CODEWITHSUNDEEP
pointersoperating-systemvirtual-memoryqnxdata-protection
igor
igor

Reputation: 1

why in most OS the first virtual page in any process with addresses 0:1000 is protected by OS

i understand that NULL pointer has special meaning and if pointer points to virtual address 0 then it will be same. So this is main reason of protection on first virtual page?

i tried to map the memory with fixed virtual addresses

Upvotes: 0

Views: 46

Answers (1)

user3344003
user3344003

Reputation: 21647

The only reason is to catch common programming errors involving uninitialized pointers. Doing so, makes a pointer to 0 point to nothing (NULL, NIL). Keep in mind that most operating systems allow users to map the first logical memory page to the address space if they really want to do so.

Upvotes: 0

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