[v4] Fix to avoid IS_ERR_VALUE and IS_ERR abuses on 64bit systems.
arnd at arndb.de
Tue Aug 2 17:45:18 AEST 2016
On Monday, August 1, 2016 4:55:43 PM CEST Scott Wood wrote:
> On 08/01/2016 02:02 AM, Arnd Bergmann wrote:
> >> diff --git a/include/linux/err.h b/include/linux/err.h
> >> index 1e35588..c2a2789 100644
> >> --- a/include/linux/err.h
> >> +++ b/include/linux/err.h
> >> @@ -18,7 +18,17 @@
> >> #ifndef __ASSEMBLY__
> >> -#define IS_ERR_VALUE(x) unlikely((unsigned long)(void *)(x) >= (unsigned long)-MAX_ERRNO)
> >> +#define IS_ERR_VALUE(x) unlikely(is_error_check(x))
> >> +
> >> +static inline int is_error_check(unsigned long error)
> > Please leave the existing macro alone. I think you were looking for
> > something specific to the return code of qe_muram_alloc() function,
> > so please add a helper in that subsystem if you need it, not in
> > the generic header files.
> qe_muram_alloc (a.k.a. cpm_muram_alloc) returns unsigned long. The
> problem is certain callers that store the return value in a u32. Why
> not just fix those callers to store it in unsigned long (at least until
> error checking is done)?
Yes, that would also address another problem with code like
which is not 64-bit safe when tx_bd_ring_offset is a 32-bit value
that also holds the return value of qe_muram_alloc.
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