From 8ed313001a892f240269dea05d4b925cbd150492 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 11 Feb 2015 15:15:09 +1030 Subject: 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 --- drivers/lguest/lguest_user.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'drivers/lguest') 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; } -- cgit