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_virtualboxCreateMachine: Avoid unbounded stack 

If the stars are in the right position and you're building with
VBox >= 4.2.0 it will happen that compiler thinks an array
allocated on the stack may be unbounded:

In file included from vbox/vbox_V4_2.c:13:0:
vbox/vbox_tmpl.c: In function '_virtualboxCreateMachine':
vbox/vbox_tmpl.c:2811:1: error: stack usage might be unbounded [-Werror=stack-usage=]
 _virtualboxCreateMachine(vboxGlobalData *data, virDomainDefPtr def, IMachine **machine, char *uuidstr ATTRIBUTE_UNUSED)
 ^

Well, given how the variable is declared, I had some hard time
seeing it is actually bounded. Surprisingly compiler does not
complain because of -Wframe-larger-than. This is because
variable length arrays do not count into that warning.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
This commit is contained in:
Michal Privoznik 2016-03-05 12:59:45 +01:00
parent eff43d9aba
commit 18f231e6ff
1 changed files with 7 additions and 11 deletions
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18
src/vbox/vbox_tmpl.c
View File

@ -2812,7 +2812,7 @@ _virtualboxCreateMachine(vboxGlobalData *data, virDomainDefPtr def, IMachine **m
{
vboxIID iid = VBOX_IID_INITIALIZER;
PRUnichar *machineNameUtf16 = NULL;
nsresult rc;
nsresult rc = -1;
VBOX_UTF8_TO_UTF16(def->name, &machineNameUtf16);
vboxIIDFromUUID(&iid, def->uuid);
@ -2843,18 +2843,12 @@ _virtualboxCreateMachine(vboxGlobalData *data, virDomainDefPtr def, IMachine **m
override,
machine);
#else /* VBOX_API_VERSION >= 4002000 */
const char *flagsUUIDPrefix = "UUID=";
const char *flagsForceOverwrite = "forceOverwrite=0";
const char *flagsSeparator = ",";
char createFlags[strlen(flagsUUIDPrefix) + VIR_UUID_STRING_BUFLEN + strlen(flagsSeparator) + strlen(flagsForceOverwrite) + 1];
char *createFlags = NULL;
PRUnichar *createFlagsUtf16 = NULL;
snprintf(createFlags, sizeof(createFlags), "%s%s%s%s",
flagsUUIDPrefix,
uuidstr,
flagsSeparator,
flagsForceOverwrite
);
if (virAsprintf(&createFlags,
"UUID=%s,forceOverwrite=0", uuidstr) < 0)
goto cleanup;
VBOX_UTF8_TO_UTF16(createFlags, &createFlagsUtf16);
rc = data->vboxObj->vtbl->CreateMachine(data->vboxObj,
NULL,
@ -2864,6 +2858,8 @@ _virtualboxCreateMachine(vboxGlobalData *data, virDomainDefPtr def, IMachine **m
nsnull,
createFlagsUtf16,
machine);
cleanup:
VIR_FREE(createFlags);
#endif /* VBOX_API_VERSION >= 4002000 */
}
VBOX_UTF16_FREE(machineNameUtf16);