There is a lot to explain, but I try to make it as short as
possible. I'd start by pasting some parts of sys/stat.h:
extern int stat (const char *__restrict __file,
struct stat *__restrict __buf) __THROW __nonnull ((1, 2));
extern int __REDIRECT_NTH (stat, (const char *__restrict __file,
struct stat *__restrict __buf), stat64)
__nonnull ((1, 2));
__extern_inline int
__NTH (stat (const char *__path, struct stat *__statbuf))
{
return __xstat (_STAT_VER, __path, __statbuf);
}
Only one of these is effective at once, due to some usage of
the mess we are dealing with in here. So, basically, while
compiling or linking stat() in our code can be transformed into
some other func. Or a dragon.
Now, if you read stat(2) manpage, esp. "C library/kernel
differences" section, you'll learn that glibc uses some tricks
for older applications to work. I haven't gotten around actual
code that does this, but based on my observations, if 'stat'
symbol is found, glibc assumes it's dealing with ancient
application. Unfortunately, it can be just ours stat coming from
our mock. Therefore, calling stat() from a test will end up in
our mock. But since glibc is not exposing the symbol anymore, our
call of real_stat() will SIGSEGV immediately as the pointer to
function is NULL. Therefore, we should expose only those symbols
we know glibc has.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
It wasn't as great idea as I thought. Thing around stat() are
more complicated than that. Therefore we need to revert
86d1705a8a plus drop use of the macro as introduced in
later patches.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
All the accesses to files outside our build or source directories
are now identified and appended into a file for later processing.
The location of the file that contains all the records can be
controlled via VIR_TEST_FILE_ACCESS env variable and defaults to
abs_builddir "/test_file_access.txt".
The script that will process the access file is to be added in
next commit.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
The intent is that this library is going to be called every time
to check if we are not touching anything outside srcdir or
builddir.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
