diff --git a/tools/testing/selftests/powerpc/benchmarks/context_switch.c b/tools/testing/selftests/powerpc/benchmarks/context_switch.c
index 96554e2794d1..0b245572bd45 100644
--- a/tools/testing/selftests/powerpc/benchmarks/context_switch.c
+++ b/tools/testing/selftests/powerpc/benchmarks/context_switch.c
@@ -4,8 +4,6 @@
  *
  * Copyright (C) 2015 Anton Blanchard <anton@au.ibm.com>, IBM
  */
-
-#define _GNU_SOURCE
 #include <errno.h>
 #include <sched.h>
 #include <string.h>
diff --git a/tools/testing/selftests/powerpc/benchmarks/exec_target.c b/tools/testing/selftests/powerpc/benchmarks/exec_target.c
index c14b0fc1edde..8646540037d8 100644
--- a/tools/testing/selftests/powerpc/benchmarks/exec_target.c
+++ b/tools/testing/selftests/powerpc/benchmarks/exec_target.c
@@ -5,8 +5,6 @@
  *
  * Copyright 2018, Anton Blanchard, IBM Corp.
  */
-
-#define _GNU_SOURCE
 #include <unistd.h>
 #include <sys/syscall.h>
 
diff --git a/tools/testing/selftests/powerpc/benchmarks/fork.c b/tools/testing/selftests/powerpc/benchmarks/fork.c
index d312e638cb37..327231646a2a 100644
--- a/tools/testing/selftests/powerpc/benchmarks/fork.c
+++ b/tools/testing/selftests/powerpc/benchmarks/fork.c
@@ -5,8 +5,6 @@
  *
  * Copyright 2018, Anton Blanchard, IBM Corp.
  */
-
-#define _GNU_SOURCE
 #include <assert.h>
 #include <errno.h>
 #include <getopt.h>
diff --git a/tools/testing/selftests/powerpc/benchmarks/futex_bench.c b/tools/testing/selftests/powerpc/benchmarks/futex_bench.c
index 017057090490..0483a13c88f9 100644
--- a/tools/testing/selftests/powerpc/benchmarks/futex_bench.c
+++ b/tools/testing/selftests/powerpc/benchmarks/futex_bench.c
@@ -2,9 +2,6 @@
 /*
  * Copyright 2016, Anton Blanchard, Michael Ellerman, IBM Corp.
  */
-
-#define _GNU_SOURCE
-
 #include <stdio.h>
 #include <sys/syscall.h>
 #include <time.h>
diff --git a/tools/testing/selftests/powerpc/dexcr/hashchk_test.c b/tools/testing/selftests/powerpc/dexcr/hashchk_test.c
index 645224bdc142..2499ab7fe563 100644
--- a/tools/testing/selftests/powerpc/dexcr/hashchk_test.c
+++ b/tools/testing/selftests/powerpc/dexcr/hashchk_test.c
@@ -1,7 +1,4 @@
 // SPDX-License-Identifier: GPL-2.0+
-
-#define _GNU_SOURCE
-
 #include <errno.h>
 #include <fcntl.h>
 #include <limits.h>
diff --git a/tools/testing/selftests/powerpc/dscr/dscr_default_test.c b/tools/testing/selftests/powerpc/dscr/dscr_default_test.c
index 60ab02525b79..fe6aff1e5dad 100644
--- a/tools/testing/selftests/powerpc/dscr/dscr_default_test.c
+++ b/tools/testing/selftests/powerpc/dscr/dscr_default_test.c
@@ -9,9 +9,6 @@
  * Copyright 2012, Anton Blanchard, IBM Corporation.
  * Copyright 2015, Anshuman Khandual, IBM Corporation.
  */
-
-#define _GNU_SOURCE
-
 #include "dscr.h"
 
 #include <pthread.h>
diff --git a/tools/testing/selftests/powerpc/dscr/dscr_explicit_test.c b/tools/testing/selftests/powerpc/dscr/dscr_explicit_test.c
index e2268e9183a8..93b6efdc2eef 100644
--- a/tools/testing/selftests/powerpc/dscr/dscr_explicit_test.c
+++ b/tools/testing/selftests/powerpc/dscr/dscr_explicit_test.c
@@ -15,9 +15,6 @@
  * Copyright 2012, Anton Blanchard, IBM Corporation.
