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Commit d954fbf0 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

tracing: Fix wrong usage of strstrip in trace_ksyms 



strstrip returns a pointer to the first non space character, but the
code in parse_ksym_trace_str() ignores that.

strstrip is now must_check and therefor we get the correct warning:
kernel/trace/trace_ksym.c:294: warning:
ignoring return value of ‘strstrip’, declared with attribute warn_unused_result

We are really not interested in leading whitespace here.

Fix that and cleanup the dozen kfree() exit pathes.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
parent 788d70dc

kernel/trace/trace_ksym.c

+21 −28
Original line number Diff line number Diff line
@@ -277,21 +277,20 @@ static ssize_t ksym_trace_filter_write(struct file *file, 
{

	struct trace_ksym *entry;

	struct hlist_node *node;

	char *input_string, *ksymname = NULL;

	char *buf, *input_string, *ksymname = NULL;

	unsigned long ksym_addr = 0;

	int ret, op, changed = 0;



	input_string = kzalloc(count + 1, GFP_KERNEL);

	if (!input_string)

	buf = kzalloc(count + 1, GFP_KERNEL);

	if (!buf)

		return -ENOMEM;



	if (copy_from_user(input_string, buffer, count)) {

		kfree(input_string);

		return -EFAULT;

	}

	input_string[count] = '\0';

	ret = -EFAULT;

	if (copy_from_user(buf, buffer, count))

		goto out;



	strstrip(input_string);

	buf[count] = '\0';

	input_string = strstrip(buf);



	/*

	 * Clear all breakpoints if:
@@ -302,15 +301,13 @@ static ssize_t ksym_trace_filter_write(struct file *file, 
	if (!input_string[0] || !strcmp(input_string, "0") ||

	    !strcmp(input_string, "*:---")) {

		__ksym_trace_reset();

		kfree(input_string);

		return count;

		ret = 0;

		goto out;

	}



	ret = op = parse_ksym_trace_str(input_string, &ksymname, &ksym_addr);

	if (ret < 0) {

		kfree(input_string);

		return ret;

	}

	if (ret < 0)

		goto out;



	mutex_lock(&ksym_tracer_mutex);
@@ -321,7 +318,7 @@ static ssize_t ksym_trace_filter_write(struct file *file, 
			if (entry->attr.bp_type != op)

				changed = 1;

			else

				goto out;

				goto out_unlock;

			break;

		}

	}
@@ -336,28 +333,24 @@ static ssize_t ksym_trace_filter_write(struct file *file, 
			if (IS_ERR(entry->ksym_hbp))

				ret = PTR_ERR(entry->ksym_hbp);

			else

				goto out;

				goto out_unlock;

		}

		/* Error or "symbol:---" case: drop it */

		ksym_filter_entry_count--;

		hlist_del_rcu(&(entry->ksym_hlist));

		synchronize_rcu();

		kfree(entry);

		goto out;

		goto out_unlock;

	} else {

		/* Check for malformed request: (4) */

		if (op == 0)

			goto out;

		if (op)

			ret = process_new_ksym_entry(ksymname, op, ksym_addr);

	}

out:

out_unlock:

	mutex_unlock(&ksym_tracer_mutex);



	kfree(input_string);



	if (!ret)

		ret = count;

	return ret;

out:

	kfree(buf);

	return !ret ? count : ret;

}



static const struct file_operations ksym_tracing_fops = {