Messages in this thread | | | Date | Thu, 28 May 2020 19:49:25 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH] trace/ftrace: fix maybe-uninitialized compiler warning |
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Hi Kaitao,
Sorry for the late response, I've been a bit swamped.
On Sat, 23 May 2020 23:53:04 +0800 Kaitao Cheng <pilgrimtao@gmail.com> wrote:
> During build compiler reports some 'false positive' warnings about > variables {'seq_ops', 'filtered_pids', 'other_pids'} may be used > uninitialized. This patch silences these warnings. > Also delete some useless spaces > > Signed-off-by: Kaitao Cheng <pilgrimtao@gmail.com> > --- > kernel/trace/ftrace.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c > index 7d0ebd104706..01a61bdc4e63 100644 > --- a/kernel/trace/ftrace.c > +++ b/kernel/trace/ftrace.c > @@ -2260,7 +2260,7 @@ ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, > > if (hash_contains_ip(ip, op->func_hash)) > return op; > - } > + } > > return NULL; > } > @@ -3599,7 +3599,7 @@ static int t_show(struct seq_file *m, void *v) > if (direct) > seq_printf(m, "\n\tdirect-->%pS", (void *)direct); > } > - } > + } > > seq_putc(m, '\n'); > > @@ -7151,6 +7151,9 @@ static int pid_open(struct inode *inode, struct file *file, int type) > case TRACE_NO_PIDS: > seq_ops = &ftrace_no_pid_sops; > break; > + default: > + trace_array_put(tr); > + return -EINVAL; > } > > ret = seq_open(file, seq_ops); > @@ -7229,6 +7232,9 @@ pid_write(struct file *filp, const char __user *ubuf, > other_pids = rcu_dereference_protected(tr->function_pids, > lockdep_is_held(&ftrace_lock)); > break; > + default: > + ret = -EINVAL;
As these are anomalies, and should never happen, we should probably add a WARN_ON_ONCE(1); here as well.
Care to send a v2?
Thanks!
-- Steve
> + goto out; > } > > ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
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