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2015-02-06livepatch: add missing newline to error messageJosh Poimboeuf1-1/+1
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-02-04livepatch: rename config to CONFIG_LIVEPATCHJosh Poimboeuf2-4/+4
Rename CONFIG_LIVE_PATCHING to CONFIG_LIVEPATCH to make the naming of the config and the code more consistent. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-01-21livepatch: fix uninitialized return valueJosh Poimboeuf1-1/+1
Fix a potentially uninitialized return value in klp_enable_func(). Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-01-20livepatch: support for repatching a functionJosh Poimboeuf1-51/+119
Add support for patching a function multiple times. If multiple patches affect a function, the function in the most recently enabled patch "wins". This enables a cumulative patch upgrade path, where each patch is a superset of previous patches. This requires restructuring the data a little bit. With the current design, where each klp_func struct has its own ftrace_ops, we'd have to unregister the old ops and then register the new ops, because FTRACE_OPS_FL_IPMODIFY prevents us from having two ops registered for the same function at the same time. That would leave a regression window where the function isn't patched at all (not good for a patch upgrade path). This patch replaces the per-klp_func ftrace_ops with a global klp_ops list, with one ftrace_ops per original function. A single ftrace_ops is shared between all klp_funcs which have the same old_addr. This allows the switch between function versions to happen instantaneously by updating the klp_ops struct's func_stack list. The winner is the klp_func at the top of the func_stack (front of the list). [ jkosina@suse.cz: turn WARN_ON() into WARN_ON_ONCE() in ftrace handler to avoid storm in pathological cases ] Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-01-20livepatch: enforce patch stacking semanticsJosh Poimboeuf1-0/+10
Only allow the topmost patch on the stack to be enabled or disabled, so that patches can't be removed or added in an arbitrary order. Suggested-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-01-20livepatch: change ARCH_HAVE_LIVE_PATCHING to HAVE_LIVE_PATCHINGMiroslav Benes1-2/+2
Change ARCH_HAVE_LIVE_PATCHING to HAVE_LIVE_PATCHING in Kconfigs. HAVE_ bools are prevalent there and we should go with the flow. Suggested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-01-09livepatch: fix deferred module patching orderJosh Poimboeuf1-1/+1
When applying multiple patches to a module, if the module is loaded after the patches are loaded, the patches are applied in reverse order: $ insmod patch1.ko [ 43.172992] livepatch: enabling patch 'patch1' $ insmod patch2.ko [ 46.571563] livepatch: enabling patch 'patch2' $ modprobe nfsd [ 52.888922] livepatch: applying patch 'patch2' to loading module 'nfsd' [ 52.899847] livepatch: applying patch 'patch1' to loading module 'nfsd' Fix the loading order by storing the klp_patches list in queue order. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-01-09livepatch: handle ancient compilers with more graceJiri Kosina1-0/+6
We are aborting a build in case when gcc doesn't support fentry on x86_64 (regs->ip modification can't really reliably work with mcount). This however breaks allmodconfig for people with older gccs that don't support -mfentry. Turn the build-time failure into runtime failure, resulting in the whole infrastructure not being initialized if CC_USING_FENTRY is unset. Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
2015-01-06livepatch: kconfig: use bool instead of booleanChristoph Jaeger1-2/+2
Keyword 'boolean' for type definition attributes is considered deprecated and should not be used anymore. No functional changes. Reference: http://lkml.kernel.org/r/cover.1418003065.git.cj@linux.com Reference: http://lkml.kernel.org/r/1419108071-11607-1-git-send-email-cj@linux.com Signed-off-by: Christoph Jaeger <cj@linux.com> Reviewed-by: Petr Mladek <pmladek@suse.cz> Reviewed-by: Jingoo Han <jg1.han@samsung.com> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-12-22livepatch: use FTRACE_OPS_FL_IPMODIFYJosh Poimboeuf1-1/+2
Use the FTRACE_OPS_FL_IPMODIFY flag to prevent conflicts with other ftrace users who also modify regs->ip. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Petr Mladek <pmladek@suse.cz> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-12-22livepatch: move x86 specific ftrace handler code to arch/x86Li Bin1-1/+1
The execution flow redirection related implemention in the livepatch ftrace handler is depended on the specific architecture. This patch introduces klp_arch_set_pc(like kgdb_arch_set_pc) interface to change the pt_regs. Signed-off-by: Li Bin <huawei.libin@huawei.com> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-12-22livepatch: kernel: add support for live patchingSeth Jennings3-0/+951
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>
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