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* [PATCH v1 0/2] perf build: Support building BPF skeletons with bpf-gcc
@ 2026-10-13 22:16 Ian Rogers
  2026-10-13 22:16 ` [PATCH v1 1/2] " Ian Rogers
                   ` (2 more replies)
  0 siblings, 3 replies; 9+ messages in thread
From: Ian Rogers @ 2026-10-13 22:16 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo, Namhyung Kim, Jose E . Marchesi,
	David Faust, Cupertino Miranda
  Cc: Peter Zijlstra, Ingo Molnar, Jiri Olsa, Ian Rogers,
	Adrian Hunter, James Clark, Andrii Nakryiko, Eduard Zingerman,
	Yonghong Song, linux-perf-users, bpf, linux-kernel

Currently the perf build requires clang (>= 12.0.1) to compile BPF
skeleton programs (.bpf.c -> .bpf.o). bpf-gcc (>= 14.0.0) also supports
BPF CO-RE and BTF generation and is already supported in
tools/testing/selftests/bpf/Makefile.

This series updates the perf build to support both clang and bpf-gcc:
- Patch 1 updates Makefile.config, Makefile.perf, and bpf_skel.mak to
  prefer bpf-gcc when building perf with GCC (CC_NO_CLANG=1) and clang
  when building with Clang/LLVM (CC_NO_CLANG=0), while respecting
  explicit BPF_GCC=... or CLANG=... command-line overrides and falling
  back to whichever compiler is available.
- Patch 2 adds make_bpf_skel_clang and make_bpf_skel_bpf_gcc build-test
  targets to tools/perf/tests/make and verifies with
  'perf check -q feature bpf_skeletons' that BPF skeleton support is
  enabled (or disabled for make_no_bpf_skel) as expected.

Ian Rogers (2):
  perf build: Support building BPF skeletons with bpf-gcc
  perf test make: Add BPF skeleton build tests for clang and bpf-gcc

 tools/perf/Makefile.config     | 81 +++++++++++++++++++++++++++-------
 tools/perf/Makefile.perf       |  8 +++-
 tools/perf/bpf_skel.mak        | 36 ++++++++++-----
 tools/perf/tests/make          | 29 ++++++++++++
 tools/scripts/Makefile.include |  1 +
 5 files changed, 126 insertions(+), 29 deletions(-)

-- 
2.56.0.385.gd3acb90ef8-goog


^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH v1 1/2] perf build: Support building BPF skeletons with bpf-gcc
  2026-10-13 22:16 [PATCH v1 0/2] perf build: Support building BPF skeletons with bpf-gcc Ian Rogers
@ 2026-10-13 22:16 ` Ian Rogers
  2026-10-13 22:16 ` [PATCH v1 2/2] perf test make: Add BPF skeleton build tests for clang and bpf-gcc Ian Rogers
  2026-10-13 23:14 ` [PATCH v2 0/2] perf build: Support building BPF skeletons with bpf-gcc Ian Rogers
  2 siblings, 0 replies; 9+ messages in thread
From: Ian Rogers @ 2026-10-13 22:16 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo, Namhyung Kim, Jose E . Marchesi,
	David Faust, Cupertino Miranda
  Cc: Peter Zijlstra, Ingo Molnar, Jiri Olsa, Ian Rogers,
	Adrian Hunter, James Clark, Andrii Nakryiko, Eduard Zingerman,
	Yonghong Song, linux-perf-users, bpf, linux-kernel

Support building perf BPF skeletons with bpf-gcc (>= 14.0.0) in addition
to clang (>= 12.0.1), similar to tools/testing/selftests/bpf/Makefile.

When building perf with GCC (CC_NO_CLANG=1), prefer bpf-gcc and fall
back to clang if bpf-gcc is unavailable or too old. When building with
Clang/LLVM (CC_NO_CLANG=0), prefer clang and fall back to bpf-gcc.
Explicit command-line overrides via BPF_GCC=... or CLANG=... are
respected, and setting BPF_GCC= or CLANG= to empty disables that
compiler.

In bpf_skel.mak, pass the bpf-gcc flags (-mcpu=v3, -fno-ident,
-DBPF_NO_PRESERVE_ACCESS_INDEX, -Wno-attributes,
-D__TARGET_ARCH_$(SRCARCH), and target endianness) and query system
include paths from $(CC).

Assisted-by: Antigravity:gemini-3.1-pro
Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/Makefile.config     | 81 +++++++++++++++++++++++++++-------
 tools/perf/Makefile.perf       |  8 +++-
 tools/perf/bpf_skel.mak        | 36 ++++++++++-----
 tools/scripts/Makefile.include |  1 +
 4 files changed, 97 insertions(+), 29 deletions(-)

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index cafc7be79643..6aee2665b64c 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -662,27 +662,76 @@ ifeq ($(BUILD_BPF_SKEL),1)
   else ifeq ($(filter -DHAVE_LIBOPENSSL_SUPPORT, $(CFLAGS)),)
     $(warning Warning: Disabled BPF skeletons as libopenssl is required)
     BUILD_BPF_SKEL := 0
-  else ifeq ($(call get-executable,$(CLANG)),)
-    $(warning Warning: Disabled BPF skeletons as clang ($(CLANG)) is missing)
-    BUILD_BPF_SKEL := 0
-  else
-    CLANG_VERSION := $(shell $(CLANG) --version | head -1 | sed 's/.*clang version \([[:digit:]]\+.[[:digit:]]\+.[[:digit:]]\+\).*/\1/g')
-    ifeq ($(call version-lt3,$(CLANG_VERSION),12.0.1),1)
-      $(warning Warning: Disabled BPF skeletons as reliable BTF generation needs at least $(CLANG) version 12.0.1)
-      BUILD_BPF_SKEL := 0
-    endif
   endif
   ifeq ($(BUILD_BPF_SKEL),1)
-    $(call feature_check,clang-bpf-co-re)
-    ifeq ($(feature-clang-bpf-co-re), 0)
-      $(warning Warning: Disabled BPF skeletons as clang is too old)
+    # Prefer bpf-gcc when building with gcc (CC_NO_CLANG=1) and clang when
+    # building with clang, unless CLANG or BPF_GCC was explicitly specified on
+    # the command line. Fall back to whichever compiler is available.
+    prefer_bpf_gcc := $(CC_NO_CLANG)
+    ifeq ($(origin BPF_GCC),command line)
+      ifneq ($(BPF_GCC),)
+        prefer_bpf_gcc := 1
+      endif
+    else ifeq ($(origin CLANG),command line)
+      ifneq ($(CLANG),)
+        prefer_bpf_gcc := 0
+      endif
+    endif
+
+    have_bpf_gcc := 0
+    have_clang_bpf := 0
+
+    define check_bpf_gcc
+      ifneq ($$(call get-executable,$$(BPF_GCC)),)
+        BPF_GCC_VERSION := $$(shell $$(BPF_GCC) -dumpfullversion -dumpversion 2>/dev/null)
+        ifneq ($$(call version-lt3,$$(BPF_GCC_VERSION),14.0.0),1)
+          have_bpf_gcc := 1
+        endif
+      endif
+    endef
+
+    ifeq ($(prefer_bpf_gcc),1)
+      $(eval $(check_bpf_gcc))
+    endif
+
+    ifeq ($(have_bpf_gcc),0)
+      ifneq ($(call get-executable,$(CLANG)),)
+        CLANG_VERSION := $(shell $(CLANG) --version | head -1 | sed 's/.*clang version \([[:digit:]]\+.[[:digit:]]\+.[[:digit:]]\+\).*/\1/g')
+        ifneq ($(call version-lt3,$(CLANG_VERSION),12.0.1),1)
+          $(call feature_check,clang-bpf-co-re)
+          ifeq ($(feature-clang-bpf-co-re), 1)
+            have_clang_bpf := 1
+          endif
+        endif
+      endif
+    endif
+
+    ifeq ($(prefer_bpf_gcc)$(have_clang_bpf),00)
+      $(eval $(check_bpf_gcc))
+    endif
+
+    ifeq ($(have_bpf_gcc),1)
+      $(call detected,CONFIG_PERF_BPF_SKEL_BPF_GCC)
+      $(call detected,CONFIG_PERF_BPF_SKEL)
+      CFLAGS += -DHAVE_BPF_SKEL
+    else ifeq ($(have_clang_bpf),1)
+      $(call detected,CONFIG_PERF_BPF_SKEL)
+      CFLAGS += -DHAVE_BPF_SKEL
+    else
+      ifeq ($(call get-executable,$(CLANG))$(call get-executable,$(BPF_GCC)),)
+        $(warning Warning: Disabled BPF skeletons as clang ($(CLANG)) and bpf-gcc ($(BPF_GCC)) are missing)
+      else ifneq ($(call get-executable,$(CLANG)),)
+        ifeq ($(call version-lt3,$(CLANG_VERSION),12.0.1),1)
+          $(warning Warning: Disabled BPF skeletons as reliable BTF generation needs at least $(CLANG) version 12.0.1)
+        else
+          $(warning Warning: Disabled BPF skeletons as clang is too old)
+        endif
+      else
+        $(warning Warning: Disabled BPF skeletons as bpf-gcc ($(BPF_GCC)) needs at least version 14.0.0)
+      endif
       BUILD_BPF_SKEL := 0
     endif
   endif
-  ifeq ($(BUILD_BPF_SKEL),1)
-    $(call detected,CONFIG_PERF_BPF_SKEL)
-    CFLAGS += -DHAVE_BPF_SKEL
-  endif
 endif
 
 ifndef GEN_VMLINUX_H
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 2d9379fea267..4061a79cae54 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -37,6 +37,9 @@ include ../scripts/utilities.mak
 # Define EXTRA_BPF_FLAGS="--sysroot=<path>" or other custom include paths for
 # cross-compiling BPF skeletons
 #
+# Define BPF_GCC to point to the bpf-gcc binary if the default `bpf-gcc' is not
+# correct, or set BPF_GCC= to disable using bpf-gcc for BPF skeletons.
+#
 # Define EXCLUDE_EXTLIBS=-lmylib to exclude libmylib from the auto-generated
 # EXTLIBS.
 #
@@ -208,6 +211,7 @@ FIND    = find
 INSTALL = install
 FLEX    ?= flex
 BISON   ?= bison
+BPF_GCC ?= bpf-gcc
 AWK     = awk
 
