From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: + flat-split-the-stack-data-alignments.patch added to -mm tree Date: Fri, 28 May 2010 15:36:21 -0700 Message-ID: <201005282236.o4SMaL2S018443@imap1.linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:55199 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751121Ab0E1Wl4 (ORCPT ); Fri, 28 May 2010 18:41:56 -0400 Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: mm-commits@vger.kernel.org Cc: vapier@gentoo.org, David.Woodhouse@intel.com, davidm@snapgear.com, dhowells@redhat.com, geert@linux-m68k.org, gerg@uclinux.org, herbert@gondor.hengli.com.au, jie@codesourcery.com, lethal@linux-sh.org, monstr@monstr.eu, penberg@cs.helsinki.fi, takata@linux-m32r.org, ysato@users.sourceforge.jp The patch titled fs/binfmt_flat.c: split the stack & data alignments has been added to the -mm tree. Its filename is flat-split-the-stack-data-alignments.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: fs/binfmt_flat.c: split the stack & data alignments From: Mike Frysinger The stack and data have different alignment requirements, so don't force them to wear the same shoe. Increase the data alignment to match that which the elf2flt linker script has always been using: 0x20 bytes. Not only does this bring the kernel loader in line with the toolchain, but it also fixes a swath of gcc tests which try to force larger alignment values but randomly fail when the FLAT loader fails to deliver. Signed-off-by: Mike Frysinger Cc: Herbert Xu Cc: David Woodhouse Cc: Pekka Enberg Acked-by: David McCullough Acked-by: Greg Ungerer Cc: Paul Mundt Tested-by: Michal Simek Cc: Hirokazu Takata Cc: Yoshinori Sato Cc: Geert Uytterhoeven Cc: Jie Zhang Cc: David Howells Signed-off-by: Andrew Morton --- fs/binfmt_flat.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) diff -puN fs/binfmt_flat.c~flat-split-the-stack-data-alignments fs/binfmt_flat.c --- a/fs/binfmt_flat.c~flat-split-the-stack-data-alignments +++ a/fs/binfmt_flat.c @@ -56,15 +56,22 @@ #endif /* - * User data (stack, data section and bss) needs to be aligned - * for the same reasons as SLAB memory is, and to the same amount. - * Avoid duplicating architecture specific code by using the same - * macro as with SLAB allocation: + * User data (data section and bss) needs to be aligned. + * We pick 0x20 here because it is the max value elf2flt has always + * used in producing FLAT files, and because it seems to be large + * enough to make all the gcc alignment related tests happy. + */ +#define FLAT_DATA_ALIGN (0x20) + +/* + * User data (stack) also needs to be aligned. + * 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_DATA_ALIGN (ARCH_SLAB_MINALIGN) +#define FLAT_STACK_ALIGN (ARCH_SLAB_MINALIGN) #else -#define FLAT_DATA_ALIGN (sizeof(void *)) +#define FLAT_STACK_ALIGN (sizeof(void *)) #endif #define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */ @@ -129,7 +136,7 @@ static unsigned long create_flat_tables( sp = (unsigned long *)p; sp -= (envc + argc + 2) + 1 + (flat_argvp_envp_on_stack() ? 2 : 0); - sp = (unsigned long *) ((unsigned long)sp & -FLAT_DATA_ALIGN); + sp = (unsigned long *) ((unsigned long)sp & -FLAT_STACK_ALIGN); argv = sp + 1 + (flat_argvp_envp_on_stack() ? 2 : 0); envp = argv + (argc + 1); @@ -876,7 +883,7 @@ static int load_flat_binary(struct linux stack_len = TOP_OF_ARGS - bprm->p; /* the strings */ stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */ stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */ - stack_len += FLAT_DATA_ALIGN - 1; /* reserve for upcoming alignment */ + stack_len += FLAT_STACK_ALIGN - 1; /* reserve for upcoming alignment */ res = load_flat_file(bprm, &libinfo, 0, &stack_len); if (IS_ERR_VALUE(res)) _ Patches currently in -mm which might be from vapier@gentoo.org are origin.patch linux-next.patch flat-split-the-stack-data-alignments.patch flat-tweak-default-stack-alignment.patch