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 <[email protected]>
Tested-by: Joe Lawrence <[email protected]>
Signed-off-by: Josh Poimboeuf <[email protected]>
The __LINE__ macro creates challenges for binary diffing. When a .patch
file adds or removes lines, it shifts the line numbers for all code
below it.
This can cause the code generation of functions using __LINE__ to change
due to the line number constant being embedded in a MOV instruction,
despite there being no semantic difference.
Avoid such false positives by adding a fix-patch-lines script which can
be used to insert a #line directive in each patch hunk affecting the
line numbering. This script will be used by klp-build, which will be
introduced in a subsequent patch.
Acked-by: Petr Mladek <[email protected]>
Tested-by: Joe Lawrence <[email protected]>
Signed-off-by: Josh Poimboeuf <[email protected]>
Josh Poimboeuf