41 lines
1.4 KiB
C++
41 lines
1.4 KiB
C++
#include <kernel/UserCopy.h>
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extern "C" bool safe_user_memcpy(void*, const void*, size_t);
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extern "C" bool safe_user_strncpy(void*, const void*, size_t);
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static inline bool is_valid_user_address(const void* user_addr, size_t size)
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{
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const vaddr_t user_vaddr = reinterpret_cast<vaddr_t>(user_addr);
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if (BAN::Math::will_addition_overflow<vaddr_t>(user_vaddr, size))
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return false;
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if (user_vaddr + size > USERSPACE_END)
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return false;
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return true;
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}
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BAN::ErrorOr<void> Kernel::read_from_user(const void* user_addr, void* out, size_t size)
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{
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if (!is_valid_user_address(user_addr, size))
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return BAN::Error::from_errno(EFAULT);
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if (!safe_user_memcpy(out, user_addr, size))
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return BAN::Error::from_errno(EFAULT);
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return {};
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}
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BAN::ErrorOr<void> Kernel::read_string_from_user(const char* user_addr, char* out, size_t max_size)
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{
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max_size = BAN::Math::min<size_t>(max_size, USERSPACE_END - reinterpret_cast<vaddr_t>(user_addr));
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if (!is_valid_user_address(user_addr, max_size))
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return BAN::Error::from_errno(EFAULT);
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if (!safe_user_strncpy(out, user_addr, max_size))
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return BAN::Error::from_errno(EFAULT);
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return {};
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}
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BAN::ErrorOr<void> Kernel::write_to_user(void* user_addr, const void* in, size_t size)
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{
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if (!is_valid_user_address(user_addr, size))
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return BAN::Error::from_errno(EFAULT);
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if (!safe_user_memcpy(user_addr, in, size))
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return BAN::Error::from_errno(EFAULT);
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return {};
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}
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