MFC r302515:

Implement Linux personality() system call mainly due to READ_IMPLIES_EXEC flag.
In Linux if this flag is set, PROT_READ implies PROT_EXEC for mmap().
Linux/i386 set this flag automatically if the binary requires executable stack.

READ_IMPLIES_EXEC flag will be used in the next Linux mmap() commit.

1 files changed, 56 insertions, 0 deletions

diff --git a/sys/compat/linux/linux_persona.h b/sys/compat/linux/linux_persona.h
new file mode 100644
index 0000000..8d84134
--- /dev/null
+++ b/sys/compat/linux/linux_persona.h
@@ -0,0 +1,56 @@
+/*
+ * $FreeBSD$
+ */
+
+#ifndef LINUX_PERSONALITY_H
+#define LINUX_PERSONALITY_H
+
+/*
+ * Flags for bug emulation.
+ *
+ * These occupy the top three bytes.
+ */
+enum {
+	LINUX_UNAME26 =			0x0020000,
+	LINUX_ADDR_NO_RANDOMIZE = 	0x0040000,	/* disable randomization
+							 * of VA space
+							 */
+	LINUX_FDPIC_FUNCPTRS =		0x0080000,	/* userspace function
+							 * ptrs point to descriptors
+							 * (signal handling)
+							 */
+	LINUX_MMAP_PAGE_ZERO =		0x0100000,
+	LINUX_ADDR_COMPAT_LAYOUT =	0x0200000,
+	LINUX_READ_IMPLIES_EXEC =	0x0400000,
+	LINUX_ADDR_LIMIT_32BIT =	0x0800000,
+	LINUX_SHORT_INODE =		0x1000000,
+	LINUX_WHOLE_SECONDS =		0x2000000,
+	LINUX_STICKY_TIMEOUTS =		0x4000000,
+	LINUX_ADDR_LIMIT_3GB =		0x8000000,
+};
+
+/*
+ * Security-relevant compatibility flags that must be
+ * cleared upon setuid or setgid exec:
+ */
+#define LINUX_PER_CLEAR_ON_SETID	(LINUX_READ_IMPLIES_EXEC  | \
+					LINUX_ADDR_NO_RANDOMIZE  | \
+					LINUX_ADDR_COMPAT_LAYOUT | \
+					LINUX_MMAP_PAGE_ZERO)
+
+/*
+ * Personality types.
+ *
+ * These go in the low byte.  Avoid using the top bit, it will
+ * conflict with error returns.
+ */
+enum {
+	LINUX_PER_LINUX =	0x0000,
+	LINUX_PER_LINUX_32BIT =	0x0000 | LINUX_ADDR_LIMIT_32BIT,
+	LINUX_PER_LINUX_FDPIC =	0x0000 | LINUX_FDPIC_FUNCPTRS,
+	LINUX_PER_LINUX32 =	0x0008,
+	LINUX_PER_LINUX32_3GB =	0x0008 | LINUX_ADDR_LIMIT_3GB,
+	LINUX_PER_MASK =	0x00ff,
+};
+
+#endif /* LINUX_PERSONALITY_H */