On Thu, Nov 24, 2016 at 08:16:24AM +0800, Christopher Li wrote:
> A similar patch has been applied:
>
> Chris
>
> commit f2bf519e1da89779380fd781c0eb28aae415979d
> Author: Lance Richardson <lrichard@xxxxxxxxxx>
> Date: Wed Sep 21 10:13:58 2016 -0400
>
> sparse: update __builtin_object_size() prototype
>
> Sparse emits a large number of warnings for the linux kernel source
> tree of the form:
> ./arch/x86/include/asm/uaccess.h:735:18: \
> warning: incorrect type in argument 1 (different modifiers)
> ./arch/x86/include/asm/uaccess.h:735:18: expected void *<noident>
> ./arch/x86/include/asm/uaccess.h:735:18: got void const *from
>
> Fix by making the first parameter to __builtin_object_size()
> type "const void *" instead of "void *", which is consistent with GCC
> behavior (the prototype for this builtin in GCC documentation is evidently
> incorrect).
>
> Signed-off-by: Lance Richardson <lrichard@xxxxxxxxxx>
> Acked-by: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
> Signed-off-by: Christopher Li <sparse@xxxxxxxxxxx>
Doesn't seem to be pushed yet - at least I don't see it in master
on git://git.kernel.org/pub/scm/devel/sparse/sparse.git
> diff --git a/lib.c b/lib.c
> index d5b56b0..2d66aa0 100644
> --- a/lib.c
> +++ b/lib.c
> @@ -888,7 +888,7 @@ void declare_builtin_functions(void)
> add_pre_buffer("extern long double __builtin_nanl(const char *);\n");
>
> /* And some __FORTIFY_SOURCE ones.. */
> - add_pre_buffer ("extern __SIZE_TYPE__
> __builtin_object_size(void *, int);\n");
> + add_pre_buffer ("extern __SIZE_TYPE__
> __builtin_object_size(const void *, int);\n");
> add_pre_buffer ("extern void * __builtin___memcpy_chk(void *,
> const void *, __SIZE_TYPE__, __SIZE_TYPE__);\n");
> add_pre_buffer ("extern void * __builtin___memmove_chk(void *,
> const void *, __SIZE_TYPE__, __SIZE_TYPE__);\n");
> add_pre_buffer ("extern void * __builtin___mempcpy_chk(void *,
> const void *, __SIZE_TYPE__, __SIZE_TYPE__);\n");
>
>
>
> On Thu, Nov 24, 2016 at 4:24 AM, Michael S. Tsirkin <mst@xxxxxxxxxx> wrote:
> > I'm seeing these warnings with current Linux:
> > ./arch/x86/include/asm/uaccess.h:705:18: warning: incorrect type in argument 1 (different modifiers)
> > ./arch/x86/include/asm/uaccess.h:705:18: expected void *<noident>
> > ./arch/x86/include/asm/uaccess.h:705:18: got void const *from
> >
> > Because of this code:
> >
> > static __always_inline unsigned long __must_check
> > copy_to_user(void __user *to, const void *from, unsigned long n)
> > {
> > int sz = __compiletime_object_size(from);
> >
> > ...
> > }
> >
> > where we have
> >
> > # define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
> >
> > to fix, mark the argument as const void *.
> >
> > Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
> > ---
> >
> > Sorry if this has already been reported/fixed.
> >
> > lib.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/lib.c b/lib.c
> > index d5b56b0..2d66aa0 100644
> > --- a/lib.c
> > +++ b/lib.c
> > @@ -888,7 +888,7 @@ void declare_builtin_functions(void)
> > add_pre_buffer("extern long double __builtin_nanl(const char *);\n");
> >
> > /* And some __FORTIFY_SOURCE ones.. */
> > - add_pre_buffer ("extern __SIZE_TYPE__ __builtin_object_size(void *, int);\n");
> > + add_pre_buffer ("extern __SIZE_TYPE__ __builtin_object_size(const void *, int);\n");
> > add_pre_buffer ("extern void * __builtin___memcpy_chk(void *, const void *, __SIZE_TYPE__, __SIZE_TYPE__);\n");
> > add_pre_buffer ("extern void * __builtin___memmove_chk(void *, const void *, __SIZE_TYPE__, __SIZE_TYPE__);\n");
> > add_pre_buffer ("extern void * __builtin___mempcpy_chk(void *, const void *, __SIZE_TYPE__, __SIZE_TYPE__);\n");
> > --
> > MST
> > --
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