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@xxxxxxxxxx> --- Validated with this pipeline: https://gitlab.com/berrange/libvirt/-/pipelines/209361200 meson.build | 28 ++++++++++++----- tests/virmockstathelpers.c | 62 ++++++++++++++++++++++---------------- 2 files changed, 56 insertions(+), 34 deletions(-) diff --git a/meson.build b/meson.build index c3ba34bbe0..365c16d167 100644 --- a/meson.build +++ b/meson.build @@ -636,10 +636,6 @@ libvirt_export_dynamic = cc.first_supported_link_argument([ # check availability of various common functions (non-fatal if missing) functions = [ - '__lxstat', - '__lxstat64', - '__xstat', - '__xstat64', 'elf_aux_info', 'fallocate', 'getauxval', @@ -653,8 +649,6 @@ functions = [ 'getuid', 'getutxid', 'if_indextoname', - 'lstat', - 'lstat64', 'mmap', 'newlocale', 'pipe2', @@ -666,12 +660,23 @@ functions = [ 'setgroups', 'setns', 'setrlimit', - 'stat', - 'stat64', 'symlink', 'sysctlbyname', ] +stat_functions = [ + '__lxstat', + '__lxstat64', + '__xstat', + '__xstat64', + 'lstat', + 'lstat64', + 'stat', + 'stat64', +] + +functions += stat_functions + foreach function : functions if cc.has_function(function) conf.set('WITH_@0@'.format(function.to_upper()), 1) @@ -679,6 +684,13 @@ foreach function : functions endforeach +foreach function : stat_functions + if cc.has_header_symbol('sys/stat.h', function) + conf.set('WITH_@0@_DECL'.format(function.to_upper()), 1) + endif +endforeach + + # various header checks headers = [ diff --git a/tests/virmockstathelpers.c b/tests/virmockstathelpers.c index 5c9759551d..3bd2437ffe 100644 --- a/tests/virmockstathelpers.c +++ b/tests/virmockstathelpers.c @@ -67,39 +67,49 @@ * - 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_STAT) -# if !defined(WITH___XSTAT) && !defined(WITH_STAT64) || defined(__APPLE__) -# define MOCK_STAT +#if !defined(WITH___LXSTAT_DECL) +# if defined(WITH_LSTAT) +# if !defined(WITH___LXSTAT) && !defined(WITH_LSTAT64) || defined(__APPLE__) +# define MOCK_LSTAT +# endif # endif -#endif -#if defined(WITH_STAT64) && !defined(WITH___XSTAT64) -# define MOCK_STAT64 -#endif -#if defined(WITH___XSTAT) && !defined(WITH___XSTAT64) -# define MOCK___XSTAT -#endif -#if defined(WITH___XSTAT64) -# define MOCK___XSTAT64 -#endif -#if defined(WITH_LSTAT) -# if !defined(WITH___LXSTAT) && !defined(WITH_LSTAT64) || defined(__APPLE__) -# define MOCK_LSTAT +# if defined(WITH_LSTAT64) +# define MOCK_LSTAT64 # endif -#endif -#if defined(WITH_LSTAT64) && !defined(WITH___LXSTAT64) -# define MOCK_LSTAT64 -#endif -#if defined(WITH___LXSTAT) && !defined(WITH___LXSTAT64) -# define MOCK___LXSTAT -#endif -#if defined(WITH___LXSTAT64) -# define MOCK___LXSTAT64 -#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); -- 2.28.0
