libvirt/tests/vircgroupmock.c

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/*
* Copyright (C) 2013 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#ifdef __linux__
# include "virmock.h"
# include <unistd.h>
# include <fcntl.h>
# include <sys/stat.h>
# include <sys/sysmacros.h>
# include <stdarg.h>
# include "testutilslxc.h"
# include "virstring.h"
# include "virfile.h"
# include "viralloc.h"
# include "vircgroupv2devices.h"
static int (*real_open)(const char *path, int flags, ...);
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);
/* Don't make static, since it causes problems with clang
* when passed as an arg to asprintf()
* vircgroupmock.c:462:22: error: static variable 'fakesysfsdir' is used in an inline function with external linkage [-Werror,-Wstatic-in-inline]
*/
char *fakerootdir;
char *fakesysfscgroupdir;
const char *fakedevicedir0 = FAKEDEVDIR0;
const char *fakedevicedir1 = FAKEDEVDIR1;
# define SYSFS_CGROUP_PREFIX "/not/really/sys/fs/cgroup"
# define SYSFS_CPU_PRESENT "/sys/devices/system/cpu/present"
# define SYSFS_CPU_PRESENT_MOCKED "devices_system_cpu_present"
/*
* The plan:
*
* We fake out /proc/mounts, so make it look as is cgroups
* are mounted on /not/really/sys/fs/cgroup. We don't
* use /sys/fs/cgroup, because we want to make it easy to
* detect places where we've not mocked enough syscalls.
*
* In any open/access/mkdir calls we look at path and if
* it starts with /not/really/sys/fs/cgroup, we rewrite
* the path to point at a subdirectory of the temporary
* directory referred to by LIBVIRT_FAKE_ROOT_DIR env
* variable that is set by the main test suite
*
* In mkdir() calls, we simulate the cgroups behaviour
* whereby creating the directory auto-creates a bunch
* of files beneath it
*/
static int make_file(const char *path,
const char *name,
const char *value)
{
int fd = -1;
int ret = -1;
char *filepath = NULL;
if (asprintf(&filepath, "%s/%s", path, name) < 0)
return -1;
if ((fd = real_open(filepath, O_CREAT|O_WRONLY, 0600)) < 0)
goto cleanup;
if (write(fd, value, strlen(value)) != strlen(value))
goto cleanup;
ret = 0;
cleanup:
if (fd != -1 && close(fd) < 0)
ret = -1;
free(filepath);
return ret;
}
static int make_controller_v1(const char *path, mode_t mode)
{
const char *controller;
if (!STRPREFIX(path, fakesysfscgroupdir)) {
errno = EINVAL;
return -1;
}
controller = path + strlen(fakesysfscgroupdir) + 1;
if (STREQ(controller, "cpu"))
return symlink("cpu,cpuacct", path);
if (STREQ(controller, "cpuacct"))
return symlink("cpu,cpuacct", path);
if (real_mkdir(path, mode) < 0)
return -1;
# define MAKE_FILE(name, value) \
do { \
if (make_file(path, name, value) < 0) \
return -1; \
} while (0)
if (STRPREFIX(controller, "cpu,cpuacct")) {
MAKE_FILE("cpu.cfs_period_us", "100000\n");
MAKE_FILE("cpu.cfs_quota_us", "-1\n");
MAKE_FILE("cpu.shares", "1024\n");
MAKE_FILE("cpuacct.stat",
"user 216687025\n"
"system 43421396\n");
MAKE_FILE("cpuacct.usage", "2787788855799582\n");
MAKE_FILE("cpuacct.usage_percpu",
"7059492996 0 0 0 0 0 0 0 4180532496 0 0 0 0 0 0 0 "
"1957541268 0 0 0 0 0 0 0 2065932204 0 0 0 0 0 0 0 "
"18228689414 0 0 0 0 0 0 0 4245525148 0 0 0 0 0 0 0 "
"2911161568 0 0 0 0 0 0 0 1407758136 0 0 0 0 0 0 0 "
"1836807700 0 0 0 0 0 0 0 1065296618 0 0 0 0 0 0 0 "
"2046213266 0 0 0 0 0 0 0 747889778 0 0 0 0 0 0 0 "
"709566900 0 0 0 0 0 0 0 444777342 0 0 0 0 0 0 0 "
"5683512916 0 0 0 0 0 0 0 635751356 0 0 0 0 0 0 0\n");
} else if (STRPREFIX(controller, "cpuset")) {
if (STREQ(controller, "cpuset"))
MAKE_FILE("cpuset.cpus", "0-1");
else
MAKE_FILE("cpuset.cpus", ""); /* Values don't inherit */
MAKE_FILE("cpuset.memory_migrate", "0\n");
if (STREQ(controller, "cpuset"))
MAKE_FILE("cpuset.mems", "0");
else
MAKE_FILE("cpuset.mems", ""); /* Values don't inherit */
} else if (STRPREFIX(controller, "memory")) {
MAKE_FILE("memory.limit_in_bytes", "9223372036854775807\n");
MAKE_FILE("memory.memsw.limit_in_bytes", ""); /* Not supported */
MAKE_FILE("memory.memsw.usage_in_bytes", ""); /* Not supported */
MAKE_FILE("memory.soft_limit_in_bytes", "9223372036854775807\n");
MAKE_FILE("memory.stat",
"cache 1336619008\n"
"rss 97792000\n"
"mapped_file 42090496\n"
"pgpgin 13022605027\n"
"pgpgout 13023820533\n"
"pgfault 54429417056\n"
"pgmajfault 315715\n"
"inactive_anon 145887232\n"
"active_anon 67100672\n"
"inactive_file 627400704\n"
"active_file 661872640\n"
"unevictable 3690496\n"
"hierarchical_memory_limit 9223372036854775807\n"
"total_cache 1336635392\n"
"total_rss 118689792\n"
"total_mapped_file 42106880\n"
"total_pgpgin 13022606816\n"
"total_pgpgout 13023820793\n"
"total_pgfault 54429422313\n"
"total_pgmajfault 315715\n"
