Move all the ftrace filtering and registering logic into a couple of new
helper functions. Change kpatch_num_registered to kpatch_num_patched,
which now tracks the number of patched functions rather than the number
of patch modules.
This simplifies the code a bit and will also prevent a future loaded
module scenario where ftrace_ops can be registered with an empty filter,
resulting in _all_ kernel functions getting registered with ftrace.
Use single quotes when printing the name of a patch module, rather than
double quotes. This is more consistent with other printk messages, and
looks better too!
If kpatch_ftrace_add_func fails, num_funcs will be one less than what it
needs to be for kpatch_put_modules to work properly. Instead give it
the full array size, and it can figure out which modules to put based on
whether func->mod is nonzero.
The previous commit did not adjust the indentation to ease with
reviewing. This commit corrects the indentation. Purely whitespace
change.
Signed-off-by: Seth Jennings <sjenning@redhat.com>
This commit adds support for module patching with kpatch-build.
It introduces a new option, -t/--targets, that allows the user to
specify kernel make targets that are impacted by the patch. These
targets will be examined by kpatch-build for changes.
While this approach requires the user to provide more information to
kpatch-build about what exactly has changed, it is better that
rebuilding the entire source tree (make vmlinux && make modules) which
would dramatically increase the runtime and disk space requirements of
using kpatch-build.
Future improvements could include a script that will independently
generate the targets list file.
Signed-off-by: Seth Jennings <sjenning@redhat.com>
With test/integration/data-read-mostly.patch, create-diff-object
includes the __verbose section but not the .rela__verbose section, which
is a bug, resulting in the following printk during the integration
tests:
[13740.801920] dynamic debug error adding module: (null)
If a non-bundled section is included, its rela section should also be
included. Also add support for converting those relas to dynrelas.
When renaming a foo.isra.1 function, there might also be a foo_bar
function which would be falsely matched with the current strchr logic.
Instead of matching the "foo" prefix, match "foo.isra".
Currently, kpatch unload passes the raw argument to basename since the
user may pass a path into the subcommand. This makes the argument hard
to validate. This can be improved since the set of acceptable inputs is
already known, namely the list of loaded patch modules.
This commit changes the kpatch unload subcommand to accept only the
module name, since kpatch should already be aware of it since it is
loaded. It is then trivial to validate the user input since, if it is
not the name of a loaded module, it is invalid.
Signed-off-by: Seth Jennings <sjenning@redhat.com>
Try to be more consistent with the naming of patch modules. They are
patch modules, where patch is the adjective and module is the noun. So
calling them patches is confusing.
In the case of "kpatch unload --all", just show the usage help instead
of this:
# kpatch unload --all
basename: unrecognized option '--all'
Try 'basename --help' for more information.
unloading patch module:
basename: unrecognized option '--all'
Try 'basename --help' for more information.
rmmod: ERROR: Module is builtin.
kpatch: failed to unload patch --all
A simple kernel module for testing basic kernel module patching.
Just run doit.sh from test/testmod.
Signed-off-by: Seth Jennings <sjenning@redhat.com>
This commit adds support for patching modules. If a patch or dynrela is
determined to be for a kernel module, the old_offset/src is not used and
the symbol location is looked up using kallsyms. The module being
patched is also references to keep if from disappearing from underneath
us.
This commit introduces early and limited support. The kernel module to
be patched must already be loaded or the patch module will not apply.
Signed-off-by: Seth Jennings <sjenning@redhat.com>
This commit adds module patching support to create-diff-object by:
1) generalizing the vmlinux CLI parameter
2) adding the kernel object name to each patch and dynrela
3) adding slightly different logic for vmlinux/module in the dynrela
creation
Signed-off-by: Seth Jennings <sjenning@redhat.com>
Rather than keep the logic in sync between the counting and processing
code in kpatch_create_dynamic_rela_sections() just do a "dumb" count
establishing an upper bound and allocating the buffer, then determine
the actual size (i.e. number of dynrelas) in the processing section.
No functional change intended.
Signed-off-by: Seth Jennings <sjenning@redhat.com>
Make old addresses relative to the start address of the relocatable
kernel or module.
This commit has no functional effect; it just prepares the code for
future acceptance of the module patching support.
Signed-off-by: Seth Jennings <sjenning@redhat.com>
