Add Symbols.map to explicitly define the ABIs, hiding linker defined symbols.

Use hidden aliases for internal invocations of exported symbols to avoid PLT.

ok deraadt@ kettenis@ jca@

5 files changed, 39 insertions, 5 deletions

diff --git a/lib/libkvm/Makefile b/lib/libkvm/Makefile
index 7284c60507d..60098367593 100644
--- a/lib/libkvm/Makefile
+++ b/lib/libkvm/Makefile
@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile,v 1.18 2016/03/30 06:38:42 jmc Exp $
+#	$OpenBSD: Makefile,v 1.19 2017/12/14 17:06:33 guenther Exp $
 #	$NetBSD: Makefile,v 1.11 1996/03/18 22:33:07 thorpej Exp $
 #	from: @(#)Makefile	8.1 (Berkeley) 6/4/93
 
@@ -18,6 +18,8 @@ SRCS=	kvm_${MACHINE_CPU}.c
 .endif
 .endif
 
+VERSION_SCRIPT=	${.CURDIR}/Symbols.map
+
 CFLAGS+= -D_LIBKVM
 SRCS+=	kvm.c kvm_file2.c kvm_getloadavg.c kvm_proc.c kvm_proc2.c \
 	kvm_cd9660.c kvm_udf.c kvm_ntfs.c
diff --git a/lib/libkvm/Symbols.map b/lib/libkvm/Symbols.map
new file mode 100644
index 00000000000..76cf4f2fb1c
--- /dev/null
+++ b/lib/libkvm/Symbols.map
@@ -0,0 +1,21 @@
+{
+	global:
+		kvm_close;
+		kvm_dump_inval;
+		kvm_dump_mkheader;
+		kvm_dump_wrtheader;
+		kvm_getargv;
+		kvm_getenvv;
+		kvm_geterr;
+		kvm_getfiles;
+		kvm_getloadavg;
+		kvm_getprocs;
+		kvm_nlist;
+		kvm_open;
+		kvm_openfiles;
+		kvm_read;
+		kvm_write;
+
+	local:
+		*;
+};
diff --git a/lib/libkvm/kvm.c b/lib/libkvm/kvm.c
index 5247cffb9f4..dce4359fc78 100644
--- a/lib/libkvm/kvm.c
+++ b/lib/libkvm/kvm.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kvm.c,v 1.62 2016/07/10 23:06:48 tedu Exp $ */
+/*	$OpenBSD: kvm.c,v 1.63 2017/12/14 17:06:33 guenther Exp $ */
 /*	$NetBSD: kvm.c,v 1.43 1996/05/05 04:31:59 gwr Exp $	*/
 
 /*-
@@ -664,6 +664,7 @@ kvm_close(kvm_t *kd)
 
 	return (error);
 }
+DEF(kvm_close);
 
 /*
  * Set up state necessary to do queries on the kernel namelist
@@ -802,6 +803,7 @@ kvm_nlist(kvm_t *kd, struct nlist *nl)
 	 */
 	return ((p - nl) - nvalid);
 }
+DEF(kvm_nlist);
 
 int
 kvm_dump_inval(kvm_t *kd)
@@ -894,6 +896,7 @@ kvm_read(kvm_t *kd, u_long kva, void *buf, size_t len)
 	}
 	/* NOTREACHED */
 }
+DEF(kvm_read);
 
 ssize_t
 kvm_write(kvm_t *kd, u_long kva, const void *buf, size_t len)
diff --git a/lib/libkvm/kvm_private.h b/lib/libkvm/kvm_private.h
index b42634ba969..3fe186e7365 100644
--- a/lib/libkvm/kvm_private.h
+++ b/lib/libkvm/kvm_private.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kvm_private.h,v 1.24 2015/09/04 02:55:09 dlg Exp $ */
+/*	$OpenBSD: kvm_private.h,v 1.25 2017/12/14 17:06:33 guenther Exp $ */
 /*	$NetBSD: kvm_private.h,v 1.7 1996/05/05 04:32:15 gwr Exp $	*/
 
 /*-
@@ -106,3 +106,11 @@ void	 _kvm_syserr(kvm_t *kd, const char *program, const char *fmt, ...)
 ssize_t	 _kvm_pread(kvm_t *, int, void *, size_t, off_t);
 ssize_t	 _kvm_pwrite(kvm_t *, int, const void *, size_t, off_t);
 __END_HIDDEN_DECLS
+
+
+#define	PROTO(x)	__dso_hidden typeof(x) x asm("__"#x)
+#define	DEF(x)		__strong_alias(x, __##x)
+
+PROTO(kvm_close);
+PROTO(kvm_nlist);
+PROTO(kvm_read);
diff --git a/lib/libkvm/shlib_version b/lib/libkvm/shlib_version
index cd2907e093d..ffdd3d2d569 100644
--- a/lib/libkvm/shlib_version
+++ b/lib/libkvm/shlib_version
@@ -1,2 +1,2 @@
-major=16
-minor=2
+major=17
+minor=0