Storage of variable in stack frame under Linux platform

Local variables are stored in the stack, the stack in memory is characterized by top-down growth, that is, from the high address to the low address, when the variable as a function parameter is passed as a value, the function parameters as the receiver will open a temporary space to copy the value of the argument, the following code:

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When the function stack_test is called in the main function, the local variable, a and B are passed, at which point the debug can get the storage location of a A/b.

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After entering the function stack_test, temporarily opens up another space to copy the value of a, B, debugging can be derived

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Therefore, the formal parameter and the argument is not the same thing, but the value is the same, at this time, the output B, the value should be 0xbbbb, and then assign the address of a to the temporary pointer variable p, and then the P self-added, debugging can be

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So assigning a value of 0xdddd to the space pointed to by the pointer P is to change the B value in the function struct_test to 0XDDDD, but the B in the main function does not change, at this point the output B value is 0xdddd.

The following program:

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Running the program will restart the system because the function bug uses System ("reboot"); the system function calls fork to create a sub-process, in function stack_test, debugging can be

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The entry for the function bug is assigned to the pointer variable p,

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The 0x8048414 is converted to decimal to a value of 134513684 of the space that *p points to, which is to assign an offset of 0x8048414 to *p

When the Stack_test function ends, it calls the bug function.

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Storage of variable in stack frame under Linux platform