 # include Makefile.config by default and rule out
@@ -321,8 +325,8 @@ ifneq ($(force_fixdep),1)
   endif
 endif
 
-export srctree OUTPUT RM CC CXX RUSTC CLANG LD AR CFLAGS CXXFLAGS RUST_FLAGS V BISON FLEX AWK LIBBPF READELF
-export HOSTCC HOSTLD HOSTAR HOSTCFLAGS SHELLCHECK MYPY PYLINT CONFIG_PERF_BPF_SKEL
+export srctree OUTPUT RM CC CXX RUSTC CLANG BPF_GCC LD AR CFLAGS CXXFLAGS RUST_FLAGS V BISON FLEX AWK LIBBPF READELF
+export HOSTCC HOSTLD HOSTAR HOSTCFLAGS SHELLCHECK MYPY PYLINT CONFIG_PERF_BPF_SKEL CONFIG_PERF_BPF_SKEL_BPF_GCC
 
 include $(srctree)/tools/build/Makefile.include
 
diff --git a/tools/perf/bpf_skel.mak b/tools/perf/bpf_skel.mak
index f2559de39f96..7b7edf506509 100644
--- a/tools/perf/bpf_skel.mak
+++ b/tools/perf/bpf_skel.mak
@@ -22,21 +22,35 @@ bpf-skel-prepare: $(BPFTOOL) $(VMLINUX_H)
 define get_sys_includes
 $(shell $(1) $(2) -v -E - </dev/null 2>&1 \
        | sed -n '/<...> search starts here:/,/End of search list./{ s| \(/.*\)|-idirafter \1|p }') \
-$(shell $(1) $(2) -dM -E - </dev/null | grep '__riscv_xlen ' | awk '{printf("-D__riscv_xlen=%d -D__BITS_PER_LONG=%d", $$3, $$3)}')
+$(shell $(1) $(2) -dM -E - </dev/null | grep '__riscv_xlen ' | awk '{printf("-D__riscv_xlen=%d -D__BITS_PER_LONG=%d", $$3, $$3)}') \
+$(shell $(1) $(2) -dM -E - </dev/null | grep '__loongarch_grlen ' | awk '{printf("-D__BITS_PER_LONG=%d", $$3)}') \
+$(shell $(1) $(2) -dM -E - </dev/null | grep -E 'MIPS(EL|EB)|_MIPS_SZ(PTR|LONG) |_MIPS_SIM |_ABI(O32|N32|64) ' | awk '{printf("-D%s=%s ", $$2, $$3)}')
 endef
 
-ifneq ($(CROSS_COMPILE),)
-CLANG_TARGET_ARCH = --target=$(notdir $(CROSS_COMPILE:%-=%))
+ifeq ($(CONFIG_PERF_BPF_SKEL_BPF_GCC),y)
+  BPF_CC := $(BPF_GCC)
+  QUIET_BPF_CC = $(QUIET_BPF_GCC)
+  IS_LITTLE_ENDIAN := $(shell $(CC) -dM -E - </dev/null | \
+			grep 'define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__')
+  BPF_OPTIONS = -Wall -mcpu=v3 -fno-ident -DBPF_NO_PRESERVE_ACCESS_INDEX -Wno-attributes \
+		-D__TARGET_ARCH_$(SRCARCH) $(if $(IS_LITTLE_ENDIAN),-mlittle-endian,-mbig-endian)
+  BPF_SYS_INCLUDES = $(call get_sys_includes,$(CC),)
+else
+  BPF_CC := $(CLANG)
+  QUIET_BPF_CC = $(QUIET_CLANG)
+  ifneq ($(CROSS_COMPILE),)
+    CLANG_TARGET_ARCH = --target=$(notdir $(CROSS_COMPILE:%-=%))
+  endif
+  BPF_OPTIONS = -Wall -mcpu=v3 -fno-stack-protector --target=bpf -Wno-microsoft-anon-tag
+  BPF_SYS_INCLUDES = $(call get_sys_includes,$(CLANG),$(CLANG_TARGET_ARCH))
 endif
 
-CLANG_OPTIONS = -Wall -mcpu=v3
-CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG),$(CLANG_TARGET_ARCH))
 LIBBPF_INCLUDE := $(abspath $(or $(OUTPUT),.))/libbpf/include
-BPF_INCLUDE := -I$(SKEL_TMP_OUT)/.. -I$(SKEL_TOOL_OUT) -I$(LIBBPF_INCLUDE) $(CLANG_SYS_INCLUDES)
+BPF_INCLUDE := -I$(SKEL_TMP_OUT)/.. -I$(SKEL_TOOL_OUT) -I$(LIBBPF_INCLUDE) $(BPF_SYS_INCLUDES)
 TOOLS_UAPI_INCLUDE := -I$(srctree)/tools/include/uapi
 
 ifneq ($(WERROR),0)
-  CLANG_OPTIONS += -Werror
+  BPF_OPTIONS += -Werror
 endif
 
 $(BPFTOOL):
@@ -83,11 +97,11 @@ endif
 # Consolidated Pattern rule for $(dir)/bpf_skel/
 $(SKEL_TMP_OUT)/%.bpf.o: $(srctree)/tools/perf/$(dir)/bpf_skel/%.bpf.c $(LIBBPF) $(VMLINUX_H) $(OUTPUT)PERF-VERSION-FILE util/bpf_skel/perf_version.h
 	$(call rule_mkdir)
-	$(QUIET_CLANG)
-	$(Q)$(CLANG) -g -O2 -fno-stack-protector --target=bpf \
-	  $(CLANG_OPTIONS) $(EXTRA_BPF_FLAGS) $(BPF_INCLUDE) $(TOOLS_UAPI_INCLUDE) \
+	$(QUIET_BPF_CC)
+	$(Q)$(BPF_CC) -g -O2 \
+	  $(BPF_OPTIONS) $(EXTRA_BPF_FLAGS) $(BPF_INCLUDE) $(TOOLS_UAPI_INCLUDE) \
 	  -include $(OUTPUT)PERF-VERSION-FILE -include util/bpf_skel/perf_version.h \
-	  -fms-extensions -Wno-microsoft-anon-tag \
+	  -fms-extensions \
 	  -c $< -o $@
 
 $(SKEL_OUT)/%.skel.h: $(SKEL_TMP_OUT)/%.bpf.o $(BPFTOOL)
diff --git a/tools/scripts/Makefile.include b/tools/scripts/Makefile.include
index 378387f62960..9967210b2928 100644
--- a/tools/scripts/Makefile.include
+++ b/tools/scripts/Makefile.include
@@ -217,6 +217,7 @@ ifneq ($(silent),1)
 	QUIET_CC       = @echo '  CC      '$@;
 	QUIET_CC_FPIC  = @echo '  CC FPIC '$@;
 	QUIET_CLANG    = @echo '  CLANG   '$@;
+	QUIET_BPF_GCC  = @echo '  BPF_GCC '$@;
 	QUIET_AR       = @echo '  AR      '$@;
 	QUIET_LINK     = @echo '  LINK    '$@;
 	QUIET_MKDIR    = @echo '  MKDIR   '$@;
-- 
2.56.0.385.gd3acb90ef8-goog


^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH v1 2/2] perf test make: Add BPF skeleton build tests for clang and bpf-gcc
  2026-10-13 22:16 [PATCH v1 0/2] perf build: Support building BPF skeletons with bpf-gcc Ian Rogers
  2026-10-13 22:16 ` [PATCH v1 1/2] " Ian Rogers
@ 2026-10-13 22:16 ` Ian Rogers
  2026-10-13 23:14 ` [PATCH v2 0/2] perf build: Support building BPF skeletons with bpf-gcc Ian Rogers
  2 siblings, 0 replies; 9+ messages in thread
From: Ian Rogers @ 2026-10-13 22:16 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo, Namhyung Kim, Jose E . Marchesi,
	David Faust, Cupertino Miranda
  Cc: Peter Zijlstra, Ingo Molnar, Jiri Olsa, Ian Rogers,
	Adrian Hunter, James Clark, Andrii Nakryiko, Eduard Zingerman,
	Yonghong Song, linux-perf-users, bpf, linux-kernel

Add make_bpf_skel_clang (CLANG=clang BPF_GCC=) and make_bpf_skel_bpf_gcc
(BPF_GCC=bpf-gcc CLANG=) targets to tools/perf/tests/make when the
corresponding compiler and BPF skeleton dependencies are available on
the host. Verify with 'perf check -q feature bpf_skeletons' that BPF
skeleton support is enabled for both targets and disabled for
make_no_bpf_skel.

Assisted-by: Antigravity:gemini-3.1-pro
Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/tests/make | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/tools/perf/tests/make b/tools/perf/tests/make
index 7524de522802..4e66b93cf12c 100644
--- a/tools/perf/tests/make
+++ b/tools/perf/tests/make
@@ -78,6 +78,8 @@ make_extra_tests    := EXTRA_TESTS=1
 make_no_jevents     := NO_JEVENTS=1
 make_jevents_all    := JEVENTS_ARCH=all
 make_no_bpf_skel    := BUILD_BPF_SKEL=0
+make_bpf_skel_clang := CLANG=clang BPF_GCC=
+make_bpf_skel_bpf_gcc := BPF_GCC=bpf-gcc CLANG=
 make_gen_vmlinux_h  := GEN_VMLINUX_H=1
 make_no_python_module := NO_PYTHON_MODULE=1
 make_no_scripts     := NO_PYTHON_MODULE=1
@@ -142,6 +144,20 @@ have_libllvm := $(shell printf '#include <llvm/Support/ManagedStatic.h>\n#includ
 		$(shell $(LLVM_CONFIG) --system-libs 2>/dev/null) >/dev/null 2>&1 && echo y)
 endif
 
+have_bpf_skel_deps := $(shell printf '#include <libelf.h>\n#include <zlib.h>\n#include <linux/bpf.h>\n#include <openssl/opensslv.h>\nint main(){return 0;}\n' | \
+	$(CC) -x c -I$(srctree)/tools/include/uapi - -o /dev/null -lelf -lz -lcrypto >/dev/null 2>&1 && echo y)
+
+ifneq ($(have_bpf_skel_deps),)
+ifneq ($(call has,clang),)
+have_clang_bpf := $(shell printf '#if (__clang_major__ < 12) || (__clang_major__ == 12 && __clang_minor__ == 0 && __clang_patchlevel__ < 1)\n#error "old"\n#endif\n' | \
+	clang -S -g --target=bpf -x c - -o /dev/null >/dev/null 2>&1 && echo y)
+endif
+ifneq ($(call has,bpf-gcc),)
+have_bpf_gcc := $(shell printf '#if __GNUC__ < 14\n#error "old"\n#endif\n' | \
+	bpf-gcc -E -x c - >/dev/null 2>&1 && echo y)
+endif
+endif
+
 # $(run) contains all available tests
 run := make_pure
 # Targets 'clean all' can be run together only through top level
@@ -173,6 +189,12 @@ run += make_extra_tests
 run += make_no_jevents
 run += make_jevents_all
 run += make_no_bpf_skel
+ifneq ($(have_clang_bpf),)
+run += make_bpf_skel_clang
+endif
+ifneq ($(have_bpf_gcc),)
+run += make_bpf_skel_bpf_gcc
+endif
 run += make_gen_vmlinux_h
 run += make_no_python_module
 run += make_no_scripts
@@ -313,6 +335,13 @@ test_make_clang_nondistro     := $(test_make_clang)
 test_make_clang_nondistro_O   := $(test_make_clang_O)
 endif
 
+test_make_no_bpf_skel         := test -x $(PERF_O)/perf && ! $(PERF_O)/perf check -q feature bpf_skeletons
+test_make_no_bpf_skel_O       := test -x $$TMP_O/perf && ! $$TMP_O/perf check -q feature bpf_skeletons
+test_make_bpf_skel_clang      := test -x $(PERF_O)/perf && $(PERF_O)/perf check -q feature bpf_skeletons
+test_make_bpf_skel_clang_O    := test -x $$TMP_O/perf && $$TMP_O/perf check -q feature bpf_skeletons
+test_make_bpf_skel_bpf_gcc    := test -x $(PERF_O)/perf && $(PERF_O)/perf check -q feature bpf_skeletons
+test_make_bpf_skel_bpf_gcc_O  := test -x $$TMP_O/perf && $$TMP_O/perf check -q feature bpf_skeletons
+
 test_make_python_perf_so_O    := test -f $$TMP_O/python/perf.so
 test_make_perf_o_O            := test -f $$TMP_O/perf.o
 test_make_util_map_o_O        := test -f $$TMP_O/util/map.o
-- 
2.56.0.385.gd3acb90ef8-goog


^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH v2 0/2] perf build: Support building BPF skeletons with bpf-gcc
  2026-10-13 22:16 [PATCH v1 0/2] perf build: Support building BPF skeletons with bpf-gcc Ian Rogers
  2026-10-13 22:16 ` [PATCH v1 1/2] " Ian Rogers
  2026-10-13 22:16 ` [PATCH v1 2/2] perf test make: Add BPF skeleton build tests for clang and bpf-gcc Ian Rogers
@ 2026-10-13 23:14 ` Ian Rogers
  2026-10-13 23:14   ` [PATCH v2 1/2] " Ian Rogers
                     ` (2 more replies)
  2 siblings, 3 replies; 9+ messages in thread
From: Ian Rogers @ 2026-10-13 23:14 UTC (permalink / raw)
  To: irogers, acme, cupertino.miranda, jose.marchesi, namhyung
  Cc: adrian.hunter, andrii, eddyz87, james.clark, jolsa, linux-kernel,
	linux-perf-users, mingo, peterz, yonghong.song

Currently the perf build requires clang (>= 12.0.1) to compile BPF
skeleton programs (.bpf.c -> .bpf.o). bpf-gcc (>= 14.0.0) also supports
BPF CO-RE and BTF generation and is already supported in
tools/testing/selftests/bpf/Makefile.

This series updates the perf build to support both clang and bpf-gcc:
- Patch 1 updates Makefile.config, Makefile.perf, and bpf_skel.mak to
  prefer bpf-gcc when building perf with GCC (CC_NO_CLANG=1) and clang
  when building with Clang/LLVM (CC_NO_CLANG=0), while respecting
  explicit BPF_GCC=... or CLANG=... command-line overrides and falling
  back to whichever compiler is available.
- Patch 2 adds make_bpf_skel_clang and make_bpf_skel_bpf_gcc build-test
  targets to tools/perf/tests/make and verifies with
  'perf check -q feature bpf_skeletons' that BPF skeleton support is
  enabled (or disabled for make_no_bpf_skel) as expected.

v2: Pass only -dumpfullversion when querying BPF_GCC_VERSION, guard
    against an empty version string, and fix version-ge3 / version-lt3
    in tools/scripts/utilities.mak so empty or <3-component version
    strings do not shift awk fields and evaluate as false in version-lt3.

Ian Rogers (2):
  perf build: Support building BPF skeletons with bpf-gcc
  perf test make: Add BPF skeleton build tests for clang and bpf-gcc

 tools/perf/Makefile.config     | 83 +++++++++++++++++++++++++++-------
 tools/perf/Makefile.perf       |  8 +++-
 tools/perf/bpf_skel.mak        | 36 ++++++++++-----
 tools/perf/tests/make          | 29 ++++++++++++
 tools/scripts/Makefile.include |  1 +
 tools/scripts/utilities.mak    |  4 +-
 6 files changed, 130 insertions(+), 31 deletions(-)

-- 
2.56.0.385.gd3acb90ef8-goog


^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH v2 1/2] perf build: Support building BPF skeletons with bpf-gcc
  2026-10-13 23:14 ` [PATCH v2 0/2] perf build: Support building BPF skeletons with bpf-gcc Ian Rogers
@ 2026-10-13 23:14   ` Ian Rogers
  2026-10-13 23:14   ` [PATCH v2 2/2] perf test make: Add BPF skeleton build tests for clang and bpf-gcc Ian Rogers
  2026-10-22 20:46   ` [PATCH v3 0/2] perf build: Support building BPF skeletons with bpf-gcc Ian Rogers
  2 siblings, 0 replies; 9+ messages in thread
From: Ian Rogers @ 2026-10-13 23:14 UTC (permalink / raw)
  To: irogers, acme, cupertino.miranda, jose.marchesi, namhyung
  Cc: adrian.hunter, andrii, eddyz87, james.clark, jolsa, linux-kernel,
	linux-perf-users, mingo, peterz, yonghong.song

Support building perf BPF skeletons with bpf-gcc (>= 14.0.0) in addition
to clang (>= 12.0.1), similar to tools/testing/selftests/bpf/Makefile.

When building perf with GCC (CC_NO_CLANG=1), prefer bpf-gcc and fall
back to clang if bpf-gcc is unavailable or too old. When building with
Clang/LLVM (CC_NO_CLANG=0), prefer clang and fall back to bpf-gcc.
Explicit command-line overrides via BPF_GCC=... or CLANG=... are
respected, and setting BPF_GCC= or CLANG= to empty disables that
compiler.

In bpf_skel.mak, pass the bpf-gcc flags (-mcpu=v3, -fno-ident,
-DBPF_NO_PRESERVE_ACCESS_INDEX, -Wno-attributes,
-D__TARGET_ARCH_$(SRCARCH), and target endianness) and query system
include paths from $(CC).

Also update version-ge3 and version-lt3 in tools/scripts/utilities.mak
to split the two version arguments separately in awk so empty or
fewer-than-3-component version strings do not shift fields across
arguments.

Assisted-by: Antigravity:gemini-3.1-pro
Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/Makefile.config     | 83 +++++++++++++++++++++++++++-------
 tools/perf/Makefile.perf       |  8 +++-
 tools/perf/bpf_skel.mak        | 36 ++++++++++-----
 tools/scripts/Makefile.include |  1 +
 tools/scripts/utilities.mak    |  4 +-
 5 files changed, 101 insertions(+), 31 deletions(-)

