amd/pm: added result check

Denis Arefev arefev at swemel.ru
Tue Nov 22 15:36:56 UTC 2022


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 at 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



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