From: Stephen Hemminger <stephen@networkplumber.org>
To: Khadem Ullah <14pwcse1224@uetpeshawar.edu.pk>
Cc: thomas@monjalon.net, ferruh.yigit@amd.com,
andrew.rybchenko@oktetlabs.ru, dev@dpdk.org, stable@dpdk.org
Subject: Re: [PATCH] [PATCH v4] lib/ethdev: fix segfault in secondary process by validating dev_private pointer
Date: Tue, 29 Jul 2025 14:34:20 -0700 [thread overview]
Message-ID: <20250729143420.0fd7b627@hermes.local> (raw)
In-Reply-To: <20250729054229.3537412-1-14pwcse1224@uetpeshawar.edu.pk>
On Tue, 29 Jul 2025 01:42:29 -0400
Khadem Ullah <14pwcse1224@uetpeshawar.edu.pk> wrote:
> Hi Stephen,
>
> Many Thanks for the feedback.
> I have addressed all the comments on the patch, I have removed the unnecessary check in ethdev, the only one check in rte_ethdev seems to be a neccessary one, as without it, it can still generate segfault while secondary exists after primary.
>
> Best regards,
> Khadem
Did a bunch more testing, and the problem is much deeper than your initial observation.
If primary process exits, the data structures all over secondary process are complete
garbage. Lots of use after free, linked lists that point to freed data ...
The root cause is that when secondary process starts, it requests current device
state (buses, devices, etc) from primary. When primary process exits it removes
all devices; but there is no mechanism to tell secondary!
For now, the only thing I can think of is to have the secondary process monitor
in testpmd do an immediate exit, no cleanups.
next prev parent reply other threads:[~2025-07-29 21:34 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-22 11:54 [PATCH] " Khadem Ullah
2025-07-22 13:39 ` Stephen Hemminger
2025-07-22 14:30 ` Khadem Ullah
2025-07-22 15:42 ` Stephen Hemminger
2025-07-22 16:01 ` Khadem Ullah
2025-07-22 16:13 ` Bruce Richardson
2025-07-22 17:04 ` Khadem Ullah
2025-07-22 17:38 ` Stephen Hemminger
2025-07-22 17:53 ` Khadem Ullah
2025-07-22 18:21 ` Stephen Hemminger
2025-07-22 19:03 ` Khadem Ullah
2025-07-22 19:05 ` Ivan Malov
2025-07-22 22:28 ` Stephen Hemminger
2025-07-23 4:29 ` Khadem Ullah
2025-07-23 4:50 ` [PATCH v2] " Khadem Ullah
2025-07-23 12:19 ` Khadem Ullah
2025-07-23 13:13 ` Khadem Ullah
2025-07-23 13:24 ` Ivan Malov
2025-07-23 13:26 ` Khadem Ullah
2025-07-23 13:31 ` Ivan Malov
2025-07-23 13:10 ` [PATCH] [PATCH v3] " Khadem Ullah
2025-07-23 13:19 ` Ivan Malov
2025-07-23 13:34 ` Khadem Ullah
2025-07-23 14:22 ` Stephen Hemminger
2025-07-24 5:49 ` Khadem Ullah
2025-07-25 13:00 ` Khadem Ullah
2025-07-25 12:55 ` [PATCH] [PATCH v4] " Khadem Ullah
2025-07-28 21:45 ` Stephen Hemminger
2025-07-29 5:42 ` Khadem Ullah
2025-07-29 21:34 ` Stephen Hemminger [this message]
2025-07-30 5:07 ` Khadem Ullah
2025-07-29 6:39 ` [PATCH] app/testpmd: fix segfault in secondary process by monitoring primary Khadem Ullah
2025-07-29 6:39 ` [PATCH] [PATCH v4] lib/ethdev: fix segfault in secondary process by validating dev_private pointer Khadem Ullah
2025-07-29 6:39 ` [PATCH] [PATCH v5] app/testpmd: fix segfault in secondary process by monitoring primary Khadem Ullah
2025-07-29 14:48 ` Stephen Hemminger
2025-07-29 21:48 ` Stephen Hemminger
2025-07-30 5:24 ` Khadem Ullah
2025-07-30 5:56 ` [PATCH] app/testpmd: monitor state of primary process when using secondary Khadem Ullah
2025-07-30 6:08 ` [PATCH v6] " Khadem Ullah
2025-07-23 14:21 ` [PATCH v2] lib/ethdev: fix segfault in secondary process by validating dev_private pointer Stephen Hemminger
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