The feature test programs are built without enabling '-Wall -Werror' options. As a result, a feature may appear to be available, but later building in perf can fail with stricter checks. Make the feature test program use the same warning options as perf. Fixes: 1925459b4d92 ("tools build: Fix feature Makefile issues with 'O='") Signed-off-by: Leo Yan --- tools/build/feature/Makefile | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile index b41a42818d8ac232ade78ecb41363d26ce2a9471..bd615a708a0aa89ddbe87401f04bd736e384a9c4 100644 --- a/tools/build/feature/Makefile +++ b/tools/build/feature/Makefile @@ -316,10 +316,10 @@ $(OUTPUT)test-libcapstone.bin: $(BUILD) # -lcapstone provided by $(FEATURE_CHECK_LDFLAGS-libcapstone) $(OUTPUT)test-compile-32.bin: - $(CC) -m32 -o $@ test-compile.c + $(CC) -m32 -Wall -Werror -o $@ test-compile.c $(OUTPUT)test-compile-x32.bin: - $(CC) -mx32 -o $@ test-compile.c + $(CC) -mx32 -Wall -Werror -o $@ test-compile.c $(OUTPUT)test-zlib.bin: $(BUILD) -lz -- 2.34.1 When passing a list to subprocess.Popen, each element maps to one argv token. Current code bundles multiple Clang flags into a single element, something like: cmd = ['clang', '--target=x86_64-linux-gnu -fintegrated-as -Wno-cast-function-type-mismatch', 'test-hello.c'] So Clang only sees one long, invalid option instead of separate flags, as a result, the script cannot capture any log via PIPE. Fix this by using shlex.split() to separate the string so each option becomes its own argv element. The fixed list will be: cmd = ['clang', '--target=x86_64-linux-gnu', '-fintegrated-as', '-Wno-cast-function-type-mismatch', 'test-hello.c'] Fixes: 09e6f9f98370 ("perf python: Fix splitting CC into compiler and options") Signed-off-by: Leo Yan --- tools/perf/util/setup.py | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/setup.py b/tools/perf/util/setup.py index dd289d15acfd62ff058bbaed7e565bb958e3a3c8..9cae2c472f4ad4d9579e8528b8bb0152df6fe20e 100644 --- a/tools/perf/util/setup.py +++ b/tools/perf/util/setup.py @@ -1,6 +1,7 @@ from os import getenv, path from subprocess import Popen, PIPE from re import sub +import shlex cc = getenv("CC") assert cc, "Environment variable CC not set" @@ -22,7 +23,9 @@ assert srctree, "Environment variable srctree, for the Linux sources, not set" src_feature_tests = f'{srctree}/tools/build/feature' def clang_has_option(option): - cc_output = Popen([cc, cc_options + option, path.join(src_feature_tests, "test-hello.c") ], stderr=PIPE).stderr.readlines() + cmd = shlex.split(f"{cc} {cc_options} {option}") + cmd.append(path.join(src_feature_tests, "test-hello.c")) + cc_output = Popen(cmd, stderr=PIPE).stderr.readlines() return [o for o in cc_output if ((b"unknown argument" in o) or (b"is not supported" in o) or (b"unknown warning option" in o))] == [ ] if cc_is_clang: -- 2.34.1 clang-18.1.3 on Ubuntu 24.04.2 reports warning: warning: unknown warning option '-Wformat-signedness' [-Wunknown-warning-option] Conditionally add the option only when it is supported by compiler. Signed-off-by: Leo Yan --- tools/bpf/bpftool/Makefile | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile index 9e9a5f006cd2aabe1e89bd83e394455c0d4473e0..948a0cc98b39d3f9afa0de73643eab04e8798ff5 100644 --- a/tools/bpf/bpftool/Makefile +++ b/tools/bpf/bpftool/Makefile @@ -64,11 +64,21 @@ $(LIBBPF_BOOTSTRAP)-clean: FORCE | $(LIBBPF_BOOTSTRAP_OUTPUT) prefix ?= /usr/local bash_compdir ?= /usr/share/bash-completion/completions +try-run = $(shell set -e; \ + if ($(1)) >/dev/null 2>&1; \ + then echo "$(2)"; \ + else echo "$(3)"; \ + fi) + +__cc-option = $(call try-run,\ + $(1) -Werror $(2) -c -x c /dev/null -o /dev/null,$(2),) +cc-option = $(call __cc-option, $(CC),$(1)) + CFLAGS += -O2 CFLAGS += -W CFLAGS += -Wall CFLAGS += -Wextra -CFLAGS += -Wformat-signedness +CFLAGS += $(call cc-option,-Wformat-signedness) CFLAGS += -Wno-unused-parameter CFLAGS += -Wno-missing-field-initializers CFLAGS += $(filter-out -Wswitch-enum -Wnested-externs,$(EXTRA_WARNINGS)) -- 2.34.1 clang-18.1.3 on Ubuntu 24.04.2 reports warning: memcpy_thread.c:30:1: warning: non-void function does not return a value in all control paths [-Wreturn-type] 30 | } | ^ Dismiss the warning with returning NULL from the thread function. Signed-off-by: Leo Yan --- tools/perf/tests/shell/coresight/memcpy_thread/memcpy_thread.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/perf/tests/shell/coresight/memcpy_thread/memcpy_thread.c b/tools/perf/tests/shell/coresight/memcpy_thread/memcpy_thread.c index 5f886cd09e6b3a62b5690dade94f1f8cae3279d2..7e879217be30a86431989dbf1f36d2134ef259cc 100644 --- a/tools/perf/tests/shell/coresight/memcpy_thread/memcpy_thread.c +++ b/tools/perf/tests/shell/coresight/memcpy_thread/memcpy_thread.c @@ -27,6 +27,8 @@ static void *thrfn(void *arg) } for (i = 0; i < len; i++) memcpy(dst, src, a->size * 1024); + + return NULL; } static pthread_t new_thr(void *(*fn) (void *arg), void *arg) -- 2.34.1 clang-18.1.3 on Ubuntu 24.04.2 reports warning: thread_loop.c:41:23: warning: value size does not match register size specified by the constraint and modifier [-Wasm-operand-widths] 41 | : /* in */ [i] "r" (i), [len] "r" (len) | ^ thread_loop.c:37:8: note: use constraint modifier "w" 37 | "add %[i], %[i], #1\n" | ^~~~ | %w[i] thread_loop.c:41:23: warning: value size does not match register size specified by the constraint and modifier [-Wasm-operand-widths] 41 | : /* in */ [i] "r" (i), [len] "r" (len) | ^ thread_loop.c:37:14: note: use constraint modifier "w" 37 | "add %[i], %[i], #1\n" | ^~~~ | %w[i] thread_loop.c:41:23: warning: value size does not match register size specified by the constraint and modifier [-Wasm-operand-widths] 41 | : /* in */ [i] "r" (i), [len] "r" (len) | ^ thread_loop.c:38:8: note: use constraint modifier "w" 38 | "cmp %[i], %[len]\n" | ^~~~ | %w[i] thread_loop.c:41:38: warning: value size does not match register size specified by the constraint and modifier [-Wasm-operand-widths] 41 | : /* in */ [i] "r" (i), [len] "r" (len) | ^ thread_loop.c:38:14: note: use constraint modifier "w" 38 | "cmp %[i], %[len]\n" | ^~~~~~ | %w[len] Use the modifier "w" for 32-bit register access. Signed-off-by: Leo Yan --- tools/perf/tests/shell/coresight/thread_loop/thread_loop.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/perf/tests/shell/coresight/thread_loop/thread_loop.c b/tools/perf/tests/shell/coresight/thread_loop/thread_loop.c index e05a559253ca9d9366ad321d520349042fb07fca..86f3f548b00631682767665fc5e9d5b8551a3634 100644 --- a/tools/perf/tests/shell/coresight/thread_loop/thread_loop.c +++ b/tools/perf/tests/shell/coresight/thread_loop/thread_loop.c @@ -34,8 +34,8 @@ static void *thrfn(void *arg) } asm volatile( "loop:\n" - "add %[i], %[i], #1\n" - "cmp %[i], %[len]\n" + "add %w[i], %w[i], #1\n" + "cmp %w[i], %w[len]\n" "blt loop\n" : /* out */ : /* in */ [i] "r" (i), [len] "r" (len) -- 2.34.1 clang-18.1.3 on Ubuntu 24.04.2 reports warning: unroll_loop_thread.c:35:25: warning: value size does not match register size specified by the constraint and modifier [-Wasm-operand-widths] 35 | : /* in */ [in] "r" (in) | ^ unroll_loop_thread.c:39:1: warning: non-void function does not return a value [-Wreturn-type] 39 | } | ^ Use the modifier "w" for 32-bit register access and return NULL at the end of thread function. Signed-off-by: Leo Yan --- .../tests/shell/coresight/unroll_loop_thread/unroll_loop_thread.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/tools/perf/tests/shell/coresight/unroll_loop_thread/unroll_loop_thread.c b/tools/perf/tests/shell/coresight/unroll_loop_thread/unroll_loop_thread.c index 0fc7bf1a25af3607b40f091f62176134ddb7f9f6..8f4e1c985ca38ab545a05189432a14a6d888d34c 100644 --- a/tools/perf/tests/shell/coresight/unroll_loop_thread/unroll_loop_thread.c +++ b/tools/perf/tests/shell/coresight/unroll_loop_thread/unroll_loop_thread.c @@ -20,7 +20,7 @@ static void *thrfn(void *arg) for (i = 0; i < 10000; i++) { asm volatile ( // force an unroll of thia add instruction so we can test long runs of code -#define SNIP1 "add %[in], %[in], #1\n" +#define SNIP1 "add %w[in], %w[in], #1\n" // 10 #define