[compiler-rt] fc4c872 - [Darwin][ASan] Fix "interceptor working?" check for DriverKit platform

[Julian Lettner via llvm-commits]

Author: Blue Gaston
Date: 2022-04-06T15:49:22-07:00
New Revision: fc4c872d8f1e0c3409ba1fbc4761ffc984c7fdbd

URL: https://github.com/llvm/llvm-project/commit/fc4c872d8f1e0c3409ba1fbc4761ffc984c7fdbd
DIFF: https://github.com/llvm/llvm-project/commit/fc4c872d8f1e0c3409ba1fbc4761ffc984c7fdbd.diff

LOG: [Darwin][ASan] Fix "interceptor working?" check for DriverKit platform

The previous check for interceptors used `pthread_create()` which is not
available on DriverKit.  We need an intercepted symbol that satisfies
the following constraints:

- Symbol is available in DriverKit
- Symbol is provided by simulator runtime dylibs (`dlsym()` fails to
  look up host-provided symbols)

`puts()` satisfies all of the above constraints.

rdar://87895539

Reviewed By: yln

Differential Revision: https://reviews.llvm.org/D123245

Added: 
    

Modified: 
    compiler-rt/lib/sanitizer_common/sanitizer_mac.cpp

Removed: 
    


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diff  --git a/compiler-rt/lib/sanitizer_common/sanitizer_mac.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_mac.cpp
index a95719b06a2c0..41b90b9f35802 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_mac.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_mac.cpp
@@ -1059,12 +1059,12 @@ void MaybeReexec() {
   }
 
   // Verify that interceptors really work.  We'll use dlsym to locate
-  // "pthread_create", if interceptors are working, it should really point to
-  // "wrap_pthread_create" within our own dylib.
-  Dl_info info_pthread_create;
-  void *dlopen_addr = dlsym(RTLD_DEFAULT, "pthread_create");
-  RAW_CHECK(dladdr(dlopen_addr, &info_pthread_create));
-  if (internal_strcmp(info.dli_fname, info_pthread_create.dli_fname) != 0) {
+  // "puts", if interceptors are working, it should really point to
+  // "wrap_puts" within our own dylib.
+  Dl_info info_puts;
+  void *dlopen_addr = dlsym(RTLD_DEFAULT, "puts");
+  RAW_CHECK(dladdr(dlopen_addr, &info_puts));
+  if (internal_strcmp(info.dli_fname, info_puts.dli_fname) != 0) {
     Report(
         "ERROR: Interceptors are not working. This may be because %s is "
         "loaded too late (e.g. via dlopen). Please launch the executable "