kernel/kexec_file.c: use read-only sections in arch_kexec_apply_relocations*
authorPhilipp Rudo <prudo@linux.vnet.ibm.com>
Fri, 13 Apr 2018 22:36:24 +0000 (15:36 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 14 Apr 2018 00:10:28 +0000 (17:10 -0700)
commit8aec395b8478310521031157ef5d44ef19c2c581
treec48f8773b3c734ab3f8ebf0e51e262959948f1b9
parent961d921a1b967f76e13f9e11f2b0c2bcb5741f10
kernel/kexec_file.c: use read-only sections in arch_kexec_apply_relocations*

When the relocations are applied to the purgatory only the section the
relocations are applied to is writable.  The other sections, i.e.  the
symtab and .rel/.rela, are in read-only kexec_purgatory.  Highlight this
by marking the corresponding variables as 'const'.

While at it also change the signatures of arch_kexec_apply_relocations* to
take section pointers instead of just the index of the relocation section.
This removes the second lookup and sanity check of the sections in arch
code.

Link: http://lkml.kernel.org/r/20180321112751.22196-6-prudo@linux.vnet.ibm.com
Signed-off-by: Philipp Rudo <prudo@linux.vnet.ibm.com>
Acked-by: Dave Young <dyoung@redhat.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch/x86/kernel/machine_kexec_64.c
include/linux/kexec.h
kernel/kexec_file.c