linux.git/tools/build, branch v6.12.80

tools build: Align warning options with perf

2025-10-19T14:33:40+00:00

[ Upstream commit 53d067feb8c4f16d1f24ce3f4df4450bb18c555f ]

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 
Reviewed-by: Ian Rogers 
Link: https://lore.kernel.org/r/20251006-perf_build_android_ndk-v3-1-4305590795b2@arm.com
Cc: Palmer Dabbelt 
Cc: Albert Ou 
Cc: Alexandre Ghiti 
Cc: Nick Desaulniers 
Cc: Justin Stitt 
Cc: Bill Wendling 
Cc: Adrian Hunter 
Cc: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Nathan Chancellor 
Cc: James Clark 
Cc: linux-riscv@lists.infradead.org
Cc: llvm@lists.linux.dev
Cc: Paul Walmsley 
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

tools/build: Don't pass test log files to linker

2025-05-29T09:02:08+00:00

[ Upstream commit 935e7cb5bb80106ff4f2fe39640f430134ef8cd8 ]

Separate test log files from object files. Depend on test log output
but don't pass to the linker.

Reviewed-by: James Clark 
Signed-off-by: Ian Rogers 
Link: https://lore.kernel.org/r/20250311213628.569562-2-irogers@google.com
Signed-off-by: Namhyung Kim 
Signed-off-by: Sasha Levin

perf build: Fix build feature-dwarf_getlocations fail for old libdw

2024-10-02T21:21:49+00:00

For libdw versions below 0.177, need to link libdl.a in addition to
libbebl.a during static compilation, otherwise
feature-dwarf_getlocations compilation will fail.

Before:

  $ make LDFLAGS=-static
    BUILD:   Doing 'make -j20' parallel build
  
  Makefile.config:483: Old libdw.h, finding variables at given 'perf probe' point will not work, install elfutils-devel/libdw-dev >= 0.157
  

  $ cat ../build/feature/test-dwarf_getlocations.make.output
  /usr/bin/ld: /usr/lib/gcc/x86_64-linux-gnu/9/../../../x86_64-linux-gnu/libebl.a(eblclosebackend.o): in function `ebl_closebackend':
  (.text+0x20): undefined reference to `dlclose'
  collect2: error: ld returned 1 exit status

After:

  $ make LDFLAGS=-static
  
    Auto-detecting system features:
  ...                                   dwarf: [ on  ]
  

    $ ./perf probe
   Usage: perf probe [] 'PROBEDEF' ['PROBEDEF' ...]
      or: perf probe [] --add 'PROBEDEF' [--add 'PROBEDEF' ...]
      or: perf probe [] --del '[GROUP:]EVENT' ...
      or: perf probe --list [GROUP:]EVENT ...
  

Fixes: 536661da6ea18fe6 ("perf: build: Only link libebl.a for old libdw")
Reviewed-by: Leo Yan 
Signed-off-by: Yang Jihong 
Acked-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20240919013513.118527-3-yangjihong@bytedance.com
Signed-off-by: Arnaldo Carvalho de Melo

perf build: Fix static compilation error when libdw is not installed

2024-10-02T21:21:49+00:00

If libdw is not installed in build environment, the output of
'pkg-config --modversion libdw' is empty, causing LIBDW_VERSION_2 to be
empty and the shell test will have the following error:

  /bin/sh: 1: test: -lt: unexpected operator

Before:

  $ pkg-config --modversion libdw
  Package libdw was not found in the pkg-config search path.
  Perhaps you should add the directory containing `libdw.pc'
  to the PKG_CONFIG_PATH environment variable
  No package 'libdw' found
  $ make LDFLAGS=-static -j16
    BUILD:   Doing 'make -j20' parallel build
  
  Package libdw was not found in the pkg-config search path.
  Perhaps you should add the directory containing `libdw.pc'
  to the PKG_CONFIG_PATH environment variable
  No package 'libdw' found
  /bin/sh: 1: test: -lt: unexpected operator

After:

  1. libdw is not installed:

  $ pkg-config --modversion libdw
  Package libdw was not found in the pkg-config search path.
  Perhaps you should add the directory containing `libdw.pc'
  to the PKG_CONFIG_PATH environment variable
  No package 'libdw' found
  $ make LDFLAGS=-static -j16
    BUILD:   Doing 'make -j20' parallel build
  
