[Bug ld/18992] New: Linking a library implicitly using relative DT_RPATH does not work

[sourceware-bugzilla at jbeekman dot nl]

https://sourceware.org/bugzilla/show_bug.cgi?id=18992

Bug ID: 18992
   Summary: Linking a library implicitly using relative DT_RPATH
does not work
   Product: binutils
   Version: 2.24
Status: NEW
  Severity: normal
  Priority: P2
 Component: ld
  Assignee: unassigned at sourceware dot org
  Reporter: sourceware-bugzilla at jbeekman dot nl
  Target Milestone: ---

I have a shared library ./dir/liba.so and a shared library ./libb.so with
DT_RPATH "dir" and DT_NEEDED "liba.so". Now, if I compile an executable with
-L. -lb, I get: "warning: liba.so, needed by ./libb.so, not found (try using
-rpath or -rpath-link)". It works when using an absolute DT_RPATH or when using
gold. The resulting binary works with a relative RPATH.

Here's a test case:

===> a.c <===

void a() {}

===> b.c <===

extern void a();
void b() {a();}

===> main.c <===

extern void b();
void main() {b();}

$ mkdir dir
$ gcc -fPIC -shared a.c -o dir/liba.so
# Make libb with relative RPATH
$ gcc -fPIC -shared -Ldir -Wl,-rpath,dir b.c -la -o libb.so
# Fail linking in relative-RPATH libb with ld.bfd
$ gcc main.c -L. -Wl,-rpath,. -lb -o main
/usr/bin/ld.bfd.real: warning: liba.so, needed by ./libb.so, not found (try
using -rpath or -rpath-link)
./libb.so: undefined reference to `a'
collect2: error: ld returned 1 exit status
# Succeed linking in relative-RPATH libb with gold
$ gcc main.c -fuse-ld=gold -L. -Wl,-rpath,. -lb -o main
# Run binary with relative-RPATH libb
$ ./main
# Make libb with absolute RPATH
$ gcc -fPIC -shared -Ldir -Wl,-rpath,$(pwd)/dir b.c -la -o libb.so
# Succeed linking in absolute-RPATH libb with ld.bfd
$ gcc main.c -L. -Wl,-rpath,. -lb -o main
# Run binary with absolute-RPATH libb
$ ./main
# Make libb with relative RPATH
$ gcc -fPIC -shared -Ldir -Wl,-rpath,dir b.c -la -o libb.so
# Run binary with relative-RPATH libb
$ ./main

-- 
You are receiving this mail because:
You are on the CC list for the bug.

___
bug-binutils mailing list
bug-binutils@gnu.org
https://lists.gnu.org/mailman/listinfo/bug-binutils

[Bug ld/18992] Linking a library implicitly using relative DT_RPATH does not work

[jwakely.gcc at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=18992

Jonathan Wakely  changed:

   What|Removed |Added

 CC||jwakely.gcc at gmail dot com

--- Comment #1 from Jonathan Wakely  ---
(In reply to Jethro Beekman from comment #0)
> $ gcc main.c -L. -Wl,-rpath,. -lb -o main
> /usr/bin/ld.bfd.real: warning: liba.so, needed by ./libb.so, not found (try
> using -rpath or -rpath-link)
> ./libb.so: undefined reference to `a'
> collect2: error: ld returned 1 exit status

I asked the reporter to file this bug, but I've just tried it with
binutils-2.25-9.fc22.x86_64 and don't see this warning.

-- 
You are receiving this mail because:
You are on the CC list for the bug.

___
bug-binutils mailing list
bug-binutils@gnu.org
https://lists.gnu.org/mailman/listinfo/bug-binutils

[Bug ld/18992] Linking a library implicitly using relative DT_RPATH does not work

[sourceware-bugzilla at jbeekman dot nl]

https://sourceware.org/bugzilla/show_bug.cgi?id=18992

Jethro Beekman  changed:

   What|Removed |Added

 Status|NEW |UNCONFIRMED
 Ever confirmed|1   |0

--- Comment #2 from Jethro Beekman  ---
I tried this on a variety of OS'es, including various versions of Debian,
Ubuntu, RHEL and SunOS and so far I can only reproduce this on Ubuntu 14.04.

-- 
You are receiving this mail because:
You are on the CC list for the bug.

___
bug-binutils mailing list
bug-binutils@gnu.org
https://lists.gnu.org/mailman/listinfo/bug-binutils

[Bug ld/18992] Linking a library implicitly using relative DT_RPATH does not work

[vapier at gentoo dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=18992

Mike Frysinger  changed:

   What|Removed |Added

 CC||vapier at gentoo dot org

--- Comment #3 from Mike Frysinger  ---
are you using gold there ?  compare `ld --version | head -1`.

-- 
You are receiving this mail because:
You are on the CC list for the bug.

___
bug-binutils mailing list
bug-binutils@gnu.org
https://lists.gnu.org/mailman/listinfo/bug-binutils

[Bug ld/18992] Linking a library implicitly using relative DT_RPATH does not work

[amodra at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=18992

Alan Modra  changed:

   What|Removed |Added

 Status|UNCONFIRMED |NEW
   Last reconfirmed||2015-09-23
 CC||amodra at gmail dot com
 Ever confirmed|0   |1

--- Comment #4 from Alan Modra  ---
This will be because your linker is configured with a sysroot, and is
prepending the sysroot to relative paths.  I'm guessing --with-sysroot=/

-- 
You are receiving this mail because:
You are on the CC list for the bug.

___
bug-binutils mailing list
bug-binutils@gnu.org
https://lists.gnu.org/mailman/listinfo/bug-binutils

[Bug ld/18992] Linking a library implicitly using relative DT_RPATH does not work

[sourceware-bugzilla at jbeekman dot nl]

https://sourceware.org/bugzilla/show_bug.cgi?id=18992

--- Comment #5 from Jethro Beekman  ---
This indeed seems to be the case. In particular, on Ubuntu 14.04, this patch is
not applied:
http://apt-browse.org/browse/debian/wheezy/main/all/binutils-source/2.22-8/file/usr/src/binutils/patches/158_ld_system_root.patch
. It is applied on all other versions of Debian/Ubuntu I have tested. On all
these OS'es, the linker is invoked with --sysroot=/ but it only has any effect
on Ubuntu 14.04, and from the strace log I can indeed see that the linker tries
to access /dir/liba.so.

I don't think the sysroot should be prepended to relative paths. Here's a patch
to fix:

diff --git a/ld/emultempl/elf32.em b/ld/emultempl/elf32.em
index 682f5e5..a70b138 100644
--- a/ld/emultempl/elf32.em
+++ b/ld/emultempl/elf32.em
@@ -1282,9 +1282,12 @@ fragment name);
+ char *tmpname = NULL, *name;
+ if (rp->name[0] == '/')
+   tmpname = gld${EMULATION_NAME}_add_sysroot (rp->name);
+ name = tmpname ? tmpname : rp->name;
  found = (rp->by == l->by
-  && gld${EMULATION_NAME}_search_needed (tmpname,
+  && gld${EMULATION_NAME}_search_needed (name,
  &n,
  force));
  free (tmpname);

-- 
You are receiving this mail because:
You are on the CC list for the bug.

___
bug-binutils mailing list
bug-binutils@gnu.org
https://lists.gnu.org/mailman/listinfo/bug-binutils