Commit e256caa7 authored Jan 21, 2016 by Vasant Hegde Committed by Michael Ellerman Jan 25, 2016

powerpc/mm: Allow user space to map rtas_rmo_buf



With commit 90a545e9 (restrict /dev/mem to idle io memory ranges) mapping
rtas_rmo_buf from user space is failing. Hence we are not able to make
RTAS syscall.

This patch calls page_is_rtas_user_buf before calling iomem_is_exclusive
in  devmem_is_allowed(). This will allow user space to map rtas_rmo_buf
and we are able to make RTAS syscall.

Reported-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
CC: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

parent 0e2bce74

arch/powerpc/mm/mem.c

+2 −2

Original line number	Original line	Diff line number	Diff line
	@@ -560,12 +560,12 @@ subsys_initcall(add_system_ram_resources);
	*/		*/
	int devmem_is_allowed(unsigned long pfn)		int devmem_is_allowed(unsigned long pfn)
	{		{
			if (page_is_rtas_user_buf(pfn))
			return 1;
	if (iomem_is_exclusive(PFN_PHYS(pfn)))		if (iomem_is_exclusive(PFN_PHYS(pfn)))
	return 0;		return 0;
	if (!page_is_ram(pfn))		if (!page_is_ram(pfn))
	return 1;		return 1;
	if (page_is_rtas_user_buf(pfn))
	return 1;
	return 0;		return 0;
	}		}
	#endif /* CONFIG_STRICT_DEVMEM */		#endif /* CONFIG_STRICT_DEVMEM */

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