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	 146903a3b5
			
		
	
	
		146903a3b5
		
	
	
	
	
		
			
			This matches out general macro use, and specifically other verification macros like VERIFY(), VERIFY_NOT_REACHED(), VERIFY_INTERRUPTS_ENABLED(), and VERIFY_INTERRUPTS_DISABLED().
		
			
				
	
	
		
			107 lines
		
	
	
	
		
			3.3 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			107 lines
		
	
	
	
		
			3.3 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /*
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|  * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
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|  *
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|  * SPDX-License-Identifier: BSD-2-Clause
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|  */
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| 
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| #include <AK/NumericLimits.h>
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| #include <Kernel/Debug.h>
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| #include <Kernel/FileSystem/OpenFileDescription.h>
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| #include <Kernel/Process.h>
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| 
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| namespace Kernel {
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| 
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| ErrorOr<FlatPtr> Process::sys$writev(int fd, Userspace<const struct iovec*> iov, int iov_count)
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| {
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|     VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this);
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|     TRY(require_promise(Pledge::stdio));
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|     if (iov_count < 0)
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|         return EINVAL;
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| 
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|     if (iov_count > IOV_MAX)
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|         return EFAULT;
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| 
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|     u64 total_length = 0;
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|     Vector<iovec, 32> vecs;
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|     TRY(vecs.try_resize(iov_count));
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|     TRY(copy_n_from_user(vecs.data(), iov, iov_count));
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|     for (auto& vec : vecs) {
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|         total_length += vec.iov_len;
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|         if (total_length > NumericLimits<i32>::max())
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|             return EINVAL;
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|     }
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| 
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|     auto description = TRY(open_file_description(fd));
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|     if (!description->is_writable())
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|         return EBADF;
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| 
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|     int nwritten = 0;
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|     for (auto& vec : vecs) {
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|         auto buffer = TRY(UserOrKernelBuffer::for_user_buffer((u8*)vec.iov_base, vec.iov_len));
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|         auto result = do_write(*description, buffer, vec.iov_len);
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|         if (result.is_error()) {
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|             if (nwritten == 0)
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|                 return result.release_error();
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|             return nwritten;
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|         }
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|         nwritten += result.value();
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|     }
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| 
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|     return nwritten;
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| }
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| 
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| ErrorOr<FlatPtr> Process::do_write(OpenFileDescription& description, UserOrKernelBuffer const& data, size_t data_size)
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| {
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|     size_t total_nwritten = 0;
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| 
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|     if (description.should_append() && description.file().is_seekable()) {
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|         TRY(description.seek(0, SEEK_END));
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|     }
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| 
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|     while (total_nwritten < data_size) {
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|         while (!description.can_write()) {
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|             if (!description.is_blocking()) {
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|                 if (total_nwritten > 0)
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|                     return total_nwritten;
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|                 return EAGAIN;
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|             }
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|             auto unblock_flags = Thread::FileBlocker::BlockFlags::None;
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|             if (Thread::current()->block<Thread::WriteBlocker>({}, description, unblock_flags).was_interrupted()) {
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|                 if (total_nwritten == 0)
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|                     return EINTR;
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|             }
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|             // TODO: handle exceptions in unblock_flags
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|         }
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|         auto nwritten_or_error = description.write(data.offset(total_nwritten), data_size - total_nwritten);
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|         if (nwritten_or_error.is_error()) {
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|             if (total_nwritten > 0)
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|                 return total_nwritten;
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|             if (nwritten_or_error.error().code() == EAGAIN)
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|                 continue;
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|             return nwritten_or_error.release_error();
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|         }
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|         VERIFY(nwritten_or_error.value() > 0);
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|         total_nwritten += nwritten_or_error.value();
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|     }
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|     return total_nwritten;
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| }
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| 
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| ErrorOr<FlatPtr> Process::sys$write(int fd, Userspace<u8 const*> data, size_t size)
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| {
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|     VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this);
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|     TRY(require_promise(Pledge::stdio));
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|     if (size == 0)
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|         return 0;
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|     if (size > NumericLimits<ssize_t>::max())
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|         return EINVAL;
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| 
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|     dbgln_if(IO_DEBUG, "sys$write({}, {}, {})", fd, data.ptr(), size);
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|     auto description = TRY(open_file_description(fd));
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|     if (!description->is_writable())
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|         return EBADF;
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| 
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|     auto buffer = TRY(UserOrKernelBuffer::for_user_buffer(data, static_cast<size_t>(size)));
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|     return do_write(*description, buffer, size);
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| }
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| 
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| }
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