(7) Miscellaneous Information Manual attributes - POSIX : <> GNU C. , , . , . : MT-Safe MT-Safe Thread-Safe . MT MT-Safe Multi Thread. MT-Safe , - POSIX, . , MT-Safe MT-Safe. , MT-Safe , , , . - , (inline) , , GNU C Library . MT-Safety . , , . MT-Unsafe , MT-Unsafe, . , , . , . , , , , . , , , , , . init MT-Unsafe , init, MT-Unsafe . , MT-Unsafe. , . race MT-Safety , race, , . , , . const MT-Safety , const, , , GNU C . MT-Unsafe race, , , const , . MT-Unsafe, , , MT-Safe ( , ), , . const . , , -, , , const , , , . sig MT-Safety , sig, , ( ). , . , ; . term MT-Safety , term, , : tcgetattr(3), tcsetattr(3), , , , . , term, MT-Unsafe. , , , , , , . , race:tcattr(fd), fd -- . , . , , , : locale MT-Safety , locale, . , locale, , . MT-Unsafe, , , , const:locale . , , , . env MT-Safety , env, getenv(3) - . MT-Unsafe, , , , const:env . , , , . hostid Functions marked with hostid as an MT-Safety issue read from the system-wide data structures that hold the "host ID" of the machine. These data structures cannot generally be modified atomically. Since it is expected that the "host ID" will not normally change, the function that reads from it (gethostid(3)) is regarded as safe, whereas the function that modifies it (sethostid(3)) is marked with const:hostid, indicating it may require special care if it is to be called. In this specific case, the special care amounts to system-wide (not merely intra-process) coordination. sigintr MT-Safety , sigintr, _sigintr GNU C - . MT-Unsafe, , , , const:sigintr . , , , . cwd , cwd MT-, , . MT-Unsafe, (, nftw(3) FTW_CHDIR), (, openat(2)). : , , , , , race const, , , sig. lock corrupt. , , , , , , :buf(arg) -- , arg, :tcattr(fd) -- fd. , , . / , , , . , /!ps /one_per_line , ps NULL one_per_line . , , , . pthreads(7), signal-safety(7) () Dmitry Bolkhovskikh Yuri Kozlov ; GNU (GNU General Public License - GPL, 3 ) , - . - , , () () () <>. Linux 6.17 8 2026 . (7)