lkl: Fix up libhijack stat ABI

We are hijacking `stat`, where the size of the target struct is
dependent on the wordsize. Delegating to `__xstat64` is incorrect, as it
unconditionally uses the stat64 layout and will result in an out-of-bounds
write on 32-bit architectures.

Additionally, the specification claims that the version must be
specified as 3 or the behavior is undefined (contradicting the existing
version specified as 0).

Fix the issue by delegating to the normal `stat` symbol instead, which
(while not having the version number interface) should be compatible
with whatever the underlying libc expects.
This also fully sidesteps the issue of replicating the version number
interface.

Fixes: d4b9b65 ("lkl: update dpdk version to 17.02 from 2.2")
Signed-off-by: Tim Schumacher <[email protected]>

Author: timschumi

tools/lkl/lib/hijack/hijack.c

@@ -587,11 +587,11 @@ void *mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset)
 }
 
 #ifndef __ANDROID__
-HOST_CALL(__xstat64)
+HOST_CALL(stat)
 int stat(const char *pathname, struct stat *buf)
 {
-	CHECK_HOST_CALL(__xstat64);
-	return host___xstat64(0, pathname, buf);
+	CHECK_HOST_CALL(stat);
+	return host_stat(pathname, buf);
 }
 #endif