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diff --git a/Modules/_posixsubprocess.c b/Modules/_posixsubprocess.c
index 07dd54dba9..ef1b7a8ad5 100644
--- Modules/_posixsubprocess.c
+++ Modules/_posixsubprocess.c
@@ -21,6 +21,8 @@
#include <dirent.h>
#endif
+#include "posixmodule.h"
+
#ifdef _Py_MEMORY_SANITIZER
# include <sanitizer/msan_interface.h>
#endif
@@ -222,7 +222,6 @@ _close_fds_by_brute_force(long start_fd, PyObject *py_fds_to_keep)
long end_fd = safe_get_max_fd();
Py_ssize_t num_fds_to_keep = PyTuple_GET_SIZE(py_fds_to_keep);
Py_ssize_t keep_seq_idx;
- int fd_num;
/* As py_fds_to_keep is sorted we can loop through the list closing
* fds inbetween any in the keep list falling within our range. */
for (keep_seq_idx = 0; keep_seq_idx < num_fds_to_keep; ++keep_seq_idx) {
@@ -230,15 +229,11 @@ _close_fds_by_brute_force(long start_fd, PyObject *py_fds_to_keep)
int keep_fd = PyLong_AsLong(py_keep_fd);
if (keep_fd < start_fd)
continue;
- for (fd_num = start_fd; fd_num < keep_fd; ++fd_num) {
- close(fd_num);
- }
+ _Py_closerange(start_fd, keep_fd - 1);
start_fd = keep_fd + 1;
}
if (start_fd <= end_fd) {
- for (fd_num = start_fd; fd_num < end_fd; ++fd_num) {
- close(fd_num);
- }
+ _Py_closerange(start_fd, end_fd);
}
}
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 776a3d249a..f46df9ddf7 100644
--- Modules/posixmodule.c
+++ Modules/posixmodule.c
@@ -7667,6 +7667,78 @@ os_close_impl(PyObject *module, int fd)
Py_RETURN_NONE;
}
+/* Our selection logic for which function to use is as follows:
+ * 1. If close_range(2) is available, always prefer that; it's better for
+ * contiguous ranges like this than fdwalk(3) which entails iterating over
+ * the entire fd space and simply doing nothing for those outside the range.
+ * 2. If closefrom(2) is available, we'll attempt to use that next if we're
+ * closing up to sysconf(_SC_OPEN_MAX).
+ * 2a. Fallback to fdwalk(3) if we're not closing up to sysconf(_SC_OPEN_MAX),
+ * as that will be more performant if the range happens to have any chunk of
+ * non-opened fd in the middle.
+ * 2b. If fdwalk(3) isn't available, just do a plain close(2) loop.
+ */
+#ifdef __FreeBSD__
+#define USE_CLOSEFROM
+#endif /* __FreeBSD__ */
+
+#ifdef HAVE_FDWALK
+#define USE_FDWALK
+#endif /* HAVE_FDWALK */
+
+#ifdef USE_FDWALK
+static int
+_fdwalk_close_func(void *lohi, int fd)
+{
+ int lo = ((int *)lohi)[0];
+ int hi = ((int *)lohi)[1];
+
+ if (fd >= hi)
+ return 1;
+ else if (fd >= lo)
+ close(fd);
+ return 0;
+}
+#endif /* USE_FDWALK */
+
+/* Closes all file descriptors in [first, last], ignoring errors. */
+void
+_Py_closerange(int first, int last)
+{
+ first = Py_MAX(first, 0);
+ _Py_BEGIN_SUPPRESS_IPH
+#ifdef HAVE_CLOSE_RANGE
+ if (close_range(first, last, 0) == 0 || errno != ENOSYS) {
+ /* Any errors encountered while closing file descriptors are ignored;
+ * ENOSYS means no kernel support, though,
+ * so we'll fallback to the other methods. */
+ }
+ else
+#endif /* HAVE_CLOSE_RANGE */
+#ifdef USE_CLOSEFROM
+ if (last >= sysconf(_SC_OPEN_MAX)) {
+ /* Any errors encountered while closing file descriptors are ignored */
+ closefrom(first);
+ }
+ else
+#endif /* USE_CLOSEFROM */
+#ifdef USE_FDWALK
+ {
+ int lohi[2];
+ lohi[0] = first;
+ lohi[1] = last + 1;
+ fdwalk(_fdwalk_close_func, lohi);
+ }
+#else
+ {