SNIP2 SNIP1 SNIP1 SNIP1 SNIP1 SNIP1 SNIP1 SNIP1 SNIP1 SNIP1 SNIP1 // 100 @@ -36,6 +36,8 @@ static void *thrfn(void *arg) : /* clobber */ ); } + + return NULL; } static pthread_t new_thr(void *(*fn) (void *arg), void *arg) -- 2.34.1 Add support for building perf with clang. For cross compilation, the Makefile dynamically selects target flag for corresponding arch. This patch has been verified on x86_64 machine with Ubuntu distro, it can build successfully for native target, and for cross building Arm64 and s390. Example: native build on x86_64 / Ubuntu machine: $ HOSTCC=clang CC=clang CXX=clang++ make -C tools/perf Example: cross building s390 target on x86_64 / Ubuntu machine: # Install x390x cross toolchain and headers $ sudo apt-get install gcc-s390x-linux-gnu g++-s390x-linux-gnu \ libc6-dev-s390x-cross linux-libc-dev-s390x-cross # Build with clang $ HOSTCC=clang CC=clang CXX=clang++ \ ARCH=s390 CROSS_COMPILE=s390x-linux-gnu- \ make -C tools/perf NO_LIBELF=1 NO_LIBTRACEEVENT=1 NO_LIBPYTHON=1 Signed-off-by: Leo Yan --- tools/perf/Makefile.config | 32 +++++++++++++++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-) diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config index 5a5832ee7b53c604ec0d90c5ca7e2bee5bfa6a17..a2b5c291a364cbf331c16384764520dfe330a04c 100644 --- a/tools/perf/Makefile.config +++ b/tools/perf/Makefile.config @@ -23,8 +23,38 @@ HOSTCFLAGS := $(filter-out -Wnested-externs,$(EXTRA_WARNINGS)) # borrowed from kernel headers depends on it, e.g. put_unaligned_*(). CFLAGS += -fno-strict-aliasing -# Enabled Wthread-safety analysis for clang builds. +# Set target flag and options when using clang as compiler. ifeq ($(CC_NO_CLANG), 0) + CLANG_TARGET_FLAGS_arm := arm-linux-gnueabi + CLANG_TARGET_FLAGS_arm64 := aarch64-linux-gnu + CLANG_TARGET_FLAGS_m68k := m68k-linux-gnu + CLANG_TARGET_FLAGS_mips := mipsel-linux-gnu + CLANG_TARGET_FLAGS_powerpc := powerpc64le-linux-gnu + CLANG_TARGET_FLAGS_riscv := riscv64-linux-gnu + CLANG_TARGET_FLAGS_s390 := s390x-linux-gnu + CLANG_TARGET_FLAGS_x86 := x86_64-linux-gnu + + # Default to host architecture if ARCH is not explicitly given. + ifeq ($(ARCH),) + CLANG_TARGET_FLAGS := $(shell $(CLANG) -print-target-triple) + else + CLANG_TARGET_FLAGS := $(CLANG_TARGET_FLAGS_$(ARCH)) + endif + + ifeq ($(CROSS_COMPILE),) + ifeq ($(CLANG_TARGET_FLAGS),) + $(error Specify CROSS_COMPILE or add CLANG_TARGET_FLAGS for $(ARCH)) + else + CLANG_FLAGS += --target=$(CLANG_TARGET_FLAGS) + endif # CLANG_TARGET_FLAGS + else + CLANG_FLAGS += --target=$(notdir $(CROSS_COMPILE:%-=%)) + endif # CROSS_COMPILE + + CC := $(CLANG) $(CLANG_FLAGS) -fintegrated-as + CXX := $(CXX) $(CLANG_FLAGS) -fintegrated-as + + # Enabled Wthread-safety analysis for clang builds. CFLAGS += -Wthread-safety endif -- 2.34.1 Add example commands for building perf with Clang. Since recent Android NDK releases use Clang as the default compiler, a separate Android specific document is no longer needed; point to the general build documentation instead. Signed-off-by: Leo Yan --- tools/perf/Documentation/Build.txt | 18 ++++++++ tools/perf/Documentation/android.txt | 82 ++++-------------------------------- 2 files changed, 26 insertions(+), 74 deletions(-) diff --git a/tools/perf/Documentation/Build.txt b/tools/perf/Documentation/Build.txt index 83dc87c662b63ecc17553a15cc15a6b8d6f01d83..3e4104e605ac0d7d30b4408ef413cf1f90b034c1 100644 --- a/tools/perf/Documentation/Build.txt +++ b/tools/perf/Documentation/Build.txt @@ -99,3 +99,21 @@ configuration paths for cross building: 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. + +5) Build with clang +=================== +By default, the makefile uses GCC as compiler. With specifying environment +variables HOSTCC, CC and CXX, it allows to build perf with clang. + +Using clang for native build: + + $ HOSTCC=clang CC=clang CXX=clang++ make -C tools/perf + +Using clang for cross compilation: + + $ HOSTCC=clang CC=clang CXX=clang++ \ + make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- -C tools/perf \ + NO_LIBELF=1 NO_LIBTRACEEVENT=1 