The macro CHK_ERRNO() was being used to check two different error schemes, and
succeeded at neither.
Split the macro into two; CHK_ERRNO() for calls which return -1 and set errno
on error, and CHK_LIBXLERR() for calls which return a positive errno.
In both cases, ensure that strerror() now gets called with the error integer.
Coverity ID: 1055570 1090374 1130516
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Ian Campbell <Ian.Campbell@citrix.com>
CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: George Dunlap <george.dunlap@eu.citrix.com>
---
Changes in v2:
 * s/CHK_POSERRNO/CHK_LIBXLERR/
---
 tools/libxl/xl_cmdimpl.c |   39 ++++++++++++++++++++++++++-------------
 1 file changed, 26 insertions(+), 13 deletions(-)
diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
index 4977a53..45cb658 100644
--- a/tools/libxl/xl_cmdimpl.c
+++ b/tools/libxl/xl_cmdimpl.c
@@ -41,15 +41,25 @@
 #include "libxlutil.h"
 #include "xl.h"
 
-#define CHK_ERRNO( call ) ({                                            \
+/* For calls which return positive errno on failure */
+#define CHK_LIBXLERR( call ) ({                                         \
         int chk_errno = (call);                                         \
-        if (chk_errno < 0) {                                               
\
+        if (chk_errno > 0) {                                            \
             fprintf(stderr,"xl: fatal error: %s:%d: %s: %s\n",       
\
                     __FILE__,__LINE__, strerror(chk_errno), #call);     \
             exit(-ERROR_FAIL);                                          \
         }                                                               \
     })
 
+/* For calls which return -1 and set errno on failure */
+#define CHK_ERRNO( call ) ({                                            \
+        if ((call) == -1) {                                             \
+            fprintf(stderr,"xl: fatal error: %s:%d: %s: %s\n",       
\
+                    __FILE__,__LINE__, strerror(errno), #call);         \
+            exit(-ERROR_FAIL);                                          \
+        }                                                               \
+    })
+
 #define MUST( call ) ({                                                 \
         int must_rc = (call);                                           \
         if (must_rc < 0) {                                                 
\
@@ -1982,8 +1992,9 @@ static uint32_t create_domain(struct domain_create
*dom_info)
             if (rc) return rc;
         }
 
-        CHK_ERRNO( libxl_read_exactly(ctx, restore_fd, &hdr,
-                   sizeof(hdr), restore_source, "header") );
+        CHK_LIBXLERR( libxl_read_exactly(
+                          ctx, restore_fd, &hdr, sizeof(hdr),
+                          restore_source, "header") );
         if (memcmp(hdr.magic, savefileheader_magic, sizeof(hdr.magic))) {
             fprintf(stderr, "File has wrong magic number -"
                     " corrupt or for a different tool?\n");
@@ -2008,8 +2019,10 @@ static uint32_t create_domain(struct domain_create
*dom_info)
         }
         if (hdr.optional_data_len) {
             optdata_begin = xmalloc(hdr.optional_data_len);
-            CHK_ERRNO( libxl_read_exactly(ctx, restore_fd, optdata_begin,
-                   hdr.optional_data_len, restore_source, "optdata")
);
+            CHK_LIBXLERR( libxl_read_exactly(
+                              ctx, restore_fd, optdata_begin,
+                              hdr.optional_data_len, restore_source,
+                              "optdata") );
         }
 
 #define OPTDATA_LEFT  (hdr.optional_data_len - (optdata_here - optdata_begin))
@@ -3337,9 +3350,9 @@ static void save_domain_core_writeconfig(int fd, const
char *source,
 
     /* that''s the optional data */
 
-    CHK_ERRNO( libxl_write_exactly(ctx, fd,
+    CHK_LIBXLERR( libxl_write_exactly(ctx, fd,
         &hdr, sizeof(hdr), source, "header") );
-    CHK_ERRNO( libxl_write_exactly(ctx, fd,
+    CHK_LIBXLERR( libxl_write_exactly(ctx, fd,
         optdata_begin, hdr.optional_data_len, source, "header") );
 
     fprintf(stderr, "Saving to %s new xl format (info"
@@ -3695,11 +3708,11 @@ static void migrate_receive(int debug, int daemonize,
int monitor,
 
     fprintf(stderr, "migration target: Ready to receive domain.\n");
 
