mirror of
https://gitlab.com/libvirt/libvirt.git
synced 2024-11-08 22:39:56 +00:00
e9cfbd36c5
GLibC has a really complicated way of dealing with the 'stat' function historically, which means our mocks in turn have to look at four different possible functions to replace, stat, stat64, __xstat, __xstat64. In Fedora 33 and earlier: - libvirt.so links to __xstat64 - libc.so library exports stat, stat64, __xstat, __xstat64 - sys/stat.h header exposes stat and __xstat In Fedora 34 rawhide: - libvirt.so links to stat64 - libc.so library exports stat, stat64, __xstat, __xstat64 - sys/stat.h header exposes stat Historically we only looked at the exported symbols from libc.so to decide which to mock. In F34 though we must not consider __xstat / __xstat64 though because they only existance for binary compatibility. Newly built binaries won't reference them. Thus we must introduce a header file check into our logic for deciding which symbol to mock. We must ignore the __xstat / __xstat64 symbols if they don't appear in the sys/stat.h header, even if they appear in libc.so Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
357 lines
9.4 KiB
C
357 lines
9.4 KiB
C
/*
|
|
* Copyright (C) 2019 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/>.
|
|
*
|
|
* Helpers for dealing with the many variants of stat(). This
|
|
* C file should be included from any file that wants to mock
|
|
* stat() correctly.
|
|
*/
|
|
|
|
#include "virmock.h"
|
|
#include "viralloc.h"
|
|
|
|
#include <sys/stat.h>
|
|
#include <unistd.h>
|
|
|
|
/*
|
|
* 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
|
|
* referring to the 64-bit ABI.
|
|
*
|
|
* On 32-bit hosts they refer to the 32-bit & 64-bit ABIs respectively.
|
|
*
|
|
* With meson libvirt will have _FILE_OFFSET_BITS=64 always defined.
|
|
* On 32-bit hosts it 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 actually 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.
|
|
*
|
|
* On macOS stat() and lstat() are resolved to _stat$INODE64 and
|
|
* _lstat$INODE64, respectively. stat(2) man page also declares that
|
|
* stat64(), lstat64() and fstat64() are deprecated.
|
|
*
|
|
* With all this in mind the list of functions we have to mock will depend
|
|
* on several factors
|
|
*
|
|
* - If the stat or __xstat but there is no 64-bit version.
|
|
*
|
|
* - If __xstat & __xstat64 exist, then stat & stat64 will not exist
|
|
* as symbols in the library, so the latter should not be mocked.
|
|
*
|
|
* - If __xstat exists in the library, but not the header than it
|
|
* it is just there for binary back compat and should not be
|
|
* mocked
|
|
*
|
|
* The same all applies to lstat()
|
|
*/
|
|
|
|
|
|
#if !defined(WITH___XSTAT_DECL)
|
|
# if defined(WITH_STAT)
|
|
# if !defined(WITH___XSTAT) && !defined(WITH_STAT64) || defined(__APPLE__)
|
|
# define MOCK_STAT
|
|
# endif
|
|
# endif
|
|
# if defined(WITH_STAT64)
|
|
# define MOCK_STAT64
|
|
# endif
|
|
#else /* WITH___XSTAT_DECL */
|
|
# if defined(WITH___XSTAT) && !defined(WITH___XSTAT64)
|
|
# define MOCK___XSTAT
|
|
# endif
|
|
# if defined(WITH___XSTAT64)
|
|
# define MOCK___XSTAT64
|
|
# endif
|
|
#endif /* WITH___XSTAT_DECL */
|
|
|
|
#if !defined(WITH___LXSTAT_DECL)
|
|
# if defined(WITH_LSTAT)
|
|
# if !defined(WITH___LXSTAT) && !defined(WITH_LSTAT64) || defined(__APPLE__)
|
|
