Commit 561ca669 authored by Steven Rostedt (VMware)'s avatar Steven Rostedt (VMware)
Browse files

tracing: Make -ENOMEM the default error for parse_synth_field() 



parse_synth_field() returns a pointer and requires that errors get
surrounded by ERR_PTR(). The ret variable is initialized to zero, but should
never be used as zero, and if it is, it could cause a false return code and
produce a NULL pointer dereference. It makes no sense to set ret to zero.

Set ret to -ENOMEM (the most common error case), and have any other errors
set it to something else. This removes the need to initialize ret on *every*
error branch.

Fixes: 761a8c58 ("tracing, synthetic events: Replace buggy strcat() with seq_buf operations")
Reported-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent b02414c8

kernel/trace/trace_events_synth.c

+7 −10
Original line number Diff line number Diff line
@@ -584,7 +584,7 @@ static struct synth_field *parse_synth_field(int argc, const char **argv, 
{

	struct synth_field *field;

	const char *prefix = NULL, *field_type = argv[0], *field_name, *array;

	int len, ret = 0;

	int len, ret = -ENOMEM;

	struct seq_buf s;

	ssize_t size;
@@ -617,10 +617,9 @@ static struct synth_field *parse_synth_field(int argc, const char **argv, 
		len--;



	field->name = kmemdup_nul(field_name, len, GFP_KERNEL);

	if (!field->name) {

		ret = -ENOMEM;

	if (!field->name)

		goto free;

	}



	if (!is_good_name(field->name)) {

		synth_err(SYNTH_ERR_BAD_NAME, errpos(field_name));

		ret = -EINVAL;
@@ -638,10 +637,9 @@ static struct synth_field *parse_synth_field(int argc, const char **argv, 
		len += strlen(prefix);



	field->type = kzalloc(len, GFP_KERNEL);

	if (!field->type) {

		ret = -ENOMEM;

	if (!field->type)

		goto free;

	}



	seq_buf_init(&s, field->type, len);

	if (prefix)

		seq_buf_puts(&s, prefix);
@@ -653,6 +651,7 @@ static struct synth_field *parse_synth_field(int argc, const char **argv, 
	}

	if (WARN_ON_ONCE(!seq_buf_buffer_left(&s)))

		goto free;



	s.buffer[s.len] = '\0';



	size = synth_field_size(field->type);
@@ -666,10 +665,8 @@ static struct synth_field *parse_synth_field(int argc, const char **argv, 


			len = sizeof("__data_loc ") + strlen(field->type) + 1;

			type = kzalloc(len, GFP_KERNEL);

			if (!type) {

				ret = -ENOMEM;

			if (!type)

				goto free;

			}



			seq_buf_init(&s, type, len);

			seq_buf_puts(&s, "__data_loc ");

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