From 35227fec9781dd85ef30257f12b857d58dec1840 Mon Sep 17 00:00:00 2001 From: Jon Turney Date: Sun, 5 Jul 2020 14:42:59 +0100 Subject: [PATCH] Cygwin: Don't dump non-writable image regions After this, we will end up dumping memory regions where: - state is MEM_COMMIT (i.e. is not MEM_RESERVE or MEM_FREE), and -- type is MEM_PRIVATE and protection allows reads (i.e. not a guardpage), or -- type is MEM_IMAGE and protection allows writes Making this decision based on the current protection isn't 100% correct, because it may have been changed using VirtualProtect(). But we don't know how to determine if a region is shareable. (As a practical matter, anything which gets us the stack (MEM_PRIVATE) and .data/.bss (RW MEM_IMAGE) is going to be enough for 99% of cases) --- winsup/utils/dumper.cc | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/winsup/utils/dumper.cc b/winsup/utils/dumper.cc index 2a0c66002..b96ee54cc 100644 --- a/winsup/utils/dumper.cc +++ b/winsup/utils/dumper.cc @@ -292,6 +292,12 @@ dumper::collect_memory_sections () int skip_region_p = 0; const char *disposition = "dumped"; + if ((mbi.Type & MEM_IMAGE) && !(mbi.Protect & (PAGE_EXECUTE_READWRITE | PAGE_READWRITE))) + { + skip_region_p = 1; + disposition = "skipped due to non-writeable MEM_IMAGE"; + } + if (mbi.Protect & PAGE_NOACCESS) { skip_region_p = 1;