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authorRusty Russell <rusty@rustcorp.com.au>2015-02-11 15:15:09 +1030
committerRusty Russell <rusty@rustcorp.com.au>2015-02-11 16:47:30 +1030
commit8ed313001a892f240269dea05d4b925cbd150492 (patch)
tree340461d5b381ffc3b939bb6d414f20a732ff85c5 /drivers/lguest
parent69a09dc1742ffbb3b02f3a1e03da4801e96452e9 (diff)
downloadkernel-8ed313001a892f240269dea05d4b925cbd150492.tar.gz
lguest: add infrastructure for userspace to deliver a trap to the guest.
This is required for instruction emulation to move to userspace. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'drivers/lguest')
-rw-r--r--drivers/lguest/lguest_user.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/lguest/lguest_user.c b/drivers/lguest/lguest_user.c
index dcf9efd94cf4..be996d173615 100644
--- a/drivers/lguest/lguest_user.c
+++ b/drivers/lguest/lguest_user.c
@@ -243,6 +243,23 @@ static int user_send_irq(struct lg_cpu *cpu, const unsigned long __user *input)
return 0;
}
+/*L:053
+ * Deliver a trap: this is used by the Launcher if it can't emulate
+ * an instruction.
+ */
+static int trap(struct lg_cpu *cpu, const unsigned long __user *input)
+{
+ unsigned long trapnum;
+
+ if (get_user(trapnum, input) != 0)
+ return -EFAULT;
+
+ if (!deliver_trap(cpu, trapnum))
+ return -EINVAL;
+
+ return 0;
+}
+
/*L:040
* Once our Guest is initialized, the Launcher makes it run by reading
* from /dev/lguest.
@@ -487,6 +504,8 @@ static ssize_t write(struct file *file, const char __user *in,
return getreg_setup(cpu, input);
case LHREQ_SETREG:
return setreg(cpu, input);
+ case LHREQ_TRAP:
+ return trap(cpu, input);
default:
return -EINVAL;
}