  * Copyright 2015, Anshuman Khandual, IBM Corporation.
  */
-
-#define _GNU_SOURCE
-
 #include "dscr.h"
 #include "utils.h"
 
diff --git a/tools/testing/selftests/powerpc/dscr/dscr_sysfs_thread_test.c b/tools/testing/selftests/powerpc/dscr/dscr_sysfs_thread_test.c
index 191ed126f118..ace7d23492c1 100644
--- a/tools/testing/selftests/powerpc/dscr/dscr_sysfs_thread_test.c
+++ b/tools/testing/selftests/powerpc/dscr/dscr_sysfs_thread_test.c
@@ -9,7 +9,6 @@
  *
  * Copyright 2015, Anshuman Khandual, IBM Corporation.
  */
-#define _GNU_SOURCE
 #include "dscr.h"
 
 static int test_thread_dscr(unsigned long val)
diff --git a/tools/testing/selftests/powerpc/mm/exec_prot.c b/tools/testing/selftests/powerpc/mm/exec_prot.c
index db75b2225de1..65712597cc68 100644
--- a/tools/testing/selftests/powerpc/mm/exec_prot.c
+++ b/tools/testing/selftests/powerpc/mm/exec_prot.c
@@ -6,8 +6,6 @@
  *
  * Test if applying execute protection on pages works as expected.
  */
-
-#define _GNU_SOURCE
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tools/testing/selftests/powerpc/mm/pkey_exec_prot.c b/tools/testing/selftests/powerpc/mm/pkey_exec_prot.c
index 0af4f02669a1..5cf72cd9694d 100644
--- a/tools/testing/selftests/powerpc/mm/pkey_exec_prot.c
+++ b/tools/testing/selftests/powerpc/mm/pkey_exec_prot.c
@@ -6,8 +6,6 @@
  * Test if applying execute protection on pages using memory
  * protection keys works as expected.
  */
-
-#define _GNU_SOURCE
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tools/testing/selftests/powerpc/mm/pkey_siginfo.c b/tools/testing/selftests/powerpc/mm/pkey_siginfo.c
index 2db76e56d4cb..fcaa591abf88 100644
--- a/tools/testing/selftests/powerpc/mm/pkey_siginfo.c
+++ b/tools/testing/selftests/powerpc/mm/pkey_siginfo.c
@@ -8,8 +8,6 @@
  * attempted to be protected by two different keys from two competing
  * threads at the same time.
  */
-
-#define _GNU_SOURCE
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tools/testing/selftests/powerpc/mm/tlbie_test.c b/tools/testing/selftests/powerpc/mm/tlbie_test.c
index 48344a74b212..512cd405de92 100644
--- a/tools/testing/selftests/powerpc/mm/tlbie_test.c
+++ b/tools/testing/selftests/powerpc/mm/tlbie_test.c
@@ -14,8 +14,6 @@
  * and copy it back to the original area. This helps us to detect if any
  * store continued to happen after we marked the memory PROT_READ.
  */
-
-#define _GNU_SOURCE
 #include <stdio.h>
 #include <sys/mman.h>
 #include <sys/types.h>
diff --git a/tools/testing/selftests/powerpc/papr_vpd/papr_vpd.c b/tools/testing/selftests/powerpc/papr_vpd/papr_vpd.c
index d6f99eb9be65..0b9b20668fa4 100644
--- a/tools/testing/selftests/powerpc/papr_vpd/papr_vpd.c
+++ b/tools/testing/selftests/powerpc/papr_vpd/papr_vpd.c
@@ -1,5 +1,4 @@
 // SPDX-License-Identifier: GPL-2.0-only
-#define _GNU_SOURCE
 #include <errno.h>
 #include <fcntl.h>
 #include <stdlib.h>
diff --git a/tools/testing/selftests/powerpc/pmu/count_instructions.c b/tools/testing/selftests/powerpc/pmu/count_instructions.c
index a3984ef1e96a..57d63ff75397 100644
--- a/tools/testing/selftests/powerpc/pmu/count_instructions.c
+++ b/tools/testing/selftests/powerpc/pmu/count_instructions.c
@@ -2,9 +2,6 @@
 /*
  * Copyright 2013, Michael Ellerman, IBM Corp.
