==================== Changes in man-pages-5.01 ==================== Released: 2019-05-09, Munich 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: Abhinav Upadhyay Andreas Korb Anisse Astier Brice Goglin Carlos O'Donell Dr. Jürgen Sauermann Egmont Koblinger Elias Benali Elliot Hughes Florian Weimer Hugues Evrard Jakub Nowak Jakub Wilk Keegan Saunders Lucas Werkmeister Marcus Huewe Michael Kerrisk Michael Witten Seth Troisi Slavomir Kaslev Vincent Lefevre Wladimir Mutel Apologies if I missed anyone! Newly documented interfaces in existing pages --------------------------------------------- tsearch.3 Florian Weimer [Michael Kerrisk] Document the twalk_r() function added in glibc 2.30 New and changed links --------------------- twalk_r.3 Michael Kerrisk New link to twalk(3) page Changes to individual pages --------------------------- accept.2 Michael Kerrisk Note that 'addrlen' is left unchanged in the event of an error See http://austingroupbugs.net/view.php?id=836. bpf.2 Michael Kerrisk Update kernel version info for JIT compiler clone.2 Michael Kerrisk [Jakub Nowak] CLONE_CHILD_SETTID has effect before clone() returns *in the child* CLONE_CHILD_SETTID may not have had effect by the time clone() returns in the parent, which could be relevant if the CLONE_VM flag is employed. The relevant kernel code is in schedule_tail(), which is called in ret_from_fork() in the child. See https://bugzilla.kernel.org/show_bug.cgi?id=203105 execve.2 exec.3 Michael Kerrisk [Dr. Jürgen Sauermann] Consistently use the term 'pathname' (not 'path') execve.2 Michael Kerrisk Note that stack+environ size is also limited to 3/4 of _STK_LIM In fs/exec.c::prepare_arg_pages(), we have: limit = _STK_LIM / 4 * 3; limit = min(limit, bprm->rlim_stack.rlim_cur / 4); Michael Kerrisk [Dr. Jürgen Sauermann] SEE ALSO: refer to exec(3) (rather than execl(3)) pipe.2 Michael Kerrisk Note that 'pipefd' is left unchanged in the event of an error See http://austingroupbugs.net/view.php?id=467. sched_setaffinity.2 Michael Kerrisk [Brice Goglin] Correct details of return value of sched_getaffinity() syscall Things changed a little with: commit cd3d8031eb4311e516329aee03c79a08333141f1 Author: KOSAKI Motohiro Date: Fri Mar 12 16:15:36 2010 +0900 setfsgid.2 Michael Kerrisk Rewrite for improved clarity and defer to setfsuid() for details Rewrite for improved clarity and defer to setfsuid(2) for the rationale of the fsGID rather than repeating the same details in this page. setfsuid.2 Michael Kerrisk Rewrite for improved clarity and to hint history more explicitly The current text reads somewhat clumsily. Rewrite it to introduce the eUID and fsUID in parallel, and more clearly hint at the the historical rationale for the fsUID, which is detailed lower in the page. socketpair.2 Michael Kerrisk Clarify that 'sv' is left unchanged in the event of an error See also http://austingroupbugs.net/view.php?id=483. splice.2 Slavomir Kaslev EAGAIN can occur when called on nonblocking file descriptors syscalls.2 Michael Kerrisk [Andreas Korb] Remove crufty text about i386 syscall dispatch table The removed text long ago ceased to be accurate. Nowadays, the dispatch table is autogenerated when building the kernel (via the kernel makefile, arch/x86/entry/syscalls/Makefile). tee.2 Slavomir Kaslev EAGAIN can occur when called on nonblocking file descriptors fopen.3 Elliot Hughes Explain BSD vs glibc "a+" difference Where is the initial read position for an "a+" stream? POSIX leaves this unspecified. Most BSD man pages are silent, and MacOS has the ambiguous "The stream is positioned at the end of the file", not differentiating between reads and writes other than to say that fseek(3) does not affect writes. glibc's documentation explicitly specifies that the initial read position is the beginning of the file. My new wording is based on the BSD implementations, so you may prefer to replace the non-glibc section with "unspecified", or indeed remove all claims about the initial read position. mallinfo.3 Elliott Hughes Further discourage use of mallinfo() The BUGS section already explains why you need to be cautious about using mallinfo, but given the number of bug reports we see on Android, it seems not many people are reading that far. Call it out up front. malloc_trim.3 Carlos O'Donell Update trimming information Since glibc 2.8, commit 68631c8eb92, the malloc_trim function has iterated over all arenas and free'd back to the OS all page runs that were free. This allows an application to call malloc_trim to consolidate fragmented chunks and free back any pages it can to potentially reduce RSS usage. posix_memalign.3 Elliot Hughes Some functions set errno True of bionic, glibc, and musl. (I didn't check elsewhere.) resolver.3 Michael Kerrisk [Wladimir Mutel] Mention that some functions set 'h_errno' stdarg.3 Michael Kerrisk [Vincent Lefevre] Remove the NOTES section describing the ancient varargs macros stdarg.h is now 30 years old, and gcc long ago (2004) ceased to implement . There seems little value in keeping this text. See https://bugzilla.kernel.org/show_bug.cgi?id=202907 Michael Kerrisk [Egmont Koblinger] Add a note that "..." in function signature means a variadic function Egmont suggested adding this, because the string "..." appears at several other points in the page, but just to indicate that some text is omitted from example code. strerror.3 Jakub Wilk Don't discuss buffer size for strerror_l() Unlike strerror_r(), strerror_l() doesn't take buffer length as an argument. strtol.3 strtoul.3 Jakub Wilk SEE ALSO: add strtoimax(3), strtoumax(3) sysconf.3 Michael Kerrisk [Hugues Evrard] Clearly note that _SC_PAGESIZE and _SC_PAGE_SIZE are synonyms tsearch.3 Florian Weimer Do not use const arguments in twalk() callback The const specifier is not part of the prototype (it only applies to the implementation), so showing it here confuses the reader. Michael Kerrisk SYNOPSIS: add missing definition of 'VISIT' type Michael Kerrisk Reformat twalk() and twalk_r() prototypes for easier readability console_codes.4 Jakub Wilk Document that \e[1;n] and \e[2;n] support 16 colors Source: setterm_command() in drivers/tty/vt/vt.c elf.5 Michael Kerrisk [Keegan Saunders] A data segment does not have PF_X proc.5 Michael Witten [Anisse Astier] Add missing Inode field to /proc/net/unix hostname.7 Florian Weimer HOSTALIASES/search path processing is DNS-specific Other NSS modules do not necessarily honor these settings. inode.7 Michael Kerrisk Note that timestamp fields measure time starting at the Epoch Michael Kerrisk Timestamp fields are structures that include a nanosecond component Michael Kerrisk Add references to execve(2) to describe set-UID/set-GID behaviors