Merge tag 'perf-tools-fixes-for-v6.11-2024-07-30' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

Pull perf tools fixes from Namhyung Kim:
 "Some more build fixes and a random crash fix:

   - Fix cross-build by setting pkg-config env according to the arch

   - Fix static build for missing library dependencies

   - Fix Segfault when callchain has no symbols"

* tag 'perf-tools-fixes-for-v6.11-2024-07-30' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools:
  perf docs: Document cross compilation
  perf: build: Link lib 'zstd' for static build
  perf: build: Link lib 'lzma' for static build
  perf: build: Only link libebl.a for old libdw
  perf: build: Set Python configuration for cross compilation
  perf: build: Setup PKG_CONFIG_LIBDIR for cross compilation
  perf tool: fix dereferencing NULL al->maps

1 files changed, 43 insertions, 10 deletions

diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
index 489cbed7e82a..12796808f07a 100644
--- a/tools/build/feature/Makefile
+++ b/tools/build/feature/Makefile
@@ -82,7 +82,30 @@ FILES=                                          \
 
 FILES := $(addprefix $(OUTPUT),$(FILES))
 
-PKG_CONFIG ?= $(CROSS_COMPILE)pkg-config
+# Some distros provide the command $(CROSS_COMPILE)pkg-config for
+# searching packges installed with Multiarch. Use it for cross
+# compilation if it is existed.
+ifneq (, $(shell which $(CROSS_COMPILE)pkg-config))
+  PKG_CONFIG ?= $(CROSS_COMPILE)pkg-config
+else
+  PKG_CONFIG ?= pkg-config
+
+  # PKG_CONFIG_PATH or PKG_CONFIG_LIBDIR, alongside PKG_CONFIG_SYSROOT_DIR
+  # for modified system root, are required for the cross compilation.
+  # If these PKG_CONFIG environment variables are not set, Multiarch library
+  # paths are used instead.
+  ifdef CROSS_COMPILE
+    ifeq ($(PKG_CONFIG_LIBDIR)$(PKG_CONFIG_PATH)$(PKG_CONFIG_SYSROOT_DIR),)
+      CROSS_ARCH = $(shell $(CC) -dumpmachine)
+      PKG_CONFIG_LIBDIR := /usr/local/$(CROSS_ARCH)/lib/pkgconfig/
+      PKG_CONFIG_LIBDIR := $(PKG_CONFIG_LIBDIR):/usr/local/lib/$(CROSS_ARCH)/pkgconfig/
+      PKG_CONFIG_LIBDIR := $(PKG_CONFIG_LIBDIR):/usr/lib/$(CROSS_ARCH)/pkgconfig/
+      PKG_CONFIG_LIBDIR := $(PKG_CONFIG_LIBDIR):/usr/local/share/pkgconfig/
+      PKG_CONFIG_LIBDIR := $(PKG_CONFIG_LIBDIR):/usr/share/pkgconfig/
+      export PKG_CONFIG_LIBDIR
+    endif
+  endif
+endif
 
 all: $(FILES)
 
@@ -147,7 +170,17 @@ $(OUTPUT)test-libopencsd.bin:
 
 DWARFLIBS := -ldw
 ifeq ($(findstring -static,${LDFLAGS}),-static)
-DWARFLIBS += -lelf -lebl -lz -llzma -lbz2
+  DWARFLIBS += -lelf -lz -llzma -lbz2 -lzstd
+
+  LIBDW_VERSION := $(shell $(PKG_CONFIG) --modversion libdw)
+  LIBDW_VERSION_1 := $(word 1, $(subst ., ,$(LIBDW_VERSION)))
+  LIBDW_VERSION_2 := $(word 2, $(subst ., ,$(LIBDW_VERSION)))
+
+  # Elfutils merged libebl.a into libdw.a starting from version 0.177,
+  # Link libebl.a only if libdw is older than this version.
+  ifeq ($(shell test $(LIBDW_VERSION_2) -lt 177; echo $$?),0)
+    DWARFLIBS += -lebl
+  endif
 endif
 
 $(OUTPUT)test-dwarf.bin:
@@ -178,27 +211,27 @@ $(OUTPUT)test-numa_num_possible_cpus.bin:
 	$(BUILD) -lnuma
 
 $(OUTPUT)test-libunwind.bin:
-	$(BUILD) -lelf
+	$(BUILD) -lelf -llzma
 
 $(OUTPUT)test-libunwind-debug-frame.bin:
-	$(BUILD) -lelf
+	$(BUILD) -lelf -llzma
 $(OUTPUT)test-libunwind-x86.bin:
-	$(BUILD) -lelf -lunwind-x86
+	$(BUILD) -lelf -llzma -lunwind-x86
 
 $(OUTPUT)test-libunwind-x86_64.bin:
-	$(BUILD) -lelf -lunwind-x86_64
+	$(BUILD) -lelf -llzma -lunwind-x86_64
 
 $(OUTPUT)test-libunwind-arm.bin:
-	$(BUILD) -lelf -lunwind-arm
+	$(BUILD) -lelf -llzma -lunwind-arm
 
 $(OUTPUT)test-libunwind-aarch64.bin:
-	$(BUILD) -lelf -lunwind-aarch64
+	$(BUILD) -lelf -llzma -lunwind-aarch64
 
 $(OUTPUT)test-libunwind-debug-frame-arm.bin:
-	$(BUILD) -lelf -lunwind-arm
+	$(BUILD) -lelf -llzma -lunwind-arm
 
 $(OUTPUT)test-libunwind-debug-frame-aarch64.bin:
-	$(BUILD) -lelf -lunwind-aarch64
+	$(BUILD) -lelf -llzma -lunwind-aarch64
 
 $(OUTPUT)test-libaudit.bin:
 	$(BUILD) -laudit