klp-build: Validate short-circuit prerequisites

The --short-circuit option implicitly requires that certain directories
are already in klp-tmp. Enforce that to prevent confusing errors.

Acked-by:

klp-build: Validate short-circuit prerequisites

The --short-circuit option implicitly requires that certain directories
are already in klp-tmp. Enforce that to prevent confusing errors.

Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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objtool/klp: Remove "objtool --checksum"

The checksum functionality has been moved to "objtool klp checksum"
which is now used by klp-build. Remove the now-dead --checksum and
--debug-checksum opti

objtool/klp: Remove "objtool --checksum"

The checksum functionality has been moved to "objtool klp checksum"
which is now used by klp-build. Remove the now-dead --checksum and
--debug-checksum options from the default objtool command.

Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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klp-build: Use "objtool klp checksum" subcommand

Use the new "objtool klp checksum" subcommand instead of injecting
--checksum into every objtool invocation via OBJTOOL_ARGS during the
kernel build.

klp-build: Use "objtool klp checksum" subcommand

Use the new "objtool klp checksum" subcommand instead of injecting
--checksum into every objtool invocation via OBJTOOL_ARGS during the
kernel build.

This decouples checksum generation from the build, running it in
separate post-build passes, making the code (and the patch generation
pipeline itself) more modular.

Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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klp-build: Remove redundant SRC and OBJ variables

SRC and OBJ are both set to $(pwd) and are always identical. The script
already enforces that klp-build runs from the kernel root directory, and
bu

klp-build: Remove redundant SRC and OBJ variables

SRC and OBJ are both set to $(pwd) and are always identical. The script
already enforces that klp-build runs from the kernel root directory, and
builds are done in-place, making these variables unnecessary.

Suggested-by: Song Liu <song@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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klp-build: Print "objtool klp diff" command in verbose mode

Print the full objtool command line when '--verbose' is given to help
with debugging.

Acked-by: Song Liu <song@kernel.org>
Signed-off-by:

klp-build: Print "objtool klp diff" command in verbose mode

Print the full objtool command line when '--verbose' is given to help
with debugging.

Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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klp-build: Reject patches to realmode

Realmode code is compiled as a separate 16-bit binary and embedded into
the kernel image via rmpiggy.S. It can't be livepatched.

Acked-by: Song Liu <song@kern

klp-build: Reject patches to realmode

Realmode code is compiled as a separate 16-bit binary and embedded into
the kernel image via rmpiggy.S. It can't be livepatched.

Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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klp-build: Reject patches to vDSO

vDSO code runs in userspace and can't be livepatched. Such patches also
cause spurious "new function" errors due to generated files like
vdso*-image.c having unsta

klp-build: Reject patches to vDSO

vDSO code runs in userspace and can't be livepatched. Such patches also
cause spurious "new function" errors due to generated files like
vdso*-image.c having unstable line numbers across builds.

Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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klp-build: Fix patch cleanup on interrupt

If a build error occurs and the user hits Ctrl-C while a large patch is
being reverted during cleanup, the cleanup EXIT trap gets re-triggered
and tries to

klp-build: Fix patch cleanup on interrupt

If a build error occurs and the user hits Ctrl-C while a large patch is
being reverted during cleanup, the cleanup EXIT trap gets re-triggered
and tries to re-revert the already partially-reverted patch. That
causes 'patch -R' to repeatedly prompt

"Unreversed patch detected! Ignore -R? [n]"

for each already-reverted hunk, with no way to break out.

Fix it by adding '--force' to the patch revert command in
revert_patch(), which causes it to silently ignore already-reverted
hunks. And ignore errors, as the cleanup is always best-effort.

For similar reasons, add to APPLIED_PATCHES before (rather than after)
applying the patch in apply_patch() so an interrupted apply will also
get cleaned up.

Fixes: d36a7343f4ba ("livepatch/klp-build: switch to GNU patch and recountdiff")
Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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klp-build: Suppress excessive fuzz output by default

When a patch applies with fuzz, the detailed output from the patch tool
can be very noisy, especially for big patches.

Suppress the fuzz details

klp-build: Suppress excessive fuzz output by default

When a patch applies with fuzz, the detailed output from the patch tool
can be very noisy, especially for big patches.

