From dddf3694e9566a7e304c3c91e8fc5cd5900d551f Mon Sep 17 00:00:00 2001
From: tg <tg@mirbsd.org>
Date: Tue, 30 Oct 2018 17:10:16 +0000
Subject: [PATCH] add O_MAYEXEC support for CLIP OS, zero cost otherwise

cf. https://lwn.net/Articles/768819/
---
 exec.c | 4 ++--
 main.c | 6 +++---
 sh.h   | 6 +++++-
 3 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/exec.c b/exec.c
index 089091e..67d54be 100644
--- a/exec.c
+++ b/exec.c
@@ -23,7 +23,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/exec.c,v 1.202 2018/10/07 01:10:11 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/exec.c,v 1.203 2018/10/30 17:10:14 tg Exp $");
 
 #ifndef MKSH_DEFAULT_EXECSHELL
 #define MKSH_DEFAULT_EXECSHELL	MKSH_UNIXROOT "/bin/sh"
@@ -886,7 +886,7 @@ scriptexec(struct op *tp, const char **ap)
 	*tp->args-- = tp->str;
 
 #ifndef MKSH_SMALL
-	if ((fd = binopen2(tp->str, O_RDONLY)) >= 0) {
+	if ((fd = binopen2(tp->str, O_RDONLY | O_MAYEXEC)) >= 0) {
 		unsigned char *cp;
 #ifndef MKSH_EBCDIC
 		unsigned short m;
diff --git a/main.c b/main.c
index fbae4b2..7e05554 100644
--- a/main.c
+++ b/main.c
@@ -34,7 +34,7 @@
 #include <locale.h>
 #endif
 
-__RCSID("$MirOS: src/bin/mksh/main.c,v 1.349 2018/05/08 17:37:36 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/main.c,v 1.350 2018/10/30 17:10:15 tg Exp $");
 
 #ifndef MKSHRC_PATH
 #define MKSHRC_PATH	"~/.mkshrc"
@@ -513,7 +513,7 @@ main_init(int argc, const char *argv[], Source **sp, struct block **lp)
 #else
 		s->file = argv[argi++];
 #endif
-		s->u.shf = shf_open(s->file, O_RDONLY, 0,
+		s->u.shf = shf_open(s->file, O_RDONLY | O_MAYEXEC, 0,
 		    SHF_MAPHI | SHF_CLEXEC);
 		if (s->u.shf == NULL) {
 			shl_stdout_ok = false;
@@ -713,7 +713,7 @@ include(const char *name, int argc, const char **argv, bool intr_ok)
 	volatile int old_argc;
 	int i;
 
-	shf = shf_open(name, O_RDONLY, 0, SHF_MAPHI | SHF_CLEXEC);
+	shf = shf_open(name, O_RDONLY | O_MAYEXEC, 0, SHF_MAPHI | SHF_CLEXEC);
 	if (shf == NULL)
 		return (-1);
 
diff --git a/sh.h b/sh.h
index 1cec417..3ca8e55 100644
--- a/sh.h
+++ b/sh.h
@@ -182,7 +182,7 @@
 #endif
 
 #ifdef EXTERN
-__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.866 2018/10/20 18:45:58 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.867 2018/10/30 17:10:16 tg Exp $");
 #endif
 #define MKSH_VERSION "R56 2018/10/20"
 
@@ -491,6 +491,10 @@ extern int __cdecl setegid(gid_t);
 #define O_BINARY	0
 #endif
 
+#ifndef O_MAYEXEC
+#define O_MAYEXEC	0
+#endif
+
 #ifdef MKSH__NO_SYMLINK
 #undef S_ISLNK
 #define S_ISLNK(m)	(/* CONSTCOND */ 0)