powerpc: Reject binutils 2.24 when building little endian

There is a bug in binutils 2.24 which causes miscompilation if we're
building little endian and using weak symbols (which the kernel does).

It is fixed in binutils commit 57fa7b8c7e59 "Correct elf_merge_st_other
arguments for weak symbols", which is in binutils 2.25 and has been
backported to the binutils 2.24 branch and has been picked up by most
distros it seems.

However if we're running stock 2.24 (no extra version) then the bug is
present, so check for that and bail.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 3609504b0ad20082be3622f8ea423bf13912e47c..a314cb024c8bb237091d4320e4793e1401e7bbb7 100644 (file)
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -339,6 +339,14 @@ checkbin:
                echo 'disable kernel modules' ; \
                false ; \
        fi
+       @if test "x${CONFIG_CPU_LITTLE_ENDIAN}" = "xy" \
+           && $(LD) --version | head -1 | grep ' 2\.24$$' >/dev/null ; then \
+               echo -n '*** binutils 2.24 miscompiles weak symbols ' ; \
+               echo 'in some circumstances.' ; \
+               echo -n '*** Please use a different binutils version.' ; \
+               false ; \
+       fi
+
 
 CLEAN_FILES += $(TOUT)