diff options
Diffstat (limited to 'arch/x86/kernel/relocate_kernel_32.S')
| -rw-r--r-- | arch/x86/kernel/relocate_kernel_32.S | 30 |
1 files changed, 20 insertions, 10 deletions
diff --git a/arch/x86/kernel/relocate_kernel_32.S b/arch/x86/kernel/relocate_kernel_32.S index a160f311972..e13f8e7c22a 100644 --- a/arch/x86/kernel/relocate_kernel_32.S +++ b/arch/x86/kernel/relocate_kernel_32.S @@ -7,7 +7,7 @@ */ #include <linux/linkage.h> -#include <asm/page.h> +#include <asm/page_types.h> #include <asm/kexec.h> #include <asm/processor-flags.h> @@ -17,7 +17,8 @@ #define PTR(x) (x << 2) -/* control_page + KEXEC_CONTROL_CODE_MAX_SIZE +/* + * control_page + KEXEC_CONTROL_CODE_MAX_SIZE * ~ control_page + PAGE_SIZE are used as data storage and stack for * jumping back */ @@ -76,8 +77,10 @@ relocate_kernel: movl %eax, CP_PA_SWAP_PAGE(%edi) movl %ebx, CP_PA_BACKUP_PAGES_MAP(%edi) - /* get physical address of control page now */ - /* this is impossible after page table switch */ + /* + * get physical address of control page now + * this is impossible after page table switch + */ movl PTR(PA_CONTROL_PAGE)(%ebp), %edi /* switch to new set of page tables */ @@ -94,10 +97,13 @@ relocate_kernel: ret identity_mapped: + /* set return address to 0 if not preserving context */ + pushl $0 /* store the start address on the stack */ pushl %edx - /* Set cr0 to a known state: + /* + * Set cr0 to a known state: * - Paging disabled * - Alignment check disabled * - Write protect disabled @@ -113,7 +119,8 @@ identity_mapped: /* clear cr4 if applicable */ testl %ecx, %ecx jz 1f - /* Set cr4 to a known state: + /* + * Set cr4 to a known state: * Setting everything to zero seems safe. */ xorl %eax, %eax @@ -132,15 +139,18 @@ identity_mapped: call swap_pages addl $8, %esp - /* To be certain of avoiding problems with self-modifying code + /* + * To be certain of avoiding problems with self-modifying code * I need to execute a serializing instruction here. * So I flush the TLB, it's handy, and not processor dependent. */ xorl %eax, %eax movl %eax, %cr3 - /* set all of the registers to known values */ - /* leave %esp alone */ + /* + * set all of the registers to known values + * leave %esp alone + */ testl %esi, %esi jnz 1f @@ -176,7 +186,7 @@ identity_mapped: movl CP_PA_PGD(%ebx), %eax movl %eax, %cr3 movl %cr0, %eax - orl $(1<<31), %eax + orl $X86_CR0_PG, %eax movl %eax, %cr0 lea PAGE_SIZE(%edi), %esp movl %edi, %eax |