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From: Baoquan He To: Wandun Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, loongarch@lists.linux.dev, linux-riscv@lists.infradead.org, devicetree@vger.kernel.org, kexec@lists.infradead.org, iommu@lists.linux.dev, zhaomeijing@lixiang.com, Rob Herring , saravanak@kernel.org, bhe@redhat.com, rppt@kernel.org, pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu, chenhuacai@kernel.org, kernel@xen0n.name, catalin.marinas@arm.com, will@kernel.org, alex@ghiti.fr, akpm@linux-foundation.org, pasha.tatashin@soleen.com, pratyush@kernel.org, ruirui.yang@linux.dev, m.szyprowski@samsung.com, robin.murphy@arm.com Subject: Re: [PATCH v3 00/11] kdump: reduce vmcore size and capture time Message-ID: References: <20260527032917.3385849-1-chenwandun1@gmail.com> <7ed207fa-4c86-426a-8570-495902ce04c3@gmail.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Migadu-Flow: FLOW_OUT On 06/11/26 at 11:09am, Wandun wrote: > > > On 6/11/26 10:09, Wandun wrote: > > > > > > On 5/27/26 11:29, Wandun Chen wrote: > >> From: Wandun Chen > >> > >> On SoCs that carve out large firmware-owned reserved memory (GPU > >> firmware, DSP, modem, camera ISP, NPU, ...), kdump currently dumps > >> those carveouts as part of system RAM even though their contents are > >> firmware state that is not useful for kernel crash analysis. > >> > >> This series introduces an opt-in 'dumpable' flag [1] on struct > >> reserved_mem and uses it to filter the elfcorehdr PT_LOAD ranges on > >> DT-based architectures (arm64, riscv, loongarch). By default reserved > >> regions are treated as non-dumpable; CMA regions are explicitly opted > >> in because their pages are returned to the buddy allocator and may > >> carry key crash-analysis data. > >> > >> The series is organized as follows: > >> Patches 1-3: Pre-existing fixes and a small prep change. > >> Patches 4-5: Restructure to allow appending /memreserve/ entries. > >> Patches 6-7: Add a dumpable flag and append /memreserve/ entries. > >> Patch 8: Add generic kdump helpers. > >> Patches 9-11: Wire the helpers into arm64, riscv and loongarch kdump > >>                elfcorehdr preparation. > > Hi, > > > > Gentle ping on this series. > > > > Status summary: > > -patch 03: respun separately per Rob's suggestion, picked up for 7.2 > > -patch 06: Acked-by: Marek Szyprowski -patch 09: Acked-by: Will Deacon > > The remaining patches (01, 02, 04, 05, 07, 08, 10, 11) are still > > awaiting review. your feedback would be greately appreciated. I know we > > are at the end of 7.1 -rc cycle, I don't want to rush this series, just > > collecting more feedback, and will send next version based on 7.2-rc1. > > If spliting the series into smaller logical group would make review > > easier, please let me know. Best regards, Wandun > > Apologies for the formatting issue in my previous email. > Here is the properly formatted version. > > Gentle ping on this series. Thanks for the effort, the overral looks good to me at 1st glance. I will check if there's concern on generic part. And meanwhile, I am wondering if there's any chance x86 or other ARCH-es w/o OF/FDT can also choose to not dump some areas, e.g GPU stolen memory. Surely, that's another story. > > Status summary: > - patch 03: respun separately per Rob's suggestion, picked up for 7.2 > - patch 06: Acked-by: Marek Szyprowski > - patch 09: Acked-by: Will Deacon > > The remaining patches (01, 02, 04, 05, 07, 08, 10, 11) are still > awaiting review. Your feedback would be greatly appreciated. > > I know we are at the end of 7.1-rc cycle, I don't want to rush this > series, just collecting more feedback, and will send next version based > on 7.2-rc1. > > If splitting the series into smaller logical groups would make review > easier, please let me know. > > Best regards, > Wandun > > > >> > >> v2 --> v3: > >> 1. Fix out-of-bounds issue if device tree lacks /reserved-memory node.[2] > >> 2. Fix UAF issue when alloc_reserved_mem_array() fails. > >> 3. Add some prepare patches. > >> > >> v1 --> v2: > >> 1. v1 added an opt-out DT property ('linux,no-dump'). Per Rob's > >>     feedback [1], v2 drop that property and exclude reserve memory > >>     by default. > >> 2. Split some prepared patches from the original patches. > >> 3. Address coding-style comments on patch 5 from Rob. > >> > >> [1] https://lore.kernel.org/lkml/20260506144542.GA2072596- > >> robh@kernel.org/ > >> [2] https://sashiko.dev/#/patchset/20260520091844.592753-1- > >> chenwandun%40lixiang.com?part=4 > >> > >> Wandun Chen (11): > >>    of: reserved_mem: handle NULL name in of_reserved_mem_lookup() > >>    kexec/crash: provide crash_exclude_mem_range() stub when > >>      CONFIG_CRASH_DUMP=n > >>    of: reserved_mem: avoid post-init UAF when alloc_reserved_mem_array() > >>      fails > >>    of: reserved_mem: zero total_reserved_mem_cnt if no valid > >>      /reserved-memory entry > >>    of: reserved_mem: split alloc_reserved_mem_array() from > >>      fdt_scan_reserved_mem_late() > >>    of: reserved_mem: add dumpable flag to opt-in vmcore > >>    of: reserved_mem: save /memreserve/ entries into the reserved_mem > >>      array > >>    of: reserved_mem: add kdump helpers to exclude non-dumpable regions > >>    arm64: kdump: exclude non-dumpable reserved memory regions from vmcore > >>    riscv: kdump: exclude non-dumpable reserved memory regions from vmcore > >>    loongarch: kdump: exclude non-dumpable reserved memory regions from > >>      vmcore > >> > >>   arch/arm64/kernel/machine_kexec_file.c     |   6 ++ > >>   arch/loongarch/kernel/machine_kexec_file.c |   6 ++ > >>   arch/riscv/kernel/machine_kexec_file.c     |   4 + > >>   drivers/of/fdt.c                           |  11 +- > >>   drivers/of/of_private.h                    |   3 + > >>   drivers/of/of_reserved_mem.c               | 117 +++++++++++++++++++-- > >>   include/linux/crash_core.h                 |   6 ++ > >>   include/linux/of_reserved_mem.h            |  15 +++ > >>   kernel/dma/contiguous.c                    |   1 + > >>   9 files changed, 157 insertions(+), 12 deletions(-) > >> > > >