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