linux/arch/x86/boot/setup.ld
Ilie Halip 163159aad7 x86/boot: Discard .eh_frame sections
When using GCC as compiler and LLVM's lld as linker, linking setup.elf
fails:

   LD      arch/x86/boot/setup.elf
  ld.lld: error: init sections too big!

This happens because GCC generates .eh_frame sections for most of the
files in that directory, then ld.lld places the merged section before
__end_init, triggering an assert in the linker script.

Fix this by discarding the .eh_frame sections, as suggested by Boris.
The kernel proper linker script discards them too.

 [ bp: Going back in history, 64-bit kernel proper has been discarding
   .eh_frame since 2002:

    commit acca80acefe20420e69561cf55be64f16c34ea97
    Author: Andi Kleen <ak@muc.de>
    Date:   Tue Oct 29 23:54:35 2002 -0800

      [PATCH] x86-64 updates for 2.5.44

      ...

    - Remove the .eh_frame on linking. This saves several hundred KB in the
      bzImage
 ]

Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Ilie Halip <ilie.halip@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com
Cc: Andy Lutomirski <luto@kernel.org>
Cc: clang-built-linux@googlegroups.com
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lore.kernel.org/lkml/20191118175223.GM6363@zn.tnic/
Link: https://github.com/ClangBuiltLinux/linux/issues/760
Link: https://lkml.kernel.org/r/20191126144545.19354-1-ilie.halip@gmail.com
2019-12-13 11:45:59 +01:00

68 lines
1.1 KiB
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/*
* setup.ld
*
* Linker script for the i386 setup code
*/
OUTPUT_FORMAT("elf32-i386")
OUTPUT_ARCH(i386)
ENTRY(_start)
SECTIONS
{
. = 0;
.bstext : { *(.bstext) }
.bsdata : { *(.bsdata) }
. = 495;
.header : { *(.header) }
.entrytext : { *(.entrytext) }
.inittext : { *(.inittext) }
.initdata : { *(.initdata) }
__end_init = .;
.text : { *(.text) }
.text32 : { *(.text32) }
. = ALIGN(16);
.rodata : { *(.rodata*) }
.videocards : {
video_cards = .;
*(.videocards)
video_cards_end = .;
}
. = ALIGN(16);
.data : { *(.data*) }
.signature : {
setup_sig = .;
LONG(0x5a5aaa55)
}
. = ALIGN(16);
.bss :
{
__bss_start = .;
*(.bss)
__bss_end = .;
}
. = ALIGN(16);
_end = .;
/DISCARD/ : {
*(.eh_frame)
*(.note*)
}
/*
* The ASSERT() sink to . is intentional, for binutils 2.14 compatibility:
*/
. = ASSERT(_end <= 0x8000, "Setup too big!");
. = ASSERT(hdr == 0x1f1, "The setup header has the wrong offset!");
/* Necessary for the very-old-loader check to work... */
. = ASSERT(__end_init <= 5*512, "init sections too big!");
}