tracing/ftrace: fix unexpected -EINVAL when longest tracer name is set

Impact: fix confusing write() -EINVAL when changing the tracer

The following commit d9e540762f remade
alive the bug which made the set of a new tracer returning -EINVAL if
this is the longest name of tracer. This patch corrects it.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Frederic Weisbecker 2008-11-16 05:53:19 +01:00 коммит произвёл Ingo Molnar
Родитель ee02a2e5c8
Коммит e6e7a65aab
1 изменённых файлов: 7 добавлений и 5 удалений

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@ -2655,6 +2655,9 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
char buf[max_tracer_type_len+1];
int i;
size_t ret;
int err;
ret = cnt;
if (cnt > max_tracer_type_len)
cnt = max_tracer_type_len;
@ -2668,12 +2671,11 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
for (i = cnt - 1; i > 0 && isspace(buf[i]); i--)
buf[i] = 0;
ret = tracing_set_tracer(buf);
if (!ret)
ret = cnt;
err = tracing_set_tracer(buf);
if (err)
return err;
if (ret > 0)
filp->f_pos += ret;
filp->f_pos += ret;
return ret;
}