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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: Linn Crosetto <linn@hp.com>
Link: http://lkml.kernel.org/r/1376430401-67445-1-git-send-email-linn@hp.com
Acked-by: Yinghai Lu <yinghai@kernel.org>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This commit is contained in:
Linn Crosetto 2013-08-13 15:46:41 -06:00 committed by H. Peter Anvin
parent 2449f343e4
commit 30e46b574a
3 changed files with 13 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/x86/include/asm/e820.h
View File

@ -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))

5
arch/x86/kernel/e820.c
View File

@ -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");
}

19
arch/x86/kernel/setup.c
View File

@ -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) {
early_iounmap(data, map_len);
data = early_memremap(pa_data, data_len);
map_len = data_len;
}
data_type = data->type;
pa_next = data->next;
early_iounmap(data, map_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;
}
}