Fix very long delays during core dump (#1)

GunshipPenguin · web-flow · commit 2e28165c7904 · 2025-03-23T18:26:41.000+01:00
It seems that commit llvm/llvm-project@c2a5703 from upstream LLVM was cherry-picked slightly incorrectly. MADV_DONTNEED should have been used when _not_ executing a dry run.
diff --git a/compiler-rt/lib/msan/msan_linux.cpp b/compiler-rt/lib/msan/msan_linux.cpp
@@ -155,7 +155,7 @@ static bool InitShadow(bool init_origins, bool dry_run) {
       if (!dry_run &&
           !MmapFixedSuperNoReserve(start, size, kMemoryLayout[i].name))
         return false;
-      if (dry_run && common_flags()->use_madv_dontdump)
+      if (!dry_run && common_flags()->use_madv_dontdump)
         DontDumpShadowMemory(start, size);
     }
     if (protect) {

Original file line number	Diff line number	Diff line change
`@@ -155,7 +155,7 @@ static bool InitShadow(bool init_origins, bool dry_run) {`
`155`	`155`	`if (!dry_run &&`
`156`	`156`	`!MmapFixedSuperNoReserve(start, size, kMemoryLayout[i].name))`
`157`	`157`	`return false;`
`158`		`- if (dry_run && common_flags()->use_madv_dontdump)`
	`158`	`+ if (!dry_run && common_flags()->use_madv_dontdump)`
`159`	`159`	`DontDumpShadowMemory(start, size);`
`160`	`160`	`}`
`161`	`161`	`if (protect) {`