gh-106881: Check for linux/limits.h before including it (#107397)

* Check for linux/limits.h before including it

Co-authored-by: Erlend E. Aasland <erlend.aasland@protonmail.com>

Misc/NEWS.d/next/Build/2023-07-28-18-17-33.gh-issue-106881.U3Ezdq.rst

@@ -0,0 +1 @@
+Check for `linux/limits.h` before including it in `Modules/posixmodule.c`.

Modules/posixmodule.c

@@ -285,7 +285,7 @@ corresponding Unix manual entries for more information on calls.");
 #  undef HAVE_SCHED_SETAFFINITY
 #endif
 
-#if defined(HAVE_SYS_XATTR_H) && defined(__linux__) && !defined(__FreeBSD_kernel__) && !defined(__GNU__)
+#if defined(HAVE_SYS_XATTR_H) && defined(HAVE_LINUX_LIMITS_H) && !defined(__FreeBSD_kernel__) && !defined(__GNU__)
 #  define USE_XATTRS
 #  include <linux/limits.h>  // Needed for XATTR_SIZE_MAX on musl libc.
 #endif

configure.ac

@@ -2848,7 +2848,7 @@ AC_DEFINE([STDC_HEADERS], [1],
 # checks for header files
 AC_CHECK_HEADERS([ \
   alloca.h asm/types.h bluetooth.h conio.h direct.h dlfcn.h endian.h errno.h fcntl.h grp.h \
-  ieeefp.h io.h langinfo.h libintl.h libutil.h linux/auxvec.h sys/auxv.h linux/fs.h linux/memfd.h \
+  ieeefp.h io.h langinfo.h libintl.h libutil.h linux/auxvec.h sys/auxv.h linux/fs.h linux/limits.h linux/memfd.h \
   linux/random.h linux/soundcard.h \
   linux/tipc.h linux/wait.h netdb.h net/ethernet.h netinet/in.h netpacket/packet.h poll.h process.h pthread.h pty.h \
   sched.h setjmp.h shadow.h signal.h spawn.h stropts.h sys/audioio.h sys/bsdtty.h sys/devpoll.h \

pyconfig.h.in

@@ -721,6 +721,9 @@
 /* Define to 1 if you have the <linux/fs.h> header file. */
 #undef HAVE_LINUX_FS_H
 
+/* Define to 1 if you have the <linux/limits.h> header file. */
+#undef HAVE_LINUX_LIMITS_H
+
 /* Define to 1 if you have the <linux/memfd.h> header file. */
 #undef HAVE_LINUX_MEMFD_H