Signed-off-by: chenzefeng <chenzefeng2@huawei.com>
On x86-64, for 32-bit PC-relacive branches, we can generate PLT32
relocation, instead of PC32 relocation. and R_X86_64_PLT32 can be
treated the same as R_X86_64_PC32 since linux kernel doesn't use PLT.
commit b21ebf2fb4cd ("x86: Treat R_X86_64_PLT32 as R_X86_64_PC32") been
fixed for the module loading, but not fixed for livepatch relocation,
which will fail to load livepatch with the error message as follow:
relocation failed for symbol <symbol name> at <symbol address>
This issue only effacted the kernel version from 4.0 to 4.6, becauce the
function klp_write_module_reloc is introduced by: commit b700e7f03d
("livepatch: kernel: add support for live patching") and deleted by:
commit 425595a7fc20 ("livepatch: reuse module loader code to write
relocations")
Signed-off-by: chenzefeng <chenzefeng2@huawei.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit introduces code for the live patching core. It implements
an ftrace-based mechanism and kernel interface for doing live patching
of kernel and kernel module functions.
It represents the greatest common functionality set between kpatch and
kgraft and can accept patches built using either method.
This first version does not implement any consistency mechanism that
ensures that old and new code do not run together. In practice, ~90% of
CVEs are safe to apply in this way, since they simply add a conditional
check. However, any function change that can not execute safely with
the old version of the function can _not_ be safely applied in this
version.
[ jkosina@suse.cz: due to the number of contributions that got folded into
this original patch from Seth Jennings, add SUSE's copyright as well, as
discussed via e-mail ]
Signed-off-by: Seth Jennings <sjenning@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