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index cafc7be79643..235872e65d8f 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -662,27 +662,78 @@ ifeq ($(BUILD_BPF_SKEL),1)
   else ifeq ($(filter -DHAVE_LIBOPENSSL_SUPPORT, $(CFLAGS)),)
     $(warning Warning: Disabled BPF skeletons as libopenssl is required)
     BUILD_BPF_SKEL := 0
-  else ifeq ($(call get-executable,$(CLANG)),)
-    $(warning Warning: Disabled BPF skeletons as clang ($(CLANG)) is missing)
-    BUILD_BPF_SKEL := 0
-  else
-    CLANG_VERSION := $(shell $(CLANG) --version | head -1 | sed 's/.*clang version \([[:digit:]]\+.[[:digit:]]\+.[[:digit:]]\+\).*/\1/g')
-    ifeq ($(call version-lt3,$(CLANG_VERSION),12.0.1),1)
-      $(warning Warning: Disabled BPF skeletons as reliable BTF generation needs at least $(CLANG) version 12.0.1)
-      BUILD_BPF_SKEL := 0
-    endif
   endif
   ifeq ($(BUILD_BPF_SKEL),1)
-    $(call feature_check,clang-bpf-co-re)
-    ifeq ($(feature-clang-bpf-co-re), 0)
-      $(warning Warning: Disabled BPF skeletons as clang is too old)
+    # Prefer bpf-gcc when building with gcc (CC_NO_CLANG=1) and clang when
+    # building with clang, unless CLANG or BPF_GCC was explicitly specified on
+    # the command line. Fall back to whichever compiler is available.
+    prefer_bpf_gcc := $(CC_NO_CLANG)
+    ifeq ($(origin BPF_GCC),command line)
+      ifneq ($(BPF_GCC),)
+        prefer_bpf_gcc := 1
+      endif
+    else ifeq ($(origin CLANG),command line)
+      ifneq ($(CLANG),)
+        prefer_bpf_gcc := 0
+      endif
+    endif
+
+    have_bpf_gcc := 0
+    have_clang_bpf := 0
+
+    define check_bpf_gcc
+      ifneq ($$(call get-executable,$$(BPF_GCC)),)
+        BPF_GCC_VERSION := $$(shell $$(BPF_GCC) -dumpfullversion 2>/dev/null)
+        ifneq ($$(BPF_GCC_VERSION),)
+          ifneq ($$(call version-lt3,$$(BPF_GCC_VERSION),14.0.0),1)
+            have_bpf_gcc := 1
+          endif
+        endif
+      endif
+    endef
+
+    ifeq ($(prefer_bpf_gcc),1)
+      $(eval $(check_bpf_gcc))
+    endif
+
+    ifeq ($(have_bpf_gcc),0)
+      ifneq ($(call get-executable,$(CLANG)),)
+        CLANG_VERSION := $(shell $(CLANG) --version | head -1 | sed 's/.*clang version \([[:digit:]]\+.[[:digit:]]\+.[[:digit:]]\+\).*/\1/g')
+        ifneq ($(call version-lt3,$(CLANG_VERSION),12.0.1),1)
+          $(call feature_check,clang-bpf-co-re)
+          ifeq ($(feature-clang-bpf-co-re), 1)
+            have_clang_bpf := 1
+          endif
+        endif
+      endif
+    endif
+
+    ifeq ($(prefer_bpf_gcc)$(have_clang_bpf),00)
+      $(eval $(check_bpf_gcc))
+    endif
+
+    ifeq ($(have_bpf_gcc),1)
+      $(call detected,CONFIG_PERF_BPF_SKEL_BPF_GCC)
+      $(call detected,CONFIG_PERF_BPF_SKEL)
+      CFLAGS += -DHAVE_BPF_SKEL
+    else ifeq ($(have_clang_bpf),1)
+      $(call detected,CONFIG_PERF_BPF_SKEL)
+      CFLAGS += -DHAVE_BPF_SKEL
+    else
+      ifeq ($(call get-executable,$(CLANG))$(call get-executable,$(BPF_GCC)),)
+        $(warning Warning: Disabled BPF skeletons as clang ($(CLANG)) and bpf-gcc ($(BPF_GCC)) are missing)
+      else ifneq ($(call get-executable,$(CLANG)),)
+        ifeq ($(call version-lt3,$(CLANG_VERSION),12.0.1),1)
+          $(warning Warning: Disabled BPF skeletons as reliable BTF generation needs at least $(CLANG) version 12.0.1)
+        else
+          $(warning Warning: Disabled BPF skeletons as clang is too old)
+        endif
+      else
+        $(warning Warning: Disabled BPF skeletons as bpf-gcc ($(BPF_GCC)) needs at least version 14.0.0)
+      endif
       BUILD_BPF_SKEL := 0
     endif
   endif
-  ifeq ($(BUILD_BPF_SKEL),1)
-    $(call detected,CONFIG_PERF_BPF_SKEL)
-    CFLAGS += -DHAVE_BPF_SKEL
-  endif
 endif
 
 ifndef GEN_VMLINUX_H
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 2d9379fea267..4061a79cae54 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -37,6 +37,9 @@ include ../scripts/utilities.mak
 # Define EXTRA_BPF_FLAGS="--sysroot=<path>" or other custom include paths for
 # cross-compiling BPF skeletons
 #
+# Define BPF_GCC to point to the bpf-gcc binary if the default `bpf-gcc' is not
+# correct, or set BPF_GCC= to disable using bpf-gcc for BPF skeletons.
+#
 # Define EXCLUDE_EXTLIBS=-lmylib to exclude libmylib from the auto-generated
 # EXTLIBS.
 #
@@ -208,6 +211,7 @@ FIND    = find
 INSTALL = install
 FLEX    ?= flex
 BISON   ?= bison
+BPF_GCC ?= bpf-gcc
 AWK     = awk
 
 # include Makefile.config by default and rule out
@@ -321,8 +325,8 @@ ifneq ($(force_fixdep),1)
   endif
 endif
 
-export srctree OUTPUT RM CC CXX RUSTC CLANG LD AR CFLAGS CXXFLAGS RUST_FLAGS V BISON FLEX AWK LIBBPF READELF
-export HOSTCC HOSTLD HOSTAR HOSTCFLAGS SHELLCHECK MYPY PYLINT CONFIG_PERF_BPF_SKEL
+export srctree OUTPUT RM CC CXX RUSTC CLANG BPF_GCC LD AR CFLAGS CXXFLAGS RUST_FLAGS V BISON FLEX AWK LIBBPF READELF
+export HOSTCC HOSTLD HOSTAR HOSTCFLAGS SHELLCHECK MYPY PYLINT CONFIG_PERF_BPF_SKEL CONFIG_PERF_BPF_SKEL_BPF_GCC
 
 include $(srctree)/tools/build/Makefile.include
 
diff --git a/tools/perf/bpf_skel.mak b/tools/perf/bpf_skel.mak
index f2559de39f96..7b7edf506509 100644
--- a/tools/perf/bpf_skel.mak
+++ b/tools/perf/bpf_skel.mak
@@ -22,21 +22,35 @@ bpf-skel-prepare: $(BPFTOOL) $(VMLINUX_H)
 define get_sys_includes
 $(shell $(1) $(2) -v -E - </dev/null 2>&1 \
        | sed -n '/<...> search starts here:/,/End of search list./{ s| \(/.*\)|-idirafter \1|p }') \
-$(shell $(1) $(2) -dM -E - </dev/null | grep '__riscv_xlen ' | awk '{printf("-D__riscv_xlen=%d -D__BITS_PER_LONG=%d", $$3, $$3)}')
+$(shell $(1) $(2) -dM -E - </dev/null | grep '__riscv_xlen ' | awk '{printf("-D__riscv_xlen=%d -D__BITS_PER_LONG=%d", $$3, $$3)}') \
+$(shell $(1) $(2) -dM -E - </dev/null | grep '__loongarch_grlen ' | awk '{printf("-D__BITS_PER_LONG=%d", $$3)}') \
+$(shell $(1) $(2) -dM -E - </dev/null | grep -E 'MIPS(EL|EB)|_MIPS_SZ(PTR|LONG) |_MIPS_SIM |_ABI(O32|N32|64) ' | awk '{printf("-D%s=%s ", $$2, $$3)}')
 endef
 
-ifneq ($(CROSS_COMPILE),)
-CLANG_TARGET_ARCH = --target=$(notdir $(CROSS_COMPILE:%-=%))
+ifeq ($(CONFIG_PERF_BPF_SKEL_BPF_GCC),y)
+  BPF_CC := $(BPF_GCC)
+  QUIET_BPF_CC = $(QUIET_BPF_GCC)
+  IS_LITTLE_ENDIAN := $(shell $(CC) -dM -E - </dev/null | \
+			grep 'define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__')
+  BPF_OPTIONS = -Wall -mcpu=v3 -fno-ident -DBPF_NO_PRESERVE_ACCESS_INDEX -Wno-attributes \
+		-D__TARGET_ARCH_$(SRCARCH) $(if $(IS_LITTLE_ENDIAN),-mlittle-endian,-mbig-endian)
+  BPF_SYS_INCLUDES = $(call get_sys_includes,$(CC),)
+else
+  BPF_CC := $(CLANG)
+  QUIET_BPF_CC = $(QUIET_CLANG)
+  ifneq ($(CROSS_COMPILE),)
+    CLANG_TARGET_ARCH = --target=$(notdir $(CROSS_COMPILE:%-=%))
+  endif
+  BPF_OPTIONS = -Wall -mcpu=v3 -fno-stack-protector --target=bpf -Wno-microsoft-anon-tag
+  BPF_SYS_INCLUDES = $(call get_sys_includes,$(CLANG),$(CLANG_TARGET_ARCH))
 endif
 
-CLANG_OPTIONS = -Wall -mcpu=v3
-CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG),$(CLANG_TARGET_ARCH))
 LIBBPF_INCLUDE := $(abspath $(or $(OUTPUT),.))/libbpf/include
-BPF_INCLUDE := -I$(SKEL_TMP_OUT)/.. -I$(SKEL_TOOL_OUT) -I$(LIBBPF_INCLUDE) $(CLANG_SYS_INCLUDES)
+BPF_INCLUDE := -I$(SKEL_TMP_OUT)/.. -I$(SKEL_TOOL_OUT) -I$(LIBBPF_INCLUDE) $(BPF_SYS_INCLUDES)
 TOOLS_UAPI_INCLUDE := -I$(srctree)/tools/include/uapi
 
 ifneq ($(WERROR),0)
-  CLANG_OPTIONS += -Werror
+  BPF_OPTIONS += -Werror
 endif
 
 $(BPFTOOL):
@@ -83,11 +97,11 @@ endif
 # Consolidated Pattern rule for $(dir)/bpf_skel/
 $(SKEL_TMP_OUT)/%.bpf.o: $(srctree)/tools/perf/$(dir)/bpf_skel/%.bpf.c $(LIBBPF) $(VMLINUX_H) $(OUTPUT)PERF-VERSION-FILE util/bpf_skel/perf_version.h
 	$(call rule_mkdir)
-	$(QUIET_CLANG)
-	$(Q)$(CLANG) -g -O2 -fno-stack-protector --target=bpf \
-	  $(CLANG_OPTIONS) $(EXTRA_BPF_FLAGS) $(BPF_INCLUDE) $(TOOLS_UAPI_INCLUDE) \
+	$(QUIET_BPF_CC)
+	$(Q)$(BPF_CC) -g -O2 \
+	  $(BPF_OPTIONS) $(EXTRA_BPF_FLAGS) $(BPF_INCLUDE) $(TOOLS_UAPI_INCLUDE) \
 	  -include $(OUTPUT)PERF-VERSION-FILE -include util/bpf_skel/perf_version.h \
-	  -fms-extensions -Wno-microsoft-anon-tag \
+	  -fms-extensions \
 	  -c $< -o $@
 
 $(SKEL_OUT)/%.skel.h: $(SKEL_TMP_OUT)/%.bpf.o $(BPFTOOL)
diff --git a/tools/scripts/Makefile.include b/tools/scripts/Makefile.include
index 378387f62960..9967210b2928 100644
--- a/tools/scripts/Makefile.include
+++ b/tools/scripts/Makefile.include
@@ -217,6 +217,7 @@ ifneq ($(silent),1)
 	QUIET_CC       = @echo '  CC      '$@;
 	QUIET_CC_FPIC  = @echo '  CC FPIC '$@;
 	QUIET_CLANG    = @echo '  CLANG   '$@;
+	QUIET_BPF_GCC  = @echo '  BPF_GCC '$@;
 	QUIET_AR       = @echo '  AR      '$@;
 	QUIET_LINK     = @echo '  LINK    '$@;
 	QUIET_MKDIR    = @echo '  MKDIR   '$@;
diff --git a/tools/scripts/utilities.mak b/tools/scripts/utilities.mak
index d69d0345cc23..746aaf6e5145 100644
--- a/tools/scripts/utilities.mak
+++ b/tools/scripts/utilities.mak
@@ -186,7 +186,7 @@ _gea_err  = $(if $(1),$(error Please set '$(1)' appropriately))
 # was to check the flex version to see if we can use compiler warnings as
 # errors for one of the cases flex generates code C compilers complains about.
 
