From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
To: "Koralahalli Channabasappa,
Smita" <Smita.KoralahalliChannabasappa@amd.com>
Cc: <linux-cxl@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<nvdimm@lists.linux.dev>, <linux-fsdevel@vger.kernel.org>,
<linux-pm@vger.kernel.org>, Davidlohr Bueso <dave@stgolabs.net>,
Dave Jiang <dave.jiang@intel.com>,
Alison Schofield <alison.schofield@intel.com>,
Vishal Verma <vishal.l.verma@intel.com>,
Ira Weiny <ira.weiny@intel.com>,
Dan Williams <dan.j.williams@intel.com>,
Matthew Wilcox <willy@infradead.org>, Jan Kara <jack@suse.cz>,
"Rafael J . Wysocki" <rafael@kernel.org>,
Len Brown <len.brown@intel.com>, Pavel Machek <pavel@kernel.org>,
Li Ming <ming.li@zohomail.com>,
Jeff Johnson <jeff.johnson@oss.qualcomm.com>,
Ying Huang <huang.ying.caritas@gmail.com>,
Yao Xingtao <yaoxt.fnst@fujitsu.com>,
Peter Zijlstra <peterz@infradead.org>,
Greg KH <gregkh@linuxfoundation.org>,
"Nathan Fontenot" <nathan.fontenot@amd.com>,
Terry Bowman <terry.bowman@amd.com>,
Robert Richter <rrichter@amd.com>,
Benjamin Cheatham <benjamin.cheatham@amd.com>,
PradeepVineshReddy Kodamati <PradeepVineshReddy.Kodamati@amd.com>,
Zhijian Li <lizhijian@fujitsu.com>
Subject: Re: [PATCH v4 5/7] cxl/region: Introduce SOFT RESERVED resource removal on region teardown
Date: Tue, 10 Jun 2025 10:37:04 +0100 [thread overview]
Message-ID: <20250610103704.000023c4@huawei.com> (raw)
In-Reply-To: <f157ff2c-0849-4446-9870-19d4df9d29c5@amd.com>
Hi Smita,
> >> +/*
> >> + * normalize_resource
> >> + *
> >> + * The walk_iomem_res_desc() returns a copy of a resource, not a reference
> >> + * to the actual resource in the iomem_resource tree. As a result,
> >> + * __release_resource() which relies on pointer equality will fail.
> >
> > Probably want some statement on why nothing can race with this give
> > the resource_lock is not being held.
>
> Hmm, probably you are right that normalize_resource() is accessing the
> resource tree without holding resource_lock, which could lead to races.
>
> I will update the function to take a read_lock(&resource_lock) before
> walking res->parent->child..
>
> Let me know if you'd prefer this locking be handled before calling
> normalize_resource() instead..
I don't mind either way - see what looks better to you.
next prev parent reply other threads:[~2025-06-10 9:37 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-03 22:19 [PATCH v4 0/7] Add managed SOFT RESERVE resource handling Smita Koralahalli
2025-06-03 22:19 ` [PATCH v4 1/7] cxl/region: Avoid null pointer dereference in is_cxl_region() Smita Koralahalli
2025-06-03 23:49 ` Dave Jiang
2025-06-04 19:56 ` Nathan Fontenot
2025-06-25 15:23 ` Robert Richter
2025-06-03 22:19 ` [PATCH v4 2/7] cxl/core: Remove CONFIG_CXL_SUSPEND and always build suspend.o Smita Koralahalli
2025-06-09 11:02 ` Jonathan Cameron
2025-06-09 23:25 ` Koralahalli Channabasappa, Smita
2025-06-10 9:38 ` Jonathan Cameron
2025-06-03 22:19 ` [PATCH v4 3/7] cxl/pci: Add pci_loaded tracking to mark PCI driver readiness Smita Koralahalli
2025-06-04 9:29 ` Zhijian Li (Fujitsu)
2025-06-03 22:19 ` [PATCH v4 4/7] cxl/acpi: Add background worker to wait for cxl_pci and cxl_mem probe Smita Koralahalli
2025-06-03 23:45 ` Dave Jiang
2025-06-04 18:31 ` Koralahalli Channabasappa, Smita
2025-06-04 9:40 ` Zhijian Li (Fujitsu)
2025-06-04 14:35 ` Dave Jiang
2025-06-05 2:18 ` Zhijian Li (Fujitsu)
2025-06-03 22:19 ` [PATCH v4 5/7] cxl/region: Introduce SOFT RESERVED resource removal on region teardown Smita Koralahalli
2025-06-06 4:16 ` Zhijian Li (Fujitsu)
2025-06-06 17:53 ` Koralahalli Channabasappa, Smita
2025-06-09 12:54 ` Jonathan Cameron
2025-06-10 1:25 ` Koralahalli Channabasappa, Smita
2025-06-10 9:37 ` Jonathan Cameron [this message]
2025-06-25 15:20 ` Robert Richter
2025-07-09 1:14 ` Alison Schofield
2025-06-03 22:19 ` [PATCH v4 6/7] dax/hmem: Save the DAX HMEM platform device pointer Smita Koralahalli
2025-06-05 16:54 ` Dave Jiang
2025-06-06 8:11 ` Zhijian Li (Fujitsu)
2025-06-06 20:09 ` Nathan Fontenot
2025-06-03 22:19 ` [PATCH v4 7/7] cxl/dax: Defer DAX consumption of SOFT RESERVED resources until after CXL region creation Smita Koralahalli
2025-06-09 13:01 ` Jonathan Cameron
2025-06-13 2:12 ` Zhijian Li (Fujitsu)
2025-07-10 4:22 ` Koralahalli Channabasappa, Smita
2025-07-10 8:18 ` Zhijian Li (Fujitsu)
2025-07-15 16:27 ` Alison Schofield
2025-07-15 18:19 ` Koralahalli Channabasappa, Smita
2025-07-15 18:45 ` Alison Schofield
2025-06-04 8:43 ` [PATCH v4 0/7] Add managed SOFT RESERVE resource handling Zhijian Li (Fujitsu)
2025-06-04 18:59 ` Koralahalli Channabasappa, Smita
2025-06-16 1:00 ` Zhijian Li (Fujitsu)
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