"total_inactive_anon 145891328\n"
"total_active_anon 88010752\n"
"total_inactive_file 627400704\n"
"total_active_file 661872640\n"
"total_unevictable 3690496\n"
"recent_rotated_anon 112807028\n"
"recent_rotated_file 2547948\n"
"recent_scanned_anon 113796164\n"
"recent_scanned_file 8199863\n");
MAKE_FILE("memory.usage_in_bytes", "1455321088\n");
MAKE_FILE("memory.use_hierarchy", "0\n");
} else if (STRPREFIX(controller, "freezer")) {
MAKE_FILE("freezer.state", "THAWED");
} else if (STRPREFIX(controller, "blkio")) {
MAKE_FILE("blkio.throttle.io_service_bytes",
"8:0 Read 59542107136\n"
"8:0 Write 411440480256\n"
"8:0 Sync 248486822912\n"
"8:0 Async 222495764480\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"
"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", "");
MAKE_FILE("blkio.throttle.write_iops_device", "");
MAKE_FILE("blkio.weight", "1000\n");
MAKE_FILE("blkio.weight_device", "");
} else {
errno = EINVAL;
return -1;
}
# undef MAKE_FILE
return 0;
}
static int make_controller_v2(const char *path, mode_t mode)
{
if (!STRPREFIX(path, fakesysfscgroupdir)) {
errno = EINVAL;
return -1;
}
if (real_mkdir(path, mode) < 0 && errno != EEXIST)
return -1;
# define MAKE_FILE(name, value) \
do { \
if (make_file(path, name, value) < 0) \
return -1; \
} while (0)
MAKE_FILE("cgroup.controllers", "cpu io memory\n");
MAKE_FILE("cgroup.subtree_control", "");
MAKE_FILE("cgroup.type", "domain\n");
MAKE_FILE("cpu.max", "max 100000\n");
MAKE_FILE("cpu.stat",
"usage_usec 0\n"
"user_usec 0\n"
"system_usec 0\n"
"nr_periods 0\n"
"nr_throttled 0\n"
"throttled_usec 0\n");
MAKE_FILE("cpu.weight", "100\n");
MAKE_FILE("memory.current", "1455321088\n");
MAKE_FILE("memory.high", "max\n");
MAKE_FILE("memory.max", "max\n");
MAKE_FILE("memory.stat",
"anon 0\n"
"file 0\n"
"kernel_stack 0\n"
"slab 0\n"
"sock 0\n"
"shmem 0\n"
"file_mapped 0\n"
"file_dirty 0\n"
"file_writeback 0\n"
"inactive_anon 0\n"
"active_anon 0\n"
"inactive_file 0\n"
"active_file 0\n"
"unevictable 0\n"
"slab_reclaimable 0\n"
"slab_unreclaimable 0\n"
"pgfault 0\n"
"pgmajfault 0\n"
"pgrefill 0\n"
"pgscan 0\n"
"pgsteal 0\n"
"pgactivate 0\n"
"pgdeactivate 0\n"
"pglazyfree 0\n"
"pglazyfreed 0\n"
"workingset_refault 0\n"
"workingset_activate 0\n"
"workingset_nodereclaim 0\n");
MAKE_FILE("memory.swap.current", "0\n");
MAKE_FILE("memory.swap.max", "max\n");
MAKE_FILE("io.stat", "8:0 rbytes=26828800 wbytes=77062144 rios=2256 wios=7849 dbytes=0 dios=0\n");
MAKE_FILE("io.max", "");
MAKE_FILE("io.weight", "default 100\n");
# undef MAKE_FILE
return 0;
}
static void init_syms(void)
{
if (real_fopen)
return;
VIR_MOCK_REAL_INIT(fopen);
VIR_MOCK_REAL_INIT(access);
VIR_MOCK_REAL_INIT(mkdir);
VIR_MOCK_REAL_INIT(open);
}
static int make_controller(const char *path, mode_t mode)
{
const char *mock;
bool unified = false;
bool hybrid = false;
mock = getenv("VIR_CGROUP_MOCK_MODE");
if (mock) {
if (STREQ(mock, "unified")) {
unified = true;
} else if (STREQ(mock, "hybrid")) {
hybrid = true;
} else {
fprintf(stderr, "invalid mode '%s'\n", mock);
abort();
}
}
if (unified || (hybrid && strstr(path, "unified"))) {
return make_controller_v2(path, mode);
} else {
return make_controller_v1(path, mode);
}
}
static void init_sysfs(void)
{
const char *mock;
char *newfakerootdir;
bool unified = false;
bool hybrid = false;
if (!(newfakerootdir = getenv("LIBVIRT_FAKE_ROOT_DIR"))) {
fprintf(stderr, "Missing LIBVIRT_FAKE_ROOT_DIR env variable\n");
abort();
}
if (fakerootdir && STREQ(fakerootdir, newfakerootdir))
return;
fakerootdir = newfakerootdir;
mock = getenv("VIR_CGROUP_MOCK_MODE");
if (mock) {
if (STREQ(mock, "unified")) {
unified = true;
} else if (STREQ(mock, "hybrid")) {
hybrid = true;
} else {
fprintf(stderr, "invalid mode '%s'\n", mock);
abort();
}
}
VIR_FREE(fakesysfscgroupdir);
fakesysfscgroupdir = g_strdup_printf("%s%s",
fakerootdir, SYSFS_CGROUP_PREFIX);
if (g_mkdir_with_parents(fakesysfscgroupdir, 0777) < 0) {
fprintf(stderr, "Cannot create %s\n", fakesysfscgroupdir);
abort();
}
# define MAKE_CONTROLLER(subpath) \
do { \
char *path; \
if (asprintf(&path, "%s/%s", fakesysfscgroupdir, subpath) < 0) \
abort(); \
if (make_controller(path, 0755) < 0) { \
fprintf(stderr, "Cannot initialize %s\n", path); \
free(path); \
abort(); \
} \
free(path); \
} while (0)
if (unified) {
MAKE_CONTROLLER("");
} else if (hybrid) {
MAKE_CONTROLLER("unified");
MAKE_CONTROLLER("cpuset");
MAKE_CONTROLLER("freezer");
} else {
MAKE_CONTROLLER("cpu");
MAKE_CONTROLLER("cpuacct");
MAKE_CONTROLLER("cpu,cpuacct");
MAKE_CONTROLLER("cpuset");
MAKE_CONTROLLER("blkio");
MAKE_CONTROLLER("memory");
MAKE_CONTROLLER("freezer");
if (make_file(fakesysfscgroupdir,
