All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Gustavo A. R. Silva" <gustavoars@kernel.org>
To: "Harry Wentland" <harry.wentland@amd.com>,
	"Leo Li" <sunpeng.li@amd.com>,
	"Alex Deucher" <alexander.deucher@amd.com>,
	"Christian König" <christian.koenig@amd.com>,
	"David Airlie" <airlied@linux.ie>,
	"Daniel Vetter" <daniel@ffwll.ch>,
	"Huang Rui" <ray.huang@amd.com>,
	"Anson Jacob" <Anson.Jacob@amd.com>, "Lang Yu" <Lang.Yu@amd.com>,
	"Nicholas Kazlauskas" <Nicholas.Kazlauskas@amd.com>
Cc: amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
	linux-kernel@vger.kernel.org,
	"Gustavo A. R. Silva" <gustavoars@kernel.org>
Subject: [PATCH][next] drm/amd/display: Fix potential integer overflow
Date: Wed, 10 Feb 2021 15:23:30 -0600	[thread overview]
Message-ID: <20210210212330.GA880153@embeddedor> (raw)

Fix potential integer overflow by casting actual_calculated_clock_100hz
to u64, in order to give the compiler complete information about the
proper arithmetic to use.

Notice that such variable is used in a context that expects
an expression of type u64 (64 bits, unsigned) and the following
expression is currently being evaluated using 32-bit arithmetic:

actual_calculated_clock_100hz * post_divider

Fixes: 7a03fdf628af ("drm/amd/display: fix 64bit division issue on 32bit OS")
Addresses-Coverity-ID: 1501691 ("Unintentional integer overflow")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c b/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
index bc942725b9d8..dec58b3c42e4 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
@@ -240,7 +240,7 @@ static bool calc_fb_divider_checking_tolerance(
 		pll_settings->calculated_pix_clk_100hz =
 			actual_calculated_clock_100hz;
 		pll_settings->vco_freq =
-			div_u64(actual_calculated_clock_100hz * post_divider, 10);
+			div_u64((u64)actual_calculated_clock_100hz * post_divider, 10);
 		return true;
 	}
 	return false;
-- 
2.27.0


WARNING: multiple messages have this Message-ID (diff)
From: "Gustavo A. R. Silva" <gustavoars@kernel.org>
To: "Harry Wentland" <harry.wentland@amd.com>,
	"Leo Li" <sunpeng.li@amd.com>,
	"Alex Deucher" <alexander.deucher@amd.com>,
	"Christian König" <christian.koenig@amd.com>,
	"David Airlie" <airlied@linux.ie>,
	"Daniel Vetter" <daniel@ffwll.ch>,
	"Huang Rui" <ray.huang@amd.com>,
	"Anson Jacob" <Anson.Jacob@amd.com>, "Lang Yu" <Lang.Yu@amd.com>,
	"Nicholas Kazlauskas" <Nicholas.Kazlauskas@amd.com>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>,
	dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH][next] drm/amd/display: Fix potential integer overflow
Date: Wed, 10 Feb 2021 15:23:30 -0600	[thread overview]
Message-ID: <20210210212330.GA880153@embeddedor> (raw)

Fix potential integer overflow by casting actual_calculated_clock_100hz
to u64, in order to give the compiler complete information about the
proper arithmetic to use.

Notice that such variable is used in a context that expects
an expression of type u64 (64 bits, unsigned) and the following
expression is currently being evaluated using 32-bit arithmetic:

actual_calculated_clock_100hz * post_divider

Fixes: 7a03fdf628af ("drm/amd/display: fix 64bit division issue on 32bit OS")
Addresses-Coverity-ID: 1501691 ("Unintentional integer overflow")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c b/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
index bc942725b9d8..dec58b3c42e4 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
@@ -240,7 +240,7 @@ static bool calc_fb_divider_checking_tolerance(
 		pll_settings->calculated_pix_clk_100hz =
 			actual_calculated_clock_100hz;
 		pll_settings->vco_freq =
-			div_u64(actual_calculated_clock_100hz * post_divider, 10);
+			div_u64((u64)actual_calculated_clock_100hz * post_divider, 10);
 		return true;
 	}
 	return false;
-- 
2.27.0

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

WARNING: multiple messages have this Message-ID (diff)
From: "Gustavo A. R. Silva" <gustavoars@kernel.org>
To: "Harry Wentland" <harry.wentland@amd.com>,
	"Leo Li" <sunpeng.li@amd.com>,
	"Alex Deucher" <alexander.deucher@amd.com>,
	"Christian König" <christian.koenig@amd.com>,
	"David Airlie" <airlied@linux.ie>,
	"Daniel Vetter" <daniel@ffwll.ch>,
	"Huang Rui" <ray.huang@amd.com>,
	"Anson Jacob" <Anson.Jacob@amd.com>, "Lang Yu" <Lang.Yu@amd.com>,
	"Nicholas Kazlauskas" <Nicholas.Kazlauskas@amd.com>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>,
	dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH][next] drm/amd/display: Fix potential integer overflow
Date: Wed, 10 Feb 2021 15:23:30 -0600	[thread overview]
Message-ID: <20210210212330.GA880153@embeddedor> (raw)

Fix potential integer overflow by casting actual_calculated_clock_100hz
to u64, in order to give the compiler complete information about the
proper arithmetic to use.

Notice that such variable is used in a context that expects
an expression of type u64 (64 bits, unsigned) and the following
expression is currently being evaluated using 32-bit arithmetic:

actual_calculated_clock_100hz * post_divider

Fixes: 7a03fdf628af ("drm/amd/display: fix 64bit division issue on 32bit OS")
Addresses-Coverity-ID: 1501691 ("Unintentional integer overflow")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c b/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
index bc942725b9d8..dec58b3c42e4 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
@@ -240,7 +240,7 @@ static bool calc_fb_divider_checking_tolerance(
 		pll_settings->calculated_pix_clk_100hz =
 			actual_calculated_clock_100hz;
 		pll_settings->vco_freq =
-			div_u64(actual_calculated_clock_100hz * post_divider, 10);
+			div_u64((u64)actual_calculated_clock_100hz * post_divider, 10);
 		return true;
 	}
 	return false;
-- 
2.27.0

_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx

             reply	other threads:[~2021-02-10 21:29 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-10 21:23 Gustavo A. R. Silva [this message]
2021-02-10 21:23 ` [PATCH][next] drm/amd/display: Fix potential integer overflow Gustavo A. R. Silva
2021-02-10 21:23 ` Gustavo A. R. Silva
2021-02-15 18:51 ` Alex Deucher
2021-02-15 18:51   ` Alex Deucher
2021-02-15 18:51   ` Alex Deucher

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210210212330.GA880153@embeddedor \
    --to=gustavoars@kernel.org \
    --cc=Anson.Jacob@amd.com \
    --cc=Lang.Yu@amd.com \
    --cc=Nicholas.Kazlauskas@amd.com \
    --cc=airlied@linux.ie \
    --cc=alexander.deucher@amd.com \
    --cc=amd-gfx@lists.freedesktop.org \
    --cc=christian.koenig@amd.com \
    --cc=daniel@ffwll.ch \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=harry.wentland@amd.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=ray.huang@amd.com \
    --cc=sunpeng.li@amd.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.