[Msan] Fix some interceptors to pass initialization on FreeBSD

[eugenis]

LGTM

[eugenis]

In fact, I've seen getenv() on linux not working properly during MSan initialization, because it happens in .preinit_array and environ is simply not set at this point.

Just FYI. If msan_init somehow caused getenv() call, it might be getting unexpected results.

[kutuzov.viktor.84]

In fact, I've seen getenv() on linux not working properly during MSan initialization, because it happens in .preinit_array and environ is simply not set at this point.
Just FYI. If msan_init somehow caused getenv() call, it might be getting unexpected results.

Just checked it and it looks getenv() is fully workable at the moment of its first call. Thanks.

Closed by commit rL222885 (authored by vkutuzov).

compiler-rt/trunk/lib/msan/msan_interceptors.cc

INTERCEPTOR(void, malloc_stats, void) {
   // FIXME: implement, but don't call REAL(malloc_stats)!
 }
 #define MSAN_MAYBE_INTERCEPT_MALLOC_STATS INTERCEPT_FUNCTION(malloc_stats)
 #else
 #define MSAN_MAYBE_INTERCEPT_MALLOC_STATS
 #endif
 
 INTERCEPTOR(SIZE_T, strlen, const char *s) {
+  if (msan_init_is_running)
+    return REAL(strlen)(s);
   ENSURE_MSAN_INITED();
   SIZE_T res = REAL(strlen)(s);
   CHECK_UNPOISONED(s, res + 1);
   return res;
 }
 
 INTERCEPTOR(SIZE_T, strnlen, const char *s, SIZE_T n) {
   ENSURE_MSAN_INITED();
INTERCEPTOR(char *, fcvt, double x, int a, int *b, int *c) {
   char *res = REAL(fcvt)(x, a, b, c);
   __msan_unpoison(b, sizeof(*b));
   __msan_unpoison(c, sizeof(*c));
   if (res) __msan_unpoison(res, REAL(strlen)(res) + 1);
   return res;
 }
 
 INTERCEPTOR(char *, getenv, char *name) {
+  if (msan_init_is_running)
+    return REAL(getenv)(name);
   ENSURE_MSAN_INITED();
   char *res = REAL(getenv)(name);
   if (res) __msan_unpoison(res, REAL(strlen)(res) + 1);
   return res;
 }
 
 extern char **environ;
 
if (__msan_get_track_origins()) {
     u32 id;
     ChainedOriginDepotPut(stack_id, Origin::kHeapRoot, &id);
     __msan_set_origin(data, size, Origin(id, 1).raw_id());
   }
 }
 
 INTERCEPTOR(void *, mmap, void *addr, SIZE_T length, int prot, int flags,
             int fd, OFF_T offset) {
+  if (msan_init_is_running)
+    return REAL(mmap)(addr, length, prot, flags, fd, offset);
   ENSURE_MSAN_INITED();
   if (addr && !MEM_IS_APP(addr)) {
     if (flags & map_fixed) {
       *__errno_location() = errno_EINVAL;
       return (void *)-1;
     } else {
       addr = 0;
     }