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* Move getnameinfo from 'inet' to 'nss'Arjun Shankar2023-10-241-1/+1
| | | | | | | getnameinfo is an entry points for nss functionality. This commit moves it from the 'inet' subdirectory to 'nss'. The corresponding Versions entry is also moved from 'posix' into 'nss'. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Move getaddrinfo from 'posix' into 'nss'Arjun Shankar2023-10-2411-985/+1
| | | | | | | getaddrinfo is an entry point for nss functionality. This commit moves it from 'sysdeps/posix' to 'nss', gets rid of the stub in 'posix', and moves all associated tests as well. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Remove 'grp' and merge into 'nss' and 'posix'Arjun Shankar2023-10-243-1/+33
| | | | | | | | | | | | | | The majority of grp routines are entry points for nss functionality. This commit removes the 'grp' subdirectory and moves all nss-relevant functionality and all tests to 'nss', and the 'setgroups' stub into 'posix' (alongside the 'getgroups' stub). References to grp/ are accordingly changed. In addition, compat-initgroups.c, a fallback implementation of initgroups is renamed to initgroups-fallback.c so that the build system does not confuse it for nss_compat/compat-initgroups.c. Build time improves very slightly; e.g. down from an average of 45.5s to 44.5s on an 8-thread mobile x86_64 CPU. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Remove unused -DRESOLVER getaddrinfo build flagArjun Shankar2023-09-291-1/+1
| | | | | | | | getaddrinfo doesn't look for any RESOLVER defines for conditional compilation. Therefore, remove the unnecessary -DRESOLVER build flag in getaddrinfo's CFLAGS. Checked on x86_64 for code generation changes; none found.
* posix: Add pidfd_spawn and pidfd_spawnp (BZ 30349)Adhemerval Zanella Netto2023-09-0512-140/+271
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Returning a pidfd allows a process to keep a race-free handle for a child process, otherwise, the caller will need to either use pidfd_open (which still might be subject to TOCTOU) or keep the old racy interface base on pid_t. To correct use pifd_spawn, the kernel must support not only returning the pidfd with clone/clone3 but also waitid (P_PIDFD) (added on Linux 5.4). If kernel does not support the waitid, pidfd return ENOSYS. It avoids the need to racy workarounds, such as reading the procfs fdinfo to get the pid to use along with other wait interfaces. These interfaces are similar to the posix_spawn and posix_spawnp, with the only difference being it returns a process file descriptor (int) instead of a process ID (pid_t). Their prototypes are: int pidfd_spawn (int *restrict pidfd, const char *restrict file, const posix_spawn_file_actions_t *restrict facts, const posix_spawnattr_t *restrict attrp, char *const argv[restrict], char *const envp[restrict]) int pidfd_spawnp (int *restrict pidfd, const char *restrict path, const posix_spawn_file_actions_t *restrict facts, const posix_spawnattr_t *restrict attrp, char *const argv[restrict_arr], char *const envp[restrict_arr]); A new symbol is used instead of a posix_spawn extension to avoid possible issues with language bindings that might track the return argument lifetime. Although on Linux pid_t and int are interchangeable, POSIX only states that pid_t should be a signed integer. Both symbols reuse the posix_spawn posix_spawn_file_actions_t and posix_spawnattr_t, to void rehash posix_spawn API or add a new one. It also means that both interfaces support the same attribute and file actions, and a new flag or file action on posix_spawn is also added automatically for pidfd_spawn. Also, using posix_spawn plumbing allows the reusing of most of the current testing with some changes: - waitid is used instead of waitpid since it is a more generic interface. - tst-posix_spawn-setsid.c is adapted to take into consideration that the caller can check for session id directly. The test now spawns itself and writes the session id as a file instead. - tst-spawn3.c need to know where pidfd_spawn is used so it keeps an extra file description unused. Checked on x86_64-linux-gnu on Linux 4.15 (no CLONE_PIDFD or waitid support), Linux 5.4 (full support), and Linux 6.2. