livepatch: reuse module loader code to write relocations
authorJessica Yu <jeyu@redhat.com>
Wed, 23 Mar 2016 00:03:18 +0000 (20:03 -0400)
committerJiri Kosina <jkosina@suse.cz>
Fri, 1 Apr 2016 13:00:11 +0000 (15:00 +0200)
commit425595a7fc2096ab46c741b5ed5372c5ab5bbeac
tree9cf12348ba352e7679be0aadf370aa0a7bc5509e
parentf31e0960f395df0c9197de53674365e2a28a129b
livepatch: reuse module loader code to write relocations

Reuse module loader code to write relocations, thereby eliminating the need
for architecture specific relocation code in livepatch. Specifically, reuse
the apply_relocate_add() function in the module loader to write relocations
instead of duplicating functionality in livepatch's arch-dependent
klp_write_module_reloc() function.

In order to accomplish this, livepatch modules manage their own relocation
sections (marked with the SHF_RELA_LIVEPATCH section flag) and
livepatch-specific symbols (marked with SHN_LIVEPATCH symbol section
index). To apply livepatch relocation sections, livepatch symbols
referenced by relocs are resolved and then apply_relocate_add() is called
to apply those relocations.

In addition, remove x86 livepatch relocation code and the s390
klp_write_module_reloc() function stub. They are no longer needed since
relocation work has been offloaded to module loader.

Lastly, mark the module as a livepatch module so that the module loader
canappropriately identify and initialize it.

Signed-off-by: Jessica Yu <jeyu@redhat.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # for s390 changes
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
arch/s390/include/asm/livepatch.h
arch/x86/include/asm/livepatch.h
arch/x86/kernel/Makefile
arch/x86/kernel/livepatch.c [deleted file]
include/linux/livepatch.h
kernel/livepatch/core.c
samples/livepatch/livepatch-sample.c