I'd like to put the code into asm/io.h, and make it static. > +#ifdef CONFIG_STRICT_DEVMEM > +/* > + * devmem_is_allowed() checks to see if /dev/mem access to a certain > + * address is valid. The argument is a physical page number. > + * We mimic x86 here by disallowing access to system RAM as well as > + * device-exclusive MMIO regions. This effectively disable read()/write() > + * on /dev/mem. > + */ > +static int devmem_is_allowed(unsigned long pfn) > +{ > + if (iomem_is_exclusive(pfn << PAGE_SHIFT)) > + return 0; > + if (!page_is_ram(pfn)) > + return 1; > + return 0; > +} > +#endif /* CONFIG_STRICT_DEVMEM */
Thanks, Acked-by: Xuetao Guan <g...@mprc.pku.edu.cn> ----- Chen Gang <gang.chen.5...@gmail.com> 写道: > unicore32 supports STRICT_DEVMEM, so it needs devmem_is_allowed(), like > some of other architectures have done (e.g. arm, powerpc, x86 ...). > > The related error with allmodconfig: > > CC drivers/char/mem.o > drivers/char/mem.c: In function ‘range_is_allowed’: > drivers/char/mem.c:69: error: implicit declaration of function > ‘devmem_is_allowed’ > make[2]: *** [drivers/char/mem.o] Error 1 > make[1]: *** [drivers/char] Error 2 > make: *** [drivers] Error 2 > > > Signed-off-by: Chen Gang <gang.chen.5...@gmail.com> > --- > arch/unicore32/include/asm/page.h | 4 ++++ > arch/unicore32/mm/init.c | 18 ++++++++++++++++++ > 2 files changed, 22 insertions(+) > > diff --git a/arch/unicore32/include/asm/page.h > b/arch/unicore32/include/asm/page.h > index 594b322..231cb89 100644 > --- a/arch/unicore32/include/asm/page.h > +++ b/arch/unicore32/include/asm/page.h > @@ -68,6 +68,10 @@ typedef struct page *pgtable_t; > > extern int pfn_valid(unsigned long); > > +#ifdef CONFIG_STRICT_DEVMEM > +extern int devmem_is_allowed(unsigned long pfn); > +#endif /* CONFIG_STRICT_DEVMEM */ > + > #include <asm/memory.h> > > #endif /* !__ASSEMBLY__ */ > diff --git a/arch/unicore32/mm/init.c b/arch/unicore32/mm/init.c > index be2bde9..3bc3a59 100644 > --- a/arch/unicore32/mm/init.c > +++ b/arch/unicore32/mm/init.c > @@ -449,3 +449,21 @@ static int __init keepinitrd_setup(char *__unused) > > __setup("keepinitrd", keepinitrd_setup); > #endif > + > +#ifdef CONFIG_STRICT_DEVMEM > +/* > + * devmem_is_allowed() checks to see if /dev/mem access to a certain > + * address is valid. The argument is a physical page number. > + * We mimic x86 here by disallowing access to system RAM as well as > + * device-exclusive MMIO regions. This effectively disable read()/write() > + * on /dev/mem. > + */ > +int devmem_is_allowed(unsigned long pfn) > +{ > + if (iomem_is_exclusive(pfn << PAGE_SHIFT)) > + return 0; > + if (!page_is_ram(pfn)) > + return 1; > + return 0; > +} > +#endif /* CONFIG_STRICT_DEVMEM */ > -- > 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/