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* linux: Add posix_spawnattr_{get, set}cgroup_np (BZ 26371)Adhemerval Zanella Netto2023-09-053-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | These functions allow to posix_spawn and posix_spawnp to use CLONE_INTO_CGROUP with clone3, allowing the child process to be created in a different cgroup version 2. These are GNU extensions that are available only for Linux, and also only for the architectures that implement clone3 wrapper (HAVE_CLONE3_WRAPPER). To create a process on a different cgroupv2, one can use the: posix_spawnattr_t attr; posix_spawnattr_init (&attr); posix_spawnattr_setflags (&attr, POSIX_SPAWN_SETCGROUP); posix_spawnattr_setcgroup_np (&attr, cgroup); posix_spawn (...) Similar to other posix_spawn flags, POSIX_SPAWN_SETCGROUP control whether the cgroup file descriptor will be used or not with clone3. There is no fallback if either clone3 does not support the flag or if the architecture does not provide the clone3 wrapper, in this case posix_spawn returns EOPNOTSUPP. Checked on x86_64-linux-gnu. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* tst-*glob*: Do not check d_name sizeSamuel Thibault2023-08-032-2/+2
| | | | | | | Posix says that d_name is of unspecified size, and sizeof(d_name) should not be used. It is indeed only 1-byte long in bits/dirent.h. We can instead explictly provide the actual allocated size to __strcpy_chk.
* posix: Fix test-errno build with fortify enableAdhemerval Zanella Netto2023-07-261-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | With gcc 11.3.1, building with -D_FORTIFY_SOURCE=2 shows: In function ‘getgroups’, inlined from ‘do_test’ at test-errno.c:129:12: ../misc/sys/cdefs.h:195:6: error: argument 1 value -1 is negative [-Werror=stringop-overflow=] 195 | ? __ ## f ## _alias (__VA_ARGS__) \ | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ../posix/bits/unistd.h:115:10: note: in expansion of macro ‘__glibc_fortify’ 115 | return __glibc_fortify (getgroups, __size, sizeof (__gid_t), | ^~~~~~~~~~~~~~~ ../posix/bits/unistd.h: In function ‘do_test’: ../posix/bits/unistd-decl.h:135:28: note: in a call to function ‘__getgroups_alias’ declared with attribute ‘access (write_only, 2, 1)’ 135 | extern int __REDIRECT_NTH (__getgroups_alias, (int __size, __gid_t __list[]), | ^~~~~~~~~~~~~~~~~ ../misc/sys/cdefs.h:264:6: note: in definition of macro ‘__REDIRECT_NTH’ 264 | name proto __asm__ (__ASMNAME (#alias)) __THROW It builds fine with gcc 12 and gcc 13. Checked on x86_64-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* unistd: Avoid PLT entries with _FORTIFY_SOURCEFrédéric Bérat2023-07-051-3/+3
| | | | | | | The change is meant to avoid unwanted PLT entries for the read_chk, getdomainname_chk and getlogin_r_chk routines when _FORTIFY_SOURCE is set. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* posix/bits/unistd.h: Clearly separate declaration from definitionsFrédéric Bérat2023-07-053-153/+200
| | | | | | | | | | | This change is similar to what was done for bits/wchar2.h. Routines declaration are moved into a dedicated bits/unistd-decl.h file which is then included into the bits/unistd.h file. This will allow to adapt the files so that PLT entries are not created when _FORTIFY_SOURCE is enabled. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* Exclude routines from fortificationFrédéric Bérat2023-07-051-0/+11
| | | | | | | | | | | | | | | | | Since the _FORTIFY_SOURCE feature uses some routines of Glibc, they need to be excluded from the fortification. On top of that: - some tests explicitly verify that some level of fortification works appropriately, we therefore shouldn't modify the level set for them. - some objects need to be build with optimization disabled, which prevents _FORTIFY_SOURCE to be used for them. Assembler files that implement architecture specific versions of the fortified routines were not excluded from _FORTIFY_SOURCE as there is no C header included that would impact their behavior. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* Call "CST" a time zone abbreviation, not a namePaul Eggert2023-06-221-1/+1
| | | | | | In documentation, call strings like "CST" time zone abbreviations, not time zone names. This terminology is more precise, and is what tzdb uses. A string like "CST" is ambiguous and does not fully name a time zone.