  */
-
-#define _GNU_SOURCE
-
 #include <stdio.h>
 #include <stdbool.h>
 #include <string.h>
diff --git a/tools/testing/selftests/powerpc/pmu/count_stcx_fail.c b/tools/testing/selftests/powerpc/pmu/count_stcx_fail.c
index 2070a1e2b3a5..5d3bbd38528d 100644
--- a/tools/testing/selftests/powerpc/pmu/count_stcx_fail.c
+++ b/tools/testing/selftests/powerpc/pmu/count_stcx_fail.c
@@ -2,9 +2,6 @@
  * Copyright 2013, Michael Ellerman, IBM Corp.
  * Licensed under GPLv2.
  */
-
-#define _GNU_SOURCE
-
 #include <stdio.h>
 #include <stdbool.h>
 #include <string.h>
diff --git a/tools/testing/selftests/powerpc/pmu/ebb/ebb.c b/tools/testing/selftests/powerpc/pmu/ebb/ebb.c
index 21537d6eb6b7..e99a455e8c2e 100644
--- a/tools/testing/selftests/powerpc/pmu/ebb/ebb.c
+++ b/tools/testing/selftests/powerpc/pmu/ebb/ebb.c
@@ -2,9 +2,6 @@
 /*
  * Copyright 2014, Michael Ellerman, IBM Corp.
  */
-
-#define _GNU_SOURCE	/* For CPU_ZERO etc. */
-
 #include <sched.h>
 #include <sys/wait.h>
 #include <setjmp.h>
diff --git a/tools/testing/selftests/powerpc/pmu/ebb/instruction_count_test.c b/tools/testing/selftests/powerpc/pmu/ebb/instruction_count_test.c
index eed338b18e11..ab3f888922d6 100644
--- a/tools/testing/selftests/powerpc/pmu/ebb/instruction_count_test.c
+++ b/tools/testing/selftests/powerpc/pmu/ebb/instruction_count_test.c
@@ -2,9 +2,6 @@
 /*
  * Copyright 2014, Michael Ellerman, IBM Corp.
  */
-
-#define _GNU_SOURCE
-
 #include <stdio.h>
 #include <stdbool.h>
 #include <string.h>
diff --git a/tools/testing/selftests/powerpc/pmu/event.c b/tools/testing/selftests/powerpc/pmu/event.c
index 0c1c1bdba081..5468bd2c3c5b 100644
--- a/tools/testing/selftests/powerpc/pmu/event.c
+++ b/tools/testing/selftests/powerpc/pmu/event.c
@@ -2,8 +2,6 @@
 /*
  * Copyright 2013, Michael Ellerman, IBM Corp.
  */
-
-#define _GNU_SOURCE
 #include <unistd.h>
 #include <sys/syscall.h>
 #include <string.h>
diff --git a/tools/testing/selftests/powerpc/pmu/lib.c b/tools/testing/selftests/powerpc/pmu/lib.c
index 321357987408..fa208701dbdc 100644
--- a/tools/testing/selftests/powerpc/pmu/lib.c
+++ b/tools/testing/selftests/powerpc/pmu/lib.c
@@ -2,9 +2,6 @@
 /*
  * Copyright 2014, Michael Ellerman, IBM Corp.
  */
-
-#define _GNU_SOURCE	/* For CPU_ZERO etc. */
-
 #include <errno.h>
 #include <sched.h>
 #include <setjmp.h>
diff --git a/tools/testing/selftests/powerpc/pmu/per_event_excludes.c b/tools/testing/selftests/powerpc/pmu/per_event_excludes.c
index ad32a09a6540..066e0c4799fd 100644
--- a/tools/testing/selftests/powerpc/pmu/per_event_excludes.c
+++ b/tools/testing/selftests/powerpc/pmu/per_event_excludes.c
@@ -2,9 +2,6 @@
 /*
  * Copyright 2014, Michael Ellerman, IBM Corp.
  */
-
-#define _GNU_SOURCE
-
 #include <elf.h>
 #include <limits.h>
 #include <stdio.h>
diff --git a/tools/testing/selftests/powerpc/ptrace/perf-hwbreak.c b/tools/testing/selftests/powerpc/ptrace/perf-hwbreak.c
index e374c6b7ace6..1f7e3c63742d 100644
--- a/tools/testing/selftests/powerpc/ptrace/perf-hwbreak.c
+++ b/tools/testing/selftests/powerpc/ptrace/perf-hwbreak.c
@@ -16,9 +16,6 @@
  *
  * Copyright (C) 2018 Michael Neuling, IBM Corporation.