SYSFS_CPU_PRESENT_MOCKED, "8-23,48-159\n") < 0)
abort();
}
}
FILE *fopen(const char *path, const char *mode)
{
char *filepath = NULL;
const char *type = NULL;
FILE *rc = NULL;
const char *filename = getenv("VIR_CGROUP_MOCK_FILENAME");
init_syms();
if (STREQ(path, "/proc/mounts")) {
if (STREQ(mode, "r")) {
type = "mounts";
} else {
errno = EACCES;
return NULL;
}
}
if (STREQ(path, "/proc/cgroups")) {
if (STREQ(mode, "r")) {
type = "cgroups";
} else {
errno = EACCES;
return NULL;
}
}
if (STREQ(path, "/proc/self/cgroup")) {
if (STREQ(mode, "r")) {
type = "self.cgroup";
} else {
errno = EACCES;
return NULL;
}
}
if (type) {
if (!filename) {
errno = EACCES;
return NULL;
}
filepath = g_strdup_printf("%s/vircgroupdata/%s.%s",
abs_srcdir, filename, type);
rc = real_fopen(filepath, mode);
free(filepath);
return rc;
}
return real_fopen(path, mode);
}
int access(const char *path, int mode)
{
int ret;
init_syms();
if (STRPREFIX(path, SYSFS_CGROUP_PREFIX)) {
char *newpath;
init_sysfs();
if (asprintf(&newpath, "%s%s",
fakesysfscgroupdir,
path + strlen(SYSFS_CGROUP_PREFIX)) < 0) {
errno = ENOMEM;
return -1;
}
ret = real_access(newpath, mode);
free(newpath);
} else if (STREQ(path, "/proc/cgroups") ||
STREQ(path, "/proc/self/cgroup") ||
STREQ(path, SYSFS_CPU_PRESENT)) {
/* These files are readable for all. */
ret = (mode == F_OK || mode == R_OK) ? 0 : -1;
} else if (STREQ(path, "/proc/mounts")) {
/* This one is accessible anytime for anybody. In fact, it's just
* a symlink to /proc/self/mounts. */
ret = 0;
} else {
ret = real_access(path, mode);
}
return ret;
}
tests: fix mocking of stat() / lstat() functions Quite a few of the tests have a need to mock the stat() / lstat() functions and they are taking somewhat different & inconsistent approaches none of which are actually fully correct. This is shown by fact that 'make check' fails on 32-bit hosts. Investigation revealed that the code was calling into the native C library impl, not getting intercepted by our mocks. The POSIX stat() function might resolve to any number of different symbols in the C library. The may be an additional stat64() function exposed by the headers too. On 64-bit hosts the stat & stat64 functions are identical, always refering to the 64-bit ABI. On 32-bit hosts they refer to the 32-bit & 64-bit ABIs respectively. Libvirt uses _FILE_OFFSET_BITS=64 on 32-bit hosts, which causes the C library to transparently rewrite stat() calls to be stat64() calls. Libvirt will never see the 32-bit ABI from the traditional stat() call. We cannot assume this rewriting is done using a macro. It might be, but on GLibC it is done with a magic __asm__ statement to apply the rewrite at link time instead of at preprocessing. In GLibC there may be two additional functions exposed by the headers, __xstat() and __xstat64(). When these exist, stat() and stat64() are transparently rewritten to call __xstat() and __xstat64() respectively. The former symbols will not actally exist in the library at all, only the header. The leading "__" indicates the symbols are a private impl detail of the C library that applications should not care about. Unfortunately, because we are trying to mock replace the C library, we need to know about this internal impl detail. With all this in mind the list of functions we have to mock will depend on several factors - If _FILE_OFFSET_BITS is set, then we are on a 32-bit host, and we only need to mock stat64 and __xstat64. The other stat / __xstat functions exist, but we'll never call them so they can be ignored for mocking. - If _FILE_OFFSET_BITS is not set, then we are on a 64-bit host and we should mock stat, stat64, __xstat & __xstat64. Either may be called by app code. - If __xstat & __xstat64 exist, then stat & stat64 will not exist as symbols in the library, so the latter should not be mocked. The same all applies to lstat() These rules are complex enough that we don't want to duplicate them across every mock file, so this centralizes all the logic in a helper file virmockstathelper.c that should be #included when needed. The code merely need to provide a filename rewriting callback called virMockStatRedirect(). Optionally VIR_MOCK_STAT_HOOK can be defined as a macro if further processing is needed inline. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-04-01 16:47:25 +00:00
# define VIR_MOCK_STAT_HOOK \
do { \
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; \
} \
} while (0)
