flat: tweak default stack alignment
The recent commit 1f0ce8b3dd667dca7 ("mm: Move ARCH_SLAB_MINALIGN and
ARCH_KMALLOC_MINALIGN to <linux/slab_def.h>") which moved the
ARCH_SLAB_MINALIGN default into the global header inadvertently broke FLAT
for a bunch of systems. Blackfin systems now fail on any FLAT exec with:
Unable to read code+data+bss, errno 14 When your /init is a FLAT binary,
obviously this can be annoying ;).
This stems from the alignment usage in the FLAT loader. The behavior
before was that FLAT would default to ARCH_SLAB_MINALIGN only if it was
defined, and this was only defined by arches when they wanted a larger
alignment value. Otherwise it'd default to pointer alignment. Arguably,
this is kind of hokey that the FLAT is semi-abusing defines it shouldn't.
So let's merge the two alignment requirements so the floor is never 0.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: David McCullough <davidm@snapgear.com>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: David Howells <dhowells@redhat.com>
Cc: David Woodhouse <David.Woodhouse@intel.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index b6ab27c..811384b 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -68,11 +68,7 @@
* Here we can be a bit looser than the data sections since this
* needs to only meet arch ABI requirements.
*/
-#ifdef ARCH_SLAB_MINALIGN
-#define FLAT_STACK_ALIGN (ARCH_SLAB_MINALIGN)
-#else
-#define FLAT_STACK_ALIGN (sizeof(void *))
-#endif
+#define FLAT_STACK_ALIGN max_t(unsigned long, sizeof(void *), ARCH_SLAB_MINALIGN)
#define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */
#define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */
