[POWERPC] spufs: Don't return -ENOSYS as extra notes size if spufs is not loaded

Because the SPU coredump code might be built as part of a module (spufs),
we have a stub which is called by the coredump code, this routine then calls
into spufs if it's loaded.

Unfortunately the stub returns -ENOSYS if spufs is not loaded, which is
interpreted by the coredump code as an extra note size of -38 bytes. This
leads to a corrupt core dump.

If spufs is not loaded there will be no SPU ELF notes to write, and so the
extra notes size will be == 0.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Acked-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 6 insertions, 2 deletions

diff --git a/arch/powerpc/platforms/cell/spu_coredump.c b/arch/powerpc/platforms/cell/spu_coredump.c
index 4fd37ff1e210..656a8c52cd38 100644
--- a/arch/powerpc/platforms/cell/spu_coredump.c
+++ b/arch/powerpc/platforms/cell/spu_coredump.c
@@ -31,15 +31,19 @@ static DEFINE_MUTEX(spu_coredump_mutex);
 
 int arch_notes_size(void)
 {
-        long ret;
+        int ret;
 
-        ret = -ENOSYS;
         mutex_lock(&spu_coredump_mutex);
+
         if (spu_coredump_calls && try_module_get(spu_coredump_calls->owner)) {
                 ret = spu_coredump_calls->arch_notes_size();
                 module_put(spu_coredump_calls->owner);
+        } else {
+                ret = 0;
         }
+
         mutex_unlock(&spu_coredump_mutex);
+
         return ret;
 }