lkml.org 
[lkml]   [2015]   [Feb]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectCan this be a invalid memory access? (was: Re: [PATCH] spi/xilinx: Cast ioread32/iowrite32 function pointers)
Hello

Regarding ioread8 et al.

On include/asm-generic/io.h is defined as:
extern unsigned int ioread8(void __iomem *);

On include/asm-generic/io.h:
static inline u8 ioread8(const volatile void __iomem *addr)

Please ignore the qualifiers right now. The first function returns an
unsigned integer, the second a u8.

Through #ifdefs, different arches uses the first or the second definitions.

If we consider this code:

u8 varA;
u8 varB;
u8 varC;
void * pvar=varB;
*pvar = ioread8(valid_memory);

Depending if ioread8 returns a u8 or a unsigned int, aren't we also
accessing varC?

Could not this be a problem?

If I decide to send a patch and fix it, is there a clever script that
I can run on my x86 computer to test if the patch works on all arches?


Thanks

--
Ricardo Ribalda


\
 
 \ /
  Last update: 2015-02-02 14:01    [W:0.053 / U:0.420 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site