Add suffix ULL 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 --- Changes in v2: - Use suffix ULL instead of UL.
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..754f6b2 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 * 1000ULL; /* In Hz */ bw = bw * mode->hdisplay * mode->vdisplay * cpp; bw = div_u64(bw, mode->htotal * mode->vtotal);
"Gustavo A. R. Silva" gustavo@embeddedor.com writes:
Add suffix ULL 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
This is silly. The clock won't be over 4ghz -- we haven't seen anything over 1024x768 on this hardware as far as I know. The u64 is for the multiplication by width/height below.
I've still applied the patch to shut up the tool.
Hi Eric,
On 07/17/2018 01:40 PM, Eric Anholt wrote:
"Gustavo A. R. Silva" gustavo@embeddedor.com writes:
Add suffix ULL 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
This is silly. The clock won't be over 4ghz -- we haven't seen anything over 1024x768 on this hardware as far as I know. The u64 is for the multiplication by width/height below.
Yep. I understand. That's why I didn't use the word *fix* anywhere in the changelog.
I've still applied the patch to shut up the tool.
Thanks -- Gustavo
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