On Tue, Aug 2, 2016 at 10:36 AM, Yinghai Lu <ying...@kernel.org> wrote: > On Mon, Aug 1, 2016 at 10:07 AM, Thomas Garnier <thgar...@google.com> wrote: >> Correctly setup the temporary mapping for hibernation. Previous >> implementation assumed the address was aligned on the PGD level. With >> KASLR memory randomization enabled, the address is randomized on the PUD >> level. This change supports unaligned address up to PMD. >> >> Signed-off-by: Thomas Garnier <thgar...@google.com> >> --- >> arch/x86/mm/ident_map.c | 18 ++++++++++-------- >> 1 file changed, 10 insertions(+), 8 deletions(-) >> >> diff --git a/arch/x86/mm/ident_map.c b/arch/x86/mm/ident_map.c >> index ec21796..ea1ebf1 100644 >> --- a/arch/x86/mm/ident_map.c >> +++ b/arch/x86/mm/ident_map.c >> @@ -3,15 +3,16 @@ >> * 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); >> + int off = info->kernel_mapping ? pmd_index(__PAGE_OFFSET) : 0; >> + >> + for (addr &= PMD_MASK; addr < end; addr += PMD_SIZE) { >> + pmd_t *pmd = pmd_page + pmd_index(addr) + off; >> >> if (!pmd_present(*pmd)) >> - set_pmd(pmd, __pmd(addr | pmd_flag)); >> + set_pmd(pmd, __pmd(addr | info->pmd_flag)); >> } >> } >> >> @@ -19,9 +20,10 @@ static int ident_pud_init(struct x86_mapping_info *info, >> pud_t *pud_page, >> unsigned long addr, unsigned long end) >> { >> unsigned long next; >> + int off = info->kernel_mapping ? pud_index(__PAGE_OFFSET) : 0; >> >> for (; addr < end; addr = next) { >> - pud_t *pud = pud_page + pud_index(addr); >> + pud_t *pud = pud_page + pud_index(addr) + off; >> pmd_t *pmd; >> >> next = (addr & PUD_MASK) + PUD_SIZE; > > Is there any chance for (pud_index(addr) + off) or (pmd_index(addr) + off) > bigger than 512? > > Looks like we need to change the loop from phys address to virtual > address instead. > to avoid the overflow. >
That's a good point. I will take a look at it. > Thanks > > Yinghai