# define MOCK_LSTAT
|
|
# endif
|
|
# endif
|
|
# if defined(WITH_LSTAT64)
|
|
# define MOCK_LSTAT64
|
|
# endif
|
|
#else /* WITH___LXSTAT_DECL */
|
|
# if defined(WITH___LXSTAT) && !defined(WITH___LXSTAT64)
|
|
# define MOCK___LXSTAT
|
|
# endif
|
|
# if defined(WITH___LXSTAT64)
|
|
# define MOCK___LXSTAT64
|
|
# endif
|
|
#endif /* WITH___LXSTAT_DECL */
|
|
|
|
#ifdef MOCK_STAT
|
|
static int (*real_stat)(const char *path, struct stat *sb);
|
|
#endif
|
|
#ifdef MOCK_STAT64
|
|
static int (*real_stat64)(const char *path, struct stat64 *sb);
|
|
#endif
|
|
#ifdef MOCK___XSTAT
|
|
static int (*real___xstat)(int ver, const char *path, struct stat *sb);
|
|
#endif
|
|
#ifdef MOCK___XSTAT64
|
|
static int (*real___xstat64)(int ver, const char *path, struct stat64 *sb);
|
|
#endif
|
|
#ifdef MOCK_LSTAT
|
|
static int (*real_lstat)(const char *path, struct stat *sb);
|
|
#endif
|
|
#ifdef MOCK_LSTAT64
|
|
static int (*real_lstat64)(const char *path, struct stat64 *sb);
|
|
#endif
|
|
#ifdef MOCK___LXSTAT
|
|
static int (*real___lxstat)(int ver, const char *path, struct stat *sb);
|
|
#endif
|
|
#ifdef MOCK___LXSTAT64
|
|
static int (*real___lxstat64)(int ver, const char *path, struct stat64 *sb);
|
|
#endif
|
|
|
|
static bool init;
|
|
static bool debug;
|
|
|
|
#define fdebug(msg, ...) do { if (debug) fprintf(stderr, msg, __VA_ARGS__); } while (0)
|
|
|
|
static void virMockStatInit(void)
|
|
{
|
|
if (init)
|
|
return;
|
|
|
|
init = true;
|
|
debug = getenv("VIR_MOCK_STAT_DEBUG");
|
|
|
|
#ifdef MOCK_STAT
|
|
# ifdef __APPLE__
|
|
VIR_MOCK_REAL_INIT_ALIASED(stat, "stat$INODE64");
|
|
# else
|
|
VIR_MOCK_REAL_INIT(stat);
|
|
# endif
|
|
fdebug("real stat %p\n", real_stat);
|
|
#endif
|
|
#ifdef MOCK_STAT64
|
|
VIR_MOCK_REAL_INIT(stat64);
|
|
fdebug("real stat64 %p\n", real_stat64);
|
|
#endif
|
|
#ifdef MOCK___XSTAT
|
|
VIR_MOCK_REAL_INIT(__xstat);
|
|
fdebug("real __xstat %p\n", real___xstat);
|
|
#endif
|
|
#ifdef MOCK___XSTAT64
|
|
VIR_MOCK_REAL_INIT(__xstat64);
|
|
fdebug("real __xstat64 %p\n", real___xstat64);
|
|
#endif
|
|
#ifdef MOCK_LSTAT
|
|
# ifdef __APPLE__
|
|
VIR_MOCK_REAL_INIT_ALIASED(lstat, "lstat$INODE64");
|
|
# else
|
|
VIR_MOCK_REAL_INIT(lstat);
|
|
# endif
|
|
fdebug("real lstat %p\n", real_lstat);
|
|
#endif
|
|
#ifdef MOCK_LSTAT64
|
|
VIR_MOCK_REAL_INIT(lstat64);
|
|
fdebug("real lstat64 %p\n", real_lstat64);
|
|
#endif
|
|
#ifdef MOCK___LXSTAT
|
|
VIR_MOCK_REAL_INIT(__lxstat);
|
|
fdebug("real __lxstat %p\n", real___lxstat);
|
|
#endif
|
|
#ifdef MOCK___LXSTAT64
|
|
VIR_MOCK_REAL_INIT(__lxstat64);
|
|
fdebug("real __lxstat64 %p\n", real___lxstat64);
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* @stat: the path being queried
|
|
* @newpath: fill with redirected path, or leave NULL to use orig path
|
|
*
|
|
* Return 0 on success, -1 on allocation error
|
|
*/
|
|
static int virMockStatRedirect(const char *path, char **newpath);
|
|
|
|
#ifndef VIR_MOCK_STAT_HOOK
|
|
# define VIR_MOCK_STAT_HOOK do { } while (0)
|
|
#endif
|
|
|
|
#ifdef MOCK_STAT
|
|
# ifdef __APPLE__
|
|
int _stat(const char *path, struct stat *sb) __asm("_stat$INODE64");
|
|
int _stat(const char *path, struct stat *sb)
|
|
# else
|
|
int stat(const char *path, struct stat *sb)
|
|
# endif
|
|
{
|
|
g_autofree char *newpath = NULL;
|
|
|
|
virMockStatInit();
|
|
|
|