  */
-
-#define _GNU_SOURCE
-
 #include <unistd.h>
 #include <assert.h>
 #include <sched.h>
diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-syscall.c b/tools/testing/selftests/powerpc/ptrace/ptrace-syscall.c
index 3353210dcdbd..6e5294c1b60b 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace-syscall.c
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-syscall.c
@@ -8,8 +8,6 @@
  * test, and it was adapted to run on Powerpc by
  * Breno Leitao <leitao@debian.org>
  */
-#define _GNU_SOURCE
-
 #include <sys/ptrace.h>
 #include <sys/types.h>
 #include <sys/wait.h>
diff --git a/tools/testing/selftests/powerpc/signal/sig_sc_double_restart.c b/tools/testing/selftests/powerpc/signal/sig_sc_double_restart.c
index e3972264615b..8bad5e65bbb7 100644
--- a/tools/testing/selftests/powerpc/signal/sig_sc_double_restart.c
+++ b/tools/testing/selftests/powerpc/signal/sig_sc_double_restart.c
@@ -18,7 +18,6 @@
  *  that sucker at the same time.  Same for multiple signals of any kind
  *  interrupting that sucker on 64bit...
  */
-#define _GNU_SOURCE
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <sys/syscall.h>
diff --git a/tools/testing/selftests/powerpc/signal/sigreturn_kernel.c b/tools/testing/selftests/powerpc/signal/sigreturn_kernel.c
index 0a1b6e591eee..772c3373560f 100644
--- a/tools/testing/selftests/powerpc/signal/sigreturn_kernel.c
+++ b/tools/testing/selftests/powerpc/signal/sigreturn_kernel.c
@@ -2,9 +2,6 @@
 /*
  * Test that we can't sigreturn to kernel addresses, or to kernel mode.
  */
-
-#define _GNU_SOURCE
-
 #include <stdio.h>
 #include <signal.h>
 #include <stdlib.h>
diff --git a/tools/testing/selftests/powerpc/signal/sigreturn_vdso.c b/tools/testing/selftests/powerpc/signal/sigreturn_vdso.c
index e282fff0fe25..d5aecd2c4b95 100644
--- a/tools/testing/selftests/powerpc/signal/sigreturn_vdso.c
+++ b/tools/testing/selftests/powerpc/signal/sigreturn_vdso.c
@@ -5,9 +5,6 @@
  *
  * See handle_rt_signal64() and setup_trampoline() in signal_64.c
  */
-
-#define _GNU_SOURCE
-
 #include <errno.h>
 #include <stdio.h>
 #include <signal.h>
diff --git a/tools/testing/selftests/powerpc/syscalls/ipc_unmuxed.c b/tools/testing/selftests/powerpc/syscalls/ipc_unmuxed.c
index 4c582524aeb3..a49c699d86d4 100644
--- a/tools/testing/selftests/powerpc/syscalls/ipc_unmuxed.c
+++ b/tools/testing/selftests/powerpc/syscalls/ipc_unmuxed.c
@@ -5,8 +5,6 @@
  * This test simply tests that certain syscalls are implemented. It doesn't
  * actually exercise their logic in any way.
  */
-
-#define _GNU_SOURCE
 #include <errno.h>
 #include <stdio.h>
 #include <unistd.h>
diff --git a/tools/testing/selftests/powerpc/tm/tm-exec.c b/tools/testing/selftests/powerpc/tm/tm-exec.c
index c59919d6710d..8cfc859dcf37 100644
--- a/tools/testing/selftests/powerpc/tm/tm-exec.c
+++ b/tools/testing/selftests/powerpc/tm/tm-exec.c
@@ -8,8 +8,6 @@
  * It makes little sense for after an exec() call for the previously
  * suspended transaction to still exist.
