Re: [patch] Fix dynamic linker spec for FreeBSD powerpc64

[Andreas Tobler]

On 22.12.15 20:18, Andreas Tobler wrote:

Hi all,

The attached patch fixes a problem you get if you build dynamic binaries
for a 32-bit powerpc target on a 64-bit powerpc host.

At the time I did this port I didn't fully understand all the scenarios
you might run into.

The issue is this, on all FreeBSD archs the interpreter is ld-elf.so.1.
On powerpc64 we have also an ld-elf32.so.1 for 32-bit binaries. In case
we run a 32-bit binary on a 64-bit host the RTLD reroutes the call to
this ld-elf32.so.1.

Up to now this rerouting didn't happen since gcc used the ld-elf32.so.1
instead. The binary runs fine on the 64-bit host since the RTLD finds a
ld-elf32.so.1.

But now when I take this binary to a 32-bit host I can't run it since
the RTLD does not find the ld-elf32.so.1.

The patch fixes this and simplifies the LINK_OS_FREEBSD_SPEC_DEF for
FreeBSD powerpc64.

If there are no major objections I'm going to apply this patch to trunk,
gcc-5 and gcc-49 branch in the next days. It is FreeBSD powerpc64 only
and it is a bug.


Applied on the mentioned branches.

Andreas



2015-12-22  Andreas Tobler  

* config/rs6000/freebsd64.h: Delete FREEBSD_DYNAMIC_LINKER32/64
defines. Use FBSD_DYNAMIC_LINKER instead.
Rename and simplify LINK_OS_FREEBSD_SPEC_DEF32/64 to
LINK_OS_FREEBSD_SPEC_DEF.

[patch] Fix dynamic linker spec for FreeBSD powerpc64

[Andreas Tobler]

Hi all,

The attached patch fixes a problem you get if you build dynamic binaries 
for a 32-bit powerpc target on a 64-bit powerpc host.


At the time I did this port I didn't fully understand all the scenarios 
you might run into.


The issue is this, on all FreeBSD archs the interpreter is ld-elf.so.1.
On powerpc64 we have also an ld-elf32.so.1 for 32-bit binaries. In case 
we run a 32-bit binary on a 64-bit host the RTLD reroutes the call to 
this ld-elf32.so.1.


Up to now this rerouting didn't happen since gcc used the ld-elf32.so.1 
instead. The binary runs fine on the 64-bit host since the RTLD finds a 
ld-elf32.so.1.


But now when I take this binary to a 32-bit host I can't run it since 
the RTLD does not find the ld-elf32.so.1.


The patch fixes this and simplifies the LINK_OS_FREEBSD_SPEC_DEF for 
FreeBSD powerpc64.


If there are no major objections I'm going to apply this patch to trunk, 
gcc-5 and gcc-49 branch in the next days. It is FreeBSD powerpc64 only 
and it is a bug.


Thanks,
Andreas

2015-12-22  Andreas Tobler  

* config/rs6000/freebsd64.h: Delete FREEBSD_DYNAMIC_LINKER32/64
defines. Use FBSD_DYNAMIC_LINKER instead.
Rename and simplify LINK_OS_FREEBSD_SPEC_DEF32/64 to
LINK_OS_FREEBSD_SPEC_DEF.



Index: freebsd64.h
===
--- freebsd64.h (revision 231662)
+++ freebsd64.h (working copy)
@@ -167,10 +167,7 @@
   { "link_os_freebsd_spec32",  LINK_OS_FREEBSD_SPEC32 },   \
   { "link_os_freebsd_spec64",  LINK_OS_FREEBSD_SPEC64 },
 
-#define FREEBSD_DYNAMIC_LINKER32 "/libexec/ld-elf32.so.1"
-#define FREEBSD_DYNAMIC_LINKER64 "/libexec/ld-elf.so.1"
-
-#define LINK_OS_FREEBSD_SPEC_DEF32 "\
+#define LINK_OS_FREEBSD_SPEC_DEF "\
   %{p:%nconsider using `-pg' instead of `-p' with gprof(1)} \
   %{v:-V} \
   %{assert*} %{R*} %{rpath*} %{defsym*} \
@@ -178,25 +175,13 @@
   %{!shared: \
 %{!static: \
   %{rdynamic: -export-dynamic} \
-  %{!dynamic-linker:-dynamic-linker " FREEBSD_DYNAMIC_LINKER32 "}} \
+  %{!dynamic-linker:-dynamic-linker " FBSD_DYNAMIC_LINKER "}} \
 %{static:-Bstatic}} \
   %{symbolic:-Bsymbolic}"
 
-#define LINK_OS_FREEBSD_SPEC_DEF64 "\
-  %{p:%nconsider using `-pg' instead of `-p' with gprof(1)} \
-  %{v:-V} \
-  %{assert*} %{R*} %{rpath*} %{defsym*} \
-  %{shared:-Bshareable %{h*} %{soname*}} \
-  %{!shared: \
-%{!static: \
-  %{rdynamic: -export-dynamic} \
-  %{!dynamic-linker:-dynamic-linker " FREEBSD_DYNAMIC_LINKER64 "}} \
-%{static:-Bstatic}} \
-  %{symbolic:-Bsymbolic}"
-
-#define LINK_OS_FREEBSD_SPEC32 "-melf32ppc_fbsd " LINK_OS_FREEBSD_SPEC_DEF32
+#define LINK_OS_FREEBSD_SPEC32 "-melf32ppc_fbsd " LINK_OS_FREEBSD_SPEC_DEF
   
-#define LINK_OS_FREEBSD_SPEC64 "-melf64ppc_fbsd " LINK_OS_FREEBSD_SPEC_DEF64
+#define LINK_OS_FREEBSD_SPEC64 "-melf64ppc_fbsd " LINK_OS_FREEBSD_SPEC_DEF
 
 #undef MULTILIB_DEFAULTS
 #define MULTILIB_DEFAULTS { "m64" }