Gidday, The Linux man-pages maintainer proudly announces:
man-pages-4.14 - man pages for Linux This release resulted from patches, bug reports, reviews, and comments from 71 contributors. Nearly 400 commits changed more than 160 pages. In addition, 4 new manual pages were added. Tarball download: http://www.kernel.org/doc/man-pages/download.html Git repository: https://git.kernel.org/cgit/docs/man-pages/man-pages.git/ Online changelog: http://man7.org/linux/man-pages/changelog.html#release_4.14 A short summary of the release is blogged at: http://linux-man-pages.blogspot.com/2017/11/man-pages-414-is-released.html The current version of the pages is browsable at: http://man7.org/linux/man-pages/ A selection of changes in this release that may be of interest to readers of LKML is shown below. Cheers, Michael ==================== Changes in man-pages-4.14 ==================== Released: 2017-11-26, Paris New and rewritten pages ----------------------- pthread_spin_init.3 Michael Kerrisk [Peter Zijlstra, Thomas Gleixner, Zack Weinberg, Florian Weimer] New page describing pthread_spin_init(3) and pthread_spin_destroy(3) pthread_spin_lock.3 Michael Kerrisk [Carlos O'Donell] New page describing functions that lock and unlock spin locks Add a page describing pthread_spin_lock(3), pthread_spin_unlock(3), and pthread_spin_trylock(3). smartpqi.4 Don Brace [Michael Kerrisk, G. Branden Robinson] Document the smartpqi SCSI driver veth.4 Tomáš Pospíšek, Eric Biederman, Michael Kerrisk New page document veth virtual ethernet devices Based on a page from Tomáš Pospíšek, with some clean-ups by mtk. Newly documented interfaces in existing pages --------------------------------------------- ioctl_userfaultfd.2 userfaultfd.2 Prakash Sangappa [Andrea Arcangeli, Mike Rapoport] Add description for UFFD_FEATURE_SIGBUS madvise.2 Rik van Riel [Colm MacCárthaigh, Michael Kerrisk] Document MADV_WIPEONFORK and MADV_KEEPONFORK Michael Kerrisk Note fork() and execve() semantics for wipe-on-fork setting membarrier.2 Mathieu Desnoyers Update membarrier manpage for 4.14 Add documentation for these new membarrier() commands: MEMBARRIER_CMD_PRIVATE_EXPEDITED MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED memfd_create.2 Mike Kravetz Add description of MFD_HUGETLB (hugetlbfs) support hugetlbfs support for memfd_create() was recently merged by Linus and should be in the Linux 4.14 release. To request hugetlbfs support a new memfd_create() flag (MFD_HUGETLB) was added. readv.2 Christoph Hellwig Document RWF_NOWAIT added in Linux 4.14 seccomp.2 Tyler Hicks Document the SECCOMP_GET_ACTION_AVAIL operation added in Linux 4.14 Tyler Hicks Document the SECCOMP_FILTER_FLAG_LOG flag added in Linux 4.14 Tyler Hicks Document the SECCOMP_RET_LOG action added In Linux 4.14 Michael Kerrisk [Kees Cook] Add description of SECCOMP_RET_KILL_PROCESS Michael Kerrisk Add SECCOMP_RET_KILL_THREAD description and rework SECCOMP_RET_KILL text Michael Kerrisk Document the seccomp audit logging feature added in Linux 4.14 seccomp.2 proc.5 Tyler Hicks Document the seccomp /proc interfaces added in Linux 4.14 Document the seccomp /proc interfaces in Linux 4.14: /proc/sys/kernel/seccomp/actions_avail and /proc/sys/kernel/seccomp/actions_logged. sigaltstack.2 Michael Kerrisk [Stas Sergeev] Document the SS_AUTODISARM flag added in Linux 4.7 proc.5 Michael Kerrisk Document /proc/locks Oliver Ebert Document /proc/kpagecgroup Oliver Ebert Add KPF_BALLOON, KPF_ZERO_PAGE, and KPF_IDLE for /proc/kpageflags pid_namespaces.7 Michael Kerrisk Document /proc/sys/kernel/ns_last_pid Changes to individual pages --------------------------- capget.2 Michael Kerrisk Clarify discussion of kernels that have no VFS capability support clone.2 Michael Kerrisk Warn that the clone() wrapper modifies child_stack in the parent io_submit.2 Goldwyn Rodrigues Add iocb details to io_submit Add more information about the iocb structure. Explains the fields of the I/O control block structure which is passed to the io_submit() call. mremap.2 Mike Kravetz [Florian Weimer, Jann Horn] Add description of old_size == 0 functionality Since at least the 2.6 time frame, mremap() would create a new mapping of the same pages if 'old_size == 0'. It would also leave the original mapping. This was used to create a 'duplicate mapping'. A recent change was made to mremap() so that an attempt to create a duplicate a private mapping will fail. Michael Kerrisk [Michal Hocko, Mike Kravetz] BUGS: describe older