9 files changed, 79 insertions, 8 deletions
diff --git a/tools/perf/Documentation/Build.txt b/tools/perf/Documentation/Build.txt
index 3766886c4bca..83dc87c662b6 100644
--- a/tools/perf/Documentation/Build.txt
+++ b/tools/perf/Documentation/Build.txt
@@ -71,3 +71,31 @@ supported by GCC. UBSan detects undefined behaviors of programs at runtime.
   $ UBSAN_OPTIONS=print_stacktrace=1 ./perf record -a
 
 If UBSan detects any problem at runtime, it outputs a “runtime error:” message.
+
+4) Cross compilation
+====================
+As Multiarch is commonly supported in Linux distributions, we can install
+libraries for multiple architectures on the same system and then cross-compile
+Linux perf. For example, Aarch64 libraries and toolchains can be installed on
+an x86_64 machine, allowing us to compile perf for an Aarch64 target.
+
+Below is the command for building the perf with dynamic linking.
+
+  $ cd /path/to/Linux
+  $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- -C tools/perf
+
+For static linking, the option `LDFLAGS="-static"` is required.
+
+  $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- \
+    LDFLAGS="-static" -C tools/perf
+
+In the embedded system world, a use case is to explicitly specify the package
+configuration paths for cross building:
+
+  $ PKG_CONFIG_SYSROOT_DIR="/path/to/cross/build/sysroot" \
+    PKG_CONFIG_LIBDIR="/usr/lib/:/usr/local/lib" \
+    make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- -C tools/perf
+
+In this case, the variable PKG_CONFIG_SYSROOT_DIR can be used alongside the
+variable PKG_CONFIG_LIBDIR or PKG_CONFIG_PATH to prepend the sysroot path to
+the library paths for cross compilation.
diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index c896babf7a74..fa679db61f62 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -152,7 +152,17 @@ ifdef LIBDW_DIR
 endif
 DWARFLIBS := -ldw
 ifeq ($(findstring -static,${LDFLAGS}),-static)
-  DWARFLIBS += -lelf -lebl -ldl -lz -llzma -lbz2
+  DWARFLIBS += -lelf -ldl -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
 FEATURE_CHECK_CFLAGS-libdw-dwarf-unwind := $(LIBDW_CFLAGS)
 FEATURE_CHECK_LDFLAGS-libdw-dwarf-unwind := $(LIBDW_LDFLAGS) $(DWARFLIBS)
@@ -296,6 +306,11 @@ endif
 
 ifdef PYTHON_CONFIG
   PYTHON_EMBED_LDOPTS := $(shell $(PYTHON_CONFIG_SQ) $(PYTHON_CONFIG_LDFLAGS) 2>/dev/null)
+  # Update the python flags for cross compilation
+  ifdef CROSS_COMPILE
+    PYTHON_NATIVE := $(shell echo $(PYTHON_EMBED_LDOPTS) | sed 's/\(-L.*\/\)\(.*-linux-gnu\).*/\2/')
+    PYTHON_EMBED_LDOPTS := $(subst $(PYTHON_NATIVE),$(shell $(CC) -dumpmachine),$(PYTHON_EMBED_LDOPTS))
+  endif
   PYTHON_EMBED_LDFLAGS := $(call strip-libs,$(PYTHON_EMBED_LDOPTS))
   PYTHON_EMBED_LIBADD := $(call grep-libs,$(PYTHON_EMBED_LDOPTS)) -lutil
   PYTHON_EMBED_CCOPTS := $(shell $(PYTHON_CONFIG_SQ) --includes 2>/dev/null)
@@ -897,6 +912,9 @@ else
          PYTHON_SETUPTOOLS_INSTALLED := $(shell $(PYTHON) -c 'import setuptools;' 2> /dev/null && echo "yes" || echo "no")
          ifeq ($(PYTHON_SETUPTOOLS_INSTALLED), yes)
            PYTHON_EXTENSION_SUFFIX := $(shell $(PYTHON) -c 'from importlib import machinery; print(machinery.EXTENSION_SUFFIXES[0])')
+           ifdef CROSS_COMPILE
+             PYTHON_EXTENSION_SUFFIX := $(subst $(PYTHON_NATIVE),$(shell $(CC) -dumpmachine),$(PYTHON_EXTENSION_SUFFIX))
+           endif
            LANG_BINDINGS += $(obj-perf)python/perf$(PYTHON_EXTENSION_SUFFIX)
 	 else
            $(warning Missing python setuptools, the python binding won't be built, please install python3-setuptools or equivalent)
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 175e4c7898f0..f8148db5fc38 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -193,7 +193,32 @@ HOSTLD  ?= ld
 HOSTAR  ?= ar
 CLANG   ?= clang
 
-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 ?= $(CROSS_COMPILE)pkg-config
+else
+  PKG_CONFIG ?= pkg-config
+
+  # PKG_CONFIG_PATH or PKG_CONFIG_LIBDIR, alongside PKG_CONFIG_SYSROOT_DIR
+  # for modified system root, is required for the cross compilation.
+  # If these PKG_CONFIG environment variables are not set, Multiarch library
+  # paths are used instead.
+  ifdef CROSS_COMPILE
+    ifeq ($(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
+      $(warning Missing PKG_CONFIG_LIBDIR, PKG_CONFIG_PATH and PKG_CONFIG_SYSROOT_DIR for cross compilation,)
+      $(warning set PKG_CONFIG_LIBDIR for using Multiarch libs.)
+    endif
+  endif
+endif
 
