[compiler-rt] 8d300e6 - [hwasan] Improve support of forking with threads (#75291)

[via llvm-commits]

Author: Vitaly Buka
Date: 2023-12-13T14:50:26-08:00
New Revision: 8d300e67d2227f55fc5056cd3eec8c62d084c1b9

URL: https://github.com/llvm/llvm-project/commit/8d300e67d2227f55fc5056cd3eec8c62d084c1b9
DIFF: https://github.com/llvm/llvm-project/commit/8d300e67d2227f55fc5056cd3eec8c62d084c1b9.diff

LOG: [hwasan] Improve support of forking with threads (#75291)

Lock Lsan and Thread related date at_fork.

Clean shadow before thread starts, forked process may reuse already
mapped stack of 'lost' parent thread for new threads.

Added: 
    

Modified: 
    compiler-rt/lib/hwasan/hwasan_linux.cpp
    compiler-rt/lib/hwasan/hwasan_thread.cpp
    compiler-rt/test/sanitizer_common/TestCases/Posix/fork_threaded.c

Removed: 
    


################################################################################
diff  --git a/compiler-rt/lib/hwasan/hwasan_linux.cpp b/compiler-rt/lib/hwasan/hwasan_linux.cpp
index f01fa427641347..3271a955e7ed10 100644
--- a/compiler-rt/lib/hwasan/hwasan_linux.cpp
+++ b/compiler-rt/lib/hwasan/hwasan_linux.cpp
@@ -523,12 +523,24 @@ uptr TagMemoryAligned(uptr p, uptr size, tag_t tag) {
 
 void HwasanInstallAtForkHandler() {
   auto before = []() {
-    HwasanAllocatorLock();
+    if (CAN_SANITIZE_LEAKS) {
+      __lsan::LockGlobal();
+    }
+    // `_lsan` functions defined regardless of `CAN_SANITIZE_LEAKS` and lock the
+    // stuff we need.
+    __lsan::LockThreads();
+    __lsan::LockAllocator();
     StackDepotLockAll();
   };
   auto after = []() {
     StackDepotUnlockAll();
-    HwasanAllocatorUnlock();
+    // `_lsan` functions defined regardless of `CAN_SANITIZE_LEAKS` and unlock
+    // the stuff we need.
+    __lsan::UnlockAllocator();
+    __lsan::UnlockThreads();
+    if (CAN_SANITIZE_LEAKS) {
+      __lsan::UnlockGlobal();
+    }
   };
   pthread_atfork(before, after, after);
 }

diff  --git a/compiler-rt/lib/hwasan/hwasan_thread.cpp b/compiler-rt/lib/hwasan/hwasan_thread.cpp
index ce36547580e6e6..3e14a718513d7f 100644
--- a/compiler-rt/lib/hwasan/hwasan_thread.cpp
+++ b/compiler-rt/lib/hwasan/hwasan_thread.cpp
@@ -68,6 +68,7 @@ void Thread::Init(uptr stack_buffer_start, uptr stack_buffer_size,
     }
     Print("Creating  : ");
   }
+  ClearShadowForThreadStackAndTLS();
 }
 
 void Thread::InitStackRingBuffer(uptr stack_buffer_start,

diff  --git a/compiler-rt/test/sanitizer_common/TestCases/Posix/fork_threaded.c b/compiler-rt/test/sanitizer_common/TestCases/Posix/fork_threaded.c
index 673d35346ba83f..1b4a0ad6140db4 100644
--- a/compiler-rt/test/sanitizer_common/TestCases/Posix/fork_threaded.c
+++ b/compiler-rt/test/sanitizer_common/TestCases/Posix/fork_threaded.c
@@ -1,7 +1,5 @@
 // RUN: %clang -O0 %s -o %t && %env_tool_opts=die_after_fork=0 %run %t
 
-// UNSUPPORTED: hwasan
-
 // The test uses pthread barriers which are not available on Darwin.
 // UNSUPPORTED: darwin