blindly applying the LargeAddressAware flag to your 32bit executable deploys a ticking time bomb! by setting this flag you are testifying to the OS: yes, my application (and all DLLs being loaded during runtime) can cope with memory addresses up to 4 GB. so don’t restrict the VAS for the process to 2 GB but … Read more
I suggest that you download the full software developer’s manual. The documentation is available in separate volumes, but that link gives you all seven volumes in a single massive PDF, which makes it easier to search for things. The answer is in section 3.3.7.1. The first line of that section states In 64-bit mode, an … Read more
The best way to disable locally the ASLR on a Linux-based system is to use processes personality flags. The command to manipulate personality flags is setarch with -R, –addr-no-randomize Disables randomization of the virtual address space (turns on ADDR_NO_RANDOMIZE). Here is how to proceed: $> setarch $(uname -m) -R /bin/bash This command runs a shell … Read more
Before I answer your questions (I hope I do), here are a few introductory remarks: Remarks The problem here is that “virtual memory” has two senses. “Virtual memory” as a technical term used by low-level programmers has (almost) nothing to do with “virtual memory” as explained to consumers. In the technical sense, “virtual memory” is … Read more
As Mads pointed out, in order to catch most accesses through null pointers, Unix-like systems tend to make the page at address zero “unmapped”. Thus, accesses immediately trigger a CPU exception, in other words a segfault. This is quite better than letting the application go rogue. The exception vector table, however, can be at any … Read more
Kernel and user space work with virtual addresses (also called linear addresses) that are mapped to physical addresses by the memory management hardware. This mapping is defined by page tables, set up by the operating system. DMA devices use bus addresses. On an i386 PC, bus addresses are the same as physical addresses, but other … Read more