[PATCH] shell: Add support for disabling memfd_create(3)

In order to test the fallback path for systems without memfd_create(3),
add a --disable-memfd-create argument to the configure script.

Signed-off-by: Herbert Xu <[email protected]>

diff --git a/configure.ac b/configure.ac
index 5efd9e2..bdcb339 100644
--- a/configure.ac
+++ b/configure.ac
@@ -40,6 +40,8 @@ fi
 AC_ARG_ENABLE(fnmatch, AS_HELP_STRING(--enable-fnmatch, \
 				      [Use fnmatch(3) from libc]))
 AC_ARG_ENABLE(glob, AS_HELP_STRING(--enable-glob, [Use glob(3) from libc]))
+AC_ARG_ENABLE(memfd_create, AS_HELP_STRING(--disable-memfd-create,
+					   [Do not use memfd_create(3)]))
 
 dnl Checks for libraries.
 
@@ -131,6 +133,14 @@ if test "$use_fnmatch" = yes && test "$enable_glob" = yes; then
 	AC_CHECK_FUNCS(glob)
 fi
 
+if test "$enable_memfd_create" != no; then
+	AC_DEFINE([USE_MEMFD_CREATE], [1],
+		  [Non-zero if memfd_create(3) should be used])
+else
+	AC_DEFINE([USE_MEMFD_CREATE], [0],
+		  [Non-zero if memfd_create(3) should be used])
+fi
+
 dnl Check for klibc signal.
 AC_CHECK_FUNC(signal)
 if test "$ac_cv_func_signal" != yes; then
diff --git a/src/redir.c b/src/redir.c
index 8d1c8f6..e61d3da 100644
--- a/src/redir.c
+++ b/src/redir.c
@@ -331,7 +331,7 @@ static void dupredirect(union node *redir, int f)
 int sh_pipe(int pip[2], int memfd)
 {
 	if (memfd) {
-		pip[0] = memfd_create("dash", 0);
+		pip[0] = USE_MEMFD_CREATE ? memfd_create("dash", 0) : -1;
 		if (pip[0] >= 0) {
 			pip[1] = sh_dup2(pip[0], -1, pip[0]);
 			return 1;
-- 
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt