From 805bc0bc238f7209fca5e39c152b0d3c12046ac9 Mon Sep 17 00:00:00 2001 From: Gerald Schaefer Date: Sun, 3 Feb 2019 21:35:45 +0100 Subject: s390/kernel: build a relocatable kernel This patch adds support for building a relocatable kernel with -fPIE. The kernel will be relocated to 0 early in the boot process. Signed-off-by: Gerald Schaefer Reviewed-by: Philipp Rudo Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/machine_kexec_reloc.c | 53 ++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100644 arch/s390/kernel/machine_kexec_reloc.c (limited to 'arch/s390/kernel/machine_kexec_reloc.c') diff --git a/arch/s390/kernel/machine_kexec_reloc.c b/arch/s390/kernel/machine_kexec_reloc.c new file mode 100644 index 000000000000..1dded39239f8 --- /dev/null +++ b/arch/s390/kernel/machine_kexec_reloc.c @@ -0,0 +1,53 @@ +// SPDX-License-Identifier: GPL-2.0 +#include + +int arch_kexec_do_relocs(int r_type, void *loc, unsigned long val, + unsigned long addr) +{ + switch (r_type) { + case R_390_NONE: + break; + case R_390_8: /* Direct 8 bit. */ + *(u8 *)loc = val; + break; + case R_390_12: /* Direct 12 bit. */ + *(u16 *)loc &= 0xf000; + *(u16 *)loc |= val & 0xfff; + break; + case R_390_16: /* Direct 16 bit. */ + *(u16 *)loc = val; + break; + case R_390_20: /* Direct 20 bit. */ + *(u32 *)loc &= 0xf00000ff; + *(u32 *)loc |= (val & 0xfff) << 16; /* DL */ + *(u32 *)loc |= (val & 0xff000) >> 4; /* DH */ + break; + case R_390_32: /* Direct 32 bit. */ + *(u32 *)loc = val; + break; + case R_390_64: /* Direct 64 bit. */ + *(u64 *)loc = val; + break; + case R_390_PC16: /* PC relative 16 bit. */ + *(u16 *)loc = (val - addr); + break; + case R_390_PC16DBL: /* PC relative 16 bit shifted by 1. */ + *(u16 *)loc = (val - addr) >> 1; + break; + case R_390_PC32DBL: /* PC relative 32 bit shifted by 1. */ + *(u32 *)loc = (val - addr) >> 1; + break; + case R_390_PC32: /* PC relative 32 bit. */ + *(u32 *)loc = (val - addr); + break; + case R_390_PC64: /* PC relative 64 bit. */ + *(u64 *)loc = (val - addr); + break; + case R_390_RELATIVE: + *(unsigned long *) loc = val; + break; + default: + return 1; + } + return 0; +} -- cgit v1.2.3-59-g8ed1b