[Xen-devel] [PATCH v2 2/3] xc/tmem: Unchecked return value

[Bob Liu <lliubbo@xxxxxxxxx>]

From: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>

CID 1055045 complains that the return value needs checking.

The tmem op is a flush call and there is no expectation
right now of any return besides zero. But just in case
this changes lets blow up.

v2:
* superfluous braces and missing space (Andrew)
* Add a comment why bailing out on xc_tmem_save_done is not needed

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Signed-off-by: Bob Liu <bob.liu@xxxxxxxxxx>
---
 tools/libxc/xc_domain_save.c |    6 ++++--
 tools/libxc/xc_tmem.c        |    4 ++--
 tools/libxc/xenctrl.h        |    2 +-
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/tools/libxc/xc_domain_save.c b/tools/libxc/xc_domain_save.c
index 71f9b59..856eaa5 100644
--- a/tools/libxc/xc_domain_save.c
+++ b/tools/libxc/xc_domain_save.c
@@ -2107,8 +2107,10 @@ int xc_domain_save(xc_interface *xch, int io_fd, 
uint32_t dom, uint32_t max_iter
         goto copypages;
     }
 
-    if ( tmem_saved != 0 && live )
-        xc_tmem_save_done(xch, dom);
+    if ( tmem_saved != 0 && live && xc_tmem_save_done(xch, dom) )
+        /* N.B. No need to bail out - we leak memory, but that is all assigned
+         * to the zombie guest. */
+       DPRINTF("Warning - failed to flush tmem on originating server.");
 
     if ( live )
     {
diff --git a/tools/libxc/xc_tmem.c b/tools/libxc/xc_tmem.c
index 6832bbe..250e438 100644
--- a/tools/libxc/xc_tmem.c
+++ b/tools/libxc/xc_tmem.c
@@ -355,9 +355,9 @@ int xc_tmem_save_extra(xc_interface *xch, int dom, int 
io_fd, int field_marker)
 }
 
 /* only called for live migration */
-void xc_tmem_save_done(xc_interface *xch, int dom)
+int xc_tmem_save_done(xc_interface *xch, int dom)
 {
-    xc_tmem_control(xch,0,TMEMC_SAVE_END,dom,0,0,0,NULL);
+    return xc_tmem_control(xch,0,TMEMC_SAVE_END,dom,0,0,0,NULL);
 }
 
 /* restore routines */
diff --git a/tools/libxc/xenctrl.h b/tools/libxc/xenctrl.h
index 02129f7..23630a7 100644
--- a/tools/libxc/xenctrl.h
+++ b/tools/libxc/xenctrl.h
@@ -2011,7 +2011,7 @@ int xc_tmem_control(xc_interface *xch,
 int xc_tmem_auth(xc_interface *xch, int cli_id, char *uuid_str, int arg1);
 int xc_tmem_save(xc_interface *xch, int dom, int live, int fd, int 
field_marker);
 int xc_tmem_save_extra(xc_interface *xch, int dom, int fd, int field_marker);
-void xc_tmem_save_done(xc_interface *xch, int dom);
+int xc_tmem_save_done(xc_interface *xch, int dom);
 int xc_tmem_restore(xc_interface *xch, int dom, int fd);
 int xc_tmem_restore_extra(xc_interface *xch, int dom, int fd);
 
-- 
1.7.10.4


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