* posix: Add test case for gai_strerror()Dridi Boukelmoune2023-06-132-0/+44
| | | | | Signed-off-by: Dridi Boukelmoune <dridi.boukelmoune@gmail.com> Reviewed-by: Arjun Shankar <arjun@redhat.com>
* tests: Replace various function calls with their x variantFrédéric Bérat2023-06-062-3/+6
| | | | | | | With fortification enabled, few function calls return result need to be checked, has they get the __wur macro enabled. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* tests: fix warn unused result on asprintf callsFrédéric Bérat2023-06-066-50/+16
| | | | | | | When enabling _FORTIFY_SOURCE, some functions now lead to warnings when their result is not checked. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* Fix all the remaining misspellings -- BZ 25337Paul Pluzhnikov2023-06-0218-47/+47
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* tests: fix warn unused resultsFrédéric Bérat2023-06-012-3/+6
| | | | | | With fortification enabled, few function calls return result need to be checked, has they get the __wur macro enabled. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* tests: replace ftruncate by xftruncateFrédéric Bérat2023-06-011-1/+2
| | | | | | | With fortification enabled, ftruncate calls return result needs to be checked, has it gets the __wur macro enabled. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* posix: Reformat Makefile.Carlos O'Donell2023-05-191-20/+20
| | | | | | | | Fix LOCALE list formatting. Sort all reflowed text using scripts/sort-makefile-lines.py. No code generation changes observed in binary artifacts. No regressions on x86_64 and i686.
* Fix regex type usageнаб2023-05-011-4/+4
| | | | | | | | | | | include/regex.h had not been updated during the int -> Idx transition, and the prototypes don't matched the definitions in regexec.c. In regcomp.c, most interfaces were updated for Idx, except for two ones guarded by #if _LIBC. Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz> Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* posix: Re-flow and sort multiline Makefile definitionsAdhemerval Zanella2023-04-201-126/+425
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* posix: Fix some crashes in wordexp [BZ #18096]Julian Squires2023-03-282-7/+8
| | | | | | | | | Without these fixes, the first three included tests segfault (on a NULL dereference); the fourth aborts on an assertion, which is itself unnecessary. Signed-off-by: Julian Squires <julian@cipht.net> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Move libc_freeres_ptrs and libc_subfreeres to hidden/weak functionsAdhemerval Zanella Netto2023-03-272-2/+4
| | | | | | | | | | | | | | | | | | | | They are both used by __libc_freeres to free all library malloc allocated resources to help tooling like mtrace or valgrind with memory leak tracking. The current scheme uses assembly markers and linker script entries to consolidate the free routine function pointers in the RELRO segment and to be freed buffers in BSS. This patch changes it to use specific free functions for libc_freeres_ptrs buffers and call the function pointer array directly with call_function_static_weak. It allows the removal of both the internal macros and the linker script sections. Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* rt: fix shm_open not set ENAMETOOLONG when name exceeds {_POSIX_PATH_MAX}abushwang2023-03-081-3/+9
| | | | | | | | according to man-pages-posix-2017, shm_open() function may fail if the length of the name argument exceeds {_POSIX_PATH_MAX} and set ENAMETOOLONG Signed-off-by: abushwang <abushwangs@gmail.com> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* posix: Ensure the initial signal disposition for tst-spawn7Adhemerval Zanella Netto2023-03-081-0/+6
| | | | | | | | | | To avoid possible failure if any parent set any initial signal disposition as SIG_IGN (for instance if the testcase is issued with nohup). Checked on x86_64-linux-gnu. Tested-by: Florian Weimer <fweimer@redhat.com> Reviewed-by: Florian Weimer <fweimer@redhat.com>
* __glob64_time64: Fix typo for stub_warning call (BZ #30146)Samuel Thibault2023-02-201-1/+1
| | | | The exported symbol is actually __glob64_time64, not glob64_time64.
* glob64_time64: Fix typo for stub_warning call (BZ #30146)Samuel Thibault2023-02-191-1/+1
| | | | | We were erroneously reporting a stub warning for glob64 instead of glob64_time64.