NO_JEVENTS=1 + +In the example above, due to lack libelf, python and libtraceevent for +cross comiplation, disable the features accordingly. diff --git a/tools/perf/Documentation/android.txt b/tools/perf/Documentation/android.txt index 24a59998fc91e814ad96f658d3481d88d798b60c..e65204cf2921f6bd8a79875784c5b3d5487ce05d 100644 --- a/tools/perf/Documentation/android.txt +++ b/tools/perf/Documentation/android.txt @@ -1,78 +1,12 @@ How to compile perf for Android -========================================= +=============================== -I. Set the Android NDK environment ------------------------------------------------- +There have two ways to build perf and run it on Android. -(a). Use the Android NDK ------------------------------------------------- -1. You need to download and install the Android Native Development Kit (NDK). -Set the NDK variable to point to the path where you installed the NDK: - export NDK=/path/to/android-ndk +- The first method is to build perf with static linking, please refer to + Build.txt, section "4) Cross compilation" for how to build a static + perf binary. -2. Set cross-compiling environment variables for NDK toolchain and sysroot. -For arm: - export NDK_TOOLCHAIN=${NDK}/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/bin/arm-linux-androideabi- - export NDK_SYSROOT=${NDK}/platforms/android-24/arch-arm -For x86: - export NDK_TOOLCHAIN=${NDK}/toolchains/x86-4.9/prebuilt/linux-x86_64/bin/i686-linux-android- - export NDK_SYSROOT=${NDK}/platforms/android-24/arch-x86 - -This method is only tested for Android NDK versions Revision 11b and later. -perf uses some bionic enhancements that are not included in prior NDK versions. -You can use method (b) described below instead. - -(b). Use the Android source tree ------------------------------------------------ -1. Download the master branch of the Android source tree. -Set the environment for the target you want using: - source build/envsetup.sh - lunch - -2. Build your own NDK sysroot to contain latest bionic changes and set the -NDK sysroot environment variable. - cd ${ANDROID_BUILD_TOP}/ndk -For arm: - ./build/tools/build-ndk-sysroot.sh --abi=arm - export NDK_SYSROOT=${ANDROID_BUILD_TOP}/ndk/build/platforms/android-3/arch-arm -For x86: - ./build/tools/build-ndk-sysroot.sh --abi=x86 - export NDK_SYSROOT=${ANDROID_BUILD_TOP}/ndk/build/platforms/android-3/arch-x86 - -3. Set the NDK toolchain environment variable. -For arm: - export NDK_TOOLCHAIN=${ANDROID_TOOLCHAIN}/arm-linux-androideabi- -For x86: - export NDK_TOOLCHAIN=${ANDROID_TOOLCHAIN}/i686-linux-android- - -II. Compile perf for Android ------------------------------------------------- -You need to run make with the NDK toolchain and sysroot defined above: -For arm: - make WERROR=0 ARCH=arm CROSS_COMPILE=${NDK_TOOLCHAIN} EXTRA_CFLAGS="-pie --sysroot=${NDK_SYSROOT}" -For x86: - make WERROR=0 ARCH=x86 CROSS_COMPILE=${NDK_TOOLCHAIN} EXTRA_CFLAGS="-pie --sysroot=${NDK_SYSROOT}" - -III. Install perf ------------------------------------------------ -You need to connect to your Android device/emulator using adb. -Install perf using: - adb push perf /data/perf - -If you also want to use perf-archive you need busybox tools for Android. -For installing perf-archive, you first need to replace #!/bin/bash with #!/system/bin/sh: - sed 's/#!\/bin\/bash/#!\/system\/bin\/sh/g' perf-archive >> /tmp/perf-archive - chmod +x /tmp/perf-archive - adb push /tmp/perf-archive /data/perf-archive - -IV. Environment settings for running perf ------------------------------------------------- -Some perf features need environment variables to run properly. -You need to set these before running perf on the target: - adb shell - # PERF_PAGER=cat - -IV. Run perf ------------------------------------------------- -Run perf on your device/emulator to which you previously connected using adb: - # ./data/perf +- The second method is to download Android NDK, then use the contained + clang compiler for building perf. Please refer to Build.txt, section + "5) Build with clang" for details. -- 2.34.1