Messages in this thread Patch in this message | | | Date | Wed, 24 Jun 2009 09:54:00 +0800 | From | Li Zefan <> | Subject | [PATCH 5/7] ftrace: don't increment @pos in g_start() |
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It's wrong to increment @pos in g_start(). It causes some entries lost when reading set_graph_function, if the output of the file is large than PAGE_SIZE.
[ Impact: fix missing entries when reading set_graph_function ]
Reviewed-by: Liming Wang <liming.wang@windriver.com> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> --- kernel/trace/ftrace.c | 21 ++++++++++----------- 1 files changed, 10 insertions(+), 11 deletions(-)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 561cafc..c06e9ab 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2499,32 +2499,31 @@ int ftrace_graph_count; unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; static void * -g_next(struct seq_file *m, void *v, loff_t *pos) +__g_next(struct seq_file *m, loff_t *pos) { unsigned long *array = m->private; - int index = *pos; - - (*pos)++; - if (index >= ftrace_graph_count) + if (*pos >= ftrace_graph_count) return NULL; + return &array[*pos]; +} - return &array[index]; +static void * +g_next(struct seq_file *m, void *v, loff_t *pos) +{ + (*pos)++; + return __g_next(m, pos); } static void *g_start(struct seq_file *m, loff_t *pos) { - void *p = NULL; - mutex_lock(&graph_lock); /* Nothing, tell g_show to print all functions are enabled */ if (!ftrace_graph_count && !*pos) return (void *)1; - p = g_next(m, p, pos); - - return p; + return __g_next(m, pos); } static void g_stop(struct seq_file *m, void *p) -- 1.5.4.rc3
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