[LTP] [PATCH v4 1/3] lib: Add personality fallback and SAFE macro

[Richard Palethorpe]

Add the macro SAFE_PERSONALITY as well as fallback logic for if
sys/personality.h is missing UNAME26.

Signed-off-by: Richard Palethorpe <rpalethorpe@suse.com>
---

V4 - Remove some unecessary fallback logic and move the SAFE_PERSONALITY macro

 include/lapi/personality.h | 30 ++++++++++++++++++++++++++++++
 include/tst_safe_macros.h  |  5 +++++
 lib/tst_safe_macros.c      | 14 ++++++++++++++
 3 files changed, 49 insertions(+)
 create mode 100644 include/lapi/personality.h

diff --git a/include/lapi/personality.h b/include/lapi/personality.h
new file mode 100644
index 000000000..be45a0db2
--- /dev/null
+++ b/include/lapi/personality.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2017 Richard Palethorpe <rpalethorpe@suse.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+/* In the Linux kernel and glibc enums are (mostly) used for the constants,
+ * but in musl macros are used.
+ */
+
+#ifndef PERSONALITY_H
+#define PERSONALITY_H
+
+#include <sys/personality.h>
+
+#if !(HAVE_DECL_UNAME26 == 1 || defined(UNAME26))
+#define UNAME26 0x0020000
+#endif
+
+#endif	/* PERSONALITY_H */
diff --git a/include/tst_safe_macros.h b/include/tst_safe_macros.h
index 8245b68a3..a132d3f86 100644
--- a/include/tst_safe_macros.h
+++ b/include/tst_safe_macros.h
@@ -438,4 +438,9 @@ int safe_mknod(const char *file, const int lineno, const char *pathname,
 #define SAFE_MKNOD(pathname, mode, dev) \
 	safe_mknod(__FILE__, __LINE__, (pathname), (mode), (dev))
 
+int safe_personality(const char *filename, unsigned int lineno,
+		    unsigned long persona);
+#define SAFE_PERSONALITY(persona) safe_personality(__FILE__, __LINE__, persona)
+
+
 #endif /* SAFE_MACROS_H__ */
diff --git a/lib/tst_safe_macros.c b/lib/tst_safe_macros.c
index e7f5095e5..c928b8357 100644
--- a/lib/tst_safe_macros.c
+++ b/lib/tst_safe_macros.c
@@ -20,6 +20,7 @@
 #define TST_NO_DEFAULT_MAIN
 #include "tst_test.h"
 #include "tst_safe_macros.h"
+#include "lapi/personality.h"
 
 int safe_setpgid(const char *file, const int lineno, pid_t pid, pid_t pgid)
 {
@@ -47,3 +48,16 @@ pid_t safe_getpgid(const char *file, const int lineno, pid_t pid)
 
 	return pgid;
 }
+
+int safe_personality(const char *filename, unsigned int lineno,
+		    unsigned long persona)
+{
+	int prev_persona = personality(persona);
+
+	if (prev_persona < 0) {
+		tst_brk_(filename, lineno, TBROK | TERRNO,
+			 "persona(%ld) failed", persona);
+	}
+
+	return prev_persona;
+}
-- 
2.13.3