linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Nick Desaulniers <ndesaulniers@google.com>
To: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>
Cc: clang-built-linux <clang-built-linux@googlegroups.com>,
	"H. Peter Anvin" <hpa@zytor.com>,
	"maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
	<x86@kernel.org>, Tri Vo <trong@android.com>,
	Masahiro Yamada <yamada.masahiro@socionext.com>,
	Rob Herring <robh@kernel.org>,
	George Rimar <grimar@accesssoftek.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Sedat Dilek <sedat.dilek@gmail.com>
Subject: Re: [PATCH v2] x86, realmode: explicitly set entry via command line
Date: Tue, 24 Sep 2019 12:37:30 -0700	[thread overview]
Message-ID: <CAKwvOdnesgP8uVv3x9Ywqy0U24d_V9G-ovD5y__xJKB+t==6hg@mail.gmail.com> (raw)
In-Reply-To: <20190924193310.132104-1-ndesaulniers@google.com>

On Tue, Sep 24, 2019 at 12:33 PM Nick Desaulniers
<ndesaulniers@google.com> wrote:
>
> Linking with ld.lld via $ make LD=ld.lld produces the warning:
> ld.lld: warning: cannot find entry symbol _start; defaulting to 0x1000
>
> Linking with ld.bfd shows the default entry is 0x1000:
> $ readelf -h arch/x86/realmode/rm/realmode.elf | grep Entry
>   Entry point address:               0x1000
>
> While ld.lld is being pedantic, just set the entry point explicitly,
> instead of depending on the implicit default.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/216
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>

I meant to pick up Sedat's reported by tag:
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>

> ---
> Changes V1 -> V2:
> * Use command line flag, rather than linker script, as ld.bfd produces a
>   syntax error for `ENTRY(0x1000)` but is happy with `-e 0x1000`
>
>  arch/x86/realmode/rm/Makefile | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/realmode/rm/Makefile b/arch/x86/realmode/rm/Makefile
> index f60501a384f9..338a00c5257f 100644
> --- a/arch/x86/realmode/rm/Makefile
> +++ b/arch/x86/realmode/rm/Makefile
> @@ -46,7 +46,7 @@ $(obj)/pasyms.h: $(REALMODE_OBJS) FORCE
>  targets += realmode.lds
>  $(obj)/realmode.lds: $(obj)/pasyms.h
>
> -LDFLAGS_realmode.elf := -m elf_i386 --emit-relocs -T
> +LDFLAGS_realmode.elf := -m elf_i386 --emit-relocs -e 0x1000 -T
>  CPPFLAGS_realmode.lds += -P -C -I$(objtree)/$(obj)
>
>  targets += realmode.elf
> --
> 2.23.0.351.gc4317032e6-goog
>


-- 
Thanks,
~Nick Desaulniers

  reply	other threads:[~2019-09-24 19:37 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-23 22:24 [PATCH] x86, realmode: explicitly set ENTRY in linker script Nick Desaulniers
2019-09-24 17:30 ` Sedat Dilek
2019-09-24 18:24 ` Nathan Chancellor
2019-09-24 18:32   ` Nick Desaulniers
2019-09-24 19:33     ` [PATCH v2] x86, realmode: explicitly set entry via command line Nick Desaulniers
2019-09-24 19:37       ` Nick Desaulniers [this message]
2019-09-25 10:20       ` Borislav Petkov
2019-09-25 16:35         ` Nick Desaulniers
2019-09-25 17:02           ` Peter Smith
2019-09-25 17:10           ` Borislav Petkov
2019-09-25 18:09             ` [PATCH v3] x86, realmode: explicitly set entry via ENTRY in linker script Nick Desaulniers
2019-10-01 10:37               ` [tip: x86/boot] x86/realmode: Explicitly set entry point " tip-bot2 for Nick Desaulniers
2019-10-01 20:18               ` tip-bot2 for Nick Desaulniers

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAKwvOdnesgP8uVv3x9Ywqy0U24d_V9G-ovD5y__xJKB+t==6hg@mail.gmail.com' \
    --to=ndesaulniers@google.com \
    --cc=bp@alien8.de \
    --cc=clang-built-linux@googlegroups.com \
    --cc=grimar@accesssoftek.com \
    --cc=hpa@zytor.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=robh@kernel.org \
    --cc=sedat.dilek@gmail.com \
    --cc=tglx@linutronix.de \
    --cc=trong@android.com \
    --cc=x86@kernel.org \
    --cc=yamada.masahiro@socionext.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).