From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: Eric Anholt <eric@anholt.net>, David Airlie <airlied@linux.ie>
Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
"Gustavo A. R. Silva" <gustavo@embeddedor.com>
Subject: [PATCH] drm/pl111: Use 64-bit arithmetic instead of 32-bit
Date: Tue, 3 Jul 2018 18:51:19 -0500 [thread overview]
Message-ID: <20180703235119.GA20877@embeddedor.com> (raw)
Add suffix UL to constant 1000 in order to give the compiler complete
information about the proper arithmetic to use.
Notice that such constant 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:
mode->clock * 1000
Addresses-Coverity-ID: 1466139 ("Unintentional integer overflow")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
drivers/gpu/drm/pl111/pl111_display.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/pl111/pl111_display.c b/drivers/gpu/drm/pl111/pl111_display.c
index a432eb7..61d51b4 100644
--- a/drivers/gpu/drm/pl111/pl111_display.c
+++ b/drivers/gpu/drm/pl111/pl111_display.c
@@ -63,7 +63,7 @@ pl111_mode_valid(struct drm_crtc *crtc,
* We use the pixelclock to also account for interlaced modes, the
* resulting bandwidth is in bytes per second.
*/
- bw = mode->clock * 1000; /* In Hz */
+ bw = mode->clock * 1000UL; /* In Hz */
bw = bw * mode->hdisplay * mode->vdisplay * cpp;
bw = div_u64(bw, mode->htotal * mode->vtotal);
--
2.7.4
next reply other threads:[~2018-07-03 23:51 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-03 23:51 Gustavo A. R. Silva [this message]
2018-07-04 14:11 ` [PATCH] drm/pl111: Use 64-bit arithmetic instead of 32-bit Gustavo A. R. Silva
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=20180703235119.GA20877@embeddedor.com \
--to=gustavo@embeddedor.com \
--cc=airlied@linux.ie \
--cc=dri-devel@lists.freedesktop.org \
--cc=eric@anholt.net \
--cc=linux-kernel@vger.kernel.org \
/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.