diff options
| author | Huang Ying <ying.huang@intel.com> | 2009-03-10 02:57:04 (GMT) |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2009-03-11 01:13:25 (GMT) |
| commit | 5359454701ce51a4626b1ef6eb7b16ec35bd458d (patch) | |
| tree | 44f8d60b3cb1d06ec215387eb7e35fdbb64e70c8 /arch | |
| parent | fef3a7a17418814733ebde0b40d8e32747677c8f (diff) | |
| download | linux-fsl-qoriq-5359454701ce51a4626b1ef6eb7b16ec35bd458d.tar.xz | |
x86, kexec: x86_64: add identity map for pages at image->start
Impact: Fix corner case that cannot yet occur
image->start may be outside of 0 ~ max_pfn, for example when jumping
back to original kernel from kexeced kenrel. This patch add identity
map for pages at image->start.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/machine_kexec_64.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c index f8c796f..7cc5d3d 100644 --- a/arch/x86/kernel/machine_kexec_64.c +++ b/arch/x86/kernel/machine_kexec_64.c @@ -18,6 +18,41 @@ #include <asm/tlbflush.h> #include <asm/mmu_context.h> +static int init_one_level2_page(struct kimage *image, pgd_t *pgd, + unsigned long addr) +{ + pud_t *pud; + pmd_t *pmd; + struct page *page; + int result = -ENOMEM; + + addr &= PMD_MASK; + pgd += pgd_index(addr); + if (!pgd_present(*pgd)) { + page = kimage_alloc_control_pages(image, 0); + if (!page) + goto out; + pud = (pud_t *)page_address(page); + memset(pud, 0, PAGE_SIZE); + set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE)); + } + pud = pud_offset(pgd, addr); + if (!pud_present(*pud)) { + page = kimage_alloc_control_pages(image, 0); + if (!page) + goto out; + pmd = (pmd_t *)page_address(page); + memset(pmd, 0, PAGE_SIZE); + set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE)); + } + pmd = pmd_offset(pud, addr); + if (!pmd_present(*pmd)) + set_pmd(pmd, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC)); + result = 0; +out: + return result; +} + static void init_level2_page(pmd_t *level2p, unsigned long addr) { unsigned long end_addr; @@ -155,6 +190,13 @@ static int init_pgtable(struct kimage *image, unsigned long start_pgtable) result = init_level4_page(image, level4p, 0, max_pfn << PAGE_SHIFT); if (result) return result; + /* + * image->start may be outside 0 ~ max_pfn, for example when + * jump back to original kernel from kexeced kernel + */ + result = init_one_level2_page(image, level4p, image->start); + if (result) + return result; return init_transition_pgtable(image, level4p); } |