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>

diff --git a/scripts/livepatch/klp-build b/scripts/livepatch/klp-build
index 60c7635e65c1aea68d65f40c5be59f0c06a893ce..dc0a23a8908b65cacefe7bb3b9676fd13e2e900c 100755 (executable)
--- a/scripts/livepatch/klp-build
+++ b/scripts/livepatch/klp-build
@@ -342,7 +342,7 @@ check_unsupported_patches() {
                for file in "${files[@]}"; do
                        case "$file" in
                                lib/*|*.S)
-                                       die "unsupported patch to $file"
+                                       die "${patch}: unsupported patch to $file"
                                        ;;
                        esac
                done
@@ -487,6 +487,7 @@ clean_kernel() {
 }
 
 build_kernel() {
+       local build="$1"
        local log="$TMP_DIR/build.log"
        local objtool_args=()
        local cmd=()
@@ -524,7 +525,7 @@ build_kernel() {
                "${cmd[@]}"                                                     \
                        1> >(tee -a "$log")                                     \
                        2> >(tee -a "$log" | grep0 -v "modpost.*undefined!" >&2)
-       )
+       ) || die "$build kernel build failed"
 }
 
 find_objects() {
@@ -799,7 +800,7 @@ fi
 if (( SHORT_CIRCUIT <= 1 )); then
        status "Building original kernel"
        clean_kernel
-       build_kernel
+       build_kernel "original"
        status "Copying original object files"
        copy_orig_objects
 fi
@@ -809,7 +810,7 @@ if (( SHORT_CIRCUIT <= 2 )); then
        fix_patches
        apply_patches
        status "Building patched kernel"
-       build_kernel
+       build_kernel "patched"
        revert_patches
        status "Copying patched object files"
        copy_patched_objects