Commit d82d6244 authored by Li Zefan's avatar Li Zefan Committed by Ingo Molnar
Browse files

ftrace: Fix t_hash_start()

When the output of set_ftrace_filter is larger than PAGE_SIZE,
t_hash_start() will be called the 2nd time, and then we start
from the head of a hlist, which is wrong and causes some entries
to be outputed twice.

The worse is, if the hlist is large enough, reading set_ftrace_filter
won't stop but in a dead loop.
Reviewed-by: default avatarLiming Wang <>
Signed-off-by: default avatarLi Zefan <>
Cc: Steven Rostedt <>
Cc: Frederic Weisbecker <>
LKML-Reference: <>
Signed-off-by: default avatarIngo Molnar <>
parent 694ce0a5
......@@ -1417,10 +1417,20 @@ static void *t_hash_start(struct seq_file *m, loff_t *pos)
struct ftrace_iterator *iter = m->private;
void *p = NULL;
loff_t l;
if (!(iter->flags & FTRACE_ITER_HASH))
*pos = 0;
iter->flags |= FTRACE_ITER_HASH;
return t_hash_next(m, p, pos);
iter->hidx = 0;
for (l = 0; l <= *pos; ) {
p = t_hash_next(m, p, &l);
if (!p)
return p;
static int t_hash_show(struct seq_file *m, void *v)
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