lguest: add operations to get/set a register from the Launcher.
We use the ptrace API struct, and we currently don't let them set
anything but the normal registers (we'd have to filter the others).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/drivers/lguest/core.c b/drivers/lguest/core.c
index 6590558..cdb2f9a 100644
--- a/drivers/lguest/core.c
+++ b/drivers/lguest/core.c
@@ -208,6 +208,14 @@
*/
int run_guest(struct lg_cpu *cpu, unsigned long __user *user)
{
+ /* If the launcher asked for a register with LHREQ_GETREG */
+ if (cpu->reg_read) {
+ if (put_user(*cpu->reg_read, user))
+ return -EFAULT;
+ cpu->reg_read = NULL;
+ return sizeof(*cpu->reg_read);
+ }
+
/* We stop running once the Guest is dead. */
while (!cpu->lg->dead) {
unsigned int irq;