if (virMockStatRedirect(path, &newpath) < 0)
|
|
abort();
|
|
fdebug("stat redirect %s to %s sb=%p\n", path, newpath ? newpath : path, sb);
|
|
|
|
VIR_MOCK_STAT_HOOK;
|
|
|
|
return real_stat(newpath ? newpath : path, sb);
|
|
}
|
|
#endif
|
|
|
|
#ifdef MOCK_STAT64
|
|
int stat64(const char *path, struct stat64 *sb)
|
|
{
|
|
g_autofree char *newpath = NULL;
|
|
|
|
virMockStatInit();
|
|
|
|
if (virMockStatRedirect(path, &newpath) < 0)
|
|
abort();
|
|
fdebug("stat64 redirect %s to %s sb=%p\n", path, newpath ? newpath : path, sb);
|
|
|
|
VIR_MOCK_STAT_HOOK;
|
|
|
|
return real_stat64(newpath ? newpath : path, sb);
|
|
}
|
|
#endif
|
|
|
|
#ifdef MOCK___XSTAT
|
|
int
|
|
__xstat(int ver, const char *path, struct stat *sb)
|
|
{
|
|
g_autofree char *newpath = NULL;
|
|
|
|
virMockStatInit();
|
|
|
|
if (virMockStatRedirect(path, &newpath) < 0)
|
|
abort();
|
|
fdebug("__xstat redirect %s to %s sb=%p\n", path, newpath ? newpath : path, sb);
|
|
|
|
VIR_MOCK_STAT_HOOK;
|
|
|
|
return real___xstat(ver, newpath ? newpath : path, sb);
|
|
}
|
|
#endif
|
|
|
|
#ifdef MOCK___XSTAT64
|
|
int
|
|
__xstat64(int ver, const char *path, struct stat64 *sb)
|
|
{
|
|
g_autofree char *newpath = NULL;
|
|
|
|
virMockStatInit();
|
|
|
|
if (virMockStatRedirect(path, &newpath) < 0)
|
|
abort();
|
|
fdebug("__xstat64 redirect %s to %s sb=%p\n", path, newpath ? newpath : path, sb);
|
|
|
|
VIR_MOCK_STAT_HOOK;
|
|
|
|
return real___xstat64(ver, newpath ? newpath : path, sb);
|
|
}
|
|
#endif
|
|
|
|
#ifdef MOCK_LSTAT
|
|
# ifdef __APPLE__
|
|
int _lstat(const char *path, struct stat *sb) __asm("_lstat$INODE64");
|
|
int _lstat(const char *path, struct stat *sb)
|
|
# else
|
|
int
|
|
lstat(const char *path, struct stat *sb)
|
|
# endif
|
|
{
|
|
g_autofree char *newpath = NULL;
|
|
|
|
virMockStatInit();
|
|
|
|
if (virMockStatRedirect(path, &newpath) < 0)
|
|
abort();
|
|
fdebug("lstat redirect %s to %s sb=%p\n", path, newpath ? newpath : path, sb);
|
|
|
|
VIR_MOCK_STAT_HOOK;
|
|
|
|
return real_lstat(newpath ? newpath : path, sb);
|
|
}
|
|
#endif
|
|
|
|
#ifdef MOCK_LSTAT64
|
|
int
|
|
lstat64(const char *path, struct stat64 *sb)
|
|
{
|
|
g_autofree char *newpath = NULL;
|
|
|
|
virMockStatInit();
|
|
|
|
if (virMockStatRedirect(path, &newpath) < 0)
|
|
abort();
|
|
fdebug("lstat64 redirect %s to %s sb=%p\n", path, newpath ? newpath : path, sb);
|
|
|
|
VIR_MOCK_STAT_HOOK;
|
|
|
|
return real_lstat64(newpath ? newpath : path, sb);
|
|
}
|
|
#endif
|
|
|
|
#ifdef MOCK___LXSTAT
|
|
int
|
|
__lxstat(int ver, const char *path, struct stat *sb)
|
|
{
|
|
g_autofree char *newpath = NULL;
|
|
|
|
virMockStatInit();
|
|
|
|
if (virMockStatRedirect(path, &newpath) < 0)
|
|
abort();
|
|
fdebug("__lxstat redirect %s to %s sb=%p\n", path, newpath ? newpath : path, sb);
|
|
|
|
VIR_MOCK_STAT_HOOK;
|
|
|
|
return real___lxstat(ver, newpath ? newpath : path, sb);
|
|
}
|
|
#endif
|
|
|
|
#ifdef MOCK___LXSTAT64
|
|
int
|
|
__lxstat64(int ver, const char *path, struct stat64 *sb)
|
|
{
|
|
g_autofree char *newpath = NULL;
|
|
|
|
virMockStatInit();
|
|
|
|
if (virMockStatRedirect(path, &newpath) < 0)
|
|
abort();
|
|
fdebug("__lxstat64 redirect %s to %s sb=%p\n", path, newpath ? newpath : path, sb);
|
|
|
|
VIR_MOCK_STAT_HOOK;
|
|
|
|
return real___lxstat64(ver, newpath ? newpath : path, sb);
|
|
}
|
|
#endif
|