==================== Changes in man-pages-5.12 ==================== Released: 2021-06-20, Christchurch Contributors ------------ The following people contributed patches/fixes or (noted in brackets in the changelog below) reports, notes, and ideas that have been incorporated in changes in this release: Ahelenia Ziemiańska Akihiro Motoki Alejandro Colomar Alyssa Ross Aurelien Aptel Borislav Petkov Bruce Merry Chris Keilbart Christian Brauner Christoph Anton Mitterer dann frazier Dmitry V. Levin Florian Weimer Huang Ying Jakub Wilk James O. D. Hunt Jann Horn Johannes Berg Jon Murphy Josh Triplett Katsuhiro Numata Kees Cook Mark Kettenis Mathieu Desnoyers Michael Kerrisk Mike Rapoport Peter Xu Sargun Dhillon Stefan Puiu Štěpán Němec thomasavoss Topi Miettinen Tycho Andersen Utkarsh Singh Vishwajith K Walter Harms Yang Xu Zhiheng Li наб Apologies if I missed anyone! New and rewritten pages ----------------------- seccomp_unotify.2 Michael Kerrisk [Tycho Andersen, Jann Horn, Kees Cook, Christian Brauner Sargun Dhillon] New page documenting the seccomp user-space notification mechanism MAX.3 Alejandro Colomar New page to document MAX() and MIN() Newly documented interfaces in existing pages --------------------------------------------- seccomp.2 Tycho Andersen [MichaelKerrisk] Document SECCOMP_GET_NOTIF_SIZES Tycho Andersen Document SECCOMP_FILTER_FLAG_NEW_LISTENER [Michael Kerrisk] Tycho Andersen Document SECCOMP_RET_USER_NOTIF [Michael Kerrisk] set_mempolicy.2 Huang Ying [Alejandro Colomar, "Huang, Ying"] Add mode flag MPOL_F_NUMA_BALANCING userfaultfd.2 Peter Xu [Alejandro Colomar, Mike Rapoport] Add UFFD_FEATURE_THREAD_ID docs Peter Xu [Alejandro Colomar, Mike Rapoport] Add write-protect mode docs Peter Xu [Alejandro Colomar, Mike Rapoport] Add UFFD_FEATURE_THREAD_ID docs proc.5 Michael Kerrisk Document /proc/sys/vm/sysctl_hugetlb_shm_group system_data_types.7 Alejandro Colomar Add 'blksize_t' Alejandro Colomar Add 'blkcnt_t' Alejandro Colomar Add 'mode_t' Alejandro Colomar Add 'struct sockaddr' Alejandro Colomar Add 'cc_t' Alejandro Colomar Add 'socklen_t' New and changed links --------------------- blkcnt_t.3 Alejandro Colomar New link to system_data_types(7) blksize_t.3 Alejandro Colomar New link to system_data_types(7) cc_t.3 Alejandro Colomar New link to system_data_types(7) MIN.3 Michael Kerrisk New link to MIN.3 mode_t.3 Alejandro Colomar New link to system_data_types(7) sockaddr.3 Alejandro Colomar New link to system_data_types(7) socklen_t.3 Alejandro Colomar New link to system_data_types(7) Global changes -------------- Many pages Alejandro Colomar SYNOPSIS: Use syscall(SYS_...); for system calls without a wrapper Many pages Alejandro Colomar SYNOPSIS: Document why each header is required Many pages Alejandro Colomar SYNOPSIS: Remove unused includes Many pages Alejandro Colomar Make clear why exactly is each header needed Various pages Alejandro Colomar Add note about the use of syscall(2) Various pages Alejandro Colomar SYNOPSIS: Miscellaneous fixes to includes A few pages Alejandro Colomar SYNOPSIS: Add missing 'const' Changes to individual pages --------------------------- dup.2 Michael Kerrisk Rewrite the description of dup() somewhat As can be seen by any number of StackOverflow questions, people persistently misunderstand what dup() does, and the existing manual page text, which talks of "copying" a file descriptor doesn't help. Rewrite the text a little to try to prevent some of these misunderstandings, in particular noting at the start that dup() allocates a new file descriptor. Michael Kerrisk Clarify what silent closing means Alejandro Colomar SYNOPSIS: Use consistent comments through pages epoll_wait.2 Alejandro Colomar Move misplaced subsection to NOTES from BUGS execveat.2 Michael Kerrisk Library support has been added in glibc 2.34 _exit.2 Michael Kerrisk Add a little more detail on the raw _exit() system cal exit_group.2 Alejandro Colomar Use 'noreturn' in prototypes flock.2 Aurelien Aptel [Alejandro Colomar] Add CIFS details CIFS flock() locks behave differently than the standard. Give an overview of those differences. ioperm.2 Alejandro Colomar Remove obvious comment memfd_create.2 mmap.2 shmget.2 Michael Kerrisk [Yang Xu] Document the EPERM error for huge page allocations This error can occur if the caller is does not have