From 4c17736689ccfc44ec7dcc472577f25c34cf8724 Mon Sep 17 00:00:00 2001 From: Casey Chen Date: Mon, 22 Jul 2024 15:15:48 -0600 Subject: [PATCH 1/7] perf tool: fix dereferencing NULL al->maps With 0dd5041c9a0e ("perf addr_location: Add init/exit/copy functions"), when cpumode is 3 (macro PERF_RECORD_MISC_HYPERVISOR), thread__find_map() could return with al->maps being NULL. The path below could add a callchain_cursor_node with NULL ms.maps. add_callchain_ip() thread__find_symbol(.., &al) thread__find_map(.., &al) // al->maps becomes NULL ms.maps = maps__get(al.maps) callchain_cursor_append(..., &ms, ...) node->ms.maps = maps__get(ms->maps) Then the path below would dereference NULL maps and get segfault. fill_callchain_info() maps__machine(node->ms.maps); Fix it by checking if maps is NULL in fill_callchain_info(). Fixes: 0dd5041c9a0e ("perf addr_location: Add init/exit/copy functions") Signed-off-by: Casey Chen Reviewed-by: Ian Rogers Reviewed-by: Arnaldo Carvalho de Melo Acked-by: Namhyung Kim Cc: yzhong@purestorage.com Link: https://lore.kernel.org/r/20240722211548.61455-1-cachen@purestorage.com Signed-off-by: Namhyung Kim --- tools/perf/util/callchain.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) 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); From 440cf77625e300e683ca0edc39fbc4b6f3175feb Mon Sep 17 00:00:00 2001 From: Leo Yan Date: Wed, 17 Jul 2024 09:22:06 +0100 Subject: [PATCH 2/7] perf: build: Setup PKG_CONFIG_LIBDIR for cross compilation On recent Linux distros like Ubuntu Noble and Debian Bookworm, the 'pkg-config-aarch64-linux-gnu' package is missing. As a result, the aarch64-linux-gnu-pkg-config command is not available, which causes build failures. When a build passes the environment variables PKG_CONFIG_LIBDIR or PKG_CONFIG_PATH, like a user uses make command or a build system (like Yocto, Buildroot, etc) prepares the variables and passes to the Perf's Makefile, the commit keeps these variables for package configuration. Otherwise, this commit sets the PKG_CONFIG_LIBDIR variable to use the Multiarch libs for the cross compilation. Signed-off-by: Leo Yan Tested-by: Ian Rogers Cc: amadio@gentoo.org Cc: Thomas Richter Link: https://lore.kernel.org/r/20240717082211.524826-2-leo.yan@arm.com Signed-off-by: Namhyung Kim --- tools/build/feature/Makefile | 25 ++++++++++++++++++++++++- tools/perf/Makefile.perf | 27 ++++++++++++++++++++++++++- 2 files changed, 50 insertions(+), 2 deletions(-) diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile index ed54cef450f5..dff65d03d30d 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) 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 From cffe29d3b54aa0437bc35440ea64866bbfc418a3 Mon Sep 17 00:00:00 2001 From: Leo Yan Date: Wed, 17 Jul 2024 09:22:07 +0100 Subject: [PATCH 3/7] perf: build: Set Python configuration for cross compilation Python configuration has dedicated folders for different architectures. For example, Python 3.11 has two folders as shown below, one for Arm64 and another for x86_64: /usr/lib/python3.11/config-3.11-aarch64-linux-gnu/ /usr/lib/python3.11/config-3.11-x86_64-linux-gnu/ This commit updates the Python configuration path based on the compiler's machine type, guiding the compiler to find the correct path for Python libraries. It also renames the generated .so file name to match the machine name. Signed-off-by: Leo Yan Tested-by: Ian Rogers Cc: amadio@gentoo.org Cc: James Clark Cc: Thomas Richter Link: https://lore.kernel.org/r/20240717082211.524826-3-leo.yan@arm.com Signed-off-by: Namhyung Kim --- tools/perf/Makefile.config | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config index c896babf7a74..524a68032bdb 100644 --- a/tools/perf/Makefile.config +++ b/tools/perf/Makefile.config @@ -296,6 +296,11 @@ 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 +902,9 @@ 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) From 536661da6ea18fe6df5740bc9e9001d097b035ee Mon Sep 17 00:00:00 2001 From: Leo Yan Date: Wed, 17 Jul 2024 09:22:08 +0100 Subject: [PATCH 4/7] perf: build: Only link libebl.a for old libdw Since libdw version 0.177, elfutils has merged libebl.a into libdw (see the commit "libebl: Don't install libebl.a, libebl.h and remove backends from spec." in the elfutils repository). As a result, libebl.a does not exist on Debian Bullseye and newer releases, causing static perf builds to fail on these distributions. This commit checks the libdw version and only links libebl.a if it detects that the libdw version is older than 0.177. Signed-off-by: Leo Yan Tested-by: Ian Rogers Cc: amadio@gentoo.org Cc: James Clark Cc: Thomas Richter Link: https://lore.kernel.org/r/20240717082211.524826-4-leo.yan@arm.com Signed-off-by: Namhyung Kim --- tools/build/feature/Makefile | 12 +++++++++++- tools/perf/Makefile.config | 12 +++++++++++- 2 files