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path: root/arch/x86/xen/xen-pvh.S
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Diffstat (limited to 'arch/x86/xen/xen-pvh.S')
-rw-r--r--arch/x86/xen/xen-pvh.S47
1 files changed, 37 insertions, 10 deletions
diff --git a/arch/x86/xen/xen-pvh.S b/arch/x86/xen/xen-pvh.S
index e1a5fbeae08d..ca2d3b2bf2af 100644
--- a/arch/x86/xen/xen-pvh.S
+++ b/arch/x86/xen/xen-pvh.S
@@ -54,12 +54,19 @@
* charge of setting up it's own stack, GDT and IDT.
*/
+#define PVH_GDT_ENTRY_CS 1
+#define PVH_GDT_ENTRY_DS 2
+#define PVH_GDT_ENTRY_CANARY 3
+#define PVH_CS_SEL (PVH_GDT_ENTRY_CS * 8)
+#define PVH_DS_SEL (PVH_GDT_ENTRY_DS * 8)
+#define PVH_CANARY_SEL (PVH_GDT_ENTRY_CANARY * 8)
+
ENTRY(pvh_start_xen)
cld
lgdt (_pa(gdt))
- mov $(__BOOT_DS),%eax
+ mov $PVH_DS_SEL,%eax
mov %eax,%ds
mov %eax,%es
mov %eax,%ss
@@ -93,11 +100,17 @@ ENTRY(pvh_start_xen)
mov %eax, %cr0
/* Jump to 64-bit mode. */
- ljmp $__KERNEL_CS, $_pa(1f)
+ ljmp $PVH_CS_SEL, $_pa(1f)
/* 64-bit entry point. */
.code64
1:
+ /* Set base address in stack canary descriptor. */
+ mov $MSR_GS_BASE,%ecx
+ mov $_pa(canary), %eax
+ xor %edx, %edx
+ wrmsr
+
call xen_prepare_pvh
/* startup_64 expects boot_params in %rsi. */
@@ -107,6 +120,17 @@ ENTRY(pvh_start_xen)
#else /* CONFIG_X86_64 */
+ /* Set base address in stack canary descriptor. */
+ movl $_pa(gdt_start),%eax
+ movl $_pa(canary),%ecx
+ movw %cx, (PVH_GDT_ENTRY_CANARY * 8) + 2(%eax)
+ shrl $16, %ecx
+ movb %cl, (PVH_GDT_ENTRY_CANARY * 8) + 4(%eax)
+ movb %ch, (PVH_GDT_ENTRY_CANARY * 8) + 7(%eax)
+
+ mov $PVH_CANARY_SEL,%eax
+ mov %eax,%gs
+
call mk_early_pgtbl_32
mov $_pa(initial_page_table), %eax
@@ -116,13 +140,13 @@ ENTRY(pvh_start_xen)
or $(X86_CR0_PG | X86_CR0_PE), %eax
mov %eax, %cr0
- ljmp $__BOOT_CS, $1f
+ ljmp $PVH_CS_SEL, $1f
1:
call xen_prepare_pvh
mov $_pa(pvh_bootparams), %esi
/* startup_32 doesn't expect paging and PAE to be on. */
- ljmp $__BOOT_CS, $_pa(2f)
+ ljmp $PVH_CS_SEL, $_pa(2f)
2:
mov %cr0, %eax
and $~X86_CR0_PG, %eax
@@ -131,7 +155,7 @@ ENTRY(pvh_start_xen)
and $~X86_CR4_PAE, %eax
mov %eax, %cr4
- ljmp $__BOOT_CS, $_pa(startup_32)
+ ljmp $PVH_CS_SEL, $_pa(startup_32)
#endif
END(pvh_start_xen)
@@ -143,16 +167,19 @@ gdt:
.word 0
gdt_start:
.quad 0x0000000000000000 /* NULL descriptor */
- .quad 0x0000000000000000 /* reserved */
#ifdef CONFIG_X86_64
- .quad GDT_ENTRY(0xa09a, 0, 0xfffff) /* __KERNEL_CS */
+ .quad GDT_ENTRY(0xa09a, 0, 0xfffff) /* PVH_CS_SEL */
#else
- .quad GDT_ENTRY(0xc09a, 0, 0xfffff) /* __KERNEL_CS */
+ .quad GDT_ENTRY(0xc09a, 0, 0xfffff) /* PVH_CS_SEL */
#endif
- .quad GDT_ENTRY(0xc092, 0, 0xfffff) /* __KERNEL_DS */
+ .quad GDT_ENTRY(0xc092, 0, 0xfffff) /* PVH_DS_SEL */
+ .quad GDT_ENTRY(0x4090, 0, 0x18) /* PVH_CANARY_SEL */
gdt_end:
- .balign 4
+ .balign 16
+canary:
+ .fill 48, 1, 0
+
early_stack:
.fill 256, 1, 0
early_stack_end: