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| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2016-08-03 01:19:26 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2016-08-03 01:35:38 +0200 |
| commit | c226fab474291e3c6ac5fa30a2b0778acc311e61 (patch) | |
| tree | 99ceb9f917865e4aa4559cb503bec8191cf43ac5 /arch/x86/power | |
| parent | 4ce827b4cc58bec7952591b96cce2b28553e4d5b (diff) | |
| download | linux-c226fab474291e3c6ac5fa30a2b0778acc311e61.tar.bz2 | |
x86/power/64: Do not refer to __PAGE_OFFSET from assembly code
When CONFIG_RANDOMIZE_MEMORY is set on x86-64, __PAGE_OFFSET becomes
a variable and using it as a symbol in the image memory restoration
assembly code under core_restore_code is not correct any more.
To avoid that problem, modify set_up_temporary_mappings() to compute
the physical address of the temporary page tables and store it in
temp_level4_pgt, so that the value of that variable is ready to be
written into CR3. Then, the assembly code doesn't have to worry
about converting that value into a physical address and things work
regardless of whether or not CONFIG_RANDOMIZE_MEMORY is set.
Reported-and-tested-by: Thomas Garnier <thgarnie@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'arch/x86/power')
| -rw-r--r-- | arch/x86/power/hibernate_64.c | 18 | ||||
| -rw-r--r-- | arch/x86/power/hibernate_asm_64.S | 2 |
2 files changed, 9 insertions, 11 deletions
diff --git a/arch/x86/power/hibernate_64.c b/arch/x86/power/hibernate_64.c index f2b5e6a5cf95..f0b5f2d402af 100644 --- a/arch/x86/power/hibernate_64.c +++ b/arch/x86/power/hibernate_64.c @@ -37,11 +37,11 @@ unsigned long jump_address_phys; */ unsigned long restore_cr3 __visible; -pgd_t *temp_level4_pgt __visible; +unsigned long temp_level4_pgt __visible; unsigned long relocated_restore_code __visible; -static int set_up_temporary_text_mapping(void) +static int set_up_temporary_text_mapping(pgd_t *pgd) { pmd_t *pmd; pud_t *pud; @@ -71,7 +71,7 @@ static int set_up_temporary_text_mapping(void) __pmd((jump_address_phys & PMD_MASK) | __PAGE_KERNEL_LARGE_EXEC)); set_pud(pud + pud_index(restore_jump_address), __pud(__pa(pmd) | _KERNPG_TABLE)); - set_pgd(temp_level4_pgt + pgd_index(restore_jump_address), + set_pgd(pgd + pgd_index(restore_jump_address), __pgd(__pa(pud) | _KERNPG_TABLE)); return 0; @@ -90,15 +90,16 @@ static int set_up_temporary_mappings(void) .kernel_mapping = true, }; unsigned long mstart, mend; + pgd_t *pgd; int result; int i; - temp_level4_pgt = (pgd_t *)get_safe_page(GFP_ATOMIC); - if (!temp_level4_pgt) + pgd = (pgd_t *)get_safe_page(GFP_ATOMIC); + if (!pgd) return -ENOMEM; /* Prepare a temporary mapping for the kernel text */ - result = set_up_temporary_text_mapping(); + result = set_up_temporary_text_mapping(pgd); if (result) return result; @@ -107,13 +108,12 @@ static int set_up_temporary_mappings(void) mstart = pfn_mapped[i].start << PAGE_SHIFT; mend = pfn_mapped[i].end << PAGE_SHIFT; - result = kernel_ident_mapping_init(&info, temp_level4_pgt, - mstart, mend); - + result = kernel_ident_mapping_init(&info, pgd, mstart, mend); if (result) return result; } + temp_level4_pgt = (unsigned long)pgd - __PAGE_OFFSET; return 0; } diff --git a/arch/x86/power/hibernate_asm_64.S b/arch/x86/power/hibernate_asm_64.S index 8eee0e9c93f0..ce8da3a0412c 100644 --- a/arch/x86/power/hibernate_asm_64.S +++ b/arch/x86/power/hibernate_asm_64.S @@ -72,8 +72,6 @@ ENTRY(restore_image) /* code below has been relocated to a safe page */ ENTRY(core_restore_code) /* switch to temporary page tables */ - movq $__PAGE_OFFSET, %rcx - subq %rcx, %rax movq %rax, %cr3 /* flush TLB */ movq %rbx, %rcx |