220 }
221
222 void ZPhysicalMemoryBacking::unmap_view(ZPhysicalMemory pmem, uintptr_t addr) const {
223 // Note that we must keep the address space reservation intact and just detach
224 // the backing memory. For this reason we map a new anonymous, non-accessible
225 // and non-reserved page over the mapping instead of actually unmapping.
226 const size_t size = pmem.size();
227 const void* const res = mmap((void*)addr, size, PROT_NONE, MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE|MAP_NORESERVE, -1, 0);
228 if (res == MAP_FAILED) {
229 ZErrno err;
230 map_failed(err);
231 }
232 }
233
234 uintptr_t ZPhysicalMemoryBacking::nmt_address(uintptr_t offset) const {
235 // From an NMT point of view we treat the first heap mapping (marked0) as committed
236 return ZAddress::marked0(offset);
237 }
238
239 void ZPhysicalMemoryBacking::map(ZPhysicalMemory pmem, uintptr_t offset) const {
240 if (ZUnmapBadViews) {
241 // Only map the good view, for debugging only
242 map_view(pmem, ZAddress::good(offset), AlwaysPreTouch);
243 } else {
244 // Map all views
245 map_view(pmem, ZAddress::marked0(offset), AlwaysPreTouch);
246 map_view(pmem, ZAddress::marked1(offset), AlwaysPreTouch);
247 map_view(pmem, ZAddress::remapped(offset), AlwaysPreTouch);
248 }
249 }
250
251 void ZPhysicalMemoryBacking::unmap(ZPhysicalMemory pmem, uintptr_t offset) const {
252 if (ZUnmapBadViews) {
253 // Only map the good view, for debugging only
254 unmap_view(pmem, ZAddress::good(offset));
255 } else {
256 // Unmap all views
257 unmap_view(pmem, ZAddress::marked0(offset));
258 unmap_view(pmem, ZAddress::marked1(offset));
259 unmap_view(pmem, ZAddress::remapped(offset));
260 }
261 }
262
263 void ZPhysicalMemoryBacking::flip(ZPhysicalMemory pmem, uintptr_t offset) const {
264 assert(ZUnmapBadViews, "Should be enabled");
265 const uintptr_t addr_good = ZAddress::good(offset);
266 const uintptr_t addr_bad = ZAddress::is_marked(ZAddressGoodMask) ? ZAddress::remapped(offset) : ZAddress::marked(offset);
267 // Map/Unmap views
268 map_view(pmem, addr_good, false /* pretouch */);
269 unmap_view(pmem, addr_bad);
270 }
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220 }
221
222 void ZPhysicalMemoryBacking::unmap_view(ZPhysicalMemory pmem, uintptr_t addr) const {
223 // Note that we must keep the address space reservation intact and just detach
224 // the backing memory. For this reason we map a new anonymous, non-accessible
225 // and non-reserved page over the mapping instead of actually unmapping.
226 const size_t size = pmem.size();
227 const void* const res = mmap((void*)addr, size, PROT_NONE, MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE|MAP_NORESERVE, -1, 0);
228 if (res == MAP_FAILED) {
229 ZErrno err;
230 map_failed(err);
231 }
232 }
233
234 uintptr_t ZPhysicalMemoryBacking::nmt_address(uintptr_t offset) const {
235 // From an NMT point of view we treat the first heap mapping (marked0) as committed
236 return ZAddress::marked0(offset);
237 }
238
239 void ZPhysicalMemoryBacking::map(ZPhysicalMemory pmem, uintptr_t offset) const {
240 if (ZVerifyViews) {
241 // Map good view
242 map_view(pmem, ZAddress::good(offset), AlwaysPreTouch);
243 } else {
244 // Map all views
245 map_view(pmem, ZAddress::marked0(offset), AlwaysPreTouch);
246 map_view(pmem, ZAddress::marked1(offset), AlwaysPreTouch);
247 map_view(pmem, ZAddress::remapped(offset), AlwaysPreTouch);
248 }
249 }
250
251 void ZPhysicalMemoryBacking::unmap(ZPhysicalMemory pmem, uintptr_t offset) const {
252 if (ZVerifyViews) {
253 // Unmap good view
254 unmap_view(pmem, ZAddress::good(offset));
255 } else {
256 // Unmap all views
257 unmap_view(pmem, ZAddress::marked0(offset));
258 unmap_view(pmem, ZAddress::marked1(offset));
259 unmap_view(pmem, ZAddress::remapped(offset));
260 }
261 }
262
263 void ZPhysicalMemoryBacking::debug_map(ZPhysicalMemory pmem, uintptr_t offset) const {
264 // Map good view
265 assert(ZVerifyViews, "Should be enabled");
266 map_view(pmem, ZAddress::good(offset), false /* pretouch */);
267 }
268
269 void ZPhysicalMemoryBacking::debug_unmap(ZPhysicalMemory pmem, uintptr_t offset) const {
270 // Unmap good view
271 assert(ZVerifyViews, "Should be enabled");
272 unmap_view(pmem, ZAddress::good(offset));
273 }
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