tests: fix mocking of stat() / lstat() functions Quite a few of the tests have a need to mock the stat() / lstat() functions and they are taking somewhat different & inconsistent approaches none of which are actually fully correct. This is shown by fact that 'make check' fails on 32-bit hosts. Investigation revealed that the code was calling into the native C library impl, not getting intercepted by our mocks. The POSIX stat() function might resolve to any number of different symbols in the C library. The may be an additional stat64() function exposed by the headers too. On 64-bit hosts the stat & stat64 functions are identical, always refering to the 64-bit ABI. On 32-bit hosts they refer to the 32-bit & 64-bit ABIs respectively. Libvirt uses _FILE_OFFSET_BITS=64 on 32-bit hosts, which causes the C library to transparently rewrite stat() calls to be stat64() calls. Libvirt will never see the 32-bit ABI from the traditional stat() call. We cannot assume this rewriting is done using a macro. It might be, but on GLibC it is done with a magic __asm__ statement to apply the rewrite at link time instead of at preprocessing. In GLibC there may be two additional functions exposed by the headers, __xstat() and __xstat64(). When these exist, stat() and stat64() are transparently rewritten to call __xstat() and __xstat64() respectively. The former symbols will not actally exist in the library at all, only the header. The leading "__" indicates the symbols are a private impl detail of the C library that applications should not care about. Unfortunately, because we are trying to mock replace the C library, we need to know about this internal impl detail. With all this in mind the list of functions we have to mock will depend on several factors - If _FILE_OFFSET_BITS is set, then we are on a 32-bit host, and we only need to mock stat64 and __xstat64. The other stat / __xstat functions exist, but we'll never call them so they can be ignored for mocking. - If _FILE_OFFSET_BITS is not set, then we are on a 64-bit host and we should mock stat, stat64, __xstat & __xstat64. Either may be called by app code. - If __xstat & __xstat64 exist, then stat & stat64 will not exist as symbols in the library, so the latter should not be mocked. The same all applies to lstat() These rules are complex enough that we don't want to duplicate them across every mock file, so this centralizes all the logic in a helper file virmockstathelper.c that should be #included when needed. The code merely need to provide a filename rewriting callback called virMockStatRedirect(). Optionally VIR_MOCK_STAT_HOOK can be defined as a macro if further processing is needed inline. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-04-01 16:47:25 +00:00
# include "virmockstathelpers.c"
tests: fix mocking of stat() / lstat() functions Quite a few of the tests have a need to mock the stat() / lstat() functions and they are taking somewhat different & inconsistent approaches none of which are actually fully correct. This is shown by fact that 'make check' fails on 32-bit hosts. Investigation revealed that the code was calling into the native C library impl, not getting intercepted by our mocks. The POSIX stat() function might resolve to any number of different symbols in the C library. The may be an additional stat64() function exposed by the headers too. On 64-bit hosts the stat & stat64 functions are identical, always refering to the 64-bit ABI. On 32-bit hosts they refer to the 32-bit & 64-bit ABIs respectively. Libvirt uses _FILE_OFFSET_BITS=64 on 32-bit hosts, which causes the C library to transparently rewrite stat() calls to be stat64() calls. Libvirt will never see the 32-bit ABI from the traditional stat() call. We cannot assume this rewriting is done using a macro. It might be, but on GLibC it is done with a magic __asm__ statement to apply the rewrite at link time instead of at preprocessing. In GLibC there may be two additional functions exposed by the headers, __xstat() and __xstat64(). When these exist, stat() and stat64() are transparently rewritten to call __xstat() and __xstat64() respectively. The former symbols will not actally exist in the library at all, only the header. The leading "__" indicates the symbols are a private impl detail of the C library that applications should not care about. Unfortunately, because we are trying to mock replace the C library, we need to know about this internal impl detail. With all this in mind the list of functions we have to mock will depend on several factors - If _FILE_OFFSET_BITS is set, then we are on a 32-bit host, and we only need to mock stat64 and __xstat64. The other stat / __xstat functions exist, but we'll never call them so they can be ignored for mocking. - If _FILE_OFFSET_BITS is not set, then we are on a 64-bit host and we should mock stat, stat64, __xstat & __xstat64. Either may be called by app code. - If __xstat & __xstat64 exist, then stat & stat64 will not exist as symbols in the library, so the latter should not be mocked. The same all applies to lstat() These rules are complex enough that we don't want to duplicate them across every mock file, so this centralizes all the logic in a helper file virmockstathelper.c that should be #included when needed. The code merely need to provide a filename rewriting callback called virMockStatRedirect(). Optionally VIR_MOCK_STAT_HOOK can be defined as a macro if further processing is needed inline. