[RFCv2,03/15] rdmacm: Control symbol export from librspreload

Commit Message

Jason Gunthorpe Aug. 22, 2016, 6:13 p.m. UTC

Since librspreload is a LD_PRELOAD library it should only export
symbols it intends to override. The following internal symbols were
leaking out:

 getenv_options
 idm_clear
 idm_set
 idx_insert
 idx_remove
 idx_replace
 set_rsocket_options

The simplest way to fix this is with a map file.

Signed-off-by: Jason Gunthorpe <[e-mail]>
---
 librdmacm/Makefile.am          |  5 ++++-
 librdmacm/src/librspreload.map | 33 +++++++++++++++++++++++++++++++++
 librdmacm/src/preload.c        |  4 ++--
 3 files changed, 39 insertions(+), 3 deletions(-)
 create mode 100644 librdmacm/src/librspreload.map

Patch

diff --git a/librdmacm/Makefile.am b/librdmacm/Makefile.am
index bf721345f68d..fa82d801a4dd 100644
--- a/librdmacm/Makefile.am
+++ b/librdmacm/Makefile.am
@@ -23,7 +23,10 @@  src_librdmacm_la_LDFLAGS = -version-info 1 -export-dynamic \
 src_librdmacm_la_DEPENDENCIES =  $(srcdir)/src/librdmacm.map
 
 src_librspreload_la_SOURCES = src/preload.c src/indexer.c
-src_librspreload_la_LDFLAGS = -version-info 1 -export-dynamic
+src_librspreload_la_LDFLAGS = -version-info 1
+if HAVE_LD_VERSION_SCRIPT
+    src_librspreload_la_LDFLAGS += -Wl,--version-script=$(srcdir)/src/librspreload.map
+endif
 src_librspreload_la_LIBADD = $(top_builddir)/src/librdmacm.la
 
 bin_PROGRAMS = examples/ucmatose examples/rping examples/udaddy examples/mckey \
diff --git a/librdmacm/src/librspreload.map b/librdmacm/src/librspreload.map
new file mode 100644
index 000000000000..67ecf33b8203
--- /dev/null
+++ b/librdmacm/src/librspreload.map
@@ -0,0 +1,33 @@ 
+{
+        /* FIXME: It is probably not a great idea to not tag these with the
+	   proper symbol version from glibc, at least if glibc ever changes
+	   the signature this will go sideways.. */
+	global:
+		accept;
+		bind;
+		close;
+		connect;
+		dup2;
+		fcntl;
+		getpeername;
+		getsockname;
+		getsockopt;
+		listen;
+		poll;
+		read;
+		readv;
+		recv;
+		recvfrom;
+		recvmsg;
+		select;
+		send;
+		sendfile;
+		sendmsg;
+		sendto;
+		setsockopt;
+		shutdown;
+		socket;
+		write;
+		writev;
+	local: *;
+};
diff --git a/librdmacm/src/preload.c b/librdmacm/src/preload.c
index 3a0bc4c8c71d..7d9352ab1f90 100644
--- a/librdmacm/src/preload.c
+++ b/librdmacm/src/preload.c
@@ -356,7 +356,7 @@  static enum fd_type fd_close(int index, int *fd)
 	return type;
 }
 
-void getenv_options(void)
+static void getenv_options(void)
 {
 	char *var;
 
@@ -521,7 +521,7 @@  err:
 /*
  * Use defaults on failure.
  */
-void set_rsocket_options(int rsocket)
+static void set_rsocket_options(int rsocket)
 {
 	if (sq_size)
 		rsetsockopt(rsocket, SOL_RDMA, RDMA_SQSIZE, &sq_size, sizeof sq_size);