tests: mock __open_2()

As of commit [1] glibc may overwrite a call to open() with call
to __open_2() (if only two arguments are provided and the code is
compiled with clang). But since we are not mocking the latter our
test suite is broken as tests try to access paths outside of our
repo.

1: https://sourceware.org/git/?p=glibc.git;a=commit;h=86889e22db329abac618c6a41f86c84657a15324
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>

meson.build

@@ -604,6 +604,12 @@ stat_functions = [
 
 functions += stat_functions
 
+open_functions = [
+  '__open_2',
+]
+
+functions += open_functions
+
 foreach function : functions
   if cc.has_function(function)
     conf.set('WITH_@0@'.format(function.to_upper()), 1)
@@ -618,6 +624,13 @@ foreach function : stat_functions
 endforeach
 
 
+foreach function : open_functions
+  if cc.has_header_symbol('fcntl.h', function)
+    conf.set('WITH_@0@_DECL'.format(function.to_upper()), 1)
+  endif
+endforeach
+
+
 # various header checks
 
 headers = [

tests/nssmock.c

@@ -29,6 +29,9 @@
 # include "configmake.h"
 
 static int (*real_open)(const char *path, int flags, ...);
+# if WITH___OPEN_2
+static int (*real___open_2)(const char *path, int flags);
+# endif
 static DIR * (*real_opendir)(const char *name);
 static int (*real_access)(const char *path, int mode);
 
@@ -44,6 +47,9 @@ init_syms(void)
         return;
 
     VIR_MOCK_REAL_INIT(open);
+# if WITH___OPEN_2
+    VIR_MOCK_REAL_INIT(__open_2);
+# endif
     VIR_MOCK_REAL_INIT(opendir);
     VIR_MOCK_REAL_INIT(access);
 }
@@ -90,6 +96,26 @@ open(const char *path, int flags, ...)
     return ret;
 }
 
+# if WITH___OPEN_2
+int
+__open_2(const char *path, int flags)
+{
+    int ret;
+    char *newpath = NULL;
+
+    init_syms();
+
+    if (STRPREFIX(path, LEASEDIR) &&
+        getrealpath(&newpath, path) < 0)
+        return -1;
+
+    ret = real___open_2(newpath ? newpath : path, flags);
+
+    free(newpath);
+    return ret;
+}
+# endif
+
 DIR *
 opendir(const char *path)
 {

tests/qemusecuritymock.c

@@ -58,6 +58,9 @@
 
 static int (*real_chown)(const char *path, uid_t uid, gid_t gid);
 static int (*real_open)(const char *path, int flags, ...);
+#if WITH___OPEN_2
+static int (*real___open_2)(const char *path, int flags);
+#endif
 static int (*real_close)(int fd);
 #ifdef WITH_SELINUX
 static int (*real_setfilecon_raw)(const char *path, const char *context);
@@ -112,6 +115,9 @@ init_syms(void)
 
     VIR_MOCK_REAL_INIT(chown);
     VIR_MOCK_REAL_INIT(open);
+#if WITH___OPEN_2
+    VIR_MOCK_REAL_INIT(__open_2);
+#endif
     VIR_MOCK_REAL_INIT(close);
 #ifdef WITH_SELINUX
     VIR_MOCK_REAL_INIT(setfilecon_raw);
@@ -324,6 +330,24 @@ open(const char *path, int flags, ...)
 }
 
 
+#if WITH___OPEN_2
+int
+__open_2(const char *path, int flags)
+{
+    int ret;
+
+    init_syms();
+
+    if (getenv(ENVVAR)) {
+        ret = 42; /* Some dummy FD */
+    } else {
+        ret = real___open_2(path, flags);
+    }
+
+    return ret;
+}
+#endif
+
 int
 close(int fd)
 {

tests/vircgroupmock.c

@@ -30,6 +30,9 @@
 # include "vircgroupv2devices.h"
 
 static int (*real_open)(const char *path, int flags, ...);
+# if WITH___OPEN_2
+static int (*real___open_2)(const char *path, int flags);
+# endif
 static FILE *(*real_fopen)(const char *path, const char *mode);
 static int (*real_access)(const char *path, int mode);
 static int (*real_mkdir)(const char *path, mode_t mode);
@@ -302,6 +305,9 @@ static void init_syms(void)
     VIR_MOCK_REAL_INIT(access);
     VIR_MOCK_REAL_INIT(mkdir);
     VIR_MOCK_REAL_INIT(open);
+# if WITH___OPEN_2
+    VIR_MOCK_REAL_INIT(__open_2);
+# endif
 }
 