Suppress the fuzz details by default, while keeping the "applied with
fuzz" warning. The noise can be restored with '--verbose'.

Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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klp-build: Validate patch file existence

Make sure all patch files actually exist. Otherwise there can be
confusing errors later.

Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Miroslav Benes <

klp-build: Validate patch file existence

Make sure all patch files actually exist. Otherwise there can be
confusing errors later.

Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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klp-build: Don't use errexit

The errtrace option (combined with the ERR trap) already serves the same
function (and more) as errexit, so errexit is redundant. And it has
more pitfalls. Remove it.

klp-build: Don't use errexit

The errtrace option (combined with the ERR trap) already serves the same
function (and more) as errexit, so errexit is redundant. And it has
more pitfalls. Remove it.

Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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klp-build: Fix checksum comparison for changed offsets

The klp-build -f/--show-first-changed feature uses diff to compare
checksum log lines between original and patched objects. However, diff
comp

klp-build: Fix checksum comparison for changed offsets

The klp-build -f/--show-first-changed feature uses diff to compare
checksum log lines between original and patched objects. However, diff
compares entire lines, including the offset field. When a function is
at a different section offset, the offset field differs even though the
instruction checksum is identical, causing the wrong instruction to be
printed.

Only compare the checksum field when looking for the first changed
instruction. Also print both the original and patched offsets when they
differ.

Fixes: 78be9facfb5e ("livepatch/klp-build: Add --show-first-changed option to show function divergence")
Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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klp-build: Fix hang on out-of-date .config

If .config is out of date with the kernel source, 'make syncconfig'
hangs while waiting for user input on new config options. Detect the
mismatch and retu

klp-build: Fix hang on out-of-date .config

If .config is out of date with the kernel source, 'make syncconfig'
hangs while waiting for user input on new config options. Detect the
mismatch and return an error.

Fixes: 6f93f7b06810 ("livepatch/klp-build: Fix inconsistent kernel version")
Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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Merge tag 'objtool-core-2026-04-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool updates from Ingo Molnar:

- KLP support updates and fixes (Song Liu)

- KLP-build script

Merge tag 'objtool-core-2026-04-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool updates from Ingo Molnar:

- KLP support updates and fixes (Song Liu)

- KLP-build script updates and fixes (Joe Lawrence)

- Support Clang RAX DRAP sequence, to address clang false positive
(Josh Poimboeuf)

- Reorder ORC register numbering to match regular x86 register
numbering (Josh Poimboeuf)

- Misc cleanups (Wentong Tian, Song Liu)

* tag 'objtool-core-2026-04-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
objtool/x86: Reorder ORC register numbering
objtool: Support Clang RAX DRAP sequence
livepatch/klp-build: report patch validation fuzz
livepatch/klp-build: add terminal color output
livepatch/klp-build: provide friendlier error messages
livepatch/klp-build: improve short-circuit validation
livepatch/klp-build: fix shellcheck complaints
livepatch/klp-build: add Makefile with check target
livepatch/klp-build: add grep-override function
livepatch/klp-build: switch to GNU patch and recountdiff
livepatch/klp-build: support patches that add/remove files
objtool/klp: Correlate locals to globals
objtool/klp: Match symbols based on demangled_name for global variables
objtool/klp: Remove .llvm suffix in demangle_name()
objtool/klp: Also demangle global objects
objtool/klp: Use sym->demangled_name for symbol_name hash
objtool/klp: Remove trailing '_' in demangle_name()
objtool/klp: Remove redundant strcmp() in correlate_symbols()
objtool: Use section/symbol type helpers

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livepatch/klp-build: report patch validation fuzz

Capture the output of the patch command to detect when a patch applies
with fuzz or line offsets.

If such "fuzz" is detected during the validation

livepatch/klp-build: report patch validation fuzz

Capture the output of the patch command to detect when a patch applies
with fuzz or line offsets.

If such "fuzz" is detected during the validation phase, warn the user
and display the details. This helps identify input patches that may
need refreshing against the target source tree.

Ensure that internal patch operations (such as those in refresh_patch or
during the final build phase) can still run quietly.

Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Song Liu <song@kernel.org>
Link: https://patch.msgid.link/20260310203751.1479229-13-joe.lawrence@redhat.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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livepatch/klp-build: add terminal color output

Improve the readability of klp-build output by implementing a basic
color scheme. When the standard output and error are connected to a
terminal, high

livepatch/klp-build: add terminal color output

Improve the readability of klp-build output by implementing a basic
color scheme. When the standard output and error are connected to a
terminal, highlight status messages in bold and warning/error prefixes
in yellow/red.

Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Link: https://patch.msgid.link/20260310203751.1479229-12-joe.lawrence@redhat.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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livepatch/klp-build: provide friendlier error messages

Provide more context for common klp-build failure modes. Clarify which
user-provided patch is unsupported or failed to apply, and explicitly
i

livepatch/klp-build: provide friendlier error messages

Provide more context for common klp-build failure modes. Clarify which
user-provided patch is unsupported or failed to apply, and explicitly
identify which kernel build (original or patched) failed.

Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Link: https://patch.msgid.link/20260310203751.1479229-11-joe.lawrence@redhat.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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livepatch/klp-build: Fix inconsistent kernel version

If .config hasn't been synced with auto.conf, any recent changes to
CONFIG_LOCALVERSION* may not get reflected in the kernel version name.

Use "

livepatch/klp-build: Fix inconsistent kernel version

If .config hasn't been synced with auto.conf, any recent changes to
CONFIG_LOCALVERSION* may not get reflected in the kernel version name.

Use "make syncconfig" to force them to sync, and "make -s kernelrelease"
to get the version instead of having to construct it manually.

Fixes: 24ebfcd65a87 ("livepatch/klp-build: Introduce klp-build script for generating livepatch modules")
Closes: https://lore.kernel.org/20260217160645.3434685-10-joe.lawrence@redhat.com
Reported-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Song Liu <song@kernel.org>
Link: https://patch.msgid.link/20260310203751.1479229-10-joe.lawrence@redhat.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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livepatch/klp-build: improve short-circuit validation

Update SHORT_CIRCUIT behavior to better handle patch validation and
argument processing in later klp-build steps.

Perform patch validation for

livepatch/klp-build: improve short-circuit validation

Update SHORT_CIRCUIT behavior to better handle patch validation and
argument processing in later klp-build steps.

Perform patch validation for both step 1 (building original kernel) and
step 2 (building patched kernel) to ensure patches are verified before
any compilation occurs.

Additionally, allow the user to omit input patches when skipping past
step 2.

Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Link: https://patch.msgid.link/20260310203751.1479229-9-joe.lawrence@redhat.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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livepatch/klp-build: fix shellcheck complaints

Fix or suppress the following shellcheck warnings:

In klp-build line 57:
command grep "$@" || true
^--^ SC2317 (in

livepatch/klp-build: fix shellcheck complaints

Fix or suppress the following shellcheck warnings:

In klp-build line 57:
command grep "$@" || true
^--^ SC2317 (info): Command appears to be unreachable. Check usage (or ignore if invoked indirectly).

Fix the following warning:

In klp-build line 565:
local file_dir="$(dirname "$file")"
^------^ SC2034 (warning): file_dir appears unused. Verify use (or export if used externally).

Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Link: https://patch.msgid.link/20260310203751.1479229-8-joe.lawrence@redhat.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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livepatch/klp-build: add grep-override function

Provide a custom grep() function to catch direct usage of the command.
Bare grep calls are generally incompatible with pipefail and
errexit behavior (

livepatch/klp-build: add grep-override function

Provide a custom grep() function to catch direct usage of the command.
Bare grep calls are generally incompatible with pipefail and
errexit behavior (where a failed match causes the script to exit).

Developers can still call grep via command grep if that behavior is
explicitly desired.

Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Link: https://patch.msgid.link/20260310203751.1479229-6-joe.lawrence@redhat.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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livepatch/klp-build: switch to GNU patch and recountdiff

The klp-build script is currently very strict with input patches,
requiring them to apply cleanly via `git apply --recount`. This
prevents t

livepatch/klp-build: switch to GNU patch and recountdiff

The klp-build script is currently very strict with input patches,
requiring them to apply cleanly via `git apply --recount`. This
prevents the use of patches with minor contextual fuzz relative to the
target kernel sources.

To allow users to reuse a patch across similar kernel streams, switch to
using GNU patch and patchutils for intermediate patch manipulation.
Update the logic for applying, reverting, and regenerating patches:

- Use 'patch -p1' for better handling of context fuzz.
- Use 'recountdiff' to update line counts after FIX_PATCH_LINES.
- Drop git_refresh() and related git-specific logic.

Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Song Liu <song@kernel.org>
Link: https://patch.msgid.link/20260310203751.1479229-5-joe.lawrence@redhat.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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livepatch/klp-build: support patches that add/remove files

The klp-build script prepares a clean patch by populating two temporary
directories ('a' and 'b') with source files and diffing the result.

livepatch/klp-build: support patches that add/remove files

The klp-build script prepares a clean patch by populating two temporary
directories ('a' and 'b') with source files and diffing the result.
However, this process fails when a patch introduces a new source file,
as the script attempts to copy files that do not yet exist in the
original source tree. Likewise, it fails when a patch removes a source
file and the script attempts to copy a file that no longer exists.

Refactor the file-gathering logic to distinguish between original input
files and patched output files:

- Split get_patch_files() into get_patch_input_files() and
get_patch_output_files() to identify which files exist before and
after patch application.
- Filter out "/dev/null" from both to handle file creation/deletion.
- Update refresh_patch() to only copy existing input files to the 'a'
directory and the resulting output files to the 'b' directory.

Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Link: https://patch.msgid.link/20260310203751.1479229-4-joe.lawrence@redhat.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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livepatch/klp-build: Require Clang assembler >= 20

Some special sections specify their ELF section entsize, for example:

.pushsection section, "M", @progbits, 8

The entsize (8 in this example) i

livepatch/klp-build: Require Clang assembler >= 20

Some special sections specify their ELF section entsize, for example:

.pushsection section, "M", @progbits, 8

The entsize (8 in this example) is needed by objtool klp-diff for
extracting individual entries.

Clang assembler versions older than 20 silently ignore the above
construct and set entsize to 0, resulting in the following error:

.discard.annotate_data: missing special section entsize or annotations

Add a klp-build check to prevent the use of Clang assembler versions
prior to 20.

Fixes: 24ebfcd65a87 ("livepatch/klp-build: Introduce klp-build script for generating livepatch modules")
Reported-by: Song Liu <song@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Link: https://patch.msgid.link/957fd52e375d0e2cfa3ac729160da995084a7f5e.1769562556.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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livepatch/klp-build: Fix klp-build vs CONFIG_MODULE_SRCVERSION_ALL

When building a patch to a single-file kernel module with
CONFIG_MODULE_SRCVERSION_ALL enabled, the klp-build module link fails in

livepatch/klp-build: Fix klp-build vs CONFIG_MODULE_SRCVERSION_ALL

When building a patch to a single-file kernel module with
CONFIG_MODULE_SRCVERSION_ALL enabled, the klp-build module link fails in
modpost:

Diffing objects
drivers/md/raid0.o: changed function: raid0_run
Building patch module: livepatch-0001-patch-raid0_run.ko
drivers/md/raid0.c: No such file or directory
...

The problem here is that klp-build copied drivers/md/.raid0.o.cmd to the
module build directory, but it didn't also copy over the input source
file listed in the .cmd file:

source_drivers/md/raid0.o := drivers/md/raid0.c

So modpost dies due to the missing .c file which is needed for
calculating checksums for CONFIG_MODULE_SRCVERSION_ALL.

Instead of copying the original .cmd file, just create an empty one.
Modpost only requires that it exists. The original object's build
dependencies are irrelevant for the frankenobjects used by klp-build.

Fixes: 24ebfcd65a87 ("livepatch/klp-build: Introduce klp-build script for generating livepatch modules")
Reported-by: Song Liu <song@kernel.org>
Tested-by: Song Liu <song@kernel.org>
Link: https://patch.msgid.link/c41b6629e02775e4c1015259aa36065b3fe2f0f3.1769471792.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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