Messages in this thread Patch in this message | | | Date | Mon, 07 Apr 2014 19:28:09 +0800 | From | Chen Gang <> | Subject | [PATCH] arch:unicore32:mm: add devmem_is_allowed() to support STRICT_DEVMEM |
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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.5i5j@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 majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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