12/8/2022 0 Comments Itimer linux![]() ![]() ![]() Get_robust_list() - The robust-futex list can be retrieved with this kernel call. Get_mempolicy() - To get the NUMA memory policy for a process, use this syscall. NOTE: A symbol is a function or variable. Get_kernel_syms() - All of the exported module and kernel symbols can be read with this system call. #Itimer linux codeAny code that calls futex() must be written in non-portable assembly instructions. With this syscall, threads and processes can adhere to the futex standard so the executing code can wait for shared resources. Null bytes are designated as a backslash zero (\0).įutex() - Futex stands for Fast User-space muTEX. This may mean cutting the file, thus losing data, or enlarging the file by adding null bytes. This system call is directed to the filesystem in question by using a file descriptor of any given file on that filesystem.įtruncate() - With a given file descriptor, this kernel call will truncate the specified file to a desired length. #Itimer linux freeMany other attributes are not inherited.įree_hugepages() - Free huge pages (large chunks of memory).įremovexattr() - When using a file descriptor, this syscall can remove an extended attribute.įsetxattr() - With a known file descriptor, an extended attribute can be set.įstat() - The status of a file can be read with this syscall when given a file descriptor.įstatat() - With a directory file descriptor, a file's status can be read.įstatfs() - The statistics of a filesystem can be retrieved with this kernel call. With this call, the child process gets its own PID and memory space. However, fchown() knows the file by its file descriptor, not its path.įchownat() - This syscall is just like fchown().įcntl() - Manipulate the specified file descriptor.įgetxattr() - This syscall gets the value of the specified extended file attribute.įinit_module() - Using a file descriptor, an ELF-image is loaded into the kernel space.įlistxattr() - Given a file descriptor, this syscall will list the extended attributes owned by the specified file.įlock() - Create or remove an advisory lock on the specified file (the file must be open).įork() - Child processes are commonly created using this kernel call. fchmod() and fchmodat() work a little differently from each other.įchown() - Just like chown(), the owner of the specified file is changed. fchmodat() is exactly like chmod() with the difference being their accepted input, a file descriptor and path, respectively. The difference lies in the fact chmod() accepts a path name and fchmod() accepts a file descriptor instead.įchmodat() - This system call changes a file's permissions and the file is specified using a file descriptor. fallocate() also works on some pseudo/virtual filesystems like tmpfs.įchmod() - This syscall is the same thing as chmod(). Obviously, since every filesystem type (XFS, EXT4, NTFS, tmpfs, etc.) is different, this syscall does not work on all filesystems. ![]() This speeds up data access for the kernel.įallocate() - Disk space of a specified file is manipulated by this kernel call. #Itimer linux how toSpecifically, this syscall plans ahead what file will be accessed and how to get the data. Posix_fadvise() - (commonly called fadvice(), although the actual call is posix_fadvise()) This system call is used to optimize data access. NOTE: In the most simplest terms, a file descriptor is a special number used to access a file. Do not worry, this will not be as long as the configuration part of the kernel series.įaccessat() - The permissions for the specified file is checked, but this is performed using a directory file descriptor. In this next article, we will continue discussing the system calls. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |