linux-toradex.git/scripts/livepatch/klp-build, branch v6.19-rc2 Linux kernel for Apalis and Colibri modules objtool/klp: Only enable --checksum when needed 2025-11-18T08:59:26+00:00 Josh Poimboeuf jpoimboe@kernel.org 2025-11-12T23:32:34+00:00 2092007aa32f8dd968c38751bd1b7cac9b1f738d With CONFIG_KLP_BUILD enabled, checksums are only needed during a klp-build run. There's no need to enable them for normal kernel builds. This also has the benefit of softening the xxhash dependency. Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Michael Kelley <mhklinux@outlook.com> Link: https://patch.msgid.link/edbb1ca215e4926e02edb493b68b9d6d063e902f.1762990139.git.jpoimboe@kernel.org 
With CONFIG_KLP_BUILD enabled, checksums are only needed during a
klp-build run.  There's no need to enable them for normal kernel builds.

This also has the benefit of softening the xxhash dependency.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Link: https://patch.msgid.link/edbb1ca215e4926e02edb493b68b9d6d063e902f.1762990139.git.jpoimboe@kernel.org
livepatch/klp-build: Add --show-first-changed option to show function divergence 2025-10-14T21:50:19+00:00 Josh Poimboeuf jpoimboe@kernel.org 2025-09-17T16:04:10+00:00 78be9facfb5e711e5284ef1856401ea909eceeb2 Add a --show-first-changed option to identify where changed functions begin to diverge: - Parse 'objtool klp diff' output to find changed functions. - Run objtool again on each object with --debug-checksum=<funcs>. - Diff the per-instruction checksum debug output to locate the first differing instruction. This can be useful for quickly determining where and why a function changed. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> 
Add a --show-first-changed option to identify where changed functions
begin to diverge:

  - Parse 'objtool klp diff' output to find changed functions.

  - Run objtool again on each object with --debug-checksum=<funcs>.

  - Diff the per-instruction checksum debug output to locate the first
    differing instruction.

This can be useful for quickly determining where and why a function
changed.

Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
livepatch/klp-build: Add --debug option to show cloning decisions 2025-10-14T21:50:19+00:00 Josh Poimboeuf jpoimboe@kernel.org 2025-09-17T16:04:09+00:00 2c2f0b8626917c48e4b12827d296a3c654612b90 Add a --debug option which gets passed to "objtool klp diff" to enable debug output related to cloning decisions. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> 
Add a --debug option which gets passed to "objtool klp diff" to enable
debug output related to cloning decisions.

Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
livepatch/klp-build: Introduce klp-build script for generating livepatch modules 2025-10-14T21:50:19+00:00 Josh Poimboeuf jpoimboe@kernel.org 2025-09-17T16:04:08+00:00 24ebfcd65a871df4555b98c49c9ed9a92f146113 Add a klp-build script which automates the generation of a livepatch module from a source .patch file by performing the following steps: - Builds an original kernel with -function-sections and -fdata-sections, plus objtool function checksumming. - Applies the .patch file and rebuilds the kernel using the same options. - Runs 'objtool klp diff' to detect changed functions and generate intermediate binary diff objects. - Builds a kernel module which links the diff objects with some livepatch module init code (scripts/livepatch/init.c). - Finalizes the livepatch module (aka work around linker wreckage) using 'objtool klp post-link'. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> 
Add a klp-build script which automates the generation of a livepatch
module from a source .patch file by performing the following steps:

  - Builds an original kernel with -function-sections and
    -fdata-sections, plus objtool function checksumming.

  - Applies the .patch file and rebuilds the kernel using the same
    options.

  - Runs 'objtool klp diff' to detect changed functions and generate
    intermediate binary diff objects.

  - Builds a kernel module which links the diff objects with some
    livepatch module init code (scripts/livepatch/init.c).

  - Finalizes the livepatch module (aka work around linker wreckage)
    using 'objtool klp post-link'.

Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>