Messages in this thread | | | Date | Wed, 22 May 2019 07:52:27 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH v2] tracing: silence GCC 9 array bounds warning |
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On Wed, 22 May 2019 11:58:10 +0200 Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> wrote:
> +/* reset all but tr, trace, and overruns */ > +static __always_inline void trace_iterator_reset(struct trace_iterator *iter) > +{ > + /* > + * We do not simplify the start address to &iter->seq in order to let > + * GCC 9 know that we really want to overwrite more members than > + * just iter->seq (-Warray-bounds).
This comment is fine for the change log, but here it is too specific. Why does one care about GCC 9 when we are at version GCC 21? I care more about why we are clearing the data and less about the way we are doing it.
A comment like:
/* * Reset the state of the trace_iterator so that it can read * consumed data. Normally, the trace_iterator is used for * reading the data when it is not consumed, and must retain * state. */
That is more useful than why we have the offset hack.
> + */ > + const size_t offset = offsetof(struct trace_iterator, seq);
Need a empty line between these two.
-- Steve
> + memset((char *)(iter) + offset, 0, sizeof(struct trace_iterator) - offset); > + > + iter->pos = -1; > +} > + > #endif /* _LINUX_KERNEL_TRACE_H */
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