-version-ge3 = $(shell echo "$(1).$(2)" | awk -F'.' '{ printf("%d\n", (10000000 * $$1 + 10000 * $$2 + $$3) >= (10000000 * $$4 + 10000 * $$5 + $$6)) }')
+version-ge3 = $(shell awk -v v1="$(1)" -v v2="$(2)" 'BEGIN { split(v1, a, "."); split(v2, b, "."); printf("%d\n", (10000000 * a[1] + 10000 * a[2] + a[3]) >= (10000000 * b[1] + 10000 * b[2] + b[3])) }')
 
 # version-lt3
 #
@@ -196,4 +196,4 @@ version-ge3 = $(shell echo "$(1).$(2)" | awk -F'.' '{ printf("%d\n", (10000000 *
 # check the flex version to see if we can use compiler warnings as errors for
 # one of the cases flex generates code C compilers complains about.
 
-version-lt3 = $(shell echo "$(1).$(2)" | awk -F'.' '{ printf("%d\n", (10000000 * $$1 + 10000 * $$2 + $$3) < (10000000 * $$4 + 10000 * $$5 + $$6)) }')
+version-lt3 = $(shell awk -v v1="$(1)" -v v2="$(2)" 'BEGIN { split(v1, a, "."); split(v2, b, "."); printf("%d\n", (10000000 * a[1] + 10000 * a[2] + a[3]) < (10000000 * b[1] + 10000 * b[2] + b[3])) }')
-- 
2.56.0.385.gd3acb90ef8-goog


^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH v2 2/2] perf test make: Add BPF skeleton build tests for clang and bpf-gcc
  2026-10-13 23:14 ` [PATCH v2 0/2] perf build: Support building BPF skeletons with bpf-gcc Ian Rogers
  2026-10-13 23:14   ` [PATCH v2 1/2] " Ian Rogers
@ 2026-10-13 23:14   ` Ian Rogers
  2026-10-22 20:46   ` [PATCH v3 0/2] perf build: Support building BPF skeletons with bpf-gcc Ian Rogers
  2 siblings, 0 replies; 9+ messages in thread
From: Ian Rogers @ 2026-10-13 23:14 UTC (permalink / raw)
  To: irogers, acme, cupertino.miranda, jose.marchesi, namhyung
  Cc: adrian.hunter, andrii, eddyz87, james.clark, jolsa, linux-kernel,
	linux-perf-users, mingo, peterz, yonghong.song

Add make_bpf_skel_clang (CLANG=clang BPF_GCC=) and make_bpf_skel_bpf_gcc
(BPF_GCC=bpf-gcc CLANG=) targets to tools/perf/tests/make when the
corresponding compiler and BPF skeleton dependencies are available on
the host. Verify with 'perf check -q feature bpf_skeletons' that BPF
skeleton support is enabled for both targets and disabled for
make_no_bpf_skel.

Assisted-by: Antigravity:gemini-3.1-pro
Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/tests/make | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/tools/perf/tests/make b/tools/perf/tests/make
index 7524de522802..4e66b93cf12c 100644
--- a/tools/perf/tests/make
+++ b/tools/perf/tests/make
@@ -78,6 +78,8 @@ make_extra_tests    := EXTRA_TESTS=1
 make_no_jevents     := NO_JEVENTS=1
 make_jevents_all    := JEVENTS_ARCH=all
 make_no_bpf_skel    := BUILD_BPF_SKEL=0
+make_bpf_skel_clang := CLANG=clang BPF_GCC=
+make_bpf_skel_bpf_gcc := BPF_GCC=bpf-gcc CLANG=
 make_gen_vmlinux_h  := GEN_VMLINUX_H=1
 make_no_python_module := NO_PYTHON_MODULE=1
 make_no_scripts     := NO_PYTHON_MODULE=1
@@ -142,6 +144,20 @@ have_libllvm := $(shell printf '#include <llvm/Support/ManagedStatic.h>\n#includ
 		$(shell $(LLVM_CONFIG) --system-libs 2>/dev/null) >/dev/null 2>&1 && echo y)
 endif
 
+have_bpf_skel_deps := $(shell printf '#include <libelf.h>\n#include <zlib.h>\n#include <linux/bpf.h>\n#include <openssl/opensslv.h>\nint main(){return 0;}\n' | \
+	$(CC) -x c -I$(srctree)/tools/include/uapi - -o /dev/null -lelf -lz -lcrypto >/dev/null 2>&1 && echo y)
+
+ifneq ($(have_bpf_skel_deps),)
+ifneq ($(call has,clang),)
+have_clang_bpf := $(shell printf '#if (__clang_major__ < 12) || (__clang_major__ == 12 && __clang_minor__ == 0 && __clang_patchlevel__ < 1)\n#error "old"\n#endif\n' | \
+	clang -S -g --target=bpf -x c - -o /dev/null >/dev/null 2>&1 && echo y)
+endif
+ifneq ($(call has,bpf-gcc),)
+have_bpf_gcc := $(shell printf '#if __GNUC__ < 14\n#error "old"\n#endif\n' | \
+	bpf-gcc -E -x c - >/dev/null 2>&1 && echo y)
+endif
+endif
+
 # $(run) contains all available tests
 run := make_pure
 # Targets 'clean all' can be run together only through top level
@@ -173,6 +189,12 @@ run += make_extra_tests
 run += make_no_jevents
 run += make_jevents_all
 run += make_no_bpf_skel
+ifneq ($(have_clang_bpf),)
+run += make_bpf_skel_clang
+endif
+ifneq ($(have_bpf_gcc),)
+run += make_bpf_skel_bpf_gcc
+endif
 run += make_gen_vmlinux_h
 run += make_no_python_module
 run += make_no_scripts
@@ -313,6 +335,13 @@ test_make_clang_nondistro     := $(test_make_clang)
 test_make_clang_nondistro_O   := $(test_make_clang_O)
 endif
 
+test_make_no_bpf_skel         := test -x $(PERF_O)/perf && ! $(PERF_O)/perf check -q feature bpf_skeletons
+test_make_no_bpf_skel_O       := test -x $$TMP_O/perf && ! $$TMP_O/perf check -q feature bpf_skeletons
+test_make_bpf_skel_clang      := test -x $(PERF_O)/perf && $(PERF_O)/perf check -q feature bpf_skeletons
+test_make_bpf_skel_clang_O    := test -x $$TMP_O/perf && $$TMP_O/perf check -q feature bpf_skeletons
+test_make_bpf_skel_bpf_gcc    := test -x $(PERF_O)/perf && $(PERF_O)/perf check -q feature bpf_skeletons
+test_make_bpf_skel_bpf_gcc_O  := test -x $$TMP_O/perf && $$TMP_O/perf check -q feature bpf_skeletons
+
 test_make_python_perf_so_O    := test -f $$TMP_O/python/perf.so
 test_make_perf_o_O            := test -f $$TMP_O/perf.o
 test_make_util_map_o_O        := test -f $$TMP_O/util/map.o
-- 
2.56.0.385.gd3acb90ef8-goog


^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH v3 0/2] perf build: Support building BPF skeletons with bpf-gcc
  2026-10-13 23:14 ` [PATCH v2 0/2] perf build: Support building BPF skeletons with bpf-gcc Ian Rogers
  2026-10-13 23:14   ` [PATCH v2 1/2] " Ian Rogers
  2026-10-13 23:14   ` [PATCH v2 2/2] perf test make: Add BPF skeleton build tests for clang and bpf-gcc Ian Rogers
@ 2026-10-22 20:46   ` Ian Rogers
  2026-10-22 20:46     ` [PATCH v3 1/2] " Ian Rogers
  2026-10-22 20:46     ` [PATCH v3 2/2] perf test make: Add BPF skeleton build tests for clang and bpf-gcc Ian Rogers
  2 siblings, 2 replies; 9+ messages in thread
From: Ian Rogers @ 2026-10-22 20:46 UTC (permalink / raw)
  To: irogers, acme, cupertino.miranda, jose.marchesi, namhyung
  Cc: adrian.hunter, andrii, eddyz87, james.clark, jolsa, linux-kernel,
	linux-perf-users, mingo, peterz, yonghong.song

Currently the perf build requires clang (>= 12.0.1) to compile BPF
skeleton programs (.bpf.c -> .bpf.o). bpf-gcc (>= 14.0.0) also supports
BPF CO-RE and BTF generation and is already supported in
tools/testing/selftests/bpf/Makefile.

