lguest: fix crash on vmlinux images

[safe/jmp/linux-2.6] / drivers / lguest / x86 / core.c

diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c
index a6b7176..d6d7ac0 100644 (file)
--- a/drivers/lguest/x86/core.c
+++ b/drivers/lguest/x86/core.c
@@ -324,6 +324,11 @@ static void rewrite_hypercall(struct lg_cpu *cpu)
        u8 insn[3] = {0xcd, 0x1f, 0x90};
 
        __lgwrite(cpu, guest_pa(cpu, cpu->regs->eip), insn, sizeof(insn));
+       /* The above write might have caused a copy of that page to be made
+        * (if it was read-only).  We need to make sure the Guest has
+        * up-to-date pagetables.  As this doesn't happen often, we can just
+        * drop them all. */
+       guest_pagetable_clear_all(cpu);
 }
 
 static bool is_hypercall(struct lg_cpu *cpu)