Messages in this thread | | | Subject | Re: [PATCH] fixp-arith: prevent division by zero in fixp_sin32_rad() | From | Sergey Shtylyov <> | Date | Wed, 13 Mar 2024 21:23:38 +0300 |
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On 3/12/24 12:48 PM, Roman Smirnov wrote:
> The parameter twopi can have a zero value. It is necessary > to prevent division by zero. > > Found by Linux Verification Center (linuxtesting.org) with Svace. > > Signed-off-by: Roman Smirnov <r.smirnov@omp.ru> > --- > include/linux/fixp-arith.h | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/include/linux/fixp-arith.h b/include/linux/fixp-arith.h > index e485fb0c1201..434eee8bd9ef 100644 > --- a/include/linux/fixp-arith.h > +++ b/include/linux/fixp-arith.h > @@ -118,8 +118,9 @@ static inline s32 fixp_sin32_rad(u32 radians, u32 twopi) > > /* > * Avoid too large values for twopi, as we don't want overflows. > + * Also prevent division by zero. > */ > - BUG_ON(twopi > 1 << 18); > + BUG_ON(!twopi || twopi > 1 << 18);
Not really sure ATM that BUG_ON() is better than division by 0 (which should cause exception 0 on x86 but I'm not sure about e.g. ARM32/64)...
> > degrees = (radians * 360) / twopi; > tmp = radians - (degrees * twopi) / 360; >
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
[...]
MBR, Sergey
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