* Naming the parameter of dummy_sa_handlerMahesh Bodapati2023-02-131-1/+1
| | | | | | | | ISO C does not support omitting parameter names in function definitions before C2X,the compiler is giving an error with older versions of gcc and this commit will resolve the test failure "error: parameter name omitted" Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* hurd: Implement SHM_ANONSergey Bugaev2023-02-011-4/+21
| | | | | | | | | | | | | | | This adds a special SHM_ANON value that can be passed into shm_open () in place of a name. When called in this way, shm_open () will create a new anonymous shared memory file. The file will be created in the same way that other shared memory files are created (i.e., under /dev/shm/), except that it is not given a name and therefore cannot be reached from the file system, nor by other calls to shm_open (). This is accomplished by utilizing O_TMPFILE. This is intended to be compatible with FreeBSD's API of the same name. Signed-off-by: Sergey Bugaev <bugaevc@gmail.com> Message-Id: <20230130125216.6254-4-bugaevc@gmail.com>
* linux: Add clone3 CLONE_CLEAR_SIGHAND optimization to posix_spawnAdhemerval Zanella Netto2023-02-012-1/+181
| | | | | | | | | | | | | | | | | The clone3 flag resets all signal handlers of the child not set to SIG_IGN to SIG_DFL. It allows to skip most of the sigaction calls to setup child signal handling, where previously a posix_spawn had to issue 2 times NSIG sigaction calls (one to obtain the current disposition and another to set either SIG_DFL or SIG_IGN). With POSIX_SPAWN_SETSIGDEF the child will setup the signal for the case where the disposition is SIG_IGN. The code must handle the fallback where clone3 is not available. This is done by splitting __clone_internal_fallback from __clone_internal. Checked on x86_64-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* Update copyright dates not handled by scripts/update-copyrightsJoseph Myers2023-01-061-1/+1
| | | | | | I've updated copyright dates in glibc for 2023. This is the patch for the changes not generated by scripts/update-copyrights and subsequent build / regeneration of generated files.
* Update copyright dates with scripts/update-copyrightsJoseph Myers2023-01-06262-262/+262
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* posix: Make posix_spawn extensions available by defaultFlorian Weimer2022-11-041-2/+2
| | | | | | | | | | Some sources merely include <spawn.h> without -D_GNU_SOURCE and expect declarations for posix_spawn_file_actions_addchdir_np to be available. For consistency, declare posix_spawn_file_actions_addfchdir_np, posix_spawn_file_actions_addclosefrom_np, posix_spawn_file_actions_addtcsetpgrp_np as well. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* configure: Use -Wno-ignored-attributes if compiler warns about multiple aliasesAdhemerval Zanella2022-11-011-3/+3
| | | | | | | | | clang emits an warning when a double alias redirection is used, to warn the the original symbol will be used even when weak definition is overridden. However, this is a common pattern for weak_alias, where multiple alias are set to same symbol. Reviewed-by: Fangrui Song <maskray@google.com>
* posix: Suppress -Os may be used uninitialized warnings on regexecAdhemerval Zanella Netto2022-10-051-0/+6
| | | | | | | | GCC with -Os issues may uninitialized warnings on regexec code. Checked on x86_64-linux-gnu and i686-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* posix: Suppress -Os warnings on fnmatchAdhemerval Zanella Netto2022-10-051-0/+31
| | | | | | | | | | GCC with -Os issues some may uninitialized warnings on fnmatch code. All of the variables are already set when they are accessed on the loop prior. Checked on x86_64-linux-gnu and i686-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* Use '%z' instead of '%Z' on printf functionsAdhemerval Zanella Netto2022-09-222-3/+3
| | | | | | | | The Z modifier is a nonstandard synonymn for z (that predates z itself) and compiler might issue an warning for in invalid conversion specifier. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* Merge getopt patch from GnulibPaul Eggert2022-08-231-1/+2
| | | | | | * posix/getopt.c [!_LIBC]: Merge _WIN32 patch from Gnulib so that these source files are identical. This makes no difference for glibc.
