Commit 68accac3 authored Nov 06, 2015 by Krzysztof Mazur Committed by Thomas Gleixner Nov 07, 2015

x86/setup: Fix low identity map for >= 2GB kernel range



The commit f5f3497c extended the low identity mapping. However, if
the kernel uses more than 2 GB (VMSPLIT_2G_OPT or VMSPLIT_1G memory
split), the normal memory mapping is overwritten by the low identity
mapping causing a crash. To avoid overwritting, limit the low identity
map to cover only memory before kernel range (PAGE_OFFSET).

Fixes: f5f3497c "x86/setup: Extend low identity map to cover whole kernel range
Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1446815916-22105-1-git-send-email-krzysiek@podlesie.net


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

parent f4e342c8

arch/x86/kernel/setup.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1188,7 +1188,7 @@ void __init setup_arch(char **cmdline_p)
		*/
		clone_pgd_range(initial_page_table,
		swapper_pg_dir + KERNEL_PGD_BOUNDARY,
		KERNEL_PGD_PTRS);
		min(KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY));
		#endif

		tboot_probe();

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