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Commit 30e46b57 authored by Linn Crosetto's avatar Linn Crosetto Committed by H. Peter Anvin
Browse files

x86: avoid remapping data in parse_setup_data() 



Type SETUP_PCI, added by setup_efi_pci(), may advertise a ROM size
larger than early_memremap() is able to handle, which is currently
limited to 256kB. If this occurs it leads to a NULL dereference in
parse_setup_data().

To avoid this, remap the setup_data header and allow parsing functions
for individual types to handle their own data remapping.

Signed-off-by: default avatarLinn Crosetto <linn@hp.com>
Link: http://lkml.kernel.org/r/1376430401-67445-1-git-send-email-linn@hp.com


Acked-by: default avatarYinghai Lu <yinghai@kernel.org>
Reviewed-by: default avatarPekka Enberg <penberg@kernel.org>
Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
parent 2449f343

arch/x86/include/asm/e820.h

+1 −1
Original line number Diff line number Diff line
@@ -29,7 +29,7 @@ extern void e820_setup_gap(void); 
extern int e820_search_gap(unsigned long *gapstart, unsigned long *gapsize,

			unsigned long start_addr, unsigned long long end_addr);

struct setup_data;

extern void parse_e820_ext(struct setup_data *data);

extern void parse_e820_ext(u64 phys_addr, u32 data_len);



#if defined(CONFIG_X86_64) || \

	(defined(CONFIG_X86_32) && defined(CONFIG_HIBERNATION))

arch/x86/kernel/e820.c

+4 −1
Original line number Diff line number Diff line
@@ -658,15 +658,18 @@ __init void e820_setup_gap(void) 
 * boot_params.e820_map, others are passed via SETUP_E820_EXT node of

 * linked list of struct setup_data, which is parsed here.

 */

void __init parse_e820_ext(struct setup_data *sdata)

void __init parse_e820_ext(u64 phys_addr, u32 data_len)

{

	int entries;

	struct e820entry *extmap;

	struct setup_data *sdata;



	sdata = early_memremap(phys_addr, data_len);

	entries = sdata->len / sizeof(struct e820entry);

	extmap = (struct e820entry *)(sdata->data);

	__append_e820_map(extmap, entries);

	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);

	early_iounmap(sdata, data_len);

	printk(KERN_INFO "e820: extended physical RAM map:\n");

	e820_print_map("extended");

}

arch/x86/kernel/setup.c

+8 −11
Original line number Diff line number Diff line
@@ -426,25 +426,23 @@ static void __init reserve_initrd(void) 
static void __init parse_setup_data(void)

{

	struct setup_data *data;

	u64 pa_data;

	u64 pa_data, pa_next;



	pa_data = boot_params.hdr.setup_data;

	while (pa_data) {

		u32 data_len, map_len;

		u32 data_len, map_len, data_type;



		map_len = max(PAGE_SIZE - (pa_data & ~PAGE_MASK),

			      (u64)sizeof(struct setup_data));

		data = early_memremap(pa_data, map_len);

		data_len = data->len + sizeof(struct setup_data);

		if (data_len > map_len) {

		data_type = data->type;

		pa_next = data->next;

		early_iounmap(data, map_len);

			data = early_memremap(pa_data, data_len);

			map_len = data_len;

		}



		switch (data->type) {

		switch (data_type) {

		case SETUP_E820_EXT:

			parse_e820_ext(data);

			parse_e820_ext(pa_data, data_len);

			break;

		case SETUP_DTB:

			add_dtb(pa_data);
@@ -452,8 +450,7 @@ static void __init parse_setup_data(void) 
		default:

			break;

		}

		pa_data = data->next;

		early_iounmap(data, map_len);

		pa_data = pa_next;

	}

}