* Merge _GL_UNUSED C23 patch from GnulibPaul Eggert2022-08-231-2/+2
| | | | | | | | | * posix/getopt.c (_getopt_initialize): * sysdeps/posix/tempname.c (try_dir, try_nocreate): Put _GL_UNUSED before args instead of after. This makes no difference for glibc. It is needed for Gnulib when being compiled on non-GCC C23 compilers.
* Replace __libc_multiple_threads with __libc_single_threadedAdhemerval Zanella2022-07-051-1/+1
| | | | | | | | | | | And also fixes the SINGLE_THREAD_P macro for SINGLE_THREAD_BY_GLOBAL, since header inclusion single-thread.h is in the wrong order, the define needs to come before including sysdeps/unix/sysdep.h. The macro is now moved to a per-arch single-threade.h header. The SINGLE_THREAD_P is used on some more places. Checked on aarch64-linux-gnu and x86_64-linux-gnu.
* misc: Optimize internal usage of __libc_single_threadedAdhemerval Zanella2022-06-241-1/+1
| | | | | | | | | | | | | | | By adding an internal alias to avoid the GOT indirection. On some architecture, __libc_single_thread may be accessed through copy relocations and thus it requires to update also the copies default copy. This is done by adding a new internal macro, libc_hidden_data_{proto,def}, which has an addition argument that specifies the alias name (instead of default __GI_ one). Checked on x86_64-linux-gnu and i686-linux-gnu. Reviewed-by: Fangrui Song <maskray@google.com>
* linux: Add process_madviseAdhemerval Zanella2022-06-021-1/+1
| | | | | | | | | | It was added on Linux 5.10 (ecb8ac8b1f146915aa6b96449b66dd48984caacc) with the same functionality as madvise but using a pidfd of the target process. Checked on x86_64-linux-gnu and i686-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* Fix deadlock when pthread_atfork handler calls pthread_atfork or dlcloseArjun Shankar2022-05-252-33/+114
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In multi-threaded programs, registering via pthread_atfork, de-registering implicitly via dlclose, or running pthread_atfork handlers during fork was protected by an internal lock. This meant that a pthread_atfork handler attempting to register another handler or dlclose a dynamically loaded library would lead to a deadlock. This commit fixes the deadlock in the following way: During the execution of handlers at fork time, the atfork lock is released prior to the execution of each handler and taken again upon its return. Any handler registrations or de-registrations that occurred during the execution of the handler are accounted for before proceeding with further handler execution. If a handler that hasn't been executed yet gets de-registered by another handler during fork, it will not be executed. If a handler gets registered by another handler during fork, it will not be executed during that particular fork. The possibility that handlers may now be registered or deregistered during handler execution means that identifying the next handler to be run after a given handler may register/de-register others requires some bookkeeping. The fork_handler struct has an additional field, 'id', which is assigned sequentially during registration. Thus, handlers are executed in ascending order of 'id' during 'prepare', and descending order of 'id' during parent/child handler execution after the fork. Two tests are included: * tst-atfork3: Adhemerval Zanella <adhemerval.zanella@linaro.org> This test exercises calling dlclose from prepare, parent, and child handlers. * tst-atfork4: This test exercises calling pthread_atfork and dlclose from the prepare handler. [BZ #24595, BZ #27054] Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* linux: Add P_PIDFDAdhemerval Zanella2022-05-172-7/+2
| | | | | | | | It was added on Linux 5.4 (3695eae5fee0605f316fbaad0b9e3de791d7dfaf) to extend waitid to wait on pidfd. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* posix/glob.c: update from gnulibDJ Delorie2022-04-271-12/+58
| | | | | | | | Copied from gnulib/lib/glob.c in order to fix rhbz 1982608 Also fixes swbz 25659 Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* Replace {u}int_fast{16|32} with {u}int32_tNoah Goldstein2022-04-131-1/+1
| | | | | | | | | On 32-bit machines this has no affect. On 64-bit machines {u}int_fast{16|32} are set as {u}int64_t which is often not ideal. Particularly x86_64 this change both saves code size and may save instruction cost. Full xcheck passes on x86_64.