changed, 22 insertions(+), 2 deletions(-) diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile index dff65d03d30d..08b2be257639 100644 --- a/tools/build/feature/Makefile +++ b/tools/build/feature/Makefile @@ -170,7 +170,17 @@ $(OUTPUT)test-libopencsd.bin: DWARFLIBS := -ldw ifeq ($(findstring -static,${LDFLAGS}),-static) -DWARFLIBS += -lelf -lebl -lz -llzma -lbz2 + DWARFLIBS += -lelf -lz -llzma -lbz2 + + 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 $$?),0) + DWARFLIBS += -lebl + endif endif $(OUTPUT)test-dwarf.bin: diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config index 524a68032bdb..7cf0a39bc200 100644 --- a/tools/perf/Makefile.config +++ b/tools/perf/Makefile.config @@ -152,7 +152,17 @@ ifdef LIBDW_DIR endif DWARFLIBS := -ldw ifeq ($(findstring -static,${LDFLAGS}),-static) - DWARFLIBS += -lelf -lebl -ldl -lz -llzma -lbz2 + DWARFLIBS += -lelf -ldl -lz -llzma -lbz2 + + LIBDW_VERSION := $(shell $(PKG_CONFIG) --modversion libdw) + LIBDW_VERSION_1 := $(word 1, $(subst ., ,$(LIBDW_VERSION))) + LIBDW_VERSION_2 := $(word 2, $(subst ., ,$(LIBDW_VERSION))) + + # Elfutils merged libebl.a into libdw.a starting from version 0.177, + # Link libebl.a only if libdw is older than this version. + ifeq ($(shell test $(LIBDW_VERSION_2) -lt 177; echo $$?),0) + DWARFLIBS += -lebl + endif endif FEATURE_CHECK_CFLAGS-libdw-dwarf-unwind := $(LIBDW_CFLAGS) FEATURE_CHECK_LDFLAGS-libdw-dwarf-unwind := $(LIBDW_LDFLAGS) $(DWARFLIBS) From 91b6a536b40658c24d6f04747ddf852d30f7f259 Mon Sep 17 00:00:00 2001 From: Leo Yan Date: Wed, 17 Jul 2024 09:22:09 +0100 Subject: [PATCH 5/7] perf: build: Link lib 'lzma' for static build The libunwind feature test failed with the static linkage. This is due to the 'lzma' lib is missed, so link it to dismiss building failure. Signed-off-by: Leo Yan Tested-by: Ian Rogers Cc: amadio@gentoo.org Cc: James Clark Cc: Thomas Richter Link: https://lore.kernel.org/r/20240717082211.524826-5-leo.yan@arm.com Signed-off-by: Namhyung Kim --- tools/build/feature/Makefile | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile index 08b2be257639..2d5be5c17d65 100644 --- a/tools/build/feature/Makefile +++ b/tools/build/feature/Makefile @@ -211,27 +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 From f42596c73872b753ff1799bc7fc79b1100226da1 Mon Sep 17 00:00:00 2001 From: Leo Yan Date: Wed, 17 Jul 2024 09:22:10 +0100 Subject: [PATCH 6/7] perf: build: Link lib 'zstd' for static build When build static perf, Makefile reports the error: Makefile.config:480: No libdw DWARF unwind found, Please install elfutils-devel/libdw-dev >= 0.158 and/or set LIBDW_DIR The libdw has been installed on the system, but the build system fails to build the feature detecting binary 'test-libdw-dwarf-unwind'. The failure is caused by missing to link the lib 'zstd'. Link lib 'zstd' for the static build, in the end, the dwarf feature can be enabled in the static perf. Signed-off-by: Leo Yan Tested-by: Ian Rogers Cc: amadio@gentoo.org Cc: James Clark Cc: Thomas Richter Link: https://lore.kernel.org/r/20240717082211.524826-6-leo.yan@arm.com Signed-off-by: Namhyung Kim --- tools/build/feature/Makefile | 2 +- tools/perf/Makefile.config | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile index 2d5be5c17d65..4af6a9582f15 100644 --- a/tools/build/feature/Makefile +++ b/tools/build/feature/Makefile @@ -170,7 +170,7 @@ $(OUTPUT)test-libopencsd.bin: DWARFLIBS := -ldw ifeq ($(findstring -static,${LDFLAGS}),-static) - DWARFLIBS += -lelf -lz -llzma -lbz2 + DWARFLIBS += -lelf -lz -llzma -lbz2 -lzstd LIBDW_VERSION := $(shell $(PKG_CONFIG) --modversion libdw) LIBDW_VERSION_1 := $(word 1, $(subst ., ,$(LIBDW_VERSION))) diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config index 7cf0a39bc200..fa679db61f62 100644 --- a/tools/perf/Makefile.config +++ b/tools/perf/Makefile.config @@ -152,7 +152,7 @@ ifdef LIBDW_DIR endif DWARFLIBS := -ldw ifeq ($(findstring -static,${LDFLAGS}),-static) - DWARFLIBS += -lelf -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))) From d27087c76e3c859ea05b7581ef7ce8aa5a088dd8 Mon Sep 17 00:00:00 2001 From: Leo Yan Date: Wed, 17 Jul 2024 09:22:11 +0100 Subject: [PATCH 7/7] perf docs: Document cross compilation Records the commands for cross compilation with two methods. The first method relies on Multiarch. The second approach is to explicitly specify the PKG_CONFIG variables, which is widely used in build system (like Buildroot, Yocto, etc). Co-developed-by: James Clark Signed-off-by: James Clark Signed-off-by: Leo Yan Tested-by: Ian Rogers Cc: amadio@gentoo.org Cc: Thomas Richter Link: https://lore.kernel.org/r/20240717082211.524826-7-leo.yan@arm.com Signed-off-by: Namhyung Kim --- tools/perf/Documentation/Build.txt | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) 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.