cf47a83fb0
While copying the argument structures in HYPERVISOR_event_channel_op() and HYPERVISOR_physdev_op() into the local variable is sufficiently safe even if the actual structure is smaller than the container one, copying back eventual output values the same way isn't: This may collide with on-stack variables (particularly "rc") which may change between the first and second memcpy() (i.e. the second memcpy() could discard that change). Move the fallback code into out-of-line functions, and handle all of the operations known by this old a hypervisor individually: Some don't require copying back anything at all, and for the rest use the individual argument structures' sizes rather than the container's. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jan Beulich <jbeulich@suse.com> [v2: Reduce #define/#undef usage in HYPERVISOR_physdev_op_compat().] [v3: Fix compile errors when modules use said hypercalls] [v4: Add xen_ prefix to the HYPERCALL_..] [v5: Alter the name and only EXPORT_SYMBOL_GPL one of them] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
81 lines
1.5 KiB
C
81 lines
1.5 KiB
C
#include <linux/kernel.h>
|
|
#include <linux/string.h>
|
|
#include <linux/bug.h>
|
|
#include <linux/export.h>
|
|
#include <asm/hypervisor.h>
|
|
#include <asm/xen/hypercall.h>
|
|
|
|
int xen_event_channel_op_compat(int cmd, void *arg)
|
|
{
|
|
struct evtchn_op op;
|
|
int rc;
|
|
|
|
op.cmd = cmd;
|
|
memcpy(&op.u, arg, sizeof(op.u));
|
|
rc = _hypercall1(int, event_channel_op_compat, &op);
|
|
|
|
switch (cmd) {
|
|
case EVTCHNOP_close:
|
|
case EVTCHNOP_send:
|
|
case EVTCHNOP_bind_vcpu:
|
|
case EVTCHNOP_unmask:
|
|
/* no output */
|
|
break;
|
|
|
|
#define COPY_BACK(eop) \
|
|
case EVTCHNOP_##eop: \
|
|
memcpy(arg, &op.u.eop, sizeof(op.u.eop)); \
|
|
break
|
|
|
|
COPY_BACK(bind_interdomain);
|
|
COPY_BACK(bind_virq);
|
|
COPY_BACK(bind_pirq);
|
|
COPY_BACK(status);
|
|
COPY_BACK(alloc_unbound);
|
|
COPY_BACK(bind_ipi);
|
|
#undef COPY_BACK
|
|
|
|
default:
|
|
WARN_ON(rc != -ENOSYS);
|
|
break;
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xen_event_channel_op_compat);
|
|
|
|
int HYPERVISOR_physdev_op_compat(int cmd, void *arg)
|
|
{
|
|
struct physdev_op op;
|
|
int rc;
|
|
|
|
op.cmd = cmd;
|
|
memcpy(&op.u, arg, sizeof(op.u));
|
|
rc = _hypercall1(int, physdev_op_compat, &op);
|
|
|
|
switch (cmd) {
|
|
case PHYSDEVOP_IRQ_UNMASK_NOTIFY:
|
|
case PHYSDEVOP_set_iopl:
|
|
case PHYSDEVOP_set_iobitmap:
|
|
case PHYSDEVOP_apic_write:
|
|
/* no output */
|
|
break;
|
|
|
|
#define COPY_BACK(pop, fld) \
|
|
case PHYSDEVOP_##pop: \
|
|
memcpy(arg, &op.u.fld, sizeof(op.u.fld)); \
|
|
break
|
|
|
|
COPY_BACK(irq_status_query, irq_status_query);
|
|
COPY_BACK(apic_read, apic_op);
|
|
COPY_BACK(ASSIGN_VECTOR, irq_op);
|
|
#undef COPY_BACK
|
|
|
|
default:
|
|
WARN_ON(rc != -ENOSYS);
|
|
break;
|
|
}
|
|
|
|
return rc;
|
|
}
|