-    CHK_ERRNO( libxl_write_exactly(ctx, send_fd,
-                                   migrate_receiver_banner,
-                                   sizeof(migrate_receiver_banner)-1,
-                                   "migration ack stream",
-                                   "banner") );
+    CHK_LIBXLERR( libxl_write_exactly(ctx, send_fd,
+                                      migrate_receiver_banner,
+                                      sizeof(migrate_receiver_banner)-1,
+                                      "migration ack stream",
+                                      "banner") );
 
     memset(&dom_info, 0, sizeof(dom_info));
     dom_info.debug = debug;
-- 
1.7.10.4
On 12/09/2013 03:12 PM, Andrew Cooper wrote:> The macro CHK_ERRNO() was being used to check two different error schemes, and > succeeded at neither. > > Split the macro into two; CHK_ERRNO() for calls which return -1 and set errno > on error, and CHK_LIBXLERR() for calls which return a positive errno. > > In both cases, ensure that strerror() now gets called with the error integer. > > Coverity ID: 1055570 1090374 1130516 > > Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> > CC: Ian Campbell <Ian.Campbell@citrix.com> > CC: Ian Jackson <Ian.Jackson@eu.citrix.com> > CC: George Dunlap <george.dunlap@eu.citrix.com>Clearly a bug fix, if a minor one. It does touch the domain creation as well as save/restore path, but is fairly simple and should also be very well tested between now and the release. Release-acked-by: George Dunlap <george.dunlap@eu.citrix.com>> > --- > > Changes in v2: > * s/CHK_POSERRNO/CHK_LIBXLERR/ > --- > tools/libxl/xl_cmdimpl.c | 39 ++++++++++++++++++++++++++------------- > 1 file changed, 26 insertions(+), 13 deletions(-) > > diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c > index 4977a53..45cb658 100644 > --- a/tools/libxl/xl_cmdimpl.c > +++ b/tools/libxl/xl_cmdimpl.c > @@ -41,15 +41,25 @@ > #include "libxlutil.h" > #include "xl.h" > > -#define CHK_ERRNO( call ) ({ \ > +/* For calls which return positive errno on failure */ > +#define CHK_LIBXLERR( call ) ({ \ > int chk_errno = (call); \ > - if (chk_errno < 0) { \ > + if (chk_errno > 0) { \ > fprintf(stderr,"xl: fatal error: %s:%d: %s: %s\n", \ > __FILE__,__LINE__, strerror(chk_errno), #call); \ > exit(-ERROR_FAIL); \ > } \ > }) > > +/* For calls which return -1 and set errno on failure */ > +#define CHK_ERRNO( call ) ({ \ > + if ((call) == -1) { \ > + fprintf(stderr,"xl: fatal error: %s:%d: %s: %s\n", \ > + __FILE__,__LINE__, strerror(errno), #call); \ > + exit(-ERROR_FAIL); \ > + } \ > + }) > + > #define MUST( call ) ({ \ > int must_rc = (call); \ > if (must_rc < 0) { \ > @@ -1982,8 +1992,9 @@ static uint32_t create_domain(struct domain_create *dom_info) > if (rc) return rc; > } > > - CHK_ERRNO( libxl_read_exactly(ctx, restore_fd, &hdr, > - sizeof(hdr), restore_source, "header") ); > + CHK_LIBXLERR( libxl_read_exactly( > + ctx, restore_fd, &hdr, sizeof(hdr), > + restore_source, "header") ); > if (memcmp(hdr.magic, savefileheader_magic, sizeof(hdr.magic))) { > fprintf(stderr, "File has wrong magic number -" > " corrupt or for a different tool?\n"); > @@ -2008,8 +2019,10 @@ static uint32_t create_domain(struct domain_create *dom_info) > } > if (hdr.optional_data_len) { > optdata_begin = xmalloc(hdr.optional_data_len); > - CHK_ERRNO( libxl_read_exactly(ctx, restore_fd, optdata_begin, > - hdr.optional_data_len, restore_source, "optdata") ); > + CHK_LIBXLERR( libxl_read_exactly( > + ctx, restore_fd, optdata_begin, > + hdr.optional_data_len, restore_source, > + "optdata") ); > } > > #define OPTDATA_LEFT (hdr.optional_data_len - (optdata_here - optdata_begin)) > @@ -3337,9 +3350,9 @@ static void save_domain_core_writeconfig(int fd, const char *source, > > /* that''s the optional data */ > > - CHK_ERRNO( libxl_write_exactly(ctx, fd, > + CHK_LIBXLERR( libxl_write_exactly(ctx, fd, > &hdr, sizeof(hdr), source, "header") ); > - CHK_ERRNO( libxl_write_exactly(ctx, fd, > + CHK_LIBXLERR( libxl_write_exactly(ctx, fd, > optdata_begin, hdr.optional_data_len, source, "header") ); > > fprintf(stderr, "Saving to %s new xl format (info" > @@ -3695,11 +3708,11 @@ static void migrate_receive(int debug, int daemonize, int monitor, > > fprintf(stderr, "migration target: Ready to receive domain.\n"); > > - CHK_ERRNO( libxl_write_exactly(ctx, send_fd, > - migrate_receiver_banner, > - sizeof(migrate_receiver_banner)-1, > - "migration ack stream", > - "banner") ); > + CHK_LIBXLERR( libxl_write_exactly(ctx, send_fd, > + migrate_receiver_banner, > + sizeof(migrate_receiver_banner)-1, > + "migration ack stream", > + "banner") ); > > memset(&dom_info, 0, sizeof(dom_info)); > dom_info.debug = debug;