* [PATCH] tools/libxc: Set max_elem to zero in xc_lockprof_query_number()
@ 2014-08-13 16:40 Boris Ostrovsky
2014-08-26 21:13 ` Ian Campbell
0 siblings, 1 reply; 2+ messages in thread
From: Boris Ostrovsky @ 2014-08-13 16:40 UTC (permalink / raw)
To: ian.jackson, stefano.stabellini, ian.campbell; +Cc: xen-devel, boris.ostrovsky
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 <boris.ostrovsky@oracle.com>
---
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 4143de6..e253a58 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);
--
1.8.1.4
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [PATCH] tools/libxc: Set max_elem to zero in xc_lockprof_query_number()
2014-08-13 16:40 [PATCH] tools/libxc: Set max_elem to zero in xc_lockprof_query_number() Boris Ostrovsky
@ 2014-08-26 21:13 ` Ian Campbell
0 siblings, 0 replies; 2+ messages in thread
From: Ian Campbell @ 2014-08-26 21:13 UTC (permalink / raw)
To: Boris Ostrovsky; +Cc: xen-devel, ian.jackson, stefano.stabellini
On Wed, 2014-08-13 at 12:40 -0400, Boris Ostrovsky wrote:
> 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 <boris.ostrovsky@oracle.com>
I would have expected DECLARE_SYSCTL to zero the struct, but anyway:
Acked + applied, thanks (and sorry for the delay).
^ permalink raw reply [flat|nested] 2+ messages in thread
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2014-08-13 16:40 [PATCH] tools/libxc: Set max_elem to zero in xc_lockprof_query_number() Boris Ostrovsky
2014-08-26 21:13 ` Ian Campbell
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