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-04-01 16:47:25 +00:00
static int
virMockStatRedirect(const char *path, char **newpath)
{
if (STREQ(path, SYSFS_CPU_PRESENT)) {
init_sysfs();
tests: fix mocking of stat() / lstat() functions Quite a few of the tests have a need to mock the stat() / lstat() functions and they are taking somewhat different & inconsistent approaches none of which are actually fully correct. This is shown by fact that 'make check' fails on 32-bit hosts. Investigation revealed that the code was calling into the native C library impl, not getting intercepted by our mocks. The POSIX stat() function might resolve to any number of different symbols in the C library. The may be an additional stat64() function exposed by the headers too. On 64-bit hosts the stat & stat64 functions are identical, always refering to the 64-bit ABI. On 32-bit hosts they refer to the 32-bit & 64-bit ABIs respectively. Libvirt uses _FILE_OFFSET_BITS=64 on 32-bit hosts, which causes the C library to transparently rewrite stat() calls to be stat64() calls. Libvirt will never see the 32-bit ABI from the traditional stat() call. We cannot assume this rewriting is done using a macro. It might be, but on GLibC it is done with a magic __asm__ statement to apply the rewrite at link time instead of at preprocessing. In GLibC there may be two additional functions exposed by the headers, __xstat() and __xstat64(). When these exist, stat() and stat64() are transparently rewritten to call __xstat() and __xstat64() respectively. The former symbols will not actally exist in the library at all, only the header. The leading "__" indicates the symbols are a private impl detail of the C library that applications should not care about. Unfortunately, because we are trying to mock replace the C library, we need to know about this internal impl detail. With all this in mind the list of functions we have to mock will depend on several factors - If _FILE_OFFSET_BITS is set, then we are on a 32-bit host, and we only need to mock stat64 and __xstat64. The other stat / __xstat functions exist, but we'll never call them so they can be ignored for mocking. - If _FILE_OFFSET_BITS is not set, then we are on a 64-bit host and we should mock stat, stat64, __xstat & __xstat64. Either may be called by app code. - If __xstat & __xstat64 exist, then stat & stat64 will not exist as symbols in the library, so the latter should not be mocked. The same all applies to lstat() These rules are complex enough that we don't want to duplicate them across every mock file, so this centralizes all the logic in a helper file virmockstathelper.c that should be #included when needed. The code merely need to provide a filename rewriting callback called virMockStatRedirect(). Optionally VIR_MOCK_STAT_HOOK can be defined as a macro if further processing is needed inline. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-04-01 16:47:25 +00:00
if (asprintf(newpath, "%s/%s",
fakesysfscgroupdir,
tests: fix mocking of stat() / lstat() functions Quite a few of the tests have a need to mock the stat() / lstat() functions and they are taking somewhat different & inconsistent approaches none of which are actually fully correct. This is shown by fact that 'make check' fails on 32-bit hosts. Investigation revealed that the code was calling into the native C library impl, not getting intercepted by our mocks. The POSIX stat() function might resolve to any number of different symbols in the C library. The may be an additional stat64() function exposed by the headers too. On 64-bit hosts the stat & stat64 functions are identical, always refering to the 64-bit ABI. On 32-bit hosts they refer to the 32-bit & 64-bit ABIs respectively. Libvirt uses _FILE_OFFSET_BITS=64 on 32-bit hosts, which causes the C library to transparently rewrite stat() calls to be stat64() calls. Libvirt will never see the 32-bit ABI from the traditional stat() call. We cannot assume