linux-kernel - Re: [RFC, PATCH 2/4] elf_core_dump(): Remove DUMP

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Date:	Tue, 15 Dec 2009 16:29:13 +0800
From:	Américo Wang <xiyou.wangcong@...il.com>
To:	Daisuke HATAYAMA <d.hatayama@...fujitsu.com>
Cc:	linux-kernel@...r.kernel.org, akpm@...ux-foundation.org,
	jdike@...toit.com, tony.luck@...el.com, mhiramat@...hat.com
Subject: Re: [RFC, PATCH 2/4] elf_core_dump(): Remove DUMP_WRITE macro

On Tue, Dec 15, 2009 at 10:41 AM, Daisuke HATAYAMA
<d.hatayama@...fujitsu.com> wrote:
> In DUMP_WRITE macro, some local variables and goto statement are used
> implicitly, which makes it confusing to understand how the dumping
> process behaves. So, clean up it by unfolding the macro body directly
> to the point where the original macro is used plus a bit of style
> change.
>
> Now that the previous patch replaced ELF_CORE_EXTRA_* macros in
> fs/binfmt_elf.c, there is no users for DUMP_WRITE macro in
> fs/binfmt_elf.c. Thus remove the definition of DUMP_WRITE macro.
>
> Signed-off-by: Daisuke HATAYAMA <d.hatayama@...fujitsu.com>


I assume you at least did a build test?

I like this patch:

Acked-by: WANG Cong <xiyou.wangcong@...il.com>

> ---
>  fs/binfmt_elf.c |   17 ++++++++++-------
>  1 files changed, 10 insertions(+), 7 deletions(-)
>
> diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
> index 5f7be51..9666a8a 100644
> --- a/fs/binfmt_elf.c
> +++ b/fs/binfmt_elf.c
> @@ -1277,10 +1277,6 @@ static int writenote(struct memelfnote *men, struct file *file,
>  }
>  #undef DUMP_WRITE
>
> -#define DUMP_WRITE(addr, nr)   \
> -       if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
> -               goto end_coredump;
> -
>  static void fill_elf_header(struct elfhdr *elf, int segs,
>                            u16 machine, u32 flags, u8 osabi)
>  {
> @@ -1981,7 +1977,10 @@ static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, un
>        fs = get_fs();
>        set_fs(KERNEL_DS);
>
> -       DUMP_WRITE(elf, sizeof(*elf));
> +       size += sizeof(*elf);
> +       if (size > limit || !dump_write(file, elf, sizeof(*elf)))
> +               goto end_coredump;
> +
>        offset += sizeof(*elf);                         /* Elf header */
>        offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
>        foffset = offset;
> @@ -1995,7 +1994,9 @@ static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, un
>
>                fill_elf_note_phdr(&phdr, sz, offset);
>                offset += sz;
> -               DUMP_WRITE(&phdr, sizeof(phdr));
> +               size += sizeof(phdr);
> +               if (size > limit || !dump_write(file, &phdr, sizeof(phdr)))
> +                       goto end_coredump;
>        }
>
>        dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
> @@ -2026,7 +2027,9 @@ static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, un
>                        phdr.p_flags |= PF_X;
>                phdr.p_align = ELF_EXEC_PAGESIZE;
>
> -               DUMP_WRITE(&phdr, sizeof(phdr));
> +               size += sizeof(phdr);
> +               if (size > limit || !dump_write(file, &phdr, sizeof(phdr)))
> +                       goto end_coredump;
>        }
>
>        if (!elf_core_write_extra_phdrs(file, offset, &size, limit))
> --
> 1.6.5.1
>
> --
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