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Implement mmap Semantics: Map Region and Handle Page Faults

hard4/10

Build Simple Page Table: Map Virtual to Physical Addresses Implement Demand Paging: Allocate on First Access

Language

Compiler

2.0s Limit 256MB

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Implementation

Implement mmap() and page fault handling simulation.

Requirements:

Track memory mappings (address range, flags, backing file)
Implement mmap(addr, size, prot, flags, fd, offset)
Handle page faults when accessing mapped memory
Support MAP_ANONYMOUS and MAP_PRIVATE
Simulate demand paging (only load accessed pages)
munmap() to remove mapping
Print mapping list

Success Criteria:

mmap() returns valid address
Access triggers page fault handling
Page fault loads correct data
munmap() frees mapping

Why This Matters

mmap() is the same syscall the dynamic linker uses to map shared libraries into a process and that glibc's malloc calls directly once an allocation crosses its mmap threshold, bypassing the heap entirely. Confusing MAP_PRIVATE with MAP_SHARED is a classic production bug: one silently writes your changes back to the underlying file, the other never does.

Hints

0 / 3 revealed

Validation Suite

main.c

Workspace 1.0

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