this rewriting is done using a macro. It might be, but on GLibC it is done with a magic __asm__ statement to apply the rewrite at link time instead of at preprocessing. In GLibC there may be two additional functions exposed by the headers, __xstat() and __xstat64(). When these exist, stat() and stat64() are transparently rewritten to call __xstat() and __xstat64() respectively. The former symbols will not actally exist in the library at all, only the header. The leading "__" indicates the symbols are a private impl detail of the C library that applications should not care about. Unfortunately, because we are trying to mock replace the C library, we need to know about this internal impl detail. With all this in mind the list of functions we have to mock will depend on several factors - If _FILE_OFFSET_BITS is set, then we are on a 32-bit host, and we only need to mock stat64 and __xstat64. The other stat / __xstat functions exist, but we'll never call them so they can be ignored for mocking. - If _FILE_OFFSET_BITS is not set, then we are on a 64-bit host and we should mock stat, stat64, __xstat & __xstat64. Either may be called by app code. - If __xstat & __xstat64 exist, then stat & stat64 will not exist as symbols in the library, so the latter should not be mocked. The same all applies to lstat() These rules are complex enough that we don't want to duplicate them across every mock file, so this centralizes all the logic in a helper file virmockstathelper.c that should be #included when needed. The code merely need to provide a filename rewriting callback called virMockStatRedirect(). Optionally VIR_MOCK_STAT_HOOK can be defined as a macro if further processing is needed inline. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-04-01 16:47:25 +00:00
SYSFS_CPU_PRESENT_MOCKED) < 0)
return -1;
} else if (STRPREFIX(path, SYSFS_CGROUP_PREFIX)) {
init_sysfs();
tests: fix mocking of stat() / lstat() functions Quite a few of the tests have a need to mock the stat() / lstat() functions and they are taking somewhat different & inconsistent approaches none of which are actually fully correct. This is shown by fact that 'make check' fails on 32-bit hosts. Investigation revealed that the code was calling into the native C library impl, not getting intercepted by our mocks. The POSIX stat() function might resolve to any number of different symbols in the C library. The may be an additional stat64() function exposed by the headers too. On 64-bit hosts the stat & stat64 functions are identical, always refering to the 64-bit ABI. On 32-bit hosts they refer to the 32-bit & 64-bit ABIs respectively. Libvirt uses _FILE_OFFSET_BITS=64 on 32-bit hosts, which causes the C library to transparently rewrite stat() calls to be stat64() calls. Libvirt will never see the 32-bit ABI from the traditional stat() call. We cannot assume this rewriting is done using a macro. It might be, but on GLibC it is done with a magic __asm__ statement to apply the rewrite at link time instead of at preprocessing. In GLibC there may be two additional functions exposed by the headers, __xstat() and __xstat64(). When these exist, stat() and stat64() are transparently rewritten to call __xstat() and __xstat64() respectively. The former symbols will not actally exist in the library at all, only the header. The leading "__" indicates the symbols are a private impl detail of the C library that applications should not care about. Unfortunately, because we are trying to mock replace the C library, we need to know about this internal impl detail. With all this in mind the list of functions we have to mock will depend on several factors - If _FILE_OFFSET_BITS is set, then we are on a 32-bit host, and we only need to mock stat64 and __xstat64. The other stat / __xstat functions exist, but we'll never call them so they can be ignored for mocking. - If _FILE_OFFSET_BITS is not set, then we are on a 64-bit host and we should mock stat, stat64, __xstat & __xstat64. Either may be called by app code. - If __xstat & __xstat64 exist, then stat & stat64 will not exist as symbols in the library, so the latter should not be mocked. The same all applies to lstat() These rules are complex enough that we don't want to duplicate them across every mock file, so this centralizes all the logic in a helper file virmockstathelper.c that should be #included when needed. The code merely need to provide a filename rewriting callback called virMockStatRedirect(). Optionally VIR_MOCK_STAT_HOOK can be defined as a macro if further processing is needed inline. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-04-01 16:47:25 +00:00
