When using clang as HOSTCC, the following warnings appear:

In file included from arch/mips/boot/tools/relocs_64.c:27:0:
arch/mips/boot/tools/relocs.c: In function ‘read_relocs’:
arch/mips/boot/tools/relocs.c:397:4: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
    ELF_R_SYM(rel->r_info) = elf32_to_cpu(ELF_R_SYM(rel->r_info));
    ^~~~~~~~~
arch/mips/boot/tools/relocs.c:397:4: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
arch/mips/boot/tools/relocs.c: In function ‘walk_relocs’:
arch/mips/boot/tools/relocs.c:491:4: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
    Elf_Sym *sym = &sh_symtab[ELF_R_SYM(rel->r_info)];
    ^~~~~~~
arch/mips/boot/tools/relocs.c: In function ‘do_reloc’:
arch/mips/boot/tools/relocs.c:502:2: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
  unsigned r_type = ELF_R_TYPE(rel->r_info);
  ^~~~~~~~
arch/mips/boot/tools/relocs.c: In function ‘do_reloc_info’:
arch/mips/boot/tools/relocs.c:641:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
   rel_type(ELF_R_TYPE(rel->r_info)),
   ^~~~~~~~

Fix them by making Elf64_Mips_Rela a union

Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com>
Acked-by: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13683/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Build the relocs tool as part of the kbuild

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: kernel-hardening@lists.openwall.com
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12980/
Patchwork: https://patchwork.linux-mips.org/patch/13242/
Patchwork: https://patchwork.linux-mips.org/patch/13233/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

This tool is based on the x86/boot/tools/relocs tool.

It parses the relocations present in the vmlinux elf file, building a
table of relocations that will be necessary to run the kernel from an
address other than its link address. This table is inserted into the
vmlinux elf, in the .data.relocs section. The table is subsequently used
by the code in arch/mips/kernel/relocate.c (added later) to relocate the
kernel.

The tool, by default, also marks all relocation sections as 0 length.
This is due to objcopy currently being unable to handle copying the
relocations between 64 and 32 bit elf files as is done when building a
64 bit kernel.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: kernel-hardening@lists.openwall.com
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12981/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>