behavior for old_size==0 on private mappings Explain the older behavior, and why it changed. This is a follow-up to Mike Kravetz's patch documenting the behavior for old_size==0 with shared mappings. open.2 Michael Kerrisk By contrast with O_RDONLY, no file permissions are required for O_PATH Note one of the significant advantages of O_PATH: many of the operations applied to O_PATH file descriptors don't require read permission, so there's no reason why the open() itself should require read permission. open_by_handle_at.2 NeilBrown Clarifications needed due to NFS reexport NeilBrown [Lennart Poettering] Clarify MAX_HANDLE_SZ As hinted in the kernel source, MAX_HANDLE_SZ is a hint rather than a promise. pipe.2 Michael Kerrisk [Marin H.] Since Linux 4.5, fcntl() can be used to set O_DIRECT for a pipe See https://bugzilla.kernel.org/show_bug.cgi?id=197917 pkey_alloc.2 Breno Leitao Fix argument order Currently pkey_alloc() syscall has two arguments, and the very first argument is still not supported and should be set to zero. The second argument is the one that should specify the page access rights. reboot.2 Michael Kerrisk [Michał Zegan] Fix bogus description of reboot() from non-initial PID namespace The current text was confused (mea culpa). No signal is sent to the init() process. Rather, depending on the 'cmd' given to reboot(), the 'group_exit_code' value will set to either SIGHUP or SIGINT, with the effect that one of those signals is reported to wait() in the parent process. See https://bugzilla.kernel.org/show_bug.cgi?id=195899 sched_yield.2 Michael Kerrisk [Peter Zijlstra] sched_yield() is intended for use with real-time scheduling policies seccomp.2 Michael Kerrisk [Adhemerval Zanella, Florian Weimer, Kees Cook] Add some Caveats regarding the use of seccomp filters Michael Kerrisk Document the "default" filter return action The kernel defaults to either SECCOMP_RET_KILL_PROCESS or SECCOMP_RET_KILL_THREAD for unrecognized filter return action values. Michael Kerrisk [Kees Cook] Change SECCOMP_RET_ACTION to SECCOMP_RET_ACTION_FULL In Linux 4.14, the action component of the return value switched from being 15 bits to being 16 bits. A new macro, SECCOMP_RET_ACTION_FULL, that masks the 16 bits was added, to replace the older SECCOMP_RET_ACTION. Michael Kerrisk Explicitly note that other threads survive SECCOMP_RET_KILL_THREAD sigaction.2 Michael Kerrisk Rework discussion of SA_SIGINFO handler arguments Expand and rework the text a little, in particular adding a reference to sigreturn(2) as a source of further information about the ucontext argument. Michael Kerrisk Mention that libc sets the act.sa_restorer field sigreturn.2 Michael Kerrisk Make it a little clearer that a stack frame is created by the kernel Michael Kerrisk glibc has a simple wrapper for sigreturn() that returns ENOSYS stat.2 NeilBrown Correct AT_NO_AUTOMOUNT text and general revisions Expand on the relationship between fstatat() and the other three functions, and improve the description of AT_NO_AUTOMOUNT. Specifically, both stat() and lstat() act the same way with respect to automounts, and that behavior matches fstatat() with the AT_NO_AUTOMOUNT flag. exec.3 Michael Kerrisk glibc 2.24 dropped CWD from the default path Document the glibc 2.24 change that dropped CWD from the default search path employed by execlp(), execvp() and execvpe() when PATH is not defined. core.5 Michael Kerrisk Add some notes on systemd and core dumps Michael Kerrisk Dumps are not produced if core_pattern is empty and core_uses_pid is 0 Michael Kerrisk [Per Böhlin] RLIMIT_CORE is not enforced when piping core dump to a program proc.5 Michael Kerrisk [Miklos Szered, Ram Pai] Correct the description of the parent mount ID for /proc/PID/mountinfo Oliver Ebert Add mmap-exclusive bit for /proc/[pid]/pagemap Marcus Folkesson Update description of /proc/<pid>/oom_score Lucas Werkmeister Clarify permissions in /proc/[pid]/fd/ sysfs.5 Michael Kerrisk Add a brief explanation of /sys/kernel Michael Kerrisk Add a brief description of /sys/class/net Michael Kerrisk Add a brief description of /sys/kernel/mm Michael Kerrisk Add brief description of /sys/kernel/debug/tracing Michael Kerrisk Add a description of /sys/kernel/mm/hugepages socket.7 Michael Kerrisk [Petr Malat, Tobias Klausmann] Correct the description of SO_RXQ_OVFL user_namespaces.7 Christian Brauner [Michael Kerrisk] Document new 340 line idmap limit -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/