* posix: Remove unused variable on tst-_Fork.cAdhemerval Zanella2022-03-311-1/+0
| | | | Checked on x86_64-linux-gnu and i686-linux-gnu.
* posix: Fix tst-spawn6 terminal handling (BZ #28853)Adhemerval Zanella2022-02-031-11/+51
| | | | | | | | | | | | | | | | | | | | | | The test changes the current foreground process group, which might break testing depending of how the make check is issued. For instance: nohup make -j1 test t=posix/tst-spawn6 | less Will set 'make' and 'less' to be in the foreground process group in the current session. When tst-spawn6 new child takes over it becomes the foreground process and 'less' is stopped and backgrounded which interrupts the 'make check' command. To fix it a pseudo-terminal is allocated, the test starts in new session (so there is no controlling terminal associated), and the pseudo-terminal is set as the controlling one (similar to what login_tty does). Checked on x86_64-linux-gnu. Tested-by: Carlos O'Donell <carlos@redhat.com> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* posix: Replace posix_spawnattr_tc{get,set}pgrp_np with ↵Adhemerval Zanella2022-02-0210-101/+122
| | | | | | | | | | | | | | | | | | posix_spawn_file_actions_addtcsetpgrp_np The posix_spawnattr_tcsetpgrp_np works on a file descriptor (the controlling terminal), so it would make more sense to actually fit it on the file actions API. Also, POSIX_SPAWN_TCSETPGROUP is not really required since it is implicit by the presence of tcsetpgrp file action. The posix/tst-spawn6.c is also fixed when TTY can is not present. Checked on x86_64-linux-gnu and i686-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* posix: Add terminal control setting support for posix_spawnAdhemerval Zanella2022-01-257-3/+251
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently there is no proper way to set the controlling terminal through posix_spawn in race free manner [1]. This forces shell implementations to keep using fork+exec when launching background process groups, even when using posix_spawn yields better performance. This patch adds a new GNU extension so the creating process can configure the created process terminal group. This is done with a new flag, POSIX_SPAWN_TCSETPGROUP, along with two new attribute functions: posix_spawnattr_tcsetpgrp_np, and posix_spawnattr_tcgetpgrp_np. The function sets a new attribute, spawn-tcgroupfd, that references to the controlling terminal. The controlling terminal is set after the spawn-pgroup attribute, and uses the spawn-tcgroupfd along with current creating process group (so it is composable with POSIX_SPAWN_SETPGROUP). To create a process and set the controlling terminal, one can use the following sequence: posix_spawnattr_t attr; posix_spawnattr_init (&attr); posix_spawnattr_setflags (&attr, POSIX_SPAWN_TCSETPGROUP); posix_spawnattr_tcsetpgrp_np (&attr, tcfd); If the idea is also to create a new process groups: posix_spawnattr_t attr; posix_spawnattr_init (&attr); posix_spawnattr_setflags (&attr, POSIX_SPAWN_TCSETPGROUP | POSIX_SPAWN_SETPGROUP); posix_spawnattr_tcsetpgrp_np (&attr, tcfd); posix_spawnattr_setpgroup (&attr, 0); The controlling terminal file descriptor is ignored if the new flag is not set. This interface is slight different than the one provided by QNX [2], which only provides the POSIX_SPAWN_TCSETPGROUP flag. The QNX documentation does not specify how the controlling terminal is obtained nor how it iteracts with POSIX_SPAWN_SETPGROUP. Since a glibc implementation is library based, it is more straightforward and avoid requires additional file descriptor operations to request the caller to setup the controlling terminal file descriptor (and it also allows a bit less error handling by posix_spawn). Checked on x86_64-linux-gnu and i686-linux-gnu. [1] https://github.com/ksh93/ksh/issues/79 [2] https://www.qnx.com/developers/docs/7.0.0/index.html#com.qnx.doc.neutrino.lib_ref/topic/p/posix_spawn.html Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
generated by cgit-pink 1.4.1 (git 2.36.1) at 2024-11-28 18:51:16 +0000