[NFC][Sanitizer] Change "return type" of INTERCEPT_FUNCTION to void

[yln]

Summary

This temporary change tells us about all the places where the return
value of the INTERCEPT_FUNCTION macro is actually used. In the next
patch I will cleanup the macro and remove GetRealFuncAddress.

[yln]

compiler-rt/lib/asan/asan_interceptors.h

127

You said this protects against "double interception"?
If this works as expected, then should we push it up into INTERCEPT_FUNCTION?
Why do we only protect against "double interception" in ASan and MSan, but not the other sanitizers?

My best guess is that this has been obsolete for a while.

134

Note that this is different from above, it's essentially: (!REAL(name) || !REAL(name))

[vitalybuka]

compiler-rt/lib/interception/interception_linux.h

37

why?

compiler-rt/lib/msan/msan_interceptors.cc

1247

why you don't want to keep this comparison inside of INTERCEPT_FUNCTION_LINUX_OR_FREEBSD?

[vitalybuka]

compiler-rt/lib/asan/asan_interceptors.h

127

Yes, I would like to put this into INTERCEPT_FUNCTION
however maybe VReport is not available in all users

[yln]

compiler-rt/lib/asan/asan_interceptors.h

127

Got it. I will try to make this nicer/more uniform in follow-ups.

compiler-rt/lib/interception/interception_linux.h

37

So the compiler tells me all the places where the return value is used. I want to commit it like this so that the bots compile it for all the configurations that I can't test locally.

compiler-rt/lib/msan/msan_interceptors.cc

1247

It prevents the cleanups in [tsan_interceptors.cc] (see https://reviews.llvm.org/D59504).

We can not use TSAN_INTERCEPT to get setjmp addr,
because it does &setjmp and setjmp is not present in some versions of libc.

[rnk]

compiler-rt/trunk/lib/asan/asan_interceptors.h

125–127 ↗

(On Diff #196879)

I don't think this change is functionally correct on Windows. The interception mechanism on Windows is based on hotpatching, so the address comparison will always fail. This has created a minor regression in that now any asanified binary run with ASAN_OPTIONS=verbosity=1 emits "failed to intercept *" for every asan-specific interceptor. Checking the reteurn value was the correct thing to do for Windows. I want to revert this, WDYT?

[vitalybuka]

compiler-rt/trunk/lib/asan/asan_interceptors.h

125–127 ↗

(On Diff #196879)

Oh, I forgot about windows that didn't noticed that the check moved from LINUX_OR_FREEBSD into everything.
I guess it should be fine to revert it. but this needs to be reverted as well D61205
I guess yln@ is in different timezone.

[yln]

compiler-rt/trunk/lib/asan/asan_interceptors.h

125–127 ↗

(On Diff #196879)

Can we try to fix this for Windows instead of reverting altogether. I will provide a patch asap.

[rnk]

compiler-rt/trunk/lib/asan/asan_interceptors.h

125–127 ↗

(On Diff #196879)

The revert became rL359611. I can help review any relanding, but I'm not sure why we'd want INTERCEPT_FUNCTION to return void in the first place, it seems best to have some way to signal failure. Interception is inherently quite prone to failure, and a return value seems like the best, most portable way to signal that.

compiler-rt/lib/asan/asan_interceptors.h

 DECLARE_REAL(SIZE_T, strlen, const char *s)
 DECLARE_REAL(char*, strncpy, char *to, const char *from, uptr size)
 DECLARE_REAL(uptr, strnlen, const char *s, uptr maxlen)
 DECLARE_REAL(char*, strstr, const char *s1, const char *s2)
 
 #if !SANITIZER_MAC
 #define ASAN_INTERCEPT_FUNC(name)                                        \
   do {                                                                   \
-    if ((!INTERCEPT_FUNCTION(name) || !REAL(name)))                      \
+    INTERCEPT_FUNCTION(name);                                            \
+    bool same = (& (name) == & WRAP(name));                              \
+    if ((!same || !REAL(name)))                                          \
       VReport(1, "AddressSanitizer: failed to intercept '" #name "'\n"); \
   } while (0)
 #define ASAN_INTERCEPT_FUNC_VER(name, ver)                                     \
   do {                                                                         \
-    if ((!INTERCEPT_FUNCTION_VER(name, ver) || !REAL(name)))                   \
+    INTERCEPT_FUNCTION_VER(name, ver);                                         \
+    name##_type ptr = (::__interception::real_##name);                         \
+    if ((!ptr || !REAL(name)))                                                 \
       VReport(                                                                 \
           1, "AddressSanitizer: failed to intercept '" #name "@@" #ver "'\n"); \
   } while (0)
 #else
 // OS X interceptors don't need to be initialized with INTERCEPT_FUNCTION.
 #define ASAN_INTERCEPT_FUNC(name)
 #endif  // SANITIZER_MAC
 
