perf tools: Add script and make target to sync the header copies with the kernel

This is to be used by the perf maintainers to sync the header copies
with the kernel originals, see the description below for how it works.

A copy is left alone when only the tools/ side changed or when it carries
intentional edits, and both sides having content the other lacks needs a
manual look, --force then syncs and records the tools/ additions that are
dropped.

  $ tools/perf/scripts/sync-headers.sh --help
  Usage: sync-headers.sh [OPTIONS]

  Sync tools/ header copies with the kernel sources and create commits.

  Options:
    -n, --dry-run       Show what would be done without making changes
    -N, --no-build      Skip the perf build verification step
    -C, --no-commit     Copy files but do not create git commits
    -f, --filter PAT    Only process headers matching PAT (substring match
                        against the kernel-side path)
    -F, --force         Sync also when both copies have content the other
                        lacks, after manual investigation; tools/ additions
                        dropped are recorded in the commit
    -o, --output DIR    Build output directory (default: /tmp/build/perf-tools-1000)
    -v, --verbose       Show more details
    -h, --help          Show this help

  Environment:
    SIGN_OFF_NAME       Override git user.name for Signed-off-by
    SIGN_OFF_EMAIL      Override git user.email for Signed-off-by
    OUTPUT_DIR          Build output directory

  Through make:
    SYNC_HEADERS_ARGS   Options to pass to this script, e.g.:
                        make -C tools/perf sync-headers SYNC_HEADERS_ARGS='-n'

  The script:
    1. Runs 'make -C tools/perf check-headers' to find stale copies.
    2. For each stale header, identifies the kernel commits that changed it,
       including the merges that brought content of their own.
    3. Copies the kernel header into the tools/ tree, skipping it when only
       the tools/ copy changed (it is ahead) or when it carries intentional
       edits, and stopping for manual investigation when both sides have
       content the other lacks.
    4. For beauty headers, runs the relevant beauty script(s) before and
       after, showing new/changed string table entries.
    5. Builds perf and the other consumers of the header to verify nothing
       breaks.
    6. Creates a git commit per header (or group) with the standard commit
       message format.

  $

It is also available as:

  $ make -C tools/perf sync-headers
  ==> Running check-headers to detect stale copies...

  Stale headers found:
  tools/include/uapi/linux/if_addr.h include/uapi/linux/if_addr.h
  tools/include/uapi/linux/kvm.h include/uapi/linux/kvm.h
  tools/include/uapi/linux/perf_event.h include/uapi/linux/perf_event.h
  ...
  tools/perf/trace/beauty/include/uapi/sound/asound.h include/uapi/sound/asound.h

  ==> Processing: include/uapi/linux/if_addr.h

    Kernel commits since last sync:
    7cb8198761 ("net: ipv4: report multicast group user count")
  ==> Copied include/uapi/linux/if_addr.h -> tools/include/uapi/linux/if_addr.h
  ==> Build-testing consumers of if_addr.h:
      perf (tools/perf)
  ==> Build OK.
  ==> Committed: tools headers UAPI: Sync linux/if_addr.h with the kernel sources

  ==> Processing: include/uapi/linux/perf_event.h
  Warning: tools/include/uapi/linux/perf_event.h is ahead of the kernel sources, leaving it alone

  ==> Processing: include/uapi/linux/rtnetlink.h

    Kernel commits since last sync:
    cc17e386f8 ("ipv6: add ip6_del_rt_reason()")
  ==> Copied include/uapi/linux/rtnetlink.h -> tools/include/uapi/linux/rtnetlink.h
  ==> Build-testing consumers of rtnetlink.h:
      libbpf (tools/lib/bpf)
      bpftool (tools/bpf/bpftool)
      perf (tools/perf)
  ==> Build OK.
  ==> Committed: tools headers UAPI: Sync linux/rtnetlink.h with the kernel sources
  ...
  ==> Processing: include/linux/socket.h

    Kernel commits since last sync:
    be3a5e06b9 ("net: add SO_PASSPIDFD_THREAD to get a thread-specific SCM_PIDFD")
    5bd369c055 ("net: Add connect_socket() helper")
  ==> Copied include/linux/socket.h -> tools/perf/trace/beauty/include/linux/socket.h
  ==> Build-testing consumers of socket.h:
      perf (tools/perf)
  ==> Build OK.
  ==> Committed: tools headers: Sync linux/socket.h with the kernel sources
  ...

  ==> Processing group: KVM headers (3 files)
  ...
  ==> Build-testing consumers of group KVM headers:
      perf (tools/perf)
  ==> Build OK.
  ...

  =========================================
   Summary
  =========================================
  ==> Synced successfully (11):
      tools/include/uapi/linux/if_addr.h
      tools/include/uapi/linux/rtnetlink.h
      tools/arch/x86/include/asm/cpufeatures.h
      tools/perf/trace/beauty/include/linux/socket.h
      tools/perf/trace/beauty/include/uapi/linux/fcntl.h
      tools/perf/trace/beauty/include/uapi/linux/fs.h
      tools/perf/trace/beauty/include/uapi/linux/mount.h
      tools/perf/trace/beauty/include/uapi/sound/asound.h
      tools/include/uapi/linux/kvm.h
      tools/arch/powerpc/include/uapi/asm/kvm.h
      tools/arch/arm64/include/uapi/asm/kvm.h

  Warning: tools/ copies ahead of the kernel, left alone (2):
      tools/include/uapi/linux/perf_event.h
      tools/arch/x86/include/uapi/asm/perf_regs.h

  Error: Left for manual investigation (2):
      tools/include/linux/gfp_types.h
      tools/arch/x86/include/asm/msr-index.h

  Warning: Headers still out of sync:
  tools/include/uapi/linux/perf_event.h include/uapi/linux/perf_event.h
  tools/include/linux/gfp_types.h include/linux/gfp_types.h
  tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h
  tools/arch/x86/include/uapi/asm/perf_regs.h arch/x86/include/uapi/asm/perf_regs.h

Reviewed-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Assisted-by: LLM
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Makefile

@@ -137,6 +137,9 @@ build-test-tarball:
 check-headers:
 	@./check-headers.sh
 
+sync-headers:
+	@./scripts/sync-headers.sh $(SYNC_HEADERS_ARGS)
+
 #
 # All other targets get passed through:
 #
@@ -144,4 +147,4 @@ check-headers:
 	$(print_msg)
 	$(make)
 
-.PHONY: all clean tags TAGS FORCE Makefile build-test build-test-tarball check-headers
+.PHONY: all clean tags TAGS FORCE Makefile build-test build-test-tarball check-headers sync-headers

tools/perf/Makefile.perf

@@ -870,6 +870,9 @@ help:
 	@echo ''
 	@echo 'Perf maintainer targets:'
 	@echo '  clean			- clean all binary objects and build output'
+	@echo '  check-headers		- check which header copies are out of sync with the kernel'
+	@echo '  sync-headers		- sync those header copies with the kernel, creating commits'
+	@echo '			  (SYNC_HEADERS_ARGS="..." passes options to the script)'
 
 
 DOC_TARGETS := doc man html info pdf