  Package libdw was not found in the pkg-config search path.
  Perhaps you should add the directory containing `libdw.pc'
  to the PKG_CONFIG_PATH environment variable
  No package 'libdw' found
  Makefile.config:473: No libdw DWARF unwind found, Please install elfutils-devel/libdw-dev >= 0.158 and/or set LIBDW_DIR

  2. libdw version is lower than 0.177

  $ pkg-config --modversion libdw
  0.176
  $ make LDFLAGS=-static -j16
    BUILD:   Doing 'make -j20' parallel build
  

  Auto-detecting system features:
  ...                                   dwarf: [ on  ]
  
    INSTALL libsubcmd_headers
    INSTALL libapi_headers
    INSTALL libperf_headers
    INSTALL libsymbol_headers
    INSTALL libbpf_headers
    LINK    perf

  3. libdw version is higher than 0.177

  $ pkg-config --modversion libdw
  0.186
  $ make LDFLAGS=-static -j16
    BUILD:   Doing 'make -j20' parallel build
  

  Auto-detecting system features:
  ...                                   dwarf: [ on  ]
  
    CC      util/bpf-utils.o
    CC      util/pfm.o
    LD      util/perf-util-in.o
    LD      perf-util-in.o
    AR      libperf-util.a
    LINK    perf

Fixes: 536661da6ea18fe6 ("perf: build: Only link libebl.a for old libdw")
Reviewed-by: Leo Yan 
Signed-off-by: Yang Jihong 
Acked-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20240919013513.118527-2-yangjihong@bytedance.com
Signed-off-by: Arnaldo Carvalho de Melo

perf build: Remove unused feature test target

2024-09-10T20:32:47+00:00

llvm-version was removed in commit 56b11a2126bf ("perf bpf: Remove
support for embedding clang for compiling BPF events (-e foo.c)") but
some parts were left in the Makefile so finish removing them.

Signed-off-by: James Clark 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Bill Wendling 
Cc: Changbin Du 
Cc: Daniel Wagner 
Cc: Guilherme Amadio 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Justin Stitt 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Manu Bretelle 
Cc: Mark Rutland 
Cc: Masami Hiramatsu 
Cc: Namhyung Kim 
Cc: Nathan Chancellor 
Cc: Nick Desaulniers 
Cc: Peter Zijlstra 
Cc: Quentin Monnet 
Cc: Steinar H. Gunderson 
Link: https://lore.kernel.org/r/20240910140405.568791-2-james.clark@linaro.org
[ Removed one leftover, 'llvm-version' from FEATURE_TESTS_EXTRA ]
Signed-off-by: Arnaldo Carvalho de Melo

perf build: Autodetect minimum required llvm-dev version

2024-09-10T20:32:46+00:00

The new LLVM addr2line feature requires a minimum version of 13 to
compile. Add a feature check for the version so that NO_LLVM=1 doesn't
need to be explicitly added. Leave the existing llvm feature check
intact because it's used by tools other than Perf.

This fixes the following compilation error when the llvm-dev version
doesn't match:

  util/llvm-c-helpers.cpp: In function 'char* llvm_name_for_code(dso*, const char*, u64)':
  util/llvm-c-helpers.cpp:178:21: error: 'std::remove_reference_t' {aka 'struct llvm::DILineInfo'} has no member named 'StartAddress'
    178 |   addr, res_or_err->StartAddress ? *res_or_err->StartAddress : 0);

Fixes: c3f8644c21df9b7d ("perf report: Support LLVM for addr2line()")
Signed-off-by: James Clark 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Bill Wendling 
Cc: Changbin Du 
Cc: Guilherme Amadio 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Justin Stitt 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Manu Bretelle 
Cc: Mark Rutland 
Cc: Masami Hiramatsu 
Cc: Namhyung Kim 
Cc: Nathan Chancellor 
Cc: Nick Desaulniers 
Cc: Peter Zijlstra 
Cc: Quentin Monnet 
Cc: Steinar H. Gunderson 
Link: https://lore.kernel.org/r/20240910140405.568791-1-james.clark@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo

perf report: Support LLVM for addr2line()

2024-09-03T13:15:16+00:00

In addition to the existing support for libbfd and calling out to
an external addr2line command, add support for using libllvm directly.

This is both faster than libbfd, and can be enabled in distro builds
(the LLVM license has an explicit provision for GPLv2 compatibility).

Thus, it is set as the primary choice if available.

As an example, running 'perf report' on a medium-size profile with
DWARF-based backtraces took 58 seconds with LLVM, 78 seconds with
libbfd, 153 seconds with external llvm-addr2line, and I got tired and
aborted the test after waiting for 55 minutes with external bfd
addr2line (which is the default for perf as compiled by distributions
today).

