From: Wandun Chen <chenwandun1@gmail•com>
To: 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
Cc: catalin.marinas@arm•com, will@kernel•org, chenhuacai@kernel•org,
kernel@xen0n•name, pjw@kernel•org, palmer@dabbelt•com,
aou@eecs•berkeley.edu, alex@ghiti•fr, robh@kernel•org,
saravanak@kernel•org, akpm@linux-foundation•org, bhe@redhat•com,
rppt@kernel•org, pasha.tatashin@soleen•com, pratyush@kernel•org,
ruirui.yang@linux•dev, m.szyprowski@samsung•com,
robin.murphy@arm•com, quic_obabatun@quicinc•com
Subject: [PATCH v3 08/11] of: reserved_mem: add kdump helpers to exclude non-dumpable regions
Date: Wed, 27 May 2026 11:29:14 +0800 [thread overview]
Message-ID: <20260527032917.3385849-9-chenwandun1@gmail.com> (raw)
In-Reply-To: <20260527032917.3385849-1-chenwandun1@gmail.com>
From: Wandun Chen <chenwandun@lixiang•com>
Add two helpers to exclude non-dumpable regions for arch-specific
code.
- of_reserved_mem_kdump_nr_ranges() returns the count of regions
that are not dumpable. Each excluded region may split an existing
crash_mem range into two, so callers use this to calculate
crash_mem allocation size.
- of_reserved_mem_kdump_exclude() walks reserved_mem[] and calls
crash_exclude_mem_range() for every non-dumpable region.
Signed-off-by: Wandun Chen <chenwandun@lixiang•com>
Tested-by: Meijing Zhao <zhaomeijing@lixiang•com>
---
drivers/of/of_reserved_mem.c | 34 +++++++++++++++++++++++++++++++++
include/linux/of_reserved_mem.h | 14 ++++++++++++++
2 files changed, 48 insertions(+)
diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index 5e27f9403786..1d9aa332325b 100644
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c
@@ -24,6 +24,7 @@
#include <linux/slab.h>
#include <linux/memblock.h>
#include <linux/kmemleak.h>
+#include <linux/crash_core.h>
#include "of_private.h"
@@ -858,6 +859,39 @@ struct reserved_mem *of_reserved_mem_lookup(struct device_node *np)
}
EXPORT_SYMBOL_GPL(of_reserved_mem_lookup);
+/*
+ * Count non-dumpable reserved regions. Excluding each one may split a
+ * crash_mem range in two, callers use this to size the allocation.
+ */
+unsigned int of_reserved_mem_kdump_nr_ranges(void)
+{
+ unsigned int i, n = 0;
+
+ for (i = 0; i < reserved_mem_count; i++)
+ if (reserved_mem[i].size && !reserved_mem[i].dumpable)
+ n++;
+ return n;
+}
+
+/* Exclude non-dumpable reserved regions from @cmem. */
+int of_reserved_mem_kdump_exclude(struct crash_mem *cmem)
+{
+ unsigned int i;
+ int ret;
+
+ for (i = 0; i < reserved_mem_count; i++) {
+ struct reserved_mem *r = &reserved_mem[i];
+
+ if (!r->size || r->dumpable)
+ continue;
+ ret = crash_exclude_mem_range(cmem, r->base,
+ r->base + r->size - 1);
+ if (ret)
+ return ret;
+ }
+ return 0;
+}
+
/**
* of_reserved_mem_region_to_resource() - Get a reserved memory region as a resource
* @np: node containing 'memory-region' property
diff --git a/include/linux/of_reserved_mem.h b/include/linux/of_reserved_mem.h
index 55a67cee41ea..70db99f1fbff 100644
--- a/include/linux/of_reserved_mem.h
+++ b/include/linux/of_reserved_mem.h
@@ -8,6 +8,7 @@
struct of_phandle_args;
struct reserved_mem_ops;
struct resource;
+struct crash_mem;
struct reserved_mem {
const char *name;
@@ -48,6 +49,9 @@ int of_reserved_mem_region_to_resource_byname(const struct device_node *np,
const char *name, struct resource *res);
int of_reserved_mem_region_count(const struct device_node *np);
+unsigned int of_reserved_mem_kdump_nr_ranges(void);
+int of_reserved_mem_kdump_exclude(struct crash_mem *cmem);
+
#else
#define RESERVEDMEM_OF_DECLARE(name, compat, ops) \
@@ -92,6 +96,16 @@ static inline int of_reserved_mem_region_count(const struct device_node *np)
{
return 0;
}
+
+static inline unsigned int of_reserved_mem_kdump_nr_ranges(void)
+{
+ return 0;
+}
+
+static inline int of_reserved_mem_kdump_exclude(struct crash_mem *cmem)
+{
+ return 0;
+}
#endif
/**
--
2.43.0
next prev parent reply other threads:[~2026-05-27 3:31 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-27 3:29 [PATCH v3 00/11] kdump: reduce vmcore size and capture time Wandun Chen
2026-05-27 3:29 ` [PATCH v3 01/11] of: reserved_mem: handle NULL name in of_reserved_mem_lookup() Wandun Chen
2026-05-27 3:29 ` [PATCH v3 02/11] kexec/crash: provide crash_exclude_mem_range() stub when CONFIG_CRASH_DUMP=n Wandun Chen
2026-05-27 3:29 ` [PATCH v3 03/11] of: reserved_mem: avoid post-init UAF when alloc_reserved_mem_array() fails Wandun Chen
2026-06-02 16:24 ` Rob Herring
2026-06-03 6:44 ` Wandun
2026-06-03 17:44 ` Rob Herring
2026-06-04 1:48 ` Wandun
2026-05-27 3:29 ` [PATCH v3 04/11] of: reserved_mem: zero total_reserved_mem_cnt if no valid /reserved-memory entry Wandun Chen
2026-05-27 3:29 ` [PATCH v3 05/11] of: reserved_mem: split alloc_reserved_mem_array() from fdt_scan_reserved_mem_late() Wandun Chen
2026-05-27 3:29 ` [PATCH v3 06/11] of: reserved_mem: add dumpable flag to opt-in vmcore Wandun Chen
2026-05-27 3:29 ` [PATCH v3 07/11] of: reserved_mem: save /memreserve/ entries into the reserved_mem array Wandun Chen
2026-05-27 3:29 ` Wandun Chen [this message]
2026-05-27 3:29 ` [PATCH v3 09/11] arm64: kdump: exclude non-dumpable reserved memory regions from vmcore Wandun Chen
2026-05-29 15:08 ` Will Deacon
2026-05-30 16:25 ` Mike Rapoport
2026-06-01 5:00 ` Baoquan He
2026-06-02 9:34 ` Mike Rapoport
2026-05-27 3:29 ` [PATCH v3 10/11] riscv: " Wandun Chen
2026-05-27 3:29 ` [PATCH v3 11/11] loongarch: " Wandun Chen
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