https://github.com/python/cpython/commit/a2932e9c95640cb98828f3e78545afacf78776f5 commit: a2932e9c95640cb98828f3e78545afacf78776f5 branch: main author: Maurycy Pawłowski-Wieroński <[email protected]> committer: vstinner <[email protected]> date: 2026-05-18T16:29:58+02:00 summary:
gh-149464: Add `os.pidfd_getfd(pidfd, targetfd, flags=0)` function (#149465) Co-authored-by: Bénédikt Tran <[email protected]> files: A Misc/NEWS.d/next/Library/2026-05-06-20-10-44.gh-issue-149464.3mPhcr.rst M Doc/library/os.rst M Doc/whatsnew/3.16.rst M Include/internal/pycore_global_objects_fini_generated.h M Include/internal/pycore_global_strings.h M Include/internal/pycore_runtime_init_generated.h M Include/internal/pycore_unicodeobject_generated.h M Lib/test/test_os/test_posix.py M Modules/clinic/posixmodule.c.h M Modules/posixmodule.c diff --git a/Doc/library/os.rst b/Doc/library/os.rst index d2534b3e974f36..f6be2dec0729f2 100644 --- a/Doc/library/os.rst +++ b/Doc/library/os.rst @@ -5062,6 +5062,18 @@ written in Python, such as a mail server's external command delivery program. .. availability:: Linux >= 5.10 .. versionadded:: 3.12 +.. function:: pidfd_getfd(pidfd, targetfd, *, flags=0) + + Duplicate *targetfd* from the process referred to by the process file + descriptor *pidfd*, into the calling process. The returned file descriptor + is :ref:`non-inheritable <fd_inheritance>`. + + *flags* is reserved, and currently must be ``0``. + + See the :manpage:`pidfd_getfd(2)` man page for more details. + + .. availability:: Linux >= 5.6, Android >= :func:`build-time <sys.getandroidapilevel>` API level 31 + .. versionadded:: next .. function:: plock(op, /) diff --git a/Doc/whatsnew/3.16.rst b/Doc/whatsnew/3.16.rst index cff0b8bbe32f0b..9383ce5665993e 100644 --- a/Doc/whatsnew/3.16.rst +++ b/Doc/whatsnew/3.16.rst @@ -86,10 +86,12 @@ New modules Improved modules ================ -module_name ------------ +os +-- -* TODO +* Add :func:`os.pidfd_getfd` for duplicating a file descriptor from another + process via a pidfd. Available on Linux 5.6+. + (Contributed by Maurycy Pawłowski-Wieroński in :gh:`149464`.) .. Add improved modules above alphabetically, not here at the end. diff --git a/Include/internal/pycore_global_objects_fini_generated.h b/Include/internal/pycore_global_objects_fini_generated.h index f7d3dcd440aaf1..7e6107e54a0ab6 100644 --- a/Include/internal/pycore_global_objects_fini_generated.h +++ b/Include/internal/pycore_global_objects_fini_generated.h @@ -1990,6 +1990,7 @@ _PyStaticObjects_CheckRefcnt(PyInterpreterState *interp) { _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(person)); _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(pi_factory)); _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(pid)); + _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(pidfd)); _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(pointer_bits)); _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(policy)); _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(pos)); @@ -2108,6 +2109,7 @@ _PyStaticObjects_CheckRefcnt(PyInterpreterState *interp) { _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(take_bytes)); _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(target)); _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(target_is_directory)); + _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(targetfd)); _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(task)); _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(tb_frame)); _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(tb_lasti)); diff --git a/Include/internal/pycore_global_strings.h b/Include/internal/pycore_global_strings.h index 22494b1798cc53..e0b05dde8fa377 100644 --- a/Include/internal/pycore_global_strings.h +++ b/Include/internal/pycore_global_strings.h @@ -713,6 +713,7 @@ struct _Py_global_strings { STRUCT_FOR_ID(person) STRUCT_FOR_ID(pi_factory) STRUCT_FOR_ID(pid) + STRUCT_FOR_ID(pidfd) STRUCT_FOR_ID(pointer_bits) STRUCT_FOR_ID(policy) STRUCT_FOR_ID(pos) @@ -831,6 +832,7 @@ struct _Py_global_strings { STRUCT_FOR_ID(take_bytes) STRUCT_FOR_ID(target) STRUCT_FOR_ID(target_is_directory) + STRUCT_FOR_ID(targetfd) STRUCT_FOR_ID(task) STRUCT_FOR_ID(tb_frame) STRUCT_FOR_ID(tb_lasti) diff --git a/Include/internal/pycore_runtime_init_generated.h b/Include/internal/pycore_runtime_init_generated.h index 892c3cdd9623a2..47c6226a7d2216 100644 --- a/Include/internal/pycore_runtime_init_generated.h +++ b/Include/internal/pycore_runtime_init_generated.h @@ -1988,6 +1988,7 @@ extern "C" { INIT_ID(person), \ INIT_ID(pi_factory), \ INIT_ID(pid), \ + INIT_ID(pidfd), \ INIT_ID(pointer_bits), \ INIT_ID(policy), \ INIT_ID(pos), \ @@ -2106,6 +2107,7 @@ extern "C" { INIT_ID(take_bytes), \ INIT_ID(target), \ INIT_ID(target_is_directory), \ + INIT_ID(targetfd), \ INIT_ID(task), \ INIT_ID(tb_frame), \ INIT_ID(tb_lasti), \ diff --git a/Include/internal/pycore_unicodeobject_generated.h b/Include/internal/pycore_unicodeobject_generated.h index f0fc3c4f5b0900..acad87c5045338 100644 --- a/Include/internal/pycore_unicodeobject_generated.h +++ b/Include/internal/pycore_unicodeobject_generated.h @@ -2632,6 +2632,10 @@ _PyUnicode_InitStaticStrings(PyInterpreterState *interp) { _PyUnicode_InternStatic(interp, &string); assert(_PyUnicode_CheckConsistency(string, 1)); assert(PyUnicode_GET_LENGTH(string) != 1); + string = &_Py_ID(pidfd); + _PyUnicode_InternStatic(interp, &string); + assert(_PyUnicode_CheckConsistency(string, 1)); + assert(PyUnicode_GET_LENGTH(string) != 1); string = &_Py_ID(pointer_bits); _PyUnicode_InternStatic(interp, &string); assert(_PyUnicode_CheckConsistency(string, 1)); @@ -3104,6 +3108,10 @@ _PyUnicode_InitStaticStrings(PyInterpreterState *interp) { _PyUnicode_InternStatic(interp, &string); assert(_PyUnicode_CheckConsistency(string, 1)); assert(PyUnicode_GET_LENGTH(string) != 1); + string = &_Py_ID(targetfd); + _PyUnicode_InternStatic(interp, &string); + assert(_PyUnicode_CheckConsistency(string, 1)); + assert(PyUnicode_GET_LENGTH(string) != 1); string = &_Py_ID(task); _PyUnicode_InternStatic(interp, &string); assert(_PyUnicode_CheckConsistency(string, 1)); diff --git a/Lib/test/test_os/test_posix.py b/Lib/test/test_os/test_posix.py index d0a662a091829e..1395156539a163 100644 --- a/Lib/test/test_os/test_posix.py +++ b/Lib/test/test_os/test_posix.py @@ -1604,6 +1604,34 @@ def test_pidfd_open(self): self.assertEqual(cm.exception.errno, errno.EINVAL) os.close(os.pidfd_open(os.getpid(), 0)) + @unittest.skipUnless(hasattr(os, "pidfd_getfd"), "pidfd_getfd unavailable") + def test_pidfd_getfd(self): + fd = os.open(__file__, os.O_RDONLY) + self.addCleanup(os.close, fd) + pidfd = os.pidfd_open(os.getpid(), 0) + self.addCleanup(os.close, pidfd) + try: + dupfd = os.pidfd_getfd(pidfd, fd) + except OSError as exc: + if exc.errno == errno.ENOSYS: + self.skipTest("system does not support pidfd_getfd") + if isinstance(exc, PermissionError): + self.skipTest(f"pidfd_getfd syscall blocked: {exc!r}") + raise + self.addCleanup(os.close, dupfd) + + self.assertFalse(os.get_inheritable(dupfd)) # PEP 446 + self.assertEqual(os.fstat(fd), os.fstat(dupfd)) + + with self.assertRaises(OSError) as cm: + os.pidfd_getfd(-1, 0) + self.assertEqual(cm.exception.errno, errno.EBADF) + + with self.assertRaises(OSError) as cm: + bad_fd = os_helper.make_bad_fd() + os.pidfd_getfd(pidfd, bad_fd) + self.assertEqual(cm.exception.errno, errno.EBADF) + @os_helper.skip_unless_hardlink @os_helper.skip_unless_symlink def test_link_follow_symlinks(self): diff --git a/Misc/NEWS.d/next/Library/2026-05-06-20-10-44.gh-issue-149464.3mPhcr.rst b/Misc/NEWS.d/next/Library/2026-05-06-20-10-44.gh-issue-149464.3mPhcr.rst new file mode 100644 index 00000000000000..9f987d2a662d8f --- /dev/null +++ b/Misc/NEWS.d/next/Library/2026-05-06-20-10-44.gh-issue-149464.3mPhcr.rst @@ -0,0 +1,3 @@ +Add :func:`os.pidfd_getfd` for duplicating a file descriptor from another +process via a pidfd. Available on Linux 5.6+. Patch by Maurycy +Pawłowski-Wieroński. diff --git a/Modules/clinic/posixmodule.c.h b/Modules/clinic/posixmodule.c.h index ad4c5dd1c9bc08..5403b875b04a32 100644 --- a/Modules/clinic/posixmodule.c.h +++ b/Modules/clinic/posixmodule.c.h @@ -6393,6 +6393,93 @@ os_pidfd_open(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObjec #endif /* (defined(__linux__) && defined(__NR_pidfd_open) && !(defined(__ANDROID__) && __ANDROID_API__ < 31)) */ +#if (defined(__linux__) && defined(__NR_pidfd_getfd) && !(defined(__ANDROID__) && __ANDROID_API__ < 31)) + +PyDoc_STRVAR(os_pidfd_getfd__doc__, +"pidfd_getfd($module, /, pidfd, targetfd, *, flags=0)\n" +"--\n" +"\n" +"Duplicate a file descriptor from the process referred to by *pidfd*.\n" +"\n" +" pidfd\n" +" A process file descriptor.\n" +" targetfd\n" +" The file descriptor to duplicate from the target process.\n" +" flags\n" +" Reserved, must be 0."); + +#define OS_PIDFD_GETFD_METHODDEF \ + {"pidfd_getfd", _PyCFunction_CAST(os_pidfd_getfd), METH_FASTCALL|METH_KEYWORDS, os_pidfd_getfd__doc__}, + +static PyObject * +os_pidfd_getfd_impl(PyObject *module, int pidfd, int targetfd, + unsigned int flags); + +static PyObject * +os_pidfd_getfd(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames) +{ + PyObject *return_value = NULL; + #if defined(Py_BUILD_CORE) && !defined(Py_BUILD_CORE_MODULE) + + #define NUM_KEYWORDS 3 + static struct { + PyGC_Head _this_is_not_used; + PyObject_VAR_HEAD + Py_hash_t ob_hash; + PyObject *ob_item[NUM_KEYWORDS]; + } _kwtuple = { + .ob_base = PyVarObject_HEAD_INIT(&PyTuple_Type, NUM_KEYWORDS) + .ob_hash = -1, + .ob_item = { &_Py_ID(pidfd), &_Py_ID(targetfd), &_Py_ID(flags), }, + }; + #undef NUM_KEYWORDS + #define KWTUPLE (&_kwtuple.ob_base.ob_base) + + #else // !Py_BUILD_CORE + # define KWTUPLE NULL + #endif // !Py_BUILD_CORE + + static const char * const _keywords[] = {"pidfd", "targetfd", "flags", NULL}; + static _PyArg_Parser _parser = { + .keywords = _keywords, + .fname = "pidfd_getfd", + .kwtuple = KWTUPLE, + }; + #undef KWTUPLE + PyObject *argsbuf[3]; + Py_ssize_t noptargs = nargs + (kwnames ? PyTuple_GET_SIZE(kwnames) : 0) - 2; + int pidfd; + int targetfd; + unsigned int flags = 0; + + args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser, + /*minpos*/ 2, /*maxpos*/ 2, /*minkw*/ 0, /*varpos*/ 0, argsbuf); + if (!args) { + goto exit; + } + pidfd = PyLong_AsInt(args[0]); + if (pidfd == -1 && PyErr_Occurred()) { + goto exit; + } + targetfd = PyLong_AsInt(args[1]); + if (targetfd == -1 && PyErr_Occurred()) { + goto exit; + } + if (!noptargs) { + goto skip_optional_kwonly; + } + if (!_PyLong_UnsignedInt_Converter(args[2], &flags)) { + goto exit; + } +skip_optional_kwonly: + return_value = os_pidfd_getfd_impl(module, pidfd, targetfd, flags); + +exit: + return return_value; +} + +#endif /* (defined(__linux__) && defined(__NR_pidfd_getfd) && !(defined(__ANDROID__) && __ANDROID_API__ < 31)) */ + #if defined(HAVE_SETNS) PyDoc_STRVAR(os_setns__doc__, @@ -13296,6 +13383,10 @@ os__emscripten_log(PyObject *module, PyObject *const *args, Py_ssize_t nargs, Py #define OS_PIDFD_OPEN_METHODDEF #endif /* !defined(OS_PIDFD_OPEN_METHODDEF) */ +#ifndef OS_PIDFD_GETFD_METHODDEF + #define OS_PIDFD_GETFD_METHODDEF +#endif /* !defined(OS_PIDFD_GETFD_METHODDEF) */ + #ifndef OS_SETNS_METHODDEF #define OS_SETNS_METHODDEF #endif /* !defined(OS_SETNS_METHODDEF) */ @@ -13611,4 +13702,4 @@ os__emscripten_log(PyObject *module, PyObject *const *args, Py_ssize_t nargs, Py #ifndef OS__EMSCRIPTEN_LOG_METHODDEF #define OS__EMSCRIPTEN_LOG_METHODDEF #endif /* !defined(OS__EMSCRIPTEN_LOG_METHODDEF) */ -/*[clinic end generated code: output=e709b8b783fbc261 input=a9049054013a1b77]*/ +/*[clinic end generated code: output=c4cf19262e42e352 input=a9049054013a1b77]*/ diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c index 5bd53c2146a822..7552cd150f0c2a 100644 --- a/Modules/posixmodule.c +++ b/Modules/posixmodule.c @@ -10777,6 +10777,35 @@ os_pidfd_open_impl(PyObject *module, pid_t pid, unsigned int flags) #endif +#if defined(__linux__) && defined(__NR_pidfd_getfd) && \ + !(defined(__ANDROID__) && __ANDROID_API__ < 31) +/*[clinic input] +os.pidfd_getfd + pidfd: int + A process file descriptor. + targetfd: int + The file descriptor to duplicate from the target process. + * + flags: unsigned_int = 0 + Reserved, must be 0. + +Duplicate a file descriptor from the process referred to by *pidfd*. +[clinic start generated code]*/ + +static PyObject * +os_pidfd_getfd_impl(PyObject *module, int pidfd, int targetfd, + unsigned int flags) +/*[clinic end generated code: output=e1a1415a13c7137f input=ef6417fb10deb1cc]*/ +{ + int fd = syscall(__NR_pidfd_getfd, pidfd, targetfd, flags); + if (fd < 0) { + return posix_error(); + } + return PyLong_FromLong(fd); +} +#endif + + #ifdef HAVE_SETNS /*[clinic input] os.setns @@ -17606,6 +17635,7 @@ static PyMethodDef posix_methods[] = { OS_WAITID_METHODDEF OS_WAITPID_METHODDEF OS_PIDFD_OPEN_METHODDEF + OS_PIDFD_GETFD_METHODDEF OS_GETSID_METHODDEF OS_SETSID_METHODDEF OS_SETPGID_METHODDEF _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