if (asprintf(newpath, "%s%s",
fakesysfscgroupdir,
tests: fix mocking of stat() / lstat() functions Quite a few of the tests have a need to mock the stat() / lstat() functions and they are taking somewhat different & inconsistent approaches none of which are actually fully correct. This is shown by fact that 'make check' fails on 32-bit hosts. Investigation revealed that the code was calling into the native C library impl, not getting intercepted by our mocks. The POSIX stat() function might resolve to any number of different symbols in the C library. The may be an additional stat64() function exposed by the headers too. On 64-bit hosts the stat & stat64 functions are identical, always refering to the 64-bit ABI. On 32-bit hosts they refer to the 32-bit & 64-bit ABIs respectively. Libvirt uses _FILE_OFFSET_BITS=64 on 32-bit hosts, which causes the C library to transparently rewrite stat() calls to be stat64() calls. Libvirt will never see the 32-bit ABI from the traditional stat() call. We cannot assume this rewriting is done using a macro. It might be, but on GLibC it is done with a magic __asm__ statement to apply the rewrite at link time instead of at preprocessing. In GLibC there may be two additional functions exposed by the headers, __xstat() and __xstat64(). When these exist, stat() and stat64() are transparently rewritten to call __xstat() and __xstat64() respectively. The former symbols will not actally exist in the library at all, only the header. The leading "__" indicates the symbols are a private impl detail of the C library that applications should not care about. Unfortunately, because we are trying to mock replace the C library, we need to know about this internal impl detail. With all this in mind the list of functions we have to mock will depend on several factors - If _FILE_OFFSET_BITS is set, then we are on a 32-bit host, and we only need to mock stat64 and __xstat64. The other stat / __xstat functions exist, but we'll never call them so they can be ignored for mocking. - If _FILE_OFFSET_BITS is not set, then we are on a 64-bit host and we should mock stat, stat64, __xstat & __xstat64. Either may be called by app code. - If __xstat & __xstat64 exist, then stat & stat64 will not exist as symbols in the library, so the latter should not be mocked. The same all applies to lstat() These rules are complex enough that we don't want to duplicate them across every mock file, so this centralizes all the logic in a helper file virmockstathelper.c that should be #included when needed. The code merely need to provide a filename rewriting callback called virMockStatRedirect(). Optionally VIR_MOCK_STAT_HOOK can be defined as a macro if further processing is needed inline. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-04-01 16:47:25 +00:00
path + strlen(SYSFS_CGROUP_PREFIX)) < 0)
return -1;
}
tests: fix mocking of stat() / lstat() functions Quite a few of the tests have a need to mock the stat() / lstat() functions and they are taking somewhat different & inconsistent approaches none of which are actually fully correct. This is shown by fact that 'make check' fails on 32-bit hosts. Investigation revealed that the code was calling into the native C library impl, not getting intercepted by our mocks. The POSIX stat() function might resolve to any number of different symbols in the C library. The may be an additional stat64() function exposed by the headers too. On 64-bit hosts the stat & stat64 functions are identical, always refering to the 64-bit ABI. On 32-bit hosts they refer to the 32-bit & 64-bit ABIs respectively. Libvirt uses _FILE_OFFSET_BITS=64 on 32-bit hosts, which causes the C library to transparently rewrite stat() calls to be stat64() calls. Libvirt will never see the 32-bit ABI from the traditional stat() call. We cannot assume this rewriting is done using a macro. It might be, but on GLibC it is done with a magic __asm__ statement to apply the rewrite at link time instead of at preprocessing. In GLibC there may be two additional functions exposed by the headers, __xstat() and __xstat64(). When these exist, stat() and stat64() are transparently rewritten to call __xstat() and __xstat64() respectively. The former symbols will not actally exist in the library at all, only the header. The leading "__" indicates the symbols are a private impl detail of the C library that applications should not care about. Unfortunately, because we are trying to mock replace the C library, we need to know about this internal impl detail. With all this in mind the list of functions we have to mock will