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-rw-r--r--arch/x86/lguest/Makefile1
-rw-r--r--arch/x86/lguest/boot.c33
2 files changed, 25 insertions, 9 deletions
diff --git a/arch/x86/lguest/Makefile b/arch/x86/lguest/Makefile
index 27f0c9ed7f60..94e0e54056a9 100644
--- a/arch/x86/lguest/Makefile
+++ b/arch/x86/lguest/Makefile
@@ -1 +1,2 @@
obj-y := i386_head.o boot.o
+CFLAGS_boot.o := $(call cc-option, -fno-stack-protector)
diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c
index 45acbcf25683..4e0c26559395 100644
--- a/arch/x86/lguest/boot.c
+++ b/arch/x86/lguest/boot.c
@@ -67,6 +67,7 @@
#include <asm/mce.h>
#include <asm/io.h>
#include <asm/i387.h>
+#include <asm/stackprotector.h>
#include <asm/reboot.h> /* for struct machine_ops */
/*G:010 Welcome to the Guest!
@@ -166,10 +167,16 @@ static void lazy_hcall3(unsigned long call,
/* When lazy mode is turned off reset the per-cpu lazy mode variable and then
* issue the do-nothing hypercall to flush any stored calls. */
-static void lguest_leave_lazy_mode(void)
+static void lguest_leave_lazy_mmu_mode(void)
{
- paravirt_leave_lazy(paravirt_get_lazy_mode());
kvm_hypercall0(LHCALL_FLUSH_ASYNC);
+ paravirt_leave_lazy_mmu();
+}
+
+static void lguest_end_context_switch(struct task_struct *next)
+{
+ kvm_hypercall0(LHCALL_FLUSH_ASYNC);
+ paravirt_end_context_switch(next);
}
/*G:033
@@ -1053,8 +1060,8 @@ __init void lguest_init(void)
pv_cpu_ops.write_gdt_entry = lguest_write_gdt_entry;
pv_cpu_ops.write_idt_entry = lguest_write_idt_entry;
pv_cpu_ops.wbinvd = lguest_wbinvd;
- pv_cpu_ops.lazy_mode.enter = paravirt_enter_lazy_cpu;
- pv_cpu_ops.lazy_mode.leave = lguest_leave_lazy_mode;
+ pv_cpu_ops.start_context_switch = paravirt_start_context_switch;
+ pv_cpu_ops.end_context_switch = lguest_end_context_switch;
/* pagetable management */
pv_mmu_ops.write_cr3 = lguest_write_cr3;
@@ -1067,7 +1074,7 @@ __init void lguest_init(void)
pv_mmu_ops.read_cr2 = lguest_read_cr2;
pv_mmu_ops.read_cr3 = lguest_read_cr3;
pv_mmu_ops.lazy_mode.enter = paravirt_enter_lazy_mmu;
- pv_mmu_ops.lazy_mode.leave = lguest_leave_lazy_mode;
+ pv_mmu_ops.lazy_mode.leave = lguest_leave_lazy_mmu_mode;
pv_mmu_ops.pte_update = lguest_pte_update;
pv_mmu_ops.pte_update_defer = lguest_pte_update;
@@ -1088,13 +1095,21 @@ __init void lguest_init(void)
* lguest_init() where the rest of the fairly chaotic boot setup
* occurs. */
+ /* The stack protector is a weird thing where gcc places a canary
+ * value on the stack and then checks it on return. This file is
+ * compiled with -fno-stack-protector it, so we got this far without
+ * problems. The value of the canary is kept at offset 20 from the
+ * %gs register, so we need to set that up before calling C functions
+ * in other files. */
+ setup_stack_canary_segment(0);
+ /* We could just call load_stack_canary_segment(), but we might as
+ * call switch_to_new_gdt() which loads the whole table and sets up
+ * the per-cpu segment descriptor register %fs as well. */
+ switch_to_new_gdt(0);
+
/* As described in head_32.S, we map the first 128M of memory. */
max_pfn_mapped = (128*1024*1024) >> PAGE_SHIFT;
- /* Load the %fs segment register (the per-cpu segment register) with
- * the normal data segment to get through booting. */
- asm volatile ("mov %0, %%fs" : : "r" (__KERNEL_DS) : "memory");
-
/* The Host<->Guest Switcher lives at the top of our address space, and
* the Host told us how big it is when we made LGUEST_INIT hypercall:
* it put the answer in lguest_data.reserve_mem */
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