 
@@ -589,6 +595,42 @@ int open(const char *path, int flags, ...)
     return ret;
 }
 
+# if WITH___OPEN_2
+int
+__open_2(const char *path, int flags)
+{
+    int ret;
+    char *newpath = NULL;
+
+    init_syms();
+
+    if (STREQ(path, SYSFS_CPU_PRESENT)) {
+        init_sysfs();
+        if (asprintf(&newpath, "%s/%s",
+                     fakesysfscgroupdir,
+                     SYSFS_CPU_PRESENT_MOCKED) < 0) {
+            errno = ENOMEM;
+            return -1;
+        }
+    }
+
+    if (STRPREFIX(path, SYSFS_CGROUP_PREFIX)) {
+        init_sysfs();
+        if (asprintf(&newpath, "%s%s",
+                     fakesysfscgroupdir,
+                     path + strlen(SYSFS_CGROUP_PREFIX)) < 0) {
+            errno = ENOMEM;
+            return -1;
+        }
+    }
+
+    ret = real___open_2(newpath ? newpath : path, flags);
+
+    free(newpath);
+    return ret;
+}
+# endif
+
 bool
 virCgroupV2DevicesAvailable(virCgroup *group G_GNUC_UNUSED)
 {

tests/virfilewrapper.c

@@ -38,6 +38,9 @@ static const char **prefixes;
 
 /* TODO: callbacks */
 static int (*real_open)(const char *path, int flags, ...);
+# if WITH___OPEN_2
+static int (*real___open_2)(const char *path, int flags);
+# endif
 static FILE *(*real_fopen)(const char *path, const char *mode);
 static int (*real_access)(const char *path, int mode);
 static int (*real_mkdir)(const char *path, mode_t mode);
@@ -54,6 +57,9 @@ static void init_syms(void)
     VIR_MOCK_REAL_INIT(access);
     VIR_MOCK_REAL_INIT(mkdir);
     VIR_MOCK_REAL_INIT(open);
+# if WITH___OPEN_2
+    VIR_MOCK_REAL_INIT(__open_2);
+# endif
 # if defined(__APPLE__) && defined(__x86_64__)
     VIR_MOCK_REAL_INIT_ALIASED(opendir, "opendir$INODE64");
 # else
@@ -176,6 +182,18 @@ int open(const char *path, int flags, ...)
     return real_open(newpath ? newpath : path, flags, mode);
 }
 
+# if WITH___OPEN_2
+int
+__open_2(const char *path, int flags)
+{
+    g_autofree char *newpath = NULL;
+
+    PATH_OVERRIDE(newpath, path);
+
+    return real___open_2(newpath ? newpath : path, flags);
+}
+# endif
+
 DIR *opendir(const char *path)
 {
     g_autofree char *newpath = NULL;

tests/virmock.h

@@ -27,6 +27,10 @@
 
 #include "internal.h"
 
+#ifndef WITH___OPEN_2_DECL
+int __open_2 (const char *__path, int __oflag);
+#endif
+
 #define VIR_MOCK_COUNT_ARGS(...) VIR_MOCK_ARG27(__VA_ARGS__, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1)
 #define VIR_MOCK_ARG27(_1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _13, _14, _15, _16, _17, _18, _19, _20, _21, _22, _23, _24, _25, _26, _27, ...) _27
 #define VIR_MOCK_ARG_PASTE(a, b, ...) a##b(__VA_ARGS__)

tests/virpcimock.c

@@ -36,9 +36,9 @@
 
 static int (*real_access)(const char *path, int mode);
 static int (*real_open)(const char *path, int flags, ...);
-# ifdef __GLIBC__
+# if WITH___OPEN_2
 static int (*real___open_2)(const char *path, int flags);
-# endif /* ! __GLIBC__ */
+# endif /* ! WITH___OPEN_2 */
 static int (*real_close)(int fd);
 static DIR * (*real_opendir)(const char *name);
 static char *(*real_virFileCanonicalizePath)(const char *path);
@@ -945,9 +945,9 @@ init_syms(void)
 