 #endif  // !SANITIZER_FUCHSIA
 
 #endif  // ASAN_INTERCEPTORS_H

compiler-rt/lib/interception/interception_linux.h

 // returns true if a function with the given name was found.
 bool GetRealFunctionAddress(const char *func_name, uptr *func_addr,
     uptr real, uptr wrapper);
 void *GetFuncAddr(const char *name);
 void *GetFuncAddrVer(const char *name, const char *ver);
 }  // namespace __interception
 
 #define INTERCEPT_FUNCTION_LINUX_OR_FREEBSD(func)                          \
-  ::__interception::GetRealFunctionAddress(                                \
+  do { ::__interception::GetRealFunctionAddress(                           \
       #func, (::__interception::uptr *)&__interception::PTR_TO_REAL(func), \
       (::__interception::uptr) & (func),                                   \
-      (::__interception::uptr) & WRAP(func))
+      (::__interception::uptr) & WRAP(func));                              \
+  } while (0)  // TODO(yln): temporarily make macro void.
 
 // Android,  Solaris and OpenBSD do not have dlvsym
 #if !SANITIZER_ANDROID && !SANITIZER_SOLARIS && !SANITIZER_OPENBSD
 #define INTERCEPT_FUNCTION_VER_LINUX_OR_FREEBSD(func, symver) \
-  (::__interception::real_##func = (func##_type)(                \
-       unsigned long)::__interception::GetFuncAddrVer(#func, symver))
+  do { (::__interception::real_##func = (func##_type)(                \
+       unsigned long)::__interception::GetFuncAddrVer(#func, symver)); \
+  } while (0)
 #else
 #define INTERCEPT_FUNCTION_VER_LINUX_OR_FREEBSD(func, symver) \
   INTERCEPT_FUNCTION_LINUX_OR_FREEBSD(func)
 #endif  // !SANITIZER_ANDROID && !SANITIZER_SOLARIS
 
 #endif  // INTERCEPTION_LINUX_H
 #endif  // SANITIZER_LINUX || SANITIZER_FREEBSD || SANITIZER_NETBSD ||
         // SANITIZER_OPENBSD || SANITIZER_SOLARIS

compiler-rt/lib/msan/msan_interceptors.cc

 #define CHECK_UNPOISONED_CTX(ctx, x, n)                         \
   do {                                                          \
     if (!((MSanInterceptorContext *)ctx)->in_interceptor_scope) \
       CHECK_UNPOISONED_0(x, n);                                 \
   } while (0)
 
 #define MSAN_INTERCEPT_FUNC(name)                                       \
   do {                                                                  \
-    if ((!INTERCEPT_FUNCTION(name) || !REAL(name)))                     \
+    INTERCEPT_FUNCTION(name);                                           \
+    bool same = (& (name) == & WRAP(name));                             \
+    if ((!same || !REAL(name)))                                         \
       VReport(1, "MemorySanitizer: failed to intercept '" #name "'\n"); \
   } while (0)
 
 #define MSAN_INTERCEPT_FUNC_VER(name, ver)                                    \
   do {                                                                        \
-    if ((!INTERCEPT_FUNCTION_VER(name, ver) || !REAL(name)))                  \
+    INTERCEPT_FUNCTION_VER(name, ver);                                        \
+    name##_type ptr = (::__interception::real_##name);                        \
+    if ((!ptr || !REAL(name)))                                                \
       VReport(                                                                \
           1, "MemorySanitizer: failed to intercept '" #name "@@" #ver "'\n"); \
   } while (0)
 
 #define COMMON_INTERCEPT_FUNCTION(name) MSAN_INTERCEPT_FUNC(name)
 #define COMMON_INTERCEPT_FUNCTION_VER(name, ver)                          \
   MSAN_INTERCEPT_FUNC_VER(name, ver)
 #define COMMON_INTERCEPTOR_UNPOISON_PARAM(count)  \