Commit 05c78468 authored Jun 13, 2019 by Arnaldo Carvalho de Melo

tools build: Check if gettid() is available before providing helper



Laura reported that the perf build failed in fedora when we got a glibc
that provides gettid(), which I reproduced using fedora rawhide with the
glibc-devel-2.29.9000-26.fc31.x86_64 package.

Add a feature check to avoid providing a gettid() helper in such
systems.

On a fedora rawhide system with this patch applied we now get:

  [root@7a5f55352234 perf]# grep gettid /tmp/build/perf/FEATURE-DUMP
  feature-gettid=1
  [root@7a5f55352234 perf]# cat /tmp/build/perf/feature/test-gettid.make.output
  [root@7a5f55352234 perf]# ldd /tmp/build/perf/feature/test-gettid.bin
          linux-vdso.so.1 (0x00007ffc6b1f6000)
          libc.so.6 => /lib64/libc.so.6 (0x00007f04e0a74000)
          /lib64/ld-linux-x86-64.so.2 (0x00007f04e0c47000)
  [root@7a5f55352234 perf]# nm /tmp/build/perf/feature/test-gettid.bin | grep -w gettid
                   U gettid@@GLIBC_2.30
  [root@7a5f55352234 perf]#

While on a fedora:29 system:

  [acme@quaco perf]$ grep gettid /tmp/build/perf/FEATURE-DUMP
  feature-gettid=0
  [acme@quaco perf]$ cat /tmp/build/perf/feature/test-gettid.make.output
  test-gettid.c: In function ‘main’:
  test-gettid.c:8:9: error: implicit declaration of function ‘gettid’; did you mean ‘getgid’? [-Werror=implicit-function-declaration]
    return gettid();
           ^~~~~~
           getgid
  cc1: all warnings being treated as errors
  [acme@quaco perf]$

Reported-by: Laura Abbott <labbott@redhat.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lkml.kernel.org/n/tip-yfy3ch53agmklwu9o7rlgf9c@git.kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

parent dab0f4eb

tools/build/Makefile.feature

+1 −0

Original line number	Diff line number	Diff line
		@@ -36,6 +36,7 @@ FEATURE_TESTS_BASIC := \
		fortify-source \
		sync-compare-and-swap \
		get_current_dir_name \
		gettid \
		glibc \
		gtk2 \
		gtk2-infobar \

tools/build/feature/Makefile

+4 −0

Original line number	Diff line number	Diff line
		@@ -54,6 +54,7 @@ FILES= \
		test-get_cpuid.bin \
		test-sdt.bin \
		test-cxx.bin \
		test-gettid.bin \
		test-jvmti.bin \
		test-jvmti-cmlr.bin \
		test-sched_getcpu.bin \
		@@ -267,6 +268,9 @@ $(OUTPUT)test-sdt.bin:
		$(OUTPUT)test-cxx.bin:
		$(BUILDXX) -std=gnu++11

		$(OUTPUT)test-gettid.bin:
		$(BUILD)

		$(OUTPUT)test-jvmti.bin:
		$(BUILD)

tools/build/feature/test-all.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -38,6 +38,10 @@
		# include "test-get_current_dir_name.c"
		#undef main

		#define main main_test_gettid
		# include "test-gettid.c"
		#undef main

		#define main main_test_glibc
		# include "test-glibc.c"
		#undef main
		@@ -195,6 +199,7 @@ int main(int argc, char *argv[])
		main_test_libelf();
		main_test_libelf_mmap();
		main_test_get_current_dir_name();
		main_test_gettid();
		main_test_glibc();
		main_test_dwarf();
		main_test_dwarf_getlocations();

tools/build/feature/test-gettid.c

0 → 100644

+11 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0
		// Copyright (C) 2019, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
		#define _GNU_SOURCE
		#include <unistd.h>

		int main(void)
		{
		return gettid();
		}

		#undef _GNU_SOURCE

tools/perf/Makefile.config

+4 −0

Original line number	Diff line number	Diff line
		@@ -332,6 +332,10 @@ ifeq ($(feature-get_current_dir_name), 1)
		CFLAGS += -DHAVE_GET_CURRENT_DIR_NAME
		endif

		ifeq ($(feature-gettid), 1)
		CFLAGS += -DHAVE_GETTID
		endif

		ifdef NO_LIBELF
		NO_DWARF := 1
		NO_DEMANGLE := 1

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