     VIR_MOCK_REAL_INIT(access);
     VIR_MOCK_REAL_INIT(open);
-# ifdef __GLIBC__
+# if WITH___OPEN_2
     VIR_MOCK_REAL_INIT(__open_2);
-# endif /* ! __GLIBC__ */
+# endif /* WITH___OPEN_2 */
     VIR_MOCK_REAL_INIT(close);
 # if defined(__APPLE__) && defined(__x86_64__)
     VIR_MOCK_REAL_INIT_ALIASED(opendir, "opendir$INODE64");
@@ -1110,12 +1110,7 @@ open(const char *path, int flags, ...)
 }
 
 
-# ifdef __GLIBC__
-/* in some cases this function may not be present in headers, so we need
- * a declaration to silence the compiler */
-int
-__open_2(const char *path, int flags);
-
+# if WITH___OPEN_2
 int
 __open_2(const char *path, int flags)
 {
@@ -1139,7 +1134,7 @@ __open_2(const char *path, int flags)
 
     return ret;
 }
-# endif /* ! __GLIBC__ */
+# endif /* WITH___OPEN_2 */
 
 DIR *
 opendir(const char *path)

tests/virtestmock.c

@@ -29,6 +29,9 @@
 #include "virfile.h"
 
 static int (*real_open)(const char *path, int flags, ...);
+#if WITH___OPEN_2
+static int (*real___open_2)(const char *path, int flags);
+#endif
 static FILE *(*real_fopen)(const char *path, const char *mode);
 static int (*real_access)(const char *path, int mode);
 static int (*real_connect)(int fd, const struct sockaddr *addr, socklen_t addrlen);
@@ -44,6 +47,9 @@ static void init_syms(void)
         return;
 
     VIR_MOCK_REAL_INIT(open);
+#if WITH___OPEN_2
+    VIR_MOCK_REAL_INIT(__open_2);
+#endif
     VIR_MOCK_REAL_INIT(fopen);
     VIR_MOCK_REAL_INIT(access);
     VIR_MOCK_REAL_INIT(connect);
@@ -153,6 +159,20 @@ int open(const char *path, int flags, ...)
     return ret;
 }
 
+
+#if WITH___OPEN_2
+int
+__open_2(const char *path, int flags)
+{
+    init_syms();
+
+    CHECK_PATH(path);
+
+    return real___open_2(path, flags);
+}
+#endif
+
+
 FILE *fopen(const char *path, const char *mode)
 {
     init_syms();

tests/virusbmock.c

@@ -30,6 +30,9 @@
 #define FAKE_USB_SYSFS "virusbtestdata/sys_bus_usb"
 
 static int (*real_open)(const char *pathname, int flags, ...);
+#if WITH___OPEN_2
+static int (*real___open_2)(const char *path, int flags);
+#endif
 static DIR *(*real_opendir)(const char *name);
 
 static void init_syms(void)
@@ -38,6 +41,9 @@ static void init_syms(void)
         return;
 
     VIR_MOCK_REAL_INIT(open);
+#if WITH___OPEN_2
+    VIR_MOCK_REAL_INIT(__open_2);
+#endif
     VIR_MOCK_REAL_INIT(opendir);
 }
 
@@ -90,3 +96,19 @@ int open(const char *pathname, int flags, ...)
     ret = real_open(path, flags, mode);
     return ret;
 }
+
+#if WITH___OPEN_2
+int
+__open_2(const char *pathname, int flags)
+{
+    g_autofree char *path = NULL;
+
+    init_syms();
+
+    path = get_fake_path(pathname);
+    if (!path)
+        return -1;
+
+    return real_open(path, flags);
+}
+#endif