This series updates the perf build to support both clang and bpf-gcc:
- Patch 1 updates Makefile.config, Makefile.perf, and bpf_skel.mak to
  prefer bpf-gcc when building perf with GCC (CC_NO_CLANG=1) and clang
  when building with Clang/LLVM (CC_NO_CLANG=0), while respecting
  explicit BPF_GCC=... or CLANG=... command-line overrides and falling
  back to whichever compiler is available.
- Patch 2 adds make_bpf_skel_clang and make_bpf_skel_bpf_gcc build-test
  targets to tools/perf/tests/make, reuses tools/build/Makefile.feature
  for feature detection, and verifies with
  'perf check -q feature bpf_skeletons' that BPF skeleton support is
  enabled (or disabled for make_no_bpf_skel) as expected.

v3: Reuse tools/build/Makefile.feature and tools/scripts/utilities.mak
    in tools/perf/tests/make rather than open-coding compiler feature
    probes, and explicitly check for exit code 1 from 'perf check' in
    make_no_bpf_skel so crashes are not masked by shell negation.
v2: Pass only -dumpfullversion when querying BPF_GCC_VERSION, guard
    against an empty version string, and fix version-ge3 / version-lt3
    in tools/scripts/utilities.mak so empty or <3-component version
    strings do not shift awk fields and evaluate as false in version-lt3.

Ian Rogers (2):
  perf build: Support building BPF skeletons with bpf-gcc
  perf test make: Add BPF skeleton build tests for clang and bpf-gcc

 tools/perf/Makefile.config     | 83 +++++++++++++++++++++++++++-------
 tools/perf/Makefile.perf       |  8 +++-
 tools/perf/bpf_skel.mak        | 36 ++++++++++-----
 tools/perf/tests/make          | 71 ++++++++++++++++++++++------
 tools/scripts/Makefile.include |  1 +
 tools/scripts/utilities.mak    |  4 +-
 6 files changed, 159 insertions(+), 44 deletions(-)

-- 
2.56.0.307.g5fe7bd680c-goog


^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH v3 1/2] perf build: Support building BPF skeletons with bpf-gcc
  2026-10-22 20:46   ` [PATCH v3 0/2] perf build: Support building BPF skeletons with bpf-gcc Ian Rogers
@ 2026-10-22 20:46     ` Ian Rogers
  2026-10-22 20:46     ` [PATCH v3 2/2] perf test make: Add BPF skeleton build tests for clang and bpf-gcc Ian Rogers
  1 sibling, 0 replies; 9+ messages in thread
From: Ian Rogers @ 2026-10-22 20:46 UTC (permalink / raw)
  To: irogers, acme, cupertino.miranda, jose.marchesi, namhyung
  Cc: adrian.hunter, andrii, eddyz87, james.clark, jolsa, linux-kernel,
	linux-perf-users, mingo, peterz, yonghong.song

Support building perf BPF skeletons with bpf-gcc (>= 14.0.0) in addition
to clang (>= 12.0.1), similar to tools/testing/selftests/bpf/Makefile.

When building perf with GCC (CC_NO_CLANG=1), prefer bpf-gcc and fall
back to clang if bpf-gcc is unavailable or too old. When building with
Clang/LLVM (CC_NO_CLANG=0), prefer clang and fall back to bpf-gcc.
Explicit command-line overrides via BPF_GCC=... or CLANG=... are
respected, and setting BPF_GCC= or CLANG= to empty disables that
compiler.

In bpf_skel.mak, pass the bpf-gcc flags (-mcpu=v3, -fno-ident,
-DBPF_NO_PRESERVE_ACCESS_INDEX, -Wno-attributes,
-D__TARGET_ARCH_$(SRCARCH), and target endianness) and query system
include paths from $(CC).

Also update version-ge3 and version-lt3 in tools/scripts/utilities.mak
to split the two version arguments separately in awk so empty or
fewer-than-3-component version strings do not shift fields across
arguments.

Assisted-by: Antigravity:gemini-3.1-pro
Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/Makefile.config     | 83 +++++++++++++++++++++++++++-------
 tools/perf/Makefile.perf       |  8 +++-
 tools/perf/bpf_skel.mak        | 36 ++++++++++-----
 tools/scripts/Makefile.include |  1 +
 tools/scripts/utilities.mak    |  4 +-
 5 files changed, 101 insertions(+), 31 deletions(-)

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index cafc7be79643..ca045f7ff01d 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -662,27 +662,78 @@ ifeq ($(BUILD_BPF_SKEL),1)
   else ifeq ($(filter -DHAVE_LIBOPENSSL_SUPPORT, $(CFLAGS)),)
     $(warning Warning: Disabled BPF skeletons as libopenssl is required)
     BUILD_BPF_SKEL := 0
-  else ifeq ($(call get-executable,$(CLANG)),)
-    $(warning Warning: Disabled BPF skeletons as clang ($(CLANG)) is missing)
-    BUILD_BPF_SKEL := 0
-  else
-    CLANG_VERSION := $(shell $(CLANG) --version | head -1 | sed 's/.*clang version \([[:digit:]]\+.[[:digit:]]\+.[[:digit:]]\+\).*/\1/g')
-    ifeq ($(call version-lt3,$(CLANG_VERSION),12.0.1),1)
-      $(warning Warning: Disabled BPF skeletons as reliable BTF generation needs at least $(CLANG) version 12.0.1)
-      BUILD_BPF_SKEL := 0
-    endif
   endif
   ifeq ($(BUILD_BPF_SKEL),1)
-    $(call feature_check,clang-bpf-co-re)
-    ifeq ($(feature-clang-bpf-co-re), 0)
-      $(warning Warning: Disabled BPF skeletons as clang is too old)
+    # Prefer bpf-gcc when building with gcc (CC_NO_CLANG=1) and clang when
+    # building with clang, unless CLANG or BPF_GCC was explicitly specified on
+    # the command line. Fall back to whichever compiler is available.
+    prefer_bpf_gcc := $(CC_NO_CLANG)
+    ifeq ($(origin BPF_GCC),command line)
+      ifneq ($(BPF_GCC),)
+        prefer_bpf_gcc := 1
+      endif
+    else ifeq ($(origin CLANG),command line)
+      ifneq ($(CLANG),)
+        prefer_bpf_gcc := 0
+      endif
+    endif
+
+    have_bpf_gcc := 0
+    have_clang_bpf := 0
+
+    define check_bpf_gcc
+      ifneq ($$(call get-executable,$$(BPF_GCC)),)
+        BPF_GCC_VERSION := $$(shell $$(BPF_GCC) -dumpfullversion 2>/dev/null)
+        ifneq ($$(BPF_GCC_VERSION),)
+          ifneq ($$(call version-lt3,$$(BPF_GCC_VERSION),14.0.0),1)
+            have_bpf_gcc := 1
+          endif
+        endif
+      endif
+    endef
+
+    ifeq ($(prefer_bpf_gcc),1)
+      $(eval $(check_bpf_gcc))
+    endif
+
+    ifeq ($(have_bpf_gcc),0)
+      ifneq ($(call get-executable,$(CLANG)),)
+        CLANG_VERSION := $(shell $(CLANG) --version | head -1 | sed 's/.*clang version \([[:digit:]]\+.[[:digit:]]\+.[[:digit:]]\+\).*/\1/g')
+        ifneq ($(call version-lt3,$(CLANG_VERSION),12.0.1),1)
+          $(call feature_check,clang-bpf-co-re)
+          ifneq ($(feature-clang-bpf-co-re), 0)
+            have_clang_bpf := 1
+          endif
+        endif
+      endif
+    endif
+
+    ifeq ($(prefer_bpf_gcc)$(have_clang_bpf),00)
+      $(eval $(check_bpf_gcc))
+    endif
+
+    ifeq ($(have_bpf_gcc),1)
+      $(call detected,CONFIG_PERF_BPF_SKEL_BPF_GCC)
+      $(call detected,CONFIG_PERF_BPF_SKEL)
+      CFLAGS += -DHAVE_BPF_SKEL
+    else ifeq ($(have_clang_bpf),1)
+      $(call detected,CONFIG_PERF_BPF_SKEL)
+      CFLAGS += -DHAVE_BPF_SKEL
+    else
+      ifeq ($(call get-executable,$(CLANG))$(call get-executable,$(BPF_GCC)),)
+        $(warning Warning: Disabled BPF skeletons as clang ($(CLANG)) and bpf-gcc ($(BPF_GCC)) are missing)
+      else ifneq ($(call get-executable,$(CLANG)),)
+        ifeq ($(call version-lt3,$(CLANG_VERSION),12.0.1),1)
+          $(warning Warning: Disabled BPF skeletons as reliable BTF generation needs at least $(CLANG) version 12.0.1)
+        else
+          $(warning Warning: Disabled BPF skeletons as clang is too old)
+        endif
+      else
+        $(warning Warning: Disabled BPF skeletons as bpf-gcc ($(BPF_GCC)) needs at least version 14.0.0)
+      endif
       BUILD_BPF_SKEL := 0
     endif
   endif
-  ifeq ($(BUILD_BPF_SKEL),1)
-    $(call detected,CONFIG_PERF_BPF_SKEL)
-    CFLAGS += -DHAVE_BPF_SKEL
-  endif
 endif
 
 ifndef GEN_VMLINUX_H
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 2d9379fea267..4061a79cae54 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -37,6 +37,9 @@ include ../scripts/utilities.mak
 # Define EXTRA_BPF_FLAGS="--sysroot=<path>" or other custom include paths for
 # cross-compiling BPF skeletons
 #
+# Define BPF_GCC to point to the bpf-gcc binary if the default `bpf-gcc' is not
+# correct, or set BPF_GCC= to disable using bpf-gcc for BPF skeletons.
+#
 # Define EXCLUDE_EXTLIBS=-lmylib to exclude libmylib from the auto-generated
 # EXTLIBS.
 #
@@ -208,6 +211,7 @@ FIND    = find
 INSTALL = install
 FLEX    ?= flex
 BISON   ?= bison
+BPF_GCC ?= bpf-gcc
 AWK     = awk
 
