From: Nikolay Kuratov <kniv@yandex-team.ru>
To: linux-kernel@vger.kernel.org
Cc: linux-trace-kernel@vger.kernel.org,
Wen Yang <wenyang@linux.alibaba.com>,
Steven Rostedt <rostedt@goodmis.org>,
Mark Rutland <mark.rutland@arm.com>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
kniv@yandex-team.ru
Subject: Re: [PATCH] ftrace: Avoid potential division by zero in function_stat_show()
Date: Wed, 5 Feb 2025 14:21:54 +0300 [thread overview]
Message-ID: <20250205112154.1541872-1-kniv@yandex-team.ru> (raw)
In-Reply-To: <20250205103929.1538065-1-kniv@yandex-team.ru>
Oops, this still does not fix an overflow because of
> rec->time_square_sum += calltime * calltime;
We can't eliminate overflows easily without both using u64 and converting
ns to us prior to any squaring. I will send an appropriate patch later
if needed. Maybe we're a way too paranoid about overflows and really want
only not to divide by zero?
next prev parent reply other threads:[~2025-02-05 11:22 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-31 15:53 [PATCH] ftrace: Avoid potential division by zero in function_stat_show() Nikolay Kuratov
2025-02-03 15:06 ` Steven Rostedt
2025-02-04 7:43 ` Nikolay Kuratov
2025-02-04 22:20 ` Steven Rostedt
2025-02-05 0:48 ` Steven Rostedt
2025-02-05 10:39 ` Nikolay Kuratov
2025-02-05 11:21 ` Nikolay Kuratov [this message]
2025-02-05 14:50 ` Steven Rostedt
2025-02-06 8:57 ` Nikolay Kuratov
2025-02-06 9:01 ` [PATCH v2] " Nikolay Kuratov
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