44 lines
1005 B
C++
44 lines
1005 B
C++
namespace factor {
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inline cell align_page(cell a) { return align(a, getpagesize()); }
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bool set_memory_locked(cell base, cell size, bool locked);
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// segments set up guard pages to check for under/overflow.
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// size must be a multiple of the page size
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struct segment {
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cell start;
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cell size;
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cell end;
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segment(cell size, bool executable_p);
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~segment();
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bool underflow_p(cell addr) {
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return addr >= (start - getpagesize()) && addr < start;
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}
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bool overflow_p(cell addr) {
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return addr >= end && addr < (end + getpagesize());
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}
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bool in_segment_p(cell addr) {
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return addr >= start && addr < end;
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}
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void set_border_locked(bool locked) {
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int pagesize = getpagesize();
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cell lo = start - pagesize;
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if (!set_memory_locked(lo, pagesize, locked)) {
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fatal_error("Cannot (un)protect low guard page", lo);
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}
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cell hi = end;
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if (!set_memory_locked(hi, pagesize, locked)) {
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fatal_error("Cannot (un)protect high guard page", hi);
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}
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}
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};
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}
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