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    <blockquote> <p>if I have an array allocated on the stack a pointer to the first element will also be lower > in value than a pointer to the second element ? </p> </blockquote> <p>It is not important "how" you allocate the array, you can increase or decrease the stack pointer, but as result you have address space reserved for the array.</p> <p>You can work with them in normal way, since the lowest adress is reserved for element 0.</p> <blockquote> <p>so my question is what is the correct memory layout for a process in Linux ? </p> </blockquote> <p>You can check it yourself. Insert somewhere into you program something like <code>std::cin.get()</code> to pause your program.</p> <p>Then run in a separate shell:</p> <pre><code>ps aux | grep your_program_name cat /proc/&lt;pid show by grep&gt;/maps </code></pre> <p>This prints the memory mappings of your process, where you can see where the heap, the stack and other things are placed in memory.</p> <p>About the stack: let's assume that you have ordinary machine with Linux and Intel or AMD 64 bit CPU. Then write the following code:</p> <pre><code>extern void f(int); void g(int param) { f(param); } </code></pre> <p>compile it and disassemble:</p> <pre><code>g++ -ggdb -c test_my_stack.cc &amp;&amp; objdump -S test_my_stack.o </code></pre> <p>you can see (unimportant details removed): </p> <pre><code> void g(int param) { 0: 55 push %rbp 1: 48 89 e5 mov %rsp,%rbp 4: 48 83 ec 10 sub $0x10,%rsp 8: 89 7d fc mov %edi,-0x4(%rbp) f(param); b: 8b 45 fc mov -0x4(%rbp),%eax </code></pre> <p>as you can see in <code>sub $0x10,%rsp</code> we reserved space in the stack by decreasing (moving down) the stack pointer.</p>
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    1. COI checked out the maps of the example program in my question and unless I am reading it wrong both the stack and heap grow from low to high 016ea000-0170b000 rw-p 00000000 00:00 0 [heap] 7fffe828a000-7fffe82ab000 rw-p 00000000 00:00 0 [stack] with lots of .so in the middle and I can't seem to find the place reserved for environment and CLA [gist with map](https://gist.github.com/ah450/5992828)
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    2. COyeah I totally forgot about the whole esp so that should mean it grows from high to low, but how come when I create a short pointer to an integer created on the stack the first short is still lower address than second ? or am I missing something?
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    3. COBecause of generated by compiler code not allocate stack per value, it allocate all at once. For your program it let's say allocate 0x50 bytes, then it say hey "stack" variable is "-0x34(%rbp)", "sptr" is -0x8(%rbp), so (uint8_t *)&stack < (uint8_t *)&sptr. This is because of it decrease stack pointer only once per function.
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