With #755, we started using dynrelas for function pointers. However,
this behavior only makes sense for function pointers to existing
functions. For function pointers to *new* functions, just use a normal
rela.
The 'function-ptr-new' unit test is from the following patch:
https://github.com/dynup/kpatch/files/1927198/new-static-callback.patch.txtFixes#834.
Fixes: 495e619750 ("kpatch-build, x86: do not use the patched functions as callbacks directly")
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Don't suppress stderr in the non-fail unit tests so that
create-diff-object error messages will be printed.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Since commit 926e4e0c7d ("kmod: add support
for in-kernel livepatch hooks") livepatch-patch-hook.c unconditionally
creates callbacks. This causes build error for kernels older than 4.15:
make -C /home/rppt/git/linux M=/home/rppt/.kpatch/tmp/patch livepatch-proc-vmalloc-live.ko
make[1]: Entering directory '/home/rppt/git/linux'
CC [M] /home/rppt/.kpatch/tmp/patch/patch-hook.o
In file included from /home/rppt/.kpatch/tmp/patch/patch-hook.c:21:0:
/home/rppt/.kpatch/tmp/patch/livepatch-patch-hook.c:82:23: error: field ‘callbacks’ has incomplete type
struct klp_callbacks callbacks;
^
/home/rppt/.kpatch/tmp/patch/livepatch-patch-hook.c: In function ‘patch_init’:
/home/rppt/.kpatch/tmp/patch/livepatch-patch-hook.c:395:10: error: ‘struct klp_object’ has no member named ‘callbacks’
lobject->callbacks = object->callbacks;
^
scripts/Makefile.build:302: recipe for target '/home/rppt/.kpatch/tmp/patch/patch-hook.o' failed
make[2]: *** [/home/rppt/.kpatch/tmp/patch/patch-hook.o] Error 1
Makefile:1687: recipe for target 'livepatch-proc-vmalloc-live.ko' failed
make[1]: *** [livepatch-proc-vmalloc-live.ko] Error 2
make[1]: Leaving directory '/home/rppt/git/linux'
Makefile:20: recipe for target 'livepatch-proc-vmalloc-live.ko' failed
make: *** [livepatch-proc-vmalloc-live.ko] Error 2
Introduce HAVE_CALLBACKS to allow conditional compilation of the callbacks
addition.
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Elaborate on the difficulties in using locks/mutexes from the kpatch
callback routines and suggest a few workarounds.
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Add a simple unittest framework for create-diff-object implemented in
GNU Make.
It will automatically scan the kpatch-unit-objs/$(uname -m) directory
for specifically named files running one of 3 tests:
- creating diff object with expected success
- creating diff object with expected failure
- creating diff object and running a shell script on it with expected
success
Signed-off-by: Artem Savkov <asavkov@redhat.com>
- convert section/symbol indexes and rela->offset to unsigned int as I
couldn't find any way for them to become negative.
- cast a number of rela->addend comparisons to int (assuming an 64bit
system this should be enough)
- a number of simple for-loop counter conversions to the type it
compares against
Signed-off-by: Artem Savkov <asavkov@redhat.com>
If a patch failed a first time, kpatch-build is using the previous
cache directory on subsequent builds. The UBUNTU_KERNEL=1 variable is
not set in this case. Therefore, utsrelease.h is not updated correctly
and the appropriate structures are not used. Just check if distro is
Ubuntu and we didn't request our own specific directory.
Signed-off-by: Vincent Bernat <vincent@bernat.im>
Because of signedness difference kpatch_check_relocations() would trigger
an error on any negative addend.
Fix by casting Elf_Data->d_size from size_t to int.
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Check that none of the relocations are out-of-range of their
corresponding sections before writing the output elf.
Fixes: #618
Signed-off-by: Artem Savkov <asavkov@redhat.com>
The module notifier currently only handles newly loaded modules in the
MODULE_STATE_COMING state. If target modules need to be unloaded, the
any kpatch module that patches it must first be disabled, releasing
module references held against the target module. When the kpatch
modules are disabled, the target module is unpatched and the kpatch
core's data structures updated accordingly.
If a loading module happens to fail its init routine (missing hardware
for example), that module will not complete loading. The kpatch core
doesn't properly account for this "phantom" target module, so when the
kpatch patch module is removed, it spews out an ugly warning when
attempting to remove a non-existing ftrace filter on the target module.
Register an additional module notifier (first in the list) to handle the
MODULE_STATE_GOING case. This handler needs to do the inverse of the
MODULE_STATE_COMING handler.
Fixes#699.
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Heavy lifting of reading .toc rela entries for rela symbols
referring to .toc + offset, can be simplified using toc_rela() in
rela_equal() and remove the #ifdery guarding PowerPC code.
This patch also trims the commentary related to PowerPC.
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Currently kpatch rely on systemd to load all kmods on startup.
This patch aims to enable kpatch to be used on upstart systems.
Limitations:
With systemd, it would be possible to unload all modules by issuing:
systemctl stop kpatch
It was not possible to make a reasonable upstart's equivalent of it, so
to unload the modules it will be necessary to call kpatch explicitly:
kpatch unload --all
I believe this it an non-issue, as it is still possible to unload
the modules by calling kpatch explicitly.
The file /etc/init/kpatch.conf will be installed unconditionally, and
removed on uninstall.
On my tests I have verified that all newly added files by this commit
are also deleted on uninstall.
It was also verified that applied patches are loaded again on startup.
rpmlint does not complain about anything new.
Signed-off-by: Bruno Loreto <loretob@amazon.com>
The test case gcc-static-local-var-2 doesn't uses any macros
from kpatch-macros.h, so remove the hunk including it.
Cc: Joe Lawrence <jdl1291@gmail.com>
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
This patch adds a reproducer testcase for correlating static local
variables added in .rodata* section, ahead of .toc section. This
testcase is for issue seen on PowerPC. For more details on the issue
refer pull request: 793.
It add's the testcase for:
- Fedora-27 Kernel version 4.15.10-300
- Centos-7 Kernel version 3.10.0-693 and
- Ubuntu-16.04 Kernel version 4.13.0-25.29
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
On ppc64le, the static local variable correlation doesn't take into
account the .toc rela indirection for data references, meaning that it's
basically broken in many cases.
Fix it by making the code .toc-aware.
Fixes#793.
Reported-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Fixes sparse warnings:
kmod/core/core.c:142:20: warning: symbol 'trace' was not declared. Should it be static?
livepatch-patch-hook.c:73:18: warning: symbol 'lpatch' was not declared. Should it be static?
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Upstream 4.15 kernels provide support for pre and post (un)patch
callbacks, inspired by the kpatch load hooks. Add support for them
in the livepatch-patch-hook.
At the same time, convert the kpatch hooks to use the same API.
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Cleanup some of the new bash script code to appease 'make check':
- kpatch: Use integer comparison for $MAX_LOAD_ATTEMPTS
- kpatch-build: Quote ${TEMPDIR} variable
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
