On 03.02.2014 18:44, Thorsten Behrens wrote:
---
Adds another dummy device to push the cgroup parsing code a bit
harder
tests/vircgroupmock.c | 107 +++++++++++++++++++++++++++++++++++++++-
tests/vircgrouptest.c | 133 ++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 238 insertions(+), 2 deletions(-)
diff --git a/tests/vircgroupmock.c b/tests/vircgroupmock.c
index 6542973..d772652 100644
--- a/tests/vircgroupmock.c
+++ b/tests/vircgroupmock.c
@@ -34,6 +34,8 @@
static int (*realopen)(const char *path, int flags, ...);
static FILE *(*realfopen)(const char *path, const char *mode);
static int (*realaccess)(const char *path, int mode);
+static int (*realstat)(const char *path, struct stat *sb);
+static int (*real__xstat)(int ver, const char *path, struct stat *sb);
static int (*reallstat)(const char *path, struct stat *sb);
static int (*real__lxstat)(int ver, const char *path, struct stat *sb);
static int (*realmkdir)(const char *path, mode_t mode);
@@ -43,6 +45,8 @@ static int (*realmkdir)(const char *path, mode_t mode);
* vircgroupmock.c:462:22: error: static variable 'fakesysfsdir' is used in an
inline function with external linkage [-Werror,-Wstatic-in-inline]
*/
char *fakesysfsdir;
+char *fakedevicedir0;
+char *fakedevicedir1;
# define SYSFS_PREFIX "/not/really/sys/fs/cgroup/"
@@ -332,13 +336,23 @@ static int make_controller(const char *path, mode_t mode)
"8:0 Write 411440480256\n"
"8:0 Sync 248486822912\n"
"8:0 Async 222495764480\n"
- "8:0 Total 470982587392\n");
+ "8:0 Total 470982587392\n"
+ "9:0 Read 59542107137\n"
+ "9:0 Write 411440480257\n"
+ "9:0 Sync 248486822912\n"
+ "9:0 Async 222495764480\n"
+ "9:0 Total 470982587392\n");
MAKE_FILE("blkio.throttle.io_serviced",
"8:0 Read 4832583\n"
"8:0 Write 36641903\n"
"8:0 Sync 30723171\n"
"8:0 Async 10751315\n"
- "8:0 Total 41474486\n");
+ "8:0 Total 41474486\n"
+ "9:0 Read 4832584\n"
+ "9:0 Write 36641904\n"
+ "9:0 Sync 30723171\n"
+ "9:0 Async 10751315\n"
+ "9:0 Total 41474486\n");
MAKE_FILE("blkio.throttle.read_bps_device", "");
MAKE_FILE("blkio.throttle.read_iops_device", "");
MAKE_FILE("blkio.throttle.write_bps_device", "");
@@ -382,6 +396,7 @@ static void init_syms(void)
LOAD_SYM(fopen);
LOAD_SYM(access);
LOAD_SYM_ALT(lstat, __lxstat);
+ LOAD_SYM_ALT(stat, __xstat);
LOAD_SYM(mkdir);
LOAD_SYM(open);
}
@@ -396,6 +411,16 @@ static void init_sysfs(void)
abort();
}
+ if (!(fakedevicedir0 = getenv("LIBVIRT_FAKE_DEVICE_DIR0"))) {
+ fprintf(stderr, "Missing LIBVIRT_FAKE_DEVICE_DIR0 env variable\n");
+ abort();
+ }
+
+ if (!(fakedevicedir1 = getenv("LIBVIRT_FAKE_DEVICE_DIR1"))) {
+ fprintf(stderr, "Missing LIBVIRT_FAKE_DEVICE_DIR1 env variable\n");
+ abort();
+ }
+
# define MAKE_CONTROLLER(subpath) \
do { \
char *path; \
@@ -529,6 +554,14 @@ int __lxstat(int ver, const char *path, struct stat *sb)
}
ret = real__lxstat(ver, newpath, sb);
free(newpath);
+ } else if (STRPREFIX(path, fakedevicedir0)) {
+ sb->st_mode = S_IFBLK;
+ sb->st_rdev = makedev(8, 0);
+ return 0;
+ } else if (STRPREFIX(path, fakedevicedir1)) {
+ sb->st_mode = S_IFBLK;
+ sb->st_rdev = makedev(9, 0);
+ return 0;
} else {
ret = real__lxstat(ver, path, sb);
}
This won't work. If one __lxstat, lstat, __xstat, stat is called over path that does
not start with SYSFS_PREFIX, in fact it has not been called with such prefix yet, then the
fakedevicedir0 and fakedevicedir1 are NULL and hence strncmp will SIGSEGV:
Program received signal SIGSEGV, Segmentation fault.
__strlen_sse2_pminub () at ../sysdeps/x86_64/multiarch/strlen-sse2-pminub.S:38
38 ../sysdeps/x86_64/multiarch/strlen-sse2-pminub.S: No such file or directory.
(gdb) bt
#0 __strlen_sse2_pminub () at ../sysdeps/x86_64/multiarch/strlen-sse2-pminub.S:38
#1 0x00007ffff7df8f79 in __xstat (ver=1, path=0x6215a0 "/etc/libnl/classid",
sb=0x7fffffffd7e0) at vircgroupmock.c:619
#2 0x0000003468625627 in rtnl_tc_read_classid_file () from
/usr/lib64/libnl-route-3.so.200
#3 0x0000003468617e99 in ?? () from /usr/lib64/libnl-route-3.so.200
#4 0x000000345e80ec2a in call_init (l=<optimized out>, argc=1, argv=0x7fffffffda38,
env=0x7fffffffda48) at dl-init.c:78
#5 0x000000345e80ecfc in _dl_init (main_map=0x345ea231a8, argc=1, argv=0x7fffffffda38,
env=0x7fffffffda48) at dl-init.c:127
#6 0x000000345e80152a in _dl_start_user () from /lib64/ld-linux-x86-64.so.2
#7 0x0000000000000001 in ?? ()
#8 0x00007fffffffde35 in ?? ()
#9 0x0000000000000000 in ?? ()
(gdb) p fakedevicedir0
$5 = 0x0
(gdb) p fakedevicedir1
$6 = 0x0
Michal