depend on several factors - If _FILE_OFFSET_BITS is set, then we are on a 32-bit host, and we only need to mock stat64 and __xstat64. The other stat / __xstat functions exist, but we'll never call them so they can be ignored for mocking. - If _FILE_OFFSET_BITS is not set, then we are on a 64-bit host and we should mock stat, stat64, __xstat & __xstat64. Either may be called by app code. - If __xstat & __xstat64 exist, then stat & stat64 will not exist as symbols in the library, so the latter should not be mocked. The same all applies to lstat() These rules are complex enough that we don't want to duplicate them across every mock file, so this centralizes all the logic in a helper file virmockstathelper.c that should be #included when needed. The code merely need to provide a filename rewriting callback called virMockStatRedirect(). Optionally VIR_MOCK_STAT_HOOK can be defined as a macro if further processing is needed inline. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-04-01 16:47:25 +00:00
return 0;
}
tests: fix mocking of stat() / lstat() functions Quite a few of the tests have a need to mock the stat() / lstat() functions and they are taking somewhat different & inconsistent approaches none of which are actually fully correct. This is shown by fact that 'make check' fails on 32-bit hosts. Investigation revealed that the code was calling into the native C library impl, not getting intercepted by our mocks. The POSIX stat() function might resolve to any number of different symbols in the C library. The may be an additional stat64() function exposed by the headers too. On 64-bit hosts the stat & stat64 functions are identical, always refering to the 64-bit ABI. On 32-bit hosts they refer to the 32-bit & 64-bit ABIs respectively. Libvirt uses _FILE_OFFSET_BITS=64 on 32-bit hosts, which causes the C library to transparently rewrite stat() calls to be stat64() calls. Libvirt will never see the 32-bit ABI from the traditional stat() call. We cannot assume this rewriting is done using a macro. It might be, but on GLibC it is done with a magic __asm__ statement to apply the rewrite at link time instead of at preprocessing. In GLibC there may be two additional functions exposed by the headers, __xstat() and __xstat64(). When these exist, stat() and stat64() are transparently rewritten to call __xstat() and __xstat64() respectively. The former symbols will not actally exist in the library at all, only the header. The leading "__" indicates the symbols are a private impl detail of the C library that applications should not care about. Unfortunately, because we are trying to mock replace the C library, we need to know about this internal impl detail. With all this in mind the list of functions we have to mock will depend on several factors - If _FILE_OFFSET_BITS is set, then we are on a 32-bit host, and we only need to mock stat64 and __xstat64. The other stat / __xstat functions exist, but we'll never call them so they can be ignored for mocking. - If _FILE_OFFSET_BITS is not set, then we are on a 64-bit host and we should mock stat, stat64, __xstat & __xstat64. Either may be called by app code. - If __xstat & __xstat64 exist, then stat & stat64 will not exist as symbols in the library, so the latter should not be mocked. The same all applies to lstat() These rules are complex enough that we don't want to duplicate them across every mock file, so this centralizes all the logic in a helper file virmockstathelper.c that should be #included when needed. The code merely need to provide a filename rewriting callback called virMockStatRedirect(). Optionally VIR_MOCK_STAT_HOOK can be defined as a macro if further processing is needed inline. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-04-01 16:47:25 +00:00
int mkdir(const char *path, mode_t mode)
{
int ret;
init_syms();
if (STRPREFIX(path, SYSFS_CGROUP_PREFIX)) {
char *newpath;
init_sysfs();
if (asprintf(&newpath, "%s%s",
fakesysfscgroupdir,
path + strlen(SYSFS_CGROUP_PREFIX)) < 0) {
errno = ENOMEM;
return -1;
}
ret = make_controller(newpath, mode);
free(newpath);
} else {
ret = real_mkdir(path, mode);
}
return ret;
}
int open(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;
}
}
if (flags & O_CREAT) {
va_list ap;
mode_t mode;
va_start(ap, flags);
mode = (mode_t) va_arg(ap, int);
va_end(ap);
ret = real_open(newpath ? newpath : path, flags, mode);
} else {
ret = real_open(newpath ? newpath : path, flags);
}
free(newpath);
return ret;
}
bool
virCgroupV2DevicesAvailable(virCgroup *group G_GNUC_UNUSED)
{
return true;
}
#else
/* Nothing to override on non-__linux__ platforms */
#endif