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