From 355ed81e1a6ec3987194023d2538a3c4e5d1619d Mon Sep 17 00:00:00 2001 From: Boris Ostrovsky Date: Wed, 13 Aug 2014 12:40:38 -0400 Subject: [PATCH] tools/libxc: Set max_elem to zero in xc_lockprof_query_number() If max_elem is not zero then hypervisor's spinlock_profile_ucopy_elem() will attempt to copy profile data into user's data buffer. Since this buffer is explicitly set to (the equivalent of) NULL the copy will fail, causing xenlockprof to fail as well. Signed-off-by: Boris Ostrovsky Acked-by: Ian Campbell --- tools/libxc/xc_misc.c | 1 + 1 file changed, 1 insertion(+) diff --git a/tools/libxc/xc_misc.c b/tools/libxc/xc_misc.c index 4143de60a3..e253a58b9b 100644 --- a/tools/libxc/xc_misc.c +++ b/tools/libxc/xc_misc.c @@ -320,6 +320,7 @@ int xc_lockprof_query_number(xc_interface *xch, DECLARE_SYSCTL; sysctl.cmd = XEN_SYSCTL_lockprof_op; + sysctl.u.lockprof_op.max_elem = 0; sysctl.u.lockprof_op.cmd = XEN_SYSCTL_LOCKPROF_query; set_xen_guest_handle(sysctl.u.lockprof_op.data, HYPERCALL_BUFFER_NULL); -- 2.30.2