Update JBCodeCacheManager to allocate segment objects on mmaped memory

This commit updates `JBCodeCacheManager` to allocate the `CodeCacheMemorySegment` object on the mmaped memory. The setter methods in `OMRCodeCacheMemorySegment` are also updated to guard the code updating members by `omrthread_jit_write_protect_disable/enable` calls. Signed-off-by: Akira Saitoh <[email protected]>
midronij · Oct 20, 2023 · 6e63f2e · 6e63f2e
1 parent 03f6b90
commit 6e63f2e
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Showing 3 changed files with 40 additions and 11 deletions.
diff --git a/compiler/runtime/OMRCodeCacheMemorySegment.cpp b/compiler/runtime/OMRCodeCacheMemorySegment.cpp
@@ -21,6 +21,7 @@
 
 #include "runtime/CodeCacheMemorySegment.hpp"
 #include "runtime/CodeCacheManager.hpp"
+#include "thread_api.h"
 
 TR::CodeCacheMemorySegment*
 OMR::CodeCacheMemorySegment::self()
@@ -42,3 +43,37 @@ OMR::CodeCacheMemorySegment::free(TR::CodeCacheManager *manager)
    manager->freeMemory(_base);
    new (static_cast<TR::CodeCacheMemorySegment *>(this)) TR::CodeCacheMemorySegment();
    }
+
+void
+OMR::CodeCacheMemorySegment::setSegmentBase(uint8_t *newBase)
+   {
+   /*
+    * Assuming the code cache memory segment is allocated on the code cache memory,
+    * we need to modify the memory's permission before and after updating members.
+    */
+   omrthread_jit_write_protect_disable();
+   _base = newBase;
+   omrthread_jit_write_protect_enable();
+   }
+
+void OMR::CodeCacheMemorySegment::setSegmentAlloc(uint8_t *newAlloc)
+   {
+   /*
+    * Assuming the code cache memory segment is allocated on the code cache memory,
+    * we need to modify the memory's permission before and after updating members.
+    */
+   omrthread_jit_write_protect_disable();
+   _alloc = newAlloc;
+   omrthread_jit_write_protect_enable();
+   }
+
+void OMR::CodeCacheMemorySegment::setSegmentTop(uint8_t *newTop)
+   {
+   /*
+    * Assuming the code cache memory segment is allocated on the code cache memory,
+    * we need to modify the memory's permission before and after updating members.
+    */
+   omrthread_jit_write_protect_disable();
+   _top = newTop;
+   omrthread_jit_write_protect_enable();
+   }
diff --git a/compiler/runtime/OMRCodeCacheMemorySegment.hpp b/compiler/runtime/OMRCodeCacheMemorySegment.hpp
@@ -63,9 +63,9 @@ class OMR_EXTENSIBLE CodeCacheMemorySegment
 
    void adjustAlloc(int64_t adjust);
 
-   void setSegmentBase(uint8_t *newBase)   { _base = newBase; }
-   void setSegmentAlloc(uint8_t *newAlloc) { _alloc = newAlloc; }
-   void setSegmentTop(uint8_t *newTop)     { _top = newTop; }
+   void setSegmentBase(uint8_t *newBase);
+   void setSegmentAlloc(uint8_t *newAlloc);
+   void setSegmentTop(uint8_t *newTop);
 
    // memory is backed by something else
    void free(TR::CodeCacheManager *manager);

diff --git a/jitbuilder/runtime/JBCodeCacheManager.cpp b/jitbuilder/runtime/JBCodeCacheManager.cpp
@@ -111,13 +111,10 @@ JitBuilder::CodeCacheManager::allocateCodeCacheSegment(size_t segmentSize,
       #undef NO_MAP_ANONYMOUS
    #endif
 #endif /* OMR_OS_WINDOWS */
-#if defined(OMR_ARCH_AARCH64) && defined(OSX)
-   TR::CodeCacheMemorySegment *memSegment = (TR::CodeCacheMemorySegment *) malloc(sizeof(TR::CodeCacheMemorySegment));
-   new (memSegment) TR::CodeCacheMemorySegment(memorySlab, reinterpret_cast<uint8_t *>(memorySlab) + codeCacheSizeToAllocate);
-#else  /* OMR_ARCH_AARCH64 && OSX */
+   omrthread_jit_write_protect_disable();
    TR::CodeCacheMemorySegment *memSegment = (TR::CodeCacheMemorySegment *) ((size_t)memorySlab + codeCacheSizeToAllocate - sizeof(TR::CodeCacheMemorySegment));
    new (memSegment) TR::CodeCacheMemorySegment(memorySlab, reinterpret_cast<uint8_t *>(memSegment));
-#endif
+   omrthread_jit_write_protect_enable();
    return memSegment;
    }
 
@@ -128,9 +125,6 @@ JitBuilder::CodeCacheManager::freeCodeCacheSegment(TR::CodeCacheMemorySegment *
    VirtualFree(memSegment->_base, 0, MEM_RELEASE); // second arg must be zero when calling with MEM_RELEASE
 #elif defined(J9ZOS390)
    free(memSegment->_base);
-#elif defined(OMR_ARCH_AARCH64) && defined(OSX)
-   munmap(memSegment->_base, memSegment->_top - memSegment->_base);
-   free(memSegment);
 #else
    munmap(memSegment->_base, memSegment->_top - memSegment->_base + sizeof(TR::CodeCacheMemorySegment));
 #endif