Linux-ARM-Kernel Archive on lore.kernel.org
 help / color / mirror / Atom feed
From: Marek Szyprowski <m.szyprowski@samsung.com>
To: linux-usb@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org
Cc: Marek Szyprowski <m.szyprowski@samsung.com>,
	Chunfeng Yun <chunfeng.yun@mediatek.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Steven Rostedt <rostedt@goodmis.org>
Subject: [PATCH] USB: mtu3: tracing: fix pointers dereferencing
Date: Tue,  4 Aug 2026 12:05:30 +0200	[thread overview]
Message-ID: <20260804100531.88576-1-m.szyprowski@samsung.com> (raw)
In-Reply-To: CGME20260804100540eucas1p24c59c891e91eeeeea8032d1c80312ea3@eucas1p2.samsung.com

Commit b5cc230af5e5 ("tracing: Warn when an event dereferences a pointer
in TP_printk()") added a warning then printing an event dereferences
a pointer, because it might be already freed that time.

MTU3 driver is one of the drivers triggering this warning. Fix it by
storing also the DMA address in the event structure to avoid
dereferencing gpd_ring pointer during event printing.

Fixes: 83374e035b62 ("usb: mtu3: add tracepoints to help debug")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/usb/mtu3/mtu3_trace.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/mtu3/mtu3_trace.h b/drivers/usb/mtu3/mtu3_trace.h
index 89870175d635..b24c6411a8cf 100644
--- a/drivers/usb/mtu3/mtu3_trace.h
+++ b/drivers/usb/mtu3/mtu3_trace.h
@@ -224,6 +224,7 @@ DECLARE_EVENT_CLASS(mtu3_log_ep,
 		__field(unsigned int, flags)
 		__field(unsigned int, direction)
 		__field(struct mtu3_gpd_ring *, gpd_ring)
+		__field(dma_addr_t, gpd_ring_dma)
 	),
 	TP_fast_assign(
 		__assign_str(name);
@@ -235,12 +236,13 @@ DECLARE_EVENT_CLASS(mtu3_log_ep,
 		__entry->flags = mep->flags;
 		__entry->direction = mep->is_in;
 		__entry->gpd_ring = &mep->gpd_ring;
+		__entry->gpd_ring_dma = __entry->gpd_ring->dma;
 	),
 	TP_printk("%s: type %s maxp %d slot %d mult %d burst %d ring %p/%pad flags %c:%c%c%c:%c",
 		__get_str(name), usb_ep_type_string(__entry->type),
 		__entry->maxp, __entry->slot,
 		__entry->mult, __entry->maxburst,
-		__entry->gpd_ring, &__entry->gpd_ring->dma,
+		__entry->gpd_ring, &__entry->gpd_ring_dma,
 		__entry->flags & MTU3_EP_ENABLED ? 'E' : 'e',
 		__entry->flags & MTU3_EP_STALL ? 'S' : 's',
 		__entry->flags & MTU3_EP_WEDGE ? 'W' : 'w',
-- 
2.43.0



       reply	other threads:[~2026-08-04 10:06 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20260804100540eucas1p24c59c891e91eeeeea8032d1c80312ea3@eucas1p2.samsung.com>
2026-08-04 10:05 ` Marek Szyprowski [this message]
2026-09-03 14:14   ` [PATCH] USB: mtu3: tracing: fix pointers dereferencing Sebastian Andrzej Siewior
2026-09-03 14:22   ` Steven Rostedt

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20260804100531.88576-1-m.szyprowski@samsung.com \
    --to=m.szyprowski@samsung.com \
    --cc=chunfeng.yun@mediatek.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mediatek@lists.infradead.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=rostedt@goodmis.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox