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Commit f62995c9 authored by Baoquan He's avatar Baoquan He Committed by Ingo Molnar
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x86/boot/KASLR: Wrap e820 entries walking code into new function process_e820_entries() 



The original function process_e820_entry() only takes care of each
e820 entry passed.

And move the E820_TYPE_RAM checking logic into process_e820_entries().

And remove the redundent local variable 'addr' definition in
find_random_phys_addr().

Signed-off-by: default avatarBaoquan He <bhe@redhat.com>
Acked-by: default avatarKees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: fanc.fnst@cn.fujitsu.com
Cc: izumi.taku@jp.fujitsu.com
Cc: matt@codeblueprint.co.uk
Cc: thgarnie@google.com
Link: http://lkml.kernel.org/r/1499603862-11516-2-git-send-email-bhe@redhat.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent cb8c65cc

arch/x86/boot/compressed/kaslr.c

+21 −17
Original line number Diff line number Diff line
@@ -488,10 +488,6 @@ static void process_e820_entry(struct boot_e820_entry *entry, 
	unsigned long start_orig, end;

	struct boot_e820_entry cur_entry;



	/* Skip non-RAM entries. */

	if (entry->type != E820_TYPE_RAM)

		return;



	/* On 32-bit, ignore entries entirely above our maximum. */

	if (IS_ENABLED(CONFIG_X86_32) && entry->addr >= KERNEL_IMAGE_SIZE)

		return;
@@ -562,12 +558,29 @@ static void process_e820_entry(struct boot_e820_entry *entry, 
	}

}



static unsigned long find_random_phys_addr(unsigned long minimum,

static void process_e820_entries(unsigned long minimum,

				 unsigned long image_size)

{

	int i;

	unsigned long addr;

	struct boot_e820_entry *entry;



	/* Verify potential e820 positions, appending to slots list. */

	for (i = 0; i < boot_params->e820_entries; i++) {

		entry = &boot_params->e820_table[i];

		/* Skip non-RAM entries. */

		if (entry->type != E820_TYPE_RAM)

			continue;

		process_e820_entry(entry, minimum, image_size);

		if (slot_area_index == MAX_SLOT_AREA) {

			debug_putstr("Aborted e820 scan (slot_areas full)!\n");

			break;

		}

	}

}



static unsigned long find_random_phys_addr(unsigned long minimum,

					   unsigned long image_size)

{

	/* Check if we had too many memmaps. */

	if (memmap_too_large) {

		debug_putstr("Aborted e820 scan (more than 4 memmap= args)!\n");
@@ -577,16 +590,7 @@ static unsigned long find_random_phys_addr(unsigned long minimum, 
	/* Make sure minimum is aligned. */

	minimum = ALIGN(minimum, CONFIG_PHYSICAL_ALIGN);



	/* Verify potential e820 positions, appending to slots list. */

	for (i = 0; i < boot_params->e820_entries; i++) {

		process_e820_entry(&boot_params->e820_table[i], minimum,

				   image_size);

		if (slot_area_index == MAX_SLOT_AREA) {

			debug_putstr("Aborted e820 scan (slot_areas full)!\n");

			break;

		}

	}



	process_e820_entries(minimum, image_size);

	return slots_fetch_random();

}