An advantage of rst t is that it tends to retain

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Unformatted text preview: of these new areas are private copy-on-write The text and data areas are mapped to the text and data sections of the a.out file. The bss area is demand-zero, mapped to an anonymous file whose size is contained in a.out. The stack and heap area are also demand-zero, initially of zero-length. Figure 10.33 summarizes the different mappings of the private areas. 520 CHAPTER 10. VIRTUAL MEMORY user stack private, demand-zero .data .text Memory mapped region for shared libraries shared, file-backed runtime heap (via malloc) uninitialized data (.bss) initialized data (.data) private, demand-zero private, demand-zero private, file-backed a.out .data .text 0 program text (.text) Figure 10.33: How the loader maps the areas of the user address space. ¯ ¯ Map shared areas. If the a.out program was linked with shared objects, such as the standard C library, then these objects are dynamically linked into the program, and then mapped into the shared region of the user’s virtual address space. Set the program counter (PC). The last thing that execve does is to set the program counter in the curr...
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This note was uploaded on 09/02/2010 for the course ELECTRICAL 360 taught by Professor Schultz during the Spring '10 term at BYU.

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