 # include Makefile.config by default and rule out
@@ -321,8 +325,8 @@ ifneq ($(force_fixdep),1)
   endif
 endif
 
-export srctree OUTPUT RM CC CXX RUSTC CLANG LD AR CFLAGS CXXFLAGS RUST_FLAGS V BISON FLEX AWK LIBBPF READELF
-export HOSTCC HOSTLD HOSTAR HOSTCFLAGS SHELLCHECK MYPY PYLINT CONFIG_PERF_BPF_SKEL
+export srctree OUTPUT RM CC CXX RUSTC CLANG BPF_GCC LD AR CFLAGS CXXFLAGS RUST_FLAGS V BISON FLEX AWK LIBBPF READELF
+export HOSTCC HOSTLD HOSTAR HOSTCFLAGS SHELLCHECK MYPY PYLINT CONFIG_PERF_BPF_SKEL CONFIG_PERF_BPF_SKEL_BPF_GCC
 
 include $(srctree)/tools/build/Makefile.include
 
diff --git a/tools/perf/bpf_skel.mak b/tools/perf/bpf_skel.mak
index f2559de39f96..7b7edf506509 100644
--- a/tools/perf/bpf_skel.mak
+++ b/tools/perf/bpf_skel.mak
@@ -22,21 +22,35 @@ bpf-skel-prepare: $(BPFTOOL) $(VMLINUX_H)
 define get_sys_includes
 $(shell $(1) $(2) -v -E - </dev/null 2>&1 \
        | sed -n '/<...> search starts here:/,/End of search list./{ s| \(/.*\)|-idirafter \1|p }') \
-$(shell $(1) $(2) -dM -E - </dev/null | grep '__riscv_xlen ' | awk '{printf("-D__riscv_xlen=%d -D__BITS_PER_LONG=%d", $$3, $$3)}')
+$(shell $(1) $(2) -dM -E - </dev/null | grep '__riscv_xlen ' | awk '{printf("-D__riscv_xlen=%d -D__BITS_PER_LONG=%d", $$3, $$3)}') \
+$(shell $(1) $(2) -dM -E - </dev/null | grep '__loongarch_grlen ' | awk '{printf("-D__BITS_PER_LONG=%d", $$3)}') \
+$(shell $(1) $(2) -dM -E - </dev/null | grep -E 'MIPS(EL|EB)|_MIPS_SZ(PTR|LONG) |_MIPS_SIM |_ABI(O32|N32|64) ' | awk '{printf("-D%s=%s ", $$2, $$3)}')
 endef
 
-ifneq ($(CROSS_COMPILE),)
-CLANG_TARGET_ARCH = --target=$(notdir $(CROSS_COMPILE:%-=%))
+ifeq ($(CONFIG_PERF_BPF_SKEL_BPF_GCC),y)
+  BPF_CC := $(BPF_GCC)
+  QUIET_BPF_CC = $(QUIET_BPF_GCC)
+  IS_LITTLE_ENDIAN := $(shell $(CC) -dM -E - </dev/null | \
+			grep 'define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__')
+  BPF_OPTIONS = -Wall -mcpu=v3 -fno-ident -DBPF_NO_PRESERVE_ACCESS_INDEX -Wno-attributes \
+		-D__TARGET_ARCH_$(SRCARCH) $(if $(IS_LITTLE_ENDIAN),-mlittle-endian,-mbig-endian)
+  BPF_SYS_INCLUDES = $(call get_sys_includes,$(CC),)
+else
+  BPF_CC := $(CLANG)
+  QUIET_BPF_CC = $(QUIET_CLANG)
+  ifneq ($(CROSS_COMPILE),)
+    CLANG_TARGET_ARCH = --target=$(notdir $(CROSS_COMPILE:%-=%))
+  endif
+  BPF_OPTIONS = -Wall -mcpu=v3 -fno-stack-protector --target=bpf -Wno-microsoft-anon-tag
+  BPF_SYS_INCLUDES = $(call get_sys_includes,$(CLANG),$(CLANG_TARGET_ARCH))
 endif
 
-CLANG_OPTIONS = -Wall -mcpu=v3
-CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG),$(CLANG_TARGET_ARCH))
 LIBBPF_INCLUDE := $(abspath $(or $(OUTPUT),.))/libbpf/include
-BPF_INCLUDE := -I$(SKEL_TMP_OUT)/.. -I$(SKEL_TOOL_OUT) -I$(LIBBPF_INCLUDE) $(CLANG_SYS_INCLUDES)
+BPF_INCLUDE := -I$(SKEL_TMP_OUT)/.. -I$(SKEL_TOOL_OUT) -I$(LIBBPF_INCLUDE) $(BPF_SYS_INCLUDES)
 TOOLS_UAPI_INCLUDE := -I$(srctree)/tools/include/uapi
 
 ifneq ($(WERROR),0)
-  CLANG_OPTIONS += -Werror
+  BPF_OPTIONS += -Werror
 endif
 
 $(BPFTOOL):
@@ -83,11 +97,11 @@ endif
 # Consolidated Pattern rule for $(dir)/bpf_skel/
 $(SKEL_TMP_OUT)/%.bpf.o: $(srctree)/tools/perf/$(dir)/bpf_skel/%.bpf.c $(LIBBPF) $(VMLINUX_H) $(OUTPUT)PERF-VERSION-FILE util/bpf_skel/perf_version.h
 	$(call rule_mkdir)
-	$(QUIET_CLANG)
-	$(Q)$(CLANG) -g -O2 -fno-stack-protector --target=bpf \
-	  $(CLANG_OPTIONS) $(EXTRA_BPF_FLAGS) $(BPF_INCLUDE) $(TOOLS_UAPI_INCLUDE) \
+	$(QUIET_BPF_CC)
+	$(Q)$(BPF_CC) -g -O2 \
+	  $(BPF_OPTIONS) $(EXTRA_BPF_FLAGS) $(BPF_INCLUDE) $(TOOLS_UAPI_INCLUDE) \
 	  -include $(OUTPUT)PERF-VERSION-FILE -include util/bpf_skel/perf_version.h \
-	  -fms-extensions -Wno-microsoft-anon-tag \
+	  -fms-extensions \
 	  -c $< -o $@
 
 $(SKEL_OUT)/%.skel.h: $(SKEL_TMP_OUT)/%.bpf.o $(BPFTOOL)
diff --git a/tools/scripts/Makefile.include b/tools/scripts/Makefile.include
index 378387f62960..9967210b2928 100644
--- a/tools/scripts/Makefile.include
+++ b/tools/scripts/Makefile.include
@@ -217,6 +217,7 @@ ifneq ($(silent),1)
 	QUIET_CC       = @echo '  CC      '$@;
 	QUIET_CC_FPIC  = @echo '  CC FPIC '$@;
 	QUIET_CLANG    = @echo '  CLANG   '$@;
+	QUIET_BPF_GCC  = @echo '  BPF_GCC '$@;
 	QUIET_AR       = @echo '  AR      '$@;
 	QUIET_LINK     = @echo '  LINK    '$@;
 	QUIET_MKDIR    = @echo '  MKDIR   '$@;
diff --git a/tools/scripts/utilities.mak b/tools/scripts/utilities.mak
index d69d0345cc23..746aaf6e5145 100644
--- a/tools/scripts/utilities.mak
+++ b/tools/scripts/utilities.mak
@@ -186,7 +186,7 @@ _gea_err  = $(if $(1),$(error Please set '$(1)' appropriately))
 # was to check the flex version to see if we can use compiler warnings as
 # errors for one of the cases flex generates code C compilers complains about.
 
-version-ge3 = $(shell echo "$(1).$(2)" | awk -F'.' '{ printf("%d\n", (10000000 * $$1 + 10000 * $$2 + $$3) >= (10000000 * $$4 + 10000 * $$5 + $$6)) }')
+version-ge3 = $(shell awk -v v1="$(1)" -v v2="$(2)" 'BEGIN { split(v1, a, "."); split(v2, b, "."); printf("%d\n", (10000000 * a[1] + 10000 * a[2] + a[3]) >= (10000000 * b[1] + 10000 * b[2] + b[3])) }')
 
 # version-lt3
 #
@@ -196,4 +196,4 @@ version-ge3 = $(shell echo "$(1).$(2)" | awk -F'.' '{ printf("%d\n", (10000000 *
 # check the flex version to see if we can use compiler warnings as errors for
 # one of the cases flex generates code C compilers complains about.
 
-version-lt3 = $(shell echo "$(1).$(2)" | awk -F'.' '{ printf("%d\n", (10000000 * $$1 + 10000 * $$2 + $$3) < (10000000 * $$4 + 10000 * $$5 + $$6)) }')
+version-lt3 = $(shell awk -v v1="$(1)" -v v2="$(2)" 'BEGIN { split(v1, a, "."); split(v2, b, "."); printf("%d\n", (10000000 * a[1] + 10000 * a[2] + a[3]) < (10000000 * b[1] + 10000 * b[2] + b[3])) }')
-- 
2.56.0.307.g5fe7bd680c-goog


^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH v3 2/2] perf test make: Add BPF skeleton build tests for clang and bpf-gcc
  2026-10-22 20:46   ` [PATCH v3 0/2] perf build: Support building BPF skeletons with bpf-gcc Ian Rogers
  2026-10-22 20:46     ` [PATCH v3 1/2] " Ian Rogers
@ 2026-10-22 20:46     ` Ian Rogers
  1 sibling, 0 replies; 9+ messages in thread
From: Ian Rogers @ 2026-10-22 20:46 UTC (permalink / raw)
  To: irogers, acme, cupertino.miranda, jose.marchesi, namhyung
  Cc: adrian.hunter, andrii, eddyz87, james.clark, jolsa, linux-kernel,
	linux-perf-users, mingo, peterz, yonghong.song

Add make_bpf_skel_clang (CLANG=clang BPF_GCC=) and make_bpf_skel_bpf_gcc
(BPF_GCC=bpf-gcc CLANG=) targets to tools/perf/tests/make when the
corresponding compiler and BPF skeleton dependencies are available on
the host.

Include tools/build/Makefile.feature and tools/scripts/utilities.mak in
tools/perf/tests/make to reuse the existing feature checks
(libelf, zlib, bpf, libopenssl, clang-bpf-co-re, libbfd-threadsafe, and
llvm-perf) instead of open-coding compiler invocations.

Verify with 'perf check -q feature bpf_skeletons' that BPF skeleton
support is enabled for both targets and disabled (exit code 1) for
make_no_bpf_skel.

