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Commit 084d1283 authored by Yinghai Lu's avatar Yinghai Lu Committed by H. Peter Anvin
Browse files

x86, kexec: Set ident mapping for kernel that is above max_pfn 



When first kernel is booted with memmap= or mem=  to limit max_pfn.
kexec can load second kernel above that max_pfn.

We need to set ident mapping for whole image in this case instead of just
for first 2M.

Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1359058816-7615-23-git-send-email-yinghai@kernel.org


Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
parent 577af55d

arch/x86/kernel/machine_kexec_64.c

+37 −6
Original line number Diff line number Diff line
@@ -56,6 +56,25 @@ out: 
	return result;

}



static int ident_mapping_init(struct kimage *image, pgd_t *level4p,

				unsigned long mstart, unsigned long mend)

{

	int result;



	mstart = round_down(mstart, PMD_SIZE);

	mend   = round_up(mend - 1, PMD_SIZE);



	while (mstart < mend) {

		result = init_one_level2_page(image, level4p, mstart);

		if (result)

			return result;



		mstart += PMD_SIZE;

	}



	return 0;

}



static void init_level2_page(pmd_t *level2p, unsigned long addr)

{

	unsigned long end_addr;
@@ -184,22 +203,34 @@ err: 
	return result;

}





static int init_pgtable(struct kimage *image, unsigned long start_pgtable)

{

	unsigned long mstart, mend;

	pgd_t *level4p;

	int result;

	int i;



	level4p = (pgd_t *)__va(start_pgtable);

	result = init_level4_page(image, level4p, 0, max_pfn << PAGE_SHIFT);

	if (result)

		return result;



	/*

	 * image->start may be outside 0 ~ max_pfn, for example when

	 * jump back to original kernel from kexeced kernel

	 * segments's mem ranges could be outside 0 ~ max_pfn,

	 * for example when jump back to original kernel from kexeced kernel.

	 * or first kernel is booted with user mem map, and second kernel

	 * could be loaded out of that range.

	 */

	result = init_one_level2_page(image, level4p, image->start);

	for (i = 0; i < image->nr_segments; i++) {

		mstart = image->segment[i].mem;

		mend   = mstart + image->segment[i].memsz;



		result = ident_mapping_init(image, level4p, mstart, mend);



		if (result)

			return result;

	}



	return init_transition_pgtable(image, level4p);

}