On 5/27/26 11:29, Wandun Chen wrote:
From: Wandun Chen <[email protected]>
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
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/[email protected]/
[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(-)
