[PATCH v3 1/3] powerpc: Discard more sections in linker script

[Michael Ellerman]

Joel Stanley <joel at jms.id.au> writes:

> Building the ppc64 kernel with a modern binutils results in this
> warning:
>
>  powerpc64le-linux-gnu-ld: warning: orphan section `.gnu.hash' from
>  `linker stubs' being placed in section `.gnu.hash'
>
> Alan Modra <amodra at gmail.com> explains:
>
>  > .gnu.hash, like .hash, is used by glibc ld.so for dynamic symbol
>  > lookup.  I imagine you don't need either section in a kernel, so
>  > discarding both sounds reasonable.  Likely you could discard .interp
>  > and .dynstr too, and .dynsym when !CONFIG_PPC32.
>
> Reported-by: Stephen Rothwell <sfr at canb.auug.org.au>
> Signed-off-by: Joel Stanley <joel at jms.id.au>
> ---
> See https://lore.kernel.org/lkml/CACPK8Xft3n5KkpTjN3=7_VUCXHFcK7mxvZm2Rrqu7tppcBoyOg@mail.gmail.com/T/#m58532c86cf0c7b4fb01cc1fe724e48d4c7d8e4a7
>
> v3: Add dynstr hunk to this patch (it was incorrectly left in patch 2)
> ---
>  arch/powerpc/kernel/vmlinux.lds.S | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)

Building ppc64le_defconfig with gcc 8.1.0 / binutils 2.30, this is giving me:

  /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-nm: .tmp_vmlinux1: attempt to load strings from a non-string section (number 0)
  /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-nm: .tmp_vmlinux1: attempt to load strings from a non-string section (number 0)
  /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-nm: .tmp_vmlinux1: attempt to load strings from a non-string section (number 0)
  /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-nm: .tmp_vmlinux1: attempt to load strings from a non-string section (number 0)
  /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-nm: .tmp_vmlinux1: attempt to load strings from a non-string section (number 0)
  /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-nm: .tmp_vmlinux1: attempt to load strings from a non-string section (number 0)
  /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-nm: .tmp_vmlinux1: attempt to load strings from a non-string section (number 0)
  /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-nm: .tmp_vmlinux1: attempt to load strings from a non-string section (number 0)
  /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-nm: .tmp_vmlinux1: attempt to load strings from a non-string section (number 0)
  /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-nm: .tmp_vmlinux2: attempt to load strings from a non-string section (number 0)
  /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-nm: .tmp_vmlinux2: attempt to load strings from a non-string section (number 0)
  /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-nm: vmlinux: attempt to load strings from a non-string section (number 0)
  /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-nm: vmlinux: attempt to load strings from a non-string section (number 0)
  /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-nm: .tmp_vmlinux2: attempt to load strings from a non-string section (number 0)
  /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-nm: .tmp_vmlinux2: attempt to load strings from a non-string section (number 0)
  /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-nm: vmlinux: attempt to load strings from a non-string section (number 0)
  /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-nm: vmlinux: attempt to load strings from a non-string section (number 0)
  /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-objdump: vmlinux: attempt to load strings from a non-string section (number 0)
  /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-objdump: vmlinux: attempt to load strings from a non-string section (number 0)
  WARNING: 2 bad relocations
  c000000001490a50 R_PPC64_ADDR64    (null)
  c000000001490a68 R_PPC64_ADDR64    (null)
  /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-objdump: vmlinux: attempt to load strings from a non-string section (number 0)
  /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-objdump: vmlinux: attempt to load strings from a non-string section (number 0)
  /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-objdump: vmlinux: attempt to load strings from a non-string section (number 0)
  /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-objdump: vmlinux: attempt to load strings from a non-string section (number 0)

Haven't had time to dig into why yet.

cheers