selftests/ftrace: Fix unique symbol check in kprobe_non_uniq_symbol.tcgrafted

The current regex also matches symbols in modules, which makes the
test fail on s390 where name_show is present only once in the kernel,
but also multiple times in modules:

000001b1401cdc20 t name_show
000001b0c05e6c40 t name_show    [mdev]
000001b0c0495f30 t name_show    [i2c_core]

Fix this by changing the regular expression to only match the function
name.

Link: https://lore.kernel.org/all/20260909092954.2200558-1-svens@linux.ibm.com/

Fixes: 03b80ff8023a ("selftests/ftrace: Add new test case which checks non unique symbol")
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

1 files changed, 21 insertions, 0 deletions

diff --git a/scripts/tools-support-relr.sh b/scripts/tools-support-relr.sh
new file mode 100755
index 000000000..4c121946e
--- /dev/null
+++ b/scripts/tools-support-relr.sh
@@ -0,0 +1,21 @@
+#!/bin/sh -eu
+# SPDX-License-Identifier: GPL-2.0
+
+tmp_file=$(mktemp)
+trap "rm -f $tmp_file.o $tmp_file $tmp_file.bin" EXIT
+
+cat << "END" | $CC -c -x c - -o $tmp_file.o >/dev/null 2>&1
+void *p = &p;
+END
+
+# ld.lld before 15 did not support -z pack-relative-relocs.
+if ! $LD $tmp_file.o -shared -Bsymbolic --pack-dyn-relocs=relr -o $tmp_file 2>/dev/null; then
+	$LD $tmp_file.o -shared -Bsymbolic -z pack-relative-relocs -o $tmp_file 2>&1 |
+		grep -q pack-relative-relocs && exit 1
+fi
+
+# Despite printing an error message, GNU nm still exits with exit code 0 if it
+# sees a relr section. So we need to check that nothing is printed to stderr.
+test -z "$($NM $tmp_file 2>&1 >/dev/null)"
+
+$OBJCOPY -O binary $tmp_file $tmp_file.bin