Assisted-by: Antigravity:gemini-3.1-pro
Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/tests/make | 71 +++++++++++++++++++++++++++++++++++--------
 1 file changed, 58 insertions(+), 13 deletions(-)

diff --git a/tools/perf/tests/make b/tools/perf/tests/make
index 7524de522802..a40390ed47f1 100644
--- a/tools/perf/tests/make
+++ b/tools/perf/tests/make
@@ -54,6 +54,7 @@ srctree := $(patsubst %/,%,$(dir $(srctree)))
 endif
 
 include $(srctree)/tools/scripts/Makefile.arch
+include $(srctree)/tools/scripts/utilities.mak
 
 # FIXME looks like x86 is the only arch running tests ;-)
 # we need some IS_(32/64) flag to make this generic
@@ -65,6 +66,7 @@ endif
 
 has = $(shell which $1 2>/dev/null)
 python_perf_so := $(shell $(MAKE) python_perf_target|grep "Target is:"|awk '{print $$3}')
+BPF_GCC ?= bpf-gcc
 
 # standard single make variable specified
 make_clean_all      := clean all
@@ -78,6 +80,8 @@ make_extra_tests    := EXTRA_TESTS=1
 make_no_jevents     := NO_JEVENTS=1
 make_jevents_all    := JEVENTS_ARCH=all
 make_no_bpf_skel    := BUILD_BPF_SKEL=0
+make_bpf_skel_clang := CLANG=$(CLANG) BPF_GCC=
+make_bpf_skel_bpf_gcc := BPF_GCC=$(BPF_GCC) CLANG=
 make_gen_vmlinux_h  := GEN_VMLINUX_H=1
 make_no_python_module := NO_PYTHON_MODULE=1
 make_no_scripts     := NO_PYTHON_MODULE=1
@@ -127,21 +131,49 @@ make_minimal        += NO_LIBBPF=1
 make_minimal        += NO_SDT=1 NO_JVMTI=1 NO_LIBZSTD=1
 make_minimal        += NO_CAPSTONE=1
 
+override FEATURE_OUTPUT := $(shell mktemp -d)
+ifeq ($(FEATURE_OUTPUT),)
+$(error Failed to create temporary directory for feature checks)
+endif
+saved_OUTPUT := $(OUTPUT)
+override OUTPUT := $(FEATURE_OUTPUT)/
+FEATURE_DISPLAY_DEFERRED := 1
+FEATURE_TESTS := libelf zlib bpf libopenssl
+FEATURE_CHECK_CFLAGS-bpf = -I. -I$(srctree)/tools/include -I$(srctree)/tools/arch/$(SRCARCH)/include/uapi -I$(srctree)/tools/include/uapi
+include $(srctree)/tools/build/Makefile.feature
+
 # binutils 2_42 and newer have bfd_thread_init()
-new_libbfd := $(shell echo '#include <bfd.h>' | $(CC) -E -x c - | grep bfd_thread_init)
+$(call feature_check,libbfd-threadsafe)
 
 # Whether libLLVM can be built, which needs the llvm-devel/llvm-dev headers and
-# libraries of version 13 or newer, not just llvm-config. This mirrors the
-# llvm-perf feature test in tools/build/feature/test-llvm-perf.cpp so that
-# libLLVM is only asserted below when the default compiler can really build it.
+# libraries of version 13 or newer, not just llvm-config.
 ifneq ($(call has,$(LLVM_CONFIG)),)
-have_libllvm := $(shell printf '#include <llvm/Support/ManagedStatic.h>\n#include <llvm/Support/raw_ostream.h>\n#if LLVM_VERSION_MAJOR < 13\n#error "llvm-devel/llvm-dev version 13 or greater is required"\n#endif\nint main(){llvm::errs()<<"";llvm::llvm_shutdown();return 0;}\n' | \
-	$(CXX) -x c++ -std=gnu++17 -I$(shell $(LLVM_CONFIG) --includedir 2>/dev/null) - -o /dev/null \
-		-L$(shell $(LLVM_CONFIG) --libdir 2>/dev/null) \
-		$(shell $(LLVM_CONFIG) --libs Core BPF 2>/dev/null) \
-		$(shell $(LLVM_CONFIG) --system-libs 2>/dev/null) >/dev/null 2>&1 && echo y)
+  $(call feature_check,llvm-perf)
+endif
+
+ifeq ($(feature-libelf)$(feature-zlib)$(feature-bpf)$(feature-libopenssl),1111)
+  ifneq ($(call get-executable,$(CLANG)),)
+    CLANG_VERSION := $(shell $(CLANG) --version | head -1 | sed 's/.*clang version \([[:digit:]]\+.[[:digit:]]\+.[[:digit:]]\+\).*/\1/g')
+    ifneq ($(call version-lt3,$(CLANG_VERSION),12.0.1),1)
+      $(call feature_check,clang-bpf-co-re)
+      ifeq ($(feature-clang-bpf-co-re),1)
+        have_clang_bpf := 1
+      endif
+    endif
+  endif
+  ifneq ($(call get-executable,$(BPF_GCC)),)
+    BPF_GCC_VERSION := $(shell $(BPF_GCC) -dumpfullversion 2>/dev/null)
+    ifneq ($(BPF_GCC_VERSION),)
+      ifneq ($(call version-lt3,$(BPF_GCC_VERSION),14.0.0),1)
+        have_bpf_gcc := 1
+      endif
+    endif
+  endif
 endif
 
+$(shell rm -rf -- "$(FEATURE_OUTPUT)")
+override OUTPUT := $(saved_OUTPUT)
+
 # $(run) contains all available tests
 run := make_pure
 # Targets 'clean all' can be run together only through top level
@@ -155,7 +187,7 @@ MAKE_F := $(MAKE) -f $(MK)
 endif
 run += make_python_perf_so
 run += make_debug
-ifneq ($(new_libbfd),)
+ifeq ($(feature-libbfd-threadsafe),1)
 run += make_nondistro
 # Demangling with libbfd is only built when the C++ ABI's __cxa_demangle
 # isn't available, so it needs a build of its own to be compiled at all.
@@ -165,7 +197,7 @@ endif
 # a C compiler and a C++ compiler that don't match.
 ifneq ($(call has,clang),)
 run += make_clang
-ifneq ($(new_libbfd),)
+ifeq ($(feature-libbfd-threadsafe),1)
 run += make_clang_nondistro
 endif
 endif
@@ -173,6 +205,12 @@ run += make_extra_tests
 run += make_no_jevents
 run += make_jevents_all
 run += make_no_bpf_skel
+ifeq ($(have_clang_bpf),1)
+run += make_bpf_skel_clang
+endif
+ifeq ($(have_bpf_gcc),1)
+run += make_bpf_skel_bpf_gcc
+endif
 run += make_gen_vmlinux_h
 run += make_no_python_module
 run += make_no_scripts
@@ -306,13 +344,20 @@ test_make_libbpf_dynamic_O := ldd $$TMP_O/perf | grep -q libbpf
 # doesn't fail the build, it just quietly turns off everything that needs a
 # C++ compiler. Check a feature that does, otherwise these tests would pass
 # while producing a perf with less in it than the default build has.
-ifneq ($(have_libllvm),)
+ifeq ($(feature-llvm-perf),1)
 test_make_clang               := test -x $(PERF_O)/perf && $(PERF_O)/perf check -q feature libLLVM
 test_make_clang_O             := test -x $$TMP_O/perf && $$TMP_O/perf check -q feature libLLVM
 test_make_clang_nondistro     := $(test_make_clang)
 test_make_clang_nondistro_O   := $(test_make_clang_O)
 endif
 
+test_make_no_bpf_skel         := test -x $(PERF_O)/perf && ($(PERF_O)/perf check -q feature bpf_skeletons; test $$? -eq 1)
+test_make_no_bpf_skel_O       := test -x $$TMP_O/perf && ($$TMP_O/perf check -q feature bpf_skeletons; test $$? -eq 1)
+test_make_bpf_skel_clang      := test -x $(PERF_O)/perf && $(PERF_O)/perf check -q feature bpf_skeletons
+test_make_bpf_skel_clang_O    := test -x $$TMP_O/perf && $$TMP_O/perf check -q feature bpf_skeletons
+test_make_bpf_skel_bpf_gcc    := test -x $(PERF_O)/perf && $(PERF_O)/perf check -q feature bpf_skeletons
+test_make_bpf_skel_bpf_gcc_O  := test -x $$TMP_O/perf && $$TMP_O/perf check -q feature bpf_skeletons
+
 test_make_python_perf_so_O    := test -f $$TMP_O/python/perf.so
 test_make_perf_o_O            := test -f $$TMP_O/perf.o
 test_make_util_map_o_O        := test -f $$TMP_O/util/map.o
@@ -445,7 +490,7 @@ $(FEATURES_DUMP_FILE_STATIC):
 # The clang tests exist to run feature detection with a compiler other than
 # the default one, so they have to do their own and are left out of both the
 # dependency and the 'FEATURES_DUMP=' append below.
-no_features_dump := make_clang make_clang_nondistro
+no_features_dump := make_clang make_clang_nondistro make_bpf_skel_clang make_bpf_skel_bpf_gcc
 no_features_dump += $(addsuffix _O,$(no_features_dump))
 
 # Add feature dump dependency for run/run_O targets
-- 
2.56.0.307.g5fe7bd680c-goog


^ permalink raw reply	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2026-10-22 20:46 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2026-10-13 22:16 [PATCH v1 0/2] perf build: Support building BPF skeletons with bpf-gcc Ian Rogers
2026-10-13 22:16 ` [PATCH v1 1/2] " Ian Rogers
2026-10-13 22:16 ` [PATCH v1 2/2] perf test make: Add BPF skeleton build tests for clang and bpf-gcc Ian Rogers
2026-10-13 23:14 ` [PATCH v2 0/2] perf build: Support building BPF skeletons with bpf-gcc Ian Rogers
2026-10-13 23:14   ` [PATCH v2 1/2] " Ian Rogers
2026-10-13 23:14   ` [PATCH v2 2/2] perf test make: Add BPF skeleton build tests for clang and bpf-gcc Ian Rogers
2026-10-22 20:46   ` [PATCH v3 0/2] perf build: Support building BPF skeletons with bpf-gcc Ian Rogers
2026-10-22 20:46     ` [PATCH v3 1/2] " Ian Rogers
2026-10-22 20:46     ` [PATCH v3 2/2] perf test make: Add BPF skeleton build tests for clang and bpf-gcc Ian Rogers

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