From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Christoph Hellwig <hch@lst.de>
Cc: Greg Ungerer <gerg@linux-m68k.org>,
Michal Simek <monstr@monstr.eu>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
linux-c6x-dev@linux-c6x.org,
"moderated list:H8/300 ARCHITECTURE"
<uclinux-h8-devel@lists.sourceforge.jp>,
linux-m68k <linux-m68k@lists.linux-m68k.org>,
linux-riscv@lists.infradead.org,
Linux-sh list <linux-sh@vger.kernel.org>,
linux-xtensa@linux-xtensa.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 07/15] binfmt_flat: use __be32 for the on-disk format
Date: Tue, 11 Jun 2019 10:25:46 +0200 [thread overview]
Message-ID: <CAMuHMdXvbA=+=AQ6fYV2zRUc6CWtZ_GzEN7D5b8QNYwLEd6OjA@mail.gmail.com> (raw)
In-Reply-To: <20190610212015.9157-8-hch@lst.de>
Hi Christoph,
On Mon, Jun 10, 2019 at 11:21 PM Christoph Hellwig <hch@lst.de> wrote:
> So far binfmt_flat has onl been supported on 32-bit platforms, so the
> variable size of the fields didn't matter. But the upcoming RISC-V
> nommu port supports 64-bit CPUs, and we now have a conflict between
> the elf2flt creation tool that always uses 32-bit fields and the kernel
> that uses (unsigned) long field. Switch to the userspace view as the
> rest of the binfmt_flat format is completely architecture neutral,
> and binfmt_flat isn't the right binary format for huge executables to
> start with.
>
> While we're at it also ensure these fields are using __be types as
> they big endian and are byteswapped when loaded.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> --- a/include/linux/flat.h
> +++ b/include/linux/flat.h
> @@ -67,19 +67,19 @@ struct flat_hdr {
> #define OLD_FLAT_RELOC_TYPE_BSS 2
>
> typedef union {
> - unsigned long value;
> + u32 value;
> struct {
> # if defined(mc68000) && !defined(CONFIG_COLDFIRE)
> - signed long offset : 30;
> - unsigned long type : 2;
> + s32 offset : 30;
> + u32 type : 2;
> # define OLD_FLAT_FLAG_RAM 0x1 /* load program entirely into RAM */
> # elif defined(__BIG_ENDIAN_BITFIELD)
> - unsigned long type : 2;
> - signed long offset : 30;
> + u32 type : 2;
> + s32 offset : 30;
> # define OLD_FLAT_FLAG_RAM 0x1 /* load program entirely into RAM */
> # elif defined(__LITTLE_ENDIAN_BITFIELD)
> - signed long offset : 30;
> - unsigned long type : 2;
> + s32 offset : 30;
> + u32 type : 2;
> # define OLD_FLAT_FLAG_RAM 0x1 /* load program entirely into RAM */
The definitions of OLD_FLAT_FLAG_RAM are identical, so could be
factored out.
However, they appear to be unused.
> # else
> # error "Unknown bitfield order for flat files."
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
next prev parent reply other threads:[~2019-06-11 8:26 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-10 21:20 binfmt_flat cleanups and RISC-V support Christoph Hellwig
2019-06-10 21:20 ` [PATCH 01/15] binfmt_flat: remove flat_reloc_valid Christoph Hellwig
2019-06-11 9:44 ` Vladimir Murzin
2019-06-10 21:20 ` [PATCH 02/15] binfmt_flat: remove flat_set_persistent Christoph Hellwig
2019-06-11 9:45 ` Vladimir Murzin
2019-06-10 21:20 ` [PATCH 03/15] binfmt_flat: provide a default version of flat_get_relocate_addr Christoph Hellwig
2019-06-11 9:46 ` Vladimir Murzin
2019-06-10 21:20 ` [PATCH 04/15] binfmt_flat: remove flat_old_ram_flag Christoph Hellwig
2019-06-11 6:04 ` Greg Ungerer
2019-06-11 7:36 ` Christoph Hellwig
2019-06-11 13:07 ` Greg Ungerer
2019-06-11 9:47 ` Vladimir Murzin
2019-06-10 21:20 ` [PATCH 05/15] binfmt_flat: replace flat_argvp_envp_on_stack with a Kconfig variable Christoph Hellwig
2019-06-11 9:49 ` Vladimir Murzin
2019-06-10 21:20 ` [PATCH 06/15] binfmt_flat: remove the uapi <linux/flat.h> header Christoph Hellwig
2019-06-11 9:51 ` Vladimir Murzin
2019-06-10 21:20 ` [PATCH 07/15] binfmt_flat: use __be32 for the on-disk format Christoph Hellwig
2019-06-11 8:25 ` Geert Uytterhoeven [this message]
2019-06-11 9:57 ` Vladimir Murzin
2019-06-10 21:20 ` [PATCH 08/15] binfmt_flat: add endianess annotations Christoph Hellwig
2019-06-11 9:58 ` Vladimir Murzin
2019-06-10 21:20 ` [PATCH 09/15] binfmt_flat: add a ARCH_HAS_BINFMT_FLAT option Christoph Hellwig
2019-06-11 9:59 ` Vladimir Murzin
2019-06-10 21:20 ` [PATCH 10/15] binfmt_flat: make support for old format binaries optional Christoph Hellwig
2019-06-10 21:20 ` [PATCH 11/15] binfmt_flat: provide an asm-generic/flat.h Christoph Hellwig
2019-06-11 10:01 ` Vladimir Murzin
2019-06-10 21:20 ` [PATCH 12/15] binfmt_flat: remove the persistent argument from flat_get_addr_from_rp Christoph Hellwig
2019-06-10 21:20 ` [PATCH 13/15] binfmt_flat: move the MAX_SHARED_LIBS definition to binfmt_flat.c Christoph Hellwig
2019-06-10 21:20 ` [PATCH 14/15] binfmt_flat: don't offset the data start Christoph Hellwig
2019-06-10 21:20 ` [PATCH 15/15] riscv: add binfmt_flat support Christoph Hellwig
2019-06-11 8:16 ` Vladimir Murzin
2019-06-11 9:20 ` Christoph Hellwig
2019-06-11 6:51 ` binfmt_flat cleanups and RISC-V support Greg Ungerer
2019-06-11 7:38 ` Christoph Hellwig
2019-06-11 13:02 ` Greg Ungerer
2019-06-11 8:05 ` Vladimir Murzin
2019-06-11 8:11 ` Christoph Hellwig
2019-06-11 10:08 ` Vladimir Murzin
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