lguest: fix guest crash on non-linear addresses in gdt pvops
Fixes guest crash 'lguest: bad read address 0x4800000 len 256'
The new per-cpu allocator ends up handing a non-linear address to
write_gdt_entry. We do __pa() on it, and hand it to the host, which
kills us.
I've long wanted to make the hypercall "LOAD_GDT_ENTRY" to match the IDT
code, but had no pressing reason until now.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: lguest@ozlabs.org
diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c
index d6d7ac0..1a83910 100644
--- a/drivers/lguest/x86/core.c
+++ b/drivers/lguest/x86/core.c
@@ -568,8 +568,8 @@
int lguest_arch_do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
{
switch (args->arg0) {
- case LHCALL_LOAD_GDT:
- load_guest_gdt(cpu, args->arg1, args->arg2);
+ case LHCALL_LOAD_GDT_ENTRY:
+ load_guest_gdt_entry(cpu, args->arg1, args->arg2, args->arg3);
break;
case LHCALL_LOAD_IDT_ENTRY:
load_guest_idt_entry(cpu, args->arg1, args->arg2, args->arg3);