CAP_IPC_LOCK and is not a member of the sysctl_hugetlb_shm_group. mmap.2 Bruce Merry Clarify that MAP_POPULATE is best-effort mount.2 Topi Miettinen Document SELinux use of MS_NOSUID mount flag open.2 Alejandro Colomar [Walter Harms] Fix bug in linkat(2) call example AT_EMPTY_PATH works with empty strings (""), but not with NULL (or at least it's not obvious). Michael Kerrisk Make it clearer that an FD is an index into the process's FD table Sometimes people are confused, thinking a file descriptor is just a number.... perfmonctl.2 Michael Kerrisk This system call was removed in Linux 5.10 pipe.2 Alejandro Colomar SYNOPSIS: Fix incorrect prototype Michael Kerrisk Rearrange SYNOPSIS so that minority version pipe() is at end ptrace.2 Dmitry V. Levin [Alejandro Colomar, Mathieu Desnoyers] Mention PTRACE_GET_SYSCALL_INFO in RETURN VALUE section seccomp.2 Michael Kerrisk Reorder list of SECCOMP_SET_MODE_FILTER flags alphabetically (No content changes.) Michael Kerrisk SEE ALSO: add seccomp_unotify(2) select.2 Michael Kerrisk Strengthen the warning regarding the low value of FD_SETSIZE All modern code should avoid select(2) in favor of poll(2) or epoll(7). Michael Kerrisk Relocate sentence about the fd_set value-result arguments to BUGS syscalls.2 Michael Kerrisk perfmonctl(2) was removed in Linux 5.10 bswap.3 Alejandro Colomar bswap_*() are implemented using functions Even though it's true that they are macros, it's transparent to the user. The user will see their results casted to unsigned types after the conversion due to the underlying functions, so it's better to document these as the underlying functions, specifying the types. cmsg.3 unix.7 Michael Kerrisk Refer to seccomp_unotify(2) for an example of SCM_RIGHTS usage cpow.3 Alejandro Colomar Use 'complex' after the type consistently ctime.3 Michael Kerrisk [Katsuhiro Numata] Restore documentation of 'tm_gmtoff' field errno.3 Alejandro Colomar [Florian Weimer, Mark Kettenis] Fix ENODATA text ENODATA is an XSI STREAMS extension (not base POSIX). exec.3 Josh Triplett [Alejandro Colomar] Clarify that execvpe() uses PATH from the caller, not envp Josh Triplett [Alejandro Colomar] Fix description of 'e' variants The envp argument specifies the environment of the new process image, not "the environment of the caller". fflush.3 Alejandro Colomar SEE ALSO: Add fpurge(3) getline.3 наб [Ahelenia Ziemiańska, Alejandro Colomar] !*lineptr is sufficient No implementation or spec requires *n to be 0 to allocate a new buffer. getopt.3 James O. D. Hunt [Alejandro Colomar] Clarify behaviour printf.3 Utkarsh Singh [Alejandro Colomar] Add overall structure of format string pthread_attr_setinheritsched.3 pthread_attr_setschedparam.3 Alejandro Colomar SYNOPSIS: Use 'restrict' in prototypes pthread_mutexattr_setrobust.3 Michael Kerrisk Note that the *_np() APIs are deprecated since glibc 2.34 Alejandro Colomar SYNOPSIS: Remove incorrect 'const' pthread_mutex_consistent.3 Michael Kerrisk Note that pthread_mutexattr_setrobust() is now deprecated pthread_yield.3 Michael Kerrisk Note that this function is deprecated since glibc 2.34 rpc.3 Alejandro Colomar SYNOPSIS: Fix prototypes (misc.) scanf.3 Alyssa Ross [Alejandro Colomar] Clarify that %n supports type modifiers xdr.3 Alejandro Colomar SYNOPSIS: Fix prototype types Use the same types glibc uses, and add a missing 'const'. capabilities.7 Michael Kerrisk CAP_IPC_LOCK also governs memory allocation using huge pages environ.7 Josh Triplett [Alejandro Colomar] Remove obsolete admonishment of the GZIP environment variable kernel_lockdown.7 dann frazier [Alejandro Colomar] Remove description of lifting via SysRq (not upstream) The patch that implemented lockdown lifting via SysRq ended up getting dropped[*] before the feature was merged upstream. Having the feature documented but unsupported has caused some confusion for our users. mount_namespaces.7 namespaces.7 Michael Kerrisk Relocate reference to pam_namespace(8) from namespaces.7 to mount_namespaces.7. signal.7 Michael Kerrisk Add reference to seccomp_unotify(2) The seccomp user-space notification feature can cause changes in the semantics of SA_RESTART with respect to system calls that would never normally be restarted. Point the reader to the page that provide further details. vsock.7 Alyssa Ross ioctls are on /dev/vsock, not sockets