Evidently, for this case, the bfd addr2line process needs 18 seconds (on
a 5.2 GHz Zen 3) to load the .debug ELF in question, hits the 1-second
timeout and gets killed during initialization, getting restarted anew
every time. Having an in-process addr2line makes this much more robust.

As future extensions, libllvm can be used in many other places where
we currently use libbfd or other libraries:

 - Symbol enumeration (in particular, for PE binaries).
 - Demangling (including non-Itanium demangling, e.g. Microsoft
   or Rust).
 - Disassembling (perf annotate).

However, these are much less pressing; most people don't profile PE
binaries, and perf has non-bfd paths for ELF. The same with demangling;
the default _cxa_demangle path works fine for most users, and while bfd
objdump can be slow on large binaries, it is possible to use
--objdump=llvm-objdump to get the speed benefits.  (It appears
LLVM-based demangling is very simple, should we want that.)

Tested with LLVM 14, 15, 16, 18 and 19. For some reason, LLVM 12 was not
correctly detected using feature_check, and thus was not tested.

Committer notes:

 Added the name and a __maybe_unused to address:

   1    13.50 almalinux:8                   : FAIL gcc version 8.5.0 20210514 (Red Hat 8.5.0-22) (GCC)
    util/srcline.c: In function 'dso__free_a2l':
    util/srcline.c:184:20: error: parameter name omitted
     void dso__free_a2l(struct dso *)
                        ^~~~~~~~~~~~
    make[3]: *** [/git/perf-6.11.0-rc3/tools/build/Makefile.build:158: util] Error 2

Signed-off-by: Steinar H. Gunderson 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Ian Rogers 
Link: https://lore.kernel.org/r/20240803152008.2818485-1-sesse@google.com
Signed-off-by: Arnaldo Carvalho de Melo

Revert "tools build: Remove leftover libcap tests that prevents fast path feature detection from working"

2024-08-29T14:51:43+00:00

Ian pointed out that the libcap feature test is also used by bpftool, so
we can't remove it just because perf stopped using it, revert the
removal of the feature test.

Since both perf and libcap uses the fast path feature detection
(tools/build/feature/test-all.c), probably the best thing is to keep
libcap-devel when building perf even it not being used there.

This reverts commit 47b3b6435e4bfb61ae8ffc63a11bd3c310f69acf.

Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Namhyung Kim 
Signed-off-by: Arnaldo Carvalho de Melo

tools build: Remove leftover libcap tests that prevents fast path feature detection from working

2024-08-28T22:11:36+00:00

I noticed that the fast path feature detection was failing:

  $ cat /tmp/build/perf-tools-next/feature/test-all.make.output
  /usr/bin/ld: cannot find -lcap: No such file or directory
  collect2: error: ld returned 1 exit status
  $

The patch removing the dependency (Fixes tag below) didn't remove the
detection of libcap, and as the fast path feature detection (test-all.c)
had -lcap in its Makefile link list of libraries to link, it was failing
when libcap-devel is not available, fix it by removing those leftover
files.

Fixes: e25ebda78e230283 ("perf cap: Tidy up and improve capability testing")
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Namhyung Kim 
Link: https://lore.kernel.org/lkml/Zs-gjOGFWtAvIZit@x1
Signed-off-by: Arnaldo Carvalho de Melo

tools build: Provide consistent build options for fixdep

2024-08-15T21:08:17+00:00

The fixdep binary is being compiled and linked in one step. While the
host linker flags are passed to the compiler the host compiler flags are
missed.

That leads to build errors at least on x86_64, arm64 and s390 as result
of the compiler vs linker flags inconsistency. For example, during RPM
package build redhat-hardened-ld script is provided to gcc, while
redhat-hardened-cc1 script is missed.

Provide both KBUILD_HOSTCFLAGS and KBUILD_HOSTLDFLAGS to avoid that.

Fixes: ea974028a049f2ce ("tools build: Avoid circular .fixdep-in.o.cmd issues")
Closes: https://lore.kernel.org/lkml/99ae0d34-ed76-4ca0-a9fd-c337da33c9f9@leemhuis.info/
Reported-by: Thorsten Leemhuis 
Reviewed-by: Brian Norris 
Signed-off-by: Alexander Gordeev 
Tested-by: Thorsten Leemhuis 
Acked-by: Jiri Olsa 
Link: https://lore.kernel.org/r/20240815072046.1002837-1-agordeev@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo