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			28 lines
		
	
	
	
		
			810 B
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			28 lines
		
	
	
	
		
			810 B
		
	
	
	
		
			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 <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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| // NOTE: The length is passed by pointer because off_t is 64bit,
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| // hence it can't be passed by register on 32bit platforms.
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| ErrorOr<FlatPtr> Process::sys$ftruncate(int fd, Userspace<off_t const*> userspace_length)
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| {
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|     VERIFY_NO_PROCESS_BIG_LOCK(this);
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|     TRY(require_promise(Pledge::stdio));
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|     auto length = TRY(copy_typed_from_user(userspace_length));
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|     if (length < 0)
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|         return EINVAL;
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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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|     TRY(description->truncate(static_cast<u64>(length)));
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|     return 0;
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| }
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| 
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| }
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