ata: libata-scsi: fix ata_dsm_trim_pages() kernel-docgrafted

make htmldocs fails with:

  Documentation/driver-api/libata:604: ./drivers/ata/libata-scsi.c:2301:
  ERROR: Unexpected indentation. [docutils]

The Return: section of ata_dsm_trim_pages() ends its first sentence with
a colon and continues with an indented bullet list. reStructuredText
requires a blank line before an indented block, so docutils chokes on
the list.

Simply adding the missing blank line does not work either: Return: is a
kernel-doc "special section", which is terminated by the first blank
line, so the bullet list would end up in the Description section,
detached from the sentence introducing it.

Spell the two bounds out as prose instead, so that the Return: section
stays self-contained. Documentation-only change.

Fixes: e64e6b5dc867 ("ata: libata-scsi: scale DSM TRIM payload by MAX PAGES PER DSM COMMAND")
Reported-by: Thomas Huth <thuth@redhat.com>
Closes: https://lore.kernel.org/linux-ide/b0a0b8e8-cc4f-4c7b-8bc5-fee0712d405a@redhat.com/
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Link: https://lore.kernel.org/r/20260916130031.29990-2-cassel@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>

1 files changed, 154 insertions, 0 deletions

diff --git a/samples/fprobe/fprobe_example.c b/samples/fprobe/fprobe_example.c
new file mode 100644
index 000000000..bfe98ce82
--- /dev/null
+++ b/samples/fprobe/fprobe_example.c
@@ -0,0 +1,154 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Here's a sample kernel module showing the use of fprobe to dump a
+ * stack trace and selected registers when kernel_clone() is called.
+ *
+ * For more information on theory of operation of kprobes, see
+ * Documentation/trace/kprobes.rst
+ *
+ * You will see the trace data in /var/log/messages and on the console
+ * whenever kernel_clone() is invoked to create a new process.
+ */
+
+#define pr_fmt(fmt) "%s: " fmt, __func__
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/fprobe.h>
+#include <linux/sched/debug.h>
+#include <linux/slab.h>
+
+#define BACKTRACE_DEPTH 16
+#define MAX_SYMBOL_LEN 4096
+static struct fprobe sample_probe;
+static unsigned long nhit;
+
+static char symbol[MAX_SYMBOL_LEN] = "kernel_clone";
+module_param_string(symbol, symbol, sizeof(symbol), 0644);
+MODULE_PARM_DESC(symbol, "Probed symbol(s), given by comma separated symbols or a wildcard pattern.");
+
+static char nosymbol[MAX_SYMBOL_LEN] = "";
+module_param_string(nosymbol, nosymbol, sizeof(nosymbol), 0644);
+MODULE_PARM_DESC(nosymbol, "Not-probed symbols, given by a wildcard pattern.");
+
+static bool stackdump = true;
+module_param(stackdump, bool, 0644);
+MODULE_PARM_DESC(stackdump, "Enable stackdump.");
+
+static bool use_trace = false;
+module_param(use_trace, bool, 0644);
+MODULE_PARM_DESC(use_trace, "Use trace_printk instead of printk. This is only for debugging.");
+
+static void show_backtrace(void)
+{
+	unsigned long stacks[BACKTRACE_DEPTH];
+	unsigned int len;
+
+	len = stack_trace_save(stacks, BACKTRACE_DEPTH, 2);
+	stack_trace_print(stacks, len, 24);
+}
+
+static int sample_entry_handler(struct fprobe *fp, unsigned long ip,
+				unsigned long ret_ip,
+				struct ftrace_regs *fregs, void *data)
+{
+	if (use_trace)
+		/*
+		 * This is just an example, no kernel code should call
+		 * trace_printk() except when actively debugging.
+		 */
+		trace_printk("Enter <%pS> ip = 0x%p\n", (void *)ip, (void *)ip);
+	else
+		pr_info("Enter <%pS> ip = 0x%p\n", (void *)ip, (void *)ip);
+	nhit++;
+	if (stackdump)
+		show_backtrace();
+	return 0;
+}
+
+static void sample_exit_handler(struct fprobe *fp, unsigned long ip,
+				unsigned long ret_ip, struct ftrace_regs *regs,
+				void *data)
+{
+	unsigned long rip = ret_ip;
+
+	if (use_trace)
+		/*
+		 * This is just an example, no kernel code should call
+		 * trace_printk() except when actively debugging.
+		 */
+		trace_printk("Return from <%pS> ip = 0x%p to rip = 0x%p (%pS)\n",
+			(void *)ip, (void *)ip, (void *)rip, (void *)rip);
+	else
+		pr_info("Return from <%pS> ip = 0x%p to rip = 0x%p (%pS)\n",
+			(void *)ip, (void *)ip, (void *)rip, (void *)rip);
+	nhit++;
+	if (stackdump)
+		show_backtrace();
+}
+
+static int __init fprobe_init(void)
+{
+	char *p, *symbuf = NULL;
+	const char **syms;
+	int ret, count, i;
+
+	sample_probe.entry_handler = sample_entry_handler;
+	sample_probe.exit_handler = sample_exit_handler;
+
+	if (strchr(symbol, '*')) {
+		/* filter based fprobe */
+		ret = register_fprobe(&sample_probe, symbol,
+				      nosymbol[0] == '\0' ? NULL : nosymbol);
+		goto out;
+	} else if (!strchr(symbol, ',')) {
+		symbuf = symbol;
+		ret = register_fprobe_syms(&sample_probe, (const char **)&symbuf, 1);
+		goto out;
+	}
+
+	/* Comma separated symbols */
+	symbuf = kstrdup(symbol, GFP_KERNEL);
+	if (!symbuf)
+		return -ENOMEM;
+	p = symbuf;
+	count = 1;
+	while ((p = strchr(++p, ',')) != NULL)
+		count++;
+
+	pr_info("%d symbols found\n", count);
+
+	syms = kcalloc(count, sizeof(char *), GFP_KERNEL);
+	if (!syms) {
+		kfree(symbuf);
+		return -ENOMEM;
+	}
+
+	p = symbuf;
+	for (i = 0; i < count; i++)
+		syms[i] = strsep(&p, ",");
+
+	ret = register_fprobe_syms(&sample_probe, syms, count);
+	kfree(syms);
+	kfree(symbuf);
+out:
+	if (ret < 0)
+		pr_err("register_fprobe failed, returned %d\n", ret);
+	else
+		pr_info("Planted fprobe at %s\n", symbol);
+
+	return ret;
+}
+
+static void __exit fprobe_exit(void)
+{
+	unregister_fprobe(&sample_probe);
+
+	pr_info("fprobe at %s unregistered. %ld times hit, %ld times missed\n",
+		symbol, nhit, sample_probe.nmissed);
+}
+
+module_init(fprobe_init)
+module_exit(fprobe_exit)
+MODULE_DESCRIPTION("sample kernel module showing the use of fprobe");
+MODULE_LICENSE("GPL");