| Date | Wed, 9 Aug 2017 01:34:20 +0300 | From | "Dmitry V. Levin" <> | Subject | Re: [PATCH v06 05/36] uapi linux/sysctl.h: use __kernel_size_t instead of size_t |
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On Sun, Aug 06, 2017 at 06:43:56PM +0200, Mikko Rapeli wrote: > Fixes userspace compilation error: > > error: unknown type name ‘size_t’ > > Signed-off-by: Mikko Rapeli <mikko.rapeli@iki.fi> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: David S. Miller <davem@davemloft.net> > --- > include/uapi/linux/sysctl.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/include/uapi/linux/sysctl.h b/include/uapi/linux/sysctl.h > index e13d48058b8d..35a4b8b417fe 100644 > --- a/include/uapi/linux/sysctl.h > +++ b/include/uapi/linux/sysctl.h > @@ -35,9 +35,9 @@ struct __sysctl_args { > int __user *name; > int nlen; > void __user *oldval; > - size_t __user *oldlenp; > + __kernel_size_t __user *oldlenp; > void __user *newval; > - size_t newlen; > + __kernel_size_t newlen; > unsigned long __unused[4]; > };
You should be extremely careful when replacing size_t with __kernel_size_t because e.g. on x32 you have sizeof(size_t) < sizeof(__kernel_size_t).
In case of sysctl.h this replacement would be wrong.
I submitted an alternative fix for this bug some time ago, see http://lkml.kernel.org/r/20170222230652.GA14373@altlinux.org
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