summaryrefslogtreecommitdiffstats
path: root/arch
diff options
context:
space:
mode:
authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2016-08-08 15:31:31 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2016-08-08 22:04:30 +0200
commite4630fdd47637168927905983205d7b7c5c08c09 (patch)
tree3528e218e396d17ab5db1e74346e39b59424ec74 /arch
parentx86/power/64: Do not refer to __PAGE_OFFSET from assembly code (diff)
downloadlinux-e4630fdd47637168927905983205d7b7c5c08c09.tar.xz
linux-e4630fdd47637168927905983205d7b7c5c08c09.zip
x86/power/64: Always create temporary identity mapping correctly
The low-level resume-from-hibernation code on x86-64 uses kernel_ident_mapping_init() to create the temoprary identity mapping, but that function assumes that the offset between kernel virtual addresses and physical addresses is aligned on the PGD level. However, with a randomized identity mapping base, it may be aligned on the PUD level and if that happens, the temporary identity mapping created by set_up_temporary_mappings() will not reflect the actual kernel identity mapping and the image restoration will fail as a result (leading to a kernel panic most of the time). To fix this problem, rework kernel_ident_mapping_init() to support unaligned offsets between KVA and PA up to the PMD level and make set_up_temporary_mappings() use it as approprtiate. Reported-and-tested-by: Thomas Garnier <thgarnie@google.com> Reported-by: Borislav Petkov <bp@suse.de> Suggested-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Yinghai Lu <yinghai@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/include/asm/init.h4
-rw-r--r--arch/x86/mm/ident_map.c19
-rw-r--r--arch/x86/power/hibernate_64.c2
3 files changed, 14 insertions, 11 deletions
diff --git a/arch/x86/include/asm/init.h b/arch/x86/include/asm/init.h
index 223042086f4e..737da62bfeb0 100644
--- a/arch/x86/include/asm/init.h
+++ b/arch/x86/include/asm/init.h
@@ -5,10 +5,10 @@ struct x86_mapping_info {
void *(*alloc_pgt_page)(void *); /* allocate buf for page table */
void *context; /* context for alloc_pgt_page */
unsigned long pmd_flag; /* page flag for PMD entry */
- bool kernel_mapping; /* kernel mapping or ident mapping */
+ unsigned long offset; /* ident mapping offset */
};
int kernel_ident_mapping_init(struct x86_mapping_info *info, pgd_t *pgd_page,
- unsigned long addr, unsigned long end);
+ unsigned long pstart, unsigned long pend);
#endif /* _ASM_X86_INIT_H */
diff --git a/arch/x86/mm/ident_map.c b/arch/x86/mm/ident_map.c
index ec21796ac5fd..4473cb4f8b90 100644
--- a/arch/x86/mm/ident_map.c
+++ b/arch/x86/mm/ident_map.c
@@ -3,15 +3,17 @@
* included by both the compressed kernel and the regular kernel.
*/
-static void ident_pmd_init(unsigned long pmd_flag, pmd_t *pmd_page,
+static void ident_pmd_init(struct x86_mapping_info *info, pmd_t *pmd_page,
unsigned long addr, unsigned long end)
{
addr &= PMD_MASK;
for (; addr < end; addr += PMD_SIZE) {
pmd_t *pmd = pmd_page + pmd_index(addr);
- if (!pmd_present(*pmd))
- set_pmd(pmd, __pmd(addr | pmd_flag));
+ if (pmd_present(*pmd))
+ continue;
+
+ set_pmd(pmd, __pmd((addr - info->offset) | info->pmd_flag));
}
}
@@ -30,13 +32,13 @@ static int ident_pud_init(struct x86_mapping_info *info, pud_t *pud_page,
if (pud_present(*pud)) {
pmd = pmd_offset(pud, 0);
- ident_pmd_init(info->pmd_flag, pmd, addr, next);
+ ident_pmd_init(info, pmd, addr, next);
continue;
}
pmd = (pmd_t *)info->alloc_pgt_page(info->context);
if (!pmd)
return -ENOMEM;
- ident_pmd_init(info->pmd_flag, pmd, addr, next);
+ ident_pmd_init(info, pmd, addr, next);
set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
}
@@ -44,14 +46,15 @@ static int ident_pud_init(struct x86_mapping_info *info, pud_t *pud_page,
}
int kernel_ident_mapping_init(struct x86_mapping_info *info, pgd_t *pgd_page,
- unsigned long addr, unsigned long end)
+ unsigned long pstart, unsigned long pend)
{
+ unsigned long addr = pstart + info->offset;
+ unsigned long end = pend + info->offset;
unsigned long next;
int result;
- int off = info->kernel_mapping ? pgd_index(__PAGE_OFFSET) : 0;
for (; addr < end; addr = next) {
- pgd_t *pgd = pgd_page + pgd_index(addr) + off;
+ pgd_t *pgd = pgd_page + pgd_index(addr);
pud_t *pud;
next = (addr & PGDIR_MASK) + PGDIR_SIZE;
diff --git a/arch/x86/power/hibernate_64.c b/arch/x86/power/hibernate_64.c
index f0b5f2d402af..a3e3ccc87138 100644
--- a/arch/x86/power/hibernate_64.c
+++ b/arch/x86/power/hibernate_64.c
@@ -87,7 +87,7 @@ static int set_up_temporary_mappings(void)
struct x86_mapping_info info = {
.alloc_pgt_page = alloc_pgt_page,
.pmd_flag = __PAGE_KERNEL_LARGE_EXEC,
- .kernel_mapping = true,
+ .offset = __PAGE_OFFSET,
};
unsigned long mstart, mend;
pgd_t *pgd;