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Kernel: Flush the TLB (page only) when copying in a new kernel mapping

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Not flushing the TLB here puts us in an infinite page fault loop.
This commit is contained in:
Andreas Kling 2019-08-04 21:20:34 +02:00
parent 72798519cb
commit b5f1a4ac07
2 changed files with 3 additions and 2 deletions
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3
Kernel/VM/MemoryManager.cpp
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@ -408,8 +408,9 @@ PageFaultResponse MemoryManager::handle_page_fault(const PageFault& fault)
if (fault.is_not_present() && fault.vaddr().get() >= 0xc0000000) { if (fault.is_not_present() && fault.vaddr().get() >= 0xc0000000) {
u32 page_directory_index = (fault.vaddr().get() >> 22) & 0x3ff; u32 page_directory_index = (fault.vaddr().get() >> 22) & 0x3ff;
if (kernel_page_directory().entries()[page_directory_index].is_present()) { if (kernel_page_directory().entries()[page_directory_index].is_present()) {
current->process().page_directory().entries()[page_directory_index].copy_from({}, kernel_page_directory().entries()[page_directory_index]);
dbgprintf("NP(kernel): copying new kernel mapping for L%x into process\n", fault.vaddr().get()); dbgprintf("NP(kernel): copying new kernel mapping for L%x into process\n", fault.vaddr().get());
current->process().page_directory().entries()[page_directory_index].copy_from({}, kernel_page_directory().entries()[page_directory_index]);
flush_tlb(fault.vaddr().page_base());
return PageFaultResponse::Continue; return PageFaultResponse::Continue;
} }
} }

2
Kernel/VM/VirtualAddress.h
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@ -28,7 +28,7 @@ public:
u8* as_ptr() { return reinterpret_cast<u8*>(m_address); } u8* as_ptr() { return reinterpret_cast<u8*>(m_address); }
const u8* as_ptr() const { return reinterpret_cast<const u8*>(m_address); } const u8* as_ptr() const { return reinterpret_cast<const u8*>(m_address); }
u32 page_base() const { return m_address & 0xfffff000; } VirtualAddress page_base() const { return VirtualAddress(m_address & 0xfffff000); }
private: private:
u32 m_address { 0 }; u32 m_address { 0 };