kernel/arch/x86_64/PageTable.cpp

@@ -17,7 +17,7 @@ extern uint8_t g_userspace_end[];
 namespace Kernel
 {
 
-	SpinLock PageTable::s_fast_page_lock;
+	RecursiveSpinLock PageTable::s_fast_page_lock;
 
 	static PageTable* s_kernel = nullptr;
 	static bool s_has_nxe = false;
@@ -214,7 +214,7 @@ namespace Kernel
 		ASSERT(s_kernel);
 		ASSERT(paddr);
 
-		ASSERT(s_fast_page_lock.current_processor_has_lock());
+		SpinLockGuard _(s_fast_page_lock);
 
 		constexpr vaddr_t uc_vaddr = uncanonicalize(fast_page());
 		constexpr uint64_t pml4e = (uc_vaddr >> 39) & 0x1FF;
@@ -237,7 +237,7 @@ namespace Kernel
 	{
 		ASSERT(s_kernel);
 
-		ASSERT(s_fast_page_lock.current_processor_has_lock());
+		SpinLockGuard _(s_fast_page_lock);
 
 		constexpr vaddr_t uc_vaddr = uncanonicalize(fast_page());
 		constexpr uint64_t pml4e = (uc_vaddr >> 39) & 0x1FF;

kernel/include/kernel/Memory/PageTable.h

@@ -130,7 +130,7 @@ namespace Kernel
 	private:
 		paddr_t						m_highest_paging_struct { 0 };
 		mutable RecursiveSpinLock	m_lock;
-		static SpinLock				s_fast_page_lock;
+		static RecursiveSpinLock	s_fast_page_lock;
 	};
 
 	static constexpr size_t range_page_count(vaddr_t start, size_t bytes)

kernel/include/kernel/Process.h

@@ -198,7 +198,6 @@ namespace Kernel
 		BAN::ErrorOr<int> block_until_exit(pid_t pid);
 
 		BAN::ErrorOr<void> validate_string_access(const char*);
-		BAN::ErrorOr<void> validate_pointer_access_check(const void*, size_t);
 		BAN::ErrorOr<void> validate_pointer_access(const void*, size_t);
 
 		uint64_t signal_pending_mask() const

kernel/kernel/Process.cpp

@@ -1857,7 +1857,7 @@ namespace Kernel
 		return validate_pointer_access(str, strlen(str) + 1);
 	}
 
-	BAN::ErrorOr<void> Process::validate_pointer_access_check(const void* ptr, size_t size)
+	BAN::ErrorOr<void> Process::validate_pointer_access(const void* ptr, size_t size)
 	{
 		ASSERT(&Process::current() == this);
 		auto& thread = Thread::current();
@@ -1894,27 +1894,4 @@ unauthorized_access:
 		return BAN::Error::from_errno(EINTR);
 	}
 
-	BAN::ErrorOr<void> Process::validate_pointer_access(const void* ptr, size_t size)
-	{
-		// TODO: This seems very slow as we loop over the range twice
-
-		TRY(validate_pointer_access_check(ptr, size));
-
-		const vaddr_t vaddr = reinterpret_cast<vaddr_t>(ptr);
-
-		// Make sure all of the pages are mapped here, so demand paging does not happen
-		// while processing syscall.
-		const vaddr_t page_start = vaddr & PAGE_ADDR_MASK;
-		const size_t page_count = range_page_count(vaddr, size);
-		for (size_t i = 0; i < page_count; i++)
-		{
-			const vaddr_t current = page_start + i * PAGE_SIZE;
-			if (page_table().get_page_flags(current) & PageTable::Flags::Present)
-				continue;
-			TRY(Process::allocate_page_for_demand_paging(current));
-		}
-
-		return {};
-	}
-
 }

script/build.sh

@@ -61,11 +61,7 @@ run_bochs () {
 }
 
 if [[ -c /dev/kvm ]]; then
-	if [[ -r /dev/kvm ]] && [[ -w /dev/kvm ]]; then
-		QEMU_ACCEL="-accel kvm"
-	else
-		echo "You don't have read/write permissions for /dev/kvm" >&2
-	fi
+	QEMU_ACCEL="-accel kvm"
 fi
 
 if [[ $# -eq 0 ]]; then