NtAllocateVirtualMemory can change protection bits on existing pages

[derekbruening]

From bruen...@google.com on June 02, 2013 00:33:22

Fallout from https://code.google.com/p/drmemory/issues/detail?id=1258 **** TODO NtAllocateVirtualMemory can change protection bits on existing pages

As evidenced by this bug: so DR needs to watch it.

Currently calls app_memory_allocation() on any MEM_COMMIT -- but it returns
immediately if new prot is -x. So it won't catch app changing code from
+rx to +rw, e.g.

Need to also watch os_raw_mem_alloc() too, then!

**** TODO can NtAllocateVirtualMemory de-commit pages if new size is < old size?

**** TODO redirect_VirtualProtect() should call app_memory_protection_change()

today it blindly calls the syscall and doesn't route through DR

Original issue: http://code.google.com/p/dynamorio/issues/detail?id=1175

[derekbruening]

From derek.br...@gmail.com on June 04, 2013 07:51:26

This issue was closed by revision r2103 .

Status: Fixed