Ensure we don't reallocate during 2GB address space block #49
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simonlindholm
approved these changes
Oct 2, 2023
main.cpp
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| const unsigned int FILL_MEMORY_ABOVE = 0x80000000; // 2GB | ||
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| while (getline(procMap, procLine)) { |
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ifstream is probably using a buffer internally, so it would make sense to start by switch this to reading the entire file using read() calls and then parsing out lines of that by hand.
simonlindholm
approved these changes
Oct 3, 2023
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AddsReplaced with Linux syscalls and stack buffer to avoid any allocations.procLine.reserve(0x8000);to ensure that thestd::stringdoesn't cause memory allocation between reading/proc/self/mapsand themmapcalls.ReplacesMAP_FIXEDwithMAP_FIXED_NOREPLACE(Linux 4.17+) to ensure that we bail if our mapping would overwrite an existing one.blockUpper2GBto simplify cleanup.-fno-pie -no-piecflags to ensure that we're not using PIE. (Probably unnecessary, but seems good)