  */
-
-#define _GNU_SOURCE
 #include <errno.h>
 #include <inttypes.h>
 #include <libgen.h>
diff --git a/tools/testing/selftests/powerpc/tm/tm-poison.c b/tools/testing/selftests/powerpc/tm/tm-poison.c
index a7bbf034b5bb..1b3a596a6a51 100644
--- a/tools/testing/selftests/powerpc/tm/tm-poison.c
+++ b/tools/testing/selftests/powerpc/tm/tm-poison.c
@@ -11,8 +11,6 @@
  * present child's poison will leak into parent's f31 or vr31 registers,
  * otherwise, poison will never leak into parent's f31 and vr31 registers.
  */
-
-#define _GNU_SOURCE
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
diff --git a/tools/testing/selftests/powerpc/tm/tm-signal-context-force-tm.c b/tools/testing/selftests/powerpc/tm/tm-signal-context-force-tm.c
index 421cb082f6be..f28ba2828df6 100644
--- a/tools/testing/selftests/powerpc/tm/tm-signal-context-force-tm.c
+++ b/tools/testing/selftests/powerpc/tm/tm-signal-context-force-tm.c
@@ -15,8 +15,6 @@
  * This test never fails (as returning EXIT_FAILURE). It either succeeds,
  * or crash the kernel (on a buggy kernel).
  */
-
-#define _GNU_SOURCE
 #include <stdio.h>
 #include <stdlib.h>
 #include <signal.h>
diff --git a/tools/testing/selftests/powerpc/tm/tm-signal-sigreturn-nt.c b/tools/testing/selftests/powerpc/tm/tm-signal-sigreturn-nt.c
index 06b801906f27..73f8e7dd5a1a 100644
--- a/tools/testing/selftests/powerpc/tm/tm-signal-sigreturn-nt.c
+++ b/tools/testing/selftests/powerpc/tm/tm-signal-sigreturn-nt.c
@@ -8,8 +8,6 @@
  * It returns from the signal handler with the CPU at suspended state, but
  * without setting usercontext MSR Transaction State (TS) fields.
  */
-
-#define _GNU_SOURCE
 #include <stdio.h>
 #include <stdlib.h>
 #include <signal.h>
diff --git a/tools/testing/selftests/powerpc/tm/tm-tmspr.c b/tools/testing/selftests/powerpc/tm/tm-tmspr.c
index dd5ddffa28b7..01118f7db1b2 100644
--- a/tools/testing/selftests/powerpc/tm/tm-tmspr.c
+++ b/tools/testing/selftests/powerpc/tm/tm-tmspr.c
@@ -22,8 +22,6 @@
  *    	(b) abort transaction
  *	(c) check TEXASR to see if FS has been corrupted
  */
-
-#define _GNU_SOURCE
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
diff --git a/tools/testing/selftests/powerpc/tm/tm-trap.c b/tools/testing/selftests/powerpc/tm/tm-trap.c
index 97cb74768e30..164b345b5bd3 100644
--- a/tools/testing/selftests/powerpc/tm/tm-trap.c
+++ b/tools/testing/selftests/powerpc/tm/tm-trap.c
@@ -26,8 +26,6 @@
  * the endianness is verified on subsequent traps to determine if the
  * endianness "flipped back" to the native endianness (BE).
  */
-
-#define _GNU_SOURCE
 #include <error.h>
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/tools/testing/selftests/powerpc/tm/tm-unavailable.c b/tools/testing/selftests/powerpc/tm/tm-unavailable.c
index 6bf1b65b020d..712267831112 100644
--- a/tools/testing/selftests/powerpc/tm/tm-unavailable.c
+++ b/tools/testing/selftests/powerpc/tm/tm-unavailable.c
@@ -13,8 +13,6 @@
  * corruption, but only for registers vs0 and vs32, which are respectively
  * representatives of FP and VEC/Altivec reg sets.
  */
-
-#define _GNU_SOURCE
 #include <error.h>
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/tools/testing/selftests/powerpc/utils.c b/tools/testing/selftests/powerpc/utils.c
index e5f2d8735c64..664722a01636 100644
--- a/tools/testing/selftests/powerpc/utils.c
+++ b/tools/testing/selftests/powerpc/utils.c
@@ -2,9 +2,6 @@
 /*
  * Copyright 2013-2015, Michael Ellerman, IBM Corp.
  */
-
-#define _GNU_SOURCE	/* For CPU_ZERO etc. */
-
 #include <elf.h>
 #include <errno.h>
 #include <fcntl.h>