+ for (int i = first; i <= last; i++) {
+ /* Ignore errors */
+ (void)close(i);
+ }
+ }
+#endif /* USE_FDWALK */
+ _Py_END_SUPPRESS_IPH
+}
/*[clinic input]
os.closerange
@@ -7682,12 +7754,8 @@ static PyObject *
os_closerange_impl(PyObject *module, int fd_low, int fd_high)
/*[clinic end generated code: output=0ce5c20fcda681c2 input=5855a3d053ebd4ec]*/
{
- int i;
Py_BEGIN_ALLOW_THREADS
- _Py_BEGIN_SUPPRESS_IPH
- for (i = Py_MAX(fd_low, 0); i < fd_high; i++)
- close(i);
- _Py_END_SUPPRESS_IPH
+ _Py_closerange(fd_low, fd_high - 1);
Py_END_ALLOW_THREADS
Py_RETURN_NONE;
}
diff --git a/Modules/posixmodule.h b/Modules/posixmodule.h
index 1ec1833825..be2308ea86 100644
--- Modules/posixmodule.h
+++ Modules/posixmodule.h
@@ -19,6 +19,8 @@ PyAPI_FUNC(int) _Py_Gid_Converter(PyObject *, void *);
#endif /* MS_WINDOWS */
#endif
+PyAPI_FUNC(void) _Py_closerange(int first, int last);
+
#ifdef __cplusplus
}
#endif
diff --git a/configure b/configure
index e39c16eee2..1f34b4de74 100755
--- configure
+++ configure
@@ -11420,9 +11420,9 @@ fi
# checks for library functions
for ac_func in alarm accept4 setitimer getitimer bind_textdomain_codeset chown \
- clock confstr ctermid dup3 execv faccessat fchmod fchmodat fchown fchownat \
- fexecve fdopendir fork fpathconf fstatat ftime ftruncate futimesat \
- futimens futimes gai_strerror getentropy \
+ clock close_range confstr ctermid dup3 execv faccessat fchmod fchmodat fchown \
+ fchownat fdwalk fexecve fdopendir fork fpathconf fstatat ftime ftruncate \
+ futimesat futimens futimes gai_strerror getentropy \
getgrouplist getgroups getlogin getloadavg getpeername getpgid getpid \
getpriority getresuid getresgid getpwent getspnam getspent getsid getwd \
initgroups kill killpg lchown linkat lstat lutimes mmap \
diff --git a/configure.ac b/configure.ac
index cf280506bd..09886eaeef 100644
--- configure.ac
+++ configure.ac
@@ -3531,9 +3531,9 @@ fi
# checks for library functions
AC_CHECK_FUNCS(alarm accept4 setitimer getitimer bind_textdomain_codeset chown \
- clock confstr ctermid dup3 execv faccessat fchmod fchmodat fchown fchownat \
- fexecve fdopendir fork fpathconf fstatat ftime ftruncate futimesat \
- futimens futimes gai_strerror getentropy \
+ clock close_range confstr ctermid dup3 execv faccessat fchmod fchmodat fchown \
+ fchownat fdwalk fexecve fdopendir fork fpathconf fstatat ftime ftruncate \
+ futimesat futimens futimes gai_strerror getentropy \
getgrouplist getgroups getlogin getloadavg getpeername getpgid getpid \
getpriority getresuid getresgid getpwent getspnam getspent getsid getwd \
initgroups kill killpg lchown linkat lstat lutimes mmap \
diff --git a/pyconfig.h.in b/pyconfig.h.in
index 2fbbb6d20d..a4488cbe32 100644
--- pyconfig.h.in
+++ pyconfig.h.in
@@ -128,6 +128,9 @@
/* Define to 1 if you have the `clock_settime' function. */
#undef HAVE_CLOCK_SETTIME
+/* Define to 1 if you have the `close_range' function. */
+#undef HAVE_CLOSE_RANGE
+
/* Define if the C compiler supports computed gotos. */
#undef HAVE_COMPUTED_GOTOS
@@ -317,6 +320,9 @@
/* Define to 1 if you have the `fdopendir' function. */
#undef HAVE_FDOPENDIR
+/* Define to 1 if you have the `fdwalk' function. */
+#undef HAVE_FDWALK
+
/* Define to 1 if you have the `fexecve' function. */
#undef HAVE_FEXECVE
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