 RM      = rm -f
 LN      = ln -f
diff --git a/tools/perf/pmu-events/arch/riscv/andes/ax45/firmware.json b/tools/perf/pmu-events/arch/riscv/andes/ax45/firmware.json
index 9b4a032186a7..7149caec4f80 100644
--- a/tools/perf/pmu-events/arch/riscv/andes/ax45/firmware.json
+++ b/tools/perf/pmu-events/arch/riscv/andes/ax45/firmware.json
@@ -36,7 +36,7 @@
     "ArchStdEvent": "FW_SFENCE_VMA_RECEIVED"
   },
   {
-    "ArchStdEvent": "FW_SFENCE_VMA_RECEIVED"
+    "ArchStdEvent": "FW_SFENCE_VMA_ASID_SENT"
   },
   {
     "ArchStdEvent": "FW_SFENCE_VMA_ASID_RECEIVED"
diff --git a/tools/perf/pmu-events/arch/riscv/riscv-sbi-firmware.json b/tools/perf/pmu-events/arch/riscv/riscv-sbi-firmware.json
index a9939823b14b..0c9b9a2d2958 100644
--- a/tools/perf/pmu-events/arch/riscv/riscv-sbi-firmware.json
+++ b/tools/perf/pmu-events/arch/riscv/riscv-sbi-firmware.json
@@ -74,7 +74,7 @@
   {
     "PublicDescription": "Sent SFENCE.VMA with ASID request to other HART event",
     "ConfigCode": "0x800000000000000c",
-    "EventName": "FW_SFENCE_VMA_RECEIVED",
+    "EventName": "FW_SFENCE_VMA_ASID_SENT",
     "BriefDescription": "Sent SFENCE.VMA with ASID request to other HART event"
   },
   {
diff --git a/tools/perf/pmu-events/arch/riscv/sifive/u74/firmware.json b/tools/perf/pmu-events/arch/riscv/sifive/u74/firmware.json
index 9b4a032186a7..7149caec4f80 100644
--- a/tools/perf/pmu-events/arch/riscv/sifive/u74/firmware.json
+++ b/tools/perf/pmu-events/arch/riscv/sifive/u74/firmware.json
@@ -36,7 +36,7 @@
     "ArchStdEvent": "FW_SFENCE_VMA_RECEIVED"
   },
   {
-    "ArchStdEvent": "FW_SFENCE_VMA_RECEIVED"
+    "ArchStdEvent": "FW_SFENCE_VMA_ASID_SENT"
   },
   {
     "ArchStdEvent": "FW_SFENCE_VMA_ASID_RECEIVED"
diff --git a/tools/perf/pmu-events/arch/riscv/starfive/dubhe-80/firmware.json b/tools/perf/pmu-events/arch/riscv/starfive/dubhe-80/firmware.json
index 9b4a032186a7..7149caec4f80 100644
--- a/tools/perf/pmu-events/arch/riscv/starfive/dubhe-80/firmware.json
+++ b/tools/perf/pmu-events/arch/riscv/starfive/dubhe-80/firmware.json
@@ -36,7 +36,7 @@
     "ArchStdEvent": "FW_SFENCE_VMA_RECEIVED"
   },
   {
-    "ArchStdEvent": "FW_SFENCE_VMA_RECEIVED"
+    "ArchStdEvent": "FW_SFENCE_VMA_ASID_SENT"
   },
   {
     "ArchStdEvent": "FW_SFENCE_VMA_ASID_RECEIVED"
diff --git a/tools/perf/pmu-events/arch/riscv/thead/c900-legacy/firmware.json b/tools/perf/pmu-events/arch/riscv/thead/c900-legacy/firmware.json
index 9b4a032186a7..7149caec4f80 100644
--- a/tools/perf/pmu-events/arch/riscv/thead/c900-legacy/firmware.json
+++ b/tools/perf/pmu-events/arch/riscv/thead/c900-legacy/firmware.json
@@ -36,7 +36,7 @@
     "ArchStdEvent": "FW_SFENCE_VMA_RECEIVED"
   },
   {
-    "ArchStdEvent": "FW_SFENCE_VMA_RECEIVED"
+    "ArchStdEvent": "FW_SFENCE_VMA_ASID_SENT"
   },
   {
     "ArchStdEvent": "FW_SFENCE_VMA_ASID_RECEIVED"
diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
index 1730b852a947..6d075648d2cc 100644
--- a/tools/perf/util/callchain.c
+++ b/tools/perf/util/callchain.c
@@ -1141,7 +1141,7 @@ int hist_entry__append_callchain(struct hist_entry *he, struct perf_sample *samp
 int fill_callchain_info(struct addr_location *al, struct callchain_cursor_node *node,
 			bool hide_unresolved)
 {
-	struct machine *machine = maps__machine(node->ms.maps);
+	struct machine *machine = node->ms.maps ? maps__machine(node->ms.maps) : NULL;
 
 	maps__put(al->maps);
 	al->maps = maps__get(node->ms.maps);