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Kernel: Leave VMObject alone on OOM during CoW fault

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If we OOM during a CoW fault and fail to allocate a new page for the
writing process, just leave the original VMObject alone so everyone
else can keep using it.
This commit is contained in:
Andreas Kling 2020-04-28 16:25:04 +02:00
parent 9c856811b2
commit 4419685b7e
1 changed files with 1 additions and 1 deletions
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2
Kernel/VM/Region.cpp
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@ -397,12 +397,12 @@ PageFaultResponse Region::handle_cow_fault(size_t page_index_in_region)
#ifdef PAGE_FAULT_DEBUG #ifdef PAGE_FAULT_DEBUG
dbg() << " >> It's a COW page and it's time to COW!"; dbg() << " >> It's a COW page and it's time to COW!";
#endif #endif
auto physical_page_to_copy = move(page_slot);
auto page = MM.allocate_user_physical_page(MemoryManager::ShouldZeroFill::No); auto page = MM.allocate_user_physical_page(MemoryManager::ShouldZeroFill::No);
if (page.is_null()) { if (page.is_null()) {
klog() << "MM: handle_cow_fault was unable to allocate a physical page"; klog() << "MM: handle_cow_fault was unable to allocate a physical page";
return PageFaultResponse::ShouldCrash; return PageFaultResponse::ShouldCrash;
} }
auto physical_page_to_copy = move(page_slot);
u8* dest_ptr = MM.quickmap_page(*page); u8* dest_ptr = MM.quickmap_page(*page);
const u8* src_ptr = vaddr().offset(page_index_in_region * PAGE_SIZE).as_ptr(); const u8* src_ptr = vaddr().offset(page_index_in_region * PAGE_SIZE).as_ptr();
#ifdef PAGE_FAULT_DEBUG #ifdef PAGE_FAULT_DEBUG