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, 81 insertions, 0 deletions

diff --git a/drivers/md/dm-zero.c b/drivers/md/dm-zero.c
new file mode 100644
index 000000000..9a0bb623e
--- /dev/null
+++ b/drivers/md/dm-zero.c
@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2003 Jana Saout <jana@saout.de>
+ *
+ * This file is released under the GPL.
+ */
+
+#include <linux/device-mapper.h>
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/bio.h>
+
+#define DM_MSG_PREFIX "zero"
+
+/*
+ * Construct a dummy mapping that only returns zeros
+ */
+static int zero_ctr(struct dm_target *ti, unsigned int argc, char **argv)
+{
+	if (argc != 0) {
+		ti->error = "No arguments required";
+		return -EINVAL;
+	}
+
+	/*
+	 * Silently drop discards, avoiding -EOPNOTSUPP.
+	 */
+	ti->num_discard_bios = 1;
+	ti->discards_supported = true;
+
+	return 0;
+}
+
+/*
+ * Return zeros only on reads
+ */
+static int zero_map(struct dm_target *ti, struct bio *bio)
+{
+	switch (bio_op(bio)) {
+	case REQ_OP_READ:
+		if (bio->bi_opf & REQ_RAHEAD) {
+			/* readahead of null bytes only wastes buffer cache */
+			return DM_MAPIO_KILL;
+		}
+		zero_fill_bio(bio);
+		break;
+	case REQ_OP_WRITE:
+	case REQ_OP_DISCARD:
+		/* writes get silently dropped */
+		break;
+	default:
+		return DM_MAPIO_KILL;
+	}
+
+	bio_endio(bio);
+
+	/* accepted bio, don't make new request */
+	return DM_MAPIO_SUBMITTED;
+}
+
+static void zero_io_hints(struct dm_target *ti, struct queue_limits *limits)
+{
+	limits->max_hw_discard_sectors = UINT_MAX;
+	limits->discard_granularity = 512;
+}
+
+static struct target_type zero_target = {
+	.name   = "zero",
+	.version = {1, 2, 0},
+	.features = DM_TARGET_NOWAIT,
+	.module = THIS_MODULE,
+	.ctr    = zero_ctr,
+	.map    = zero_map,
+	.io_hints = zero_io_hints,
+};
+module_dm(zero);
+
+MODULE_AUTHOR("Jana Saout <jana@saout.de>");
+MODULE_DESCRIPTION(DM_NAME " dummy target returning zeros");
+MODULE_LICENSE("GPL");