[TSan] [Darwin] Fix off by one in TSAN init due to MemoryRangeIsAvailable (llvm#169008)

ndrewh · ndrewh · commit b5f6ecd5af7d · 2025-11-21T09:48:06.000-08:00
(cherry picked from commit bb2e468)
diff --git a/compiler-rt/lib/tsan/rtl/tsan_platform_mac.cpp b/compiler-rt/lib/tsan/rtl/tsan_platform_mac.cpp
@@ -235,7 +235,7 @@ void InitializePlatformEarly() {
   }
   // In some configurations, the max_vm is expanded, but much of this space is
   // already mapped. TSAN will not work in this configuration.
-  if (!MemoryRangeIsAvailable(HiAppMemEnd() - 1, HiAppMemEnd())) {
+  if (!MemoryRangeIsAvailable(HiAppMemEnd() - 1, HiAppMemEnd() - 1)) {
     Report(
         "ThreadSanitizer: Unsupported virtual memory layout: Address %p is "
         "already mapped.\n",

Original file line number	Diff line number	Diff line change
`@@ -235,7 +235,7 @@ void InitializePlatformEarly() {`
`235`	`235`	`}`
`236`	`236`	`// In some configurations, the max_vm is expanded, but much of this space is`
`237`	`237`	`// already mapped. TSAN will not work in this configuration.`
`238`		`- if (!MemoryRangeIsAvailable(HiAppMemEnd() - 1, HiAppMemEnd())) {`
	`238`	`+ if (!MemoryRangeIsAvailable(HiAppMemEnd() - 1, HiAppMemEnd() - 1)) {`
`239`	`239`	`Report(`
`240`	`240`	`"ThreadSanitizer: Unsupported virtual memory layout: Address %p is "`
`241`	`241`	`"already mapped.\n",`