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 05/11] of: reserved_mem: split alloc_reserved_mem_array() from fdt_scan_reserved_mem_late()
Date: Wed, 27 May 2026 11:29:11 +0800 [thread overview]
Message-ID: <20260527032917.3385849-6-chenwandun1@gmail.com> (raw)
In-Reply-To: <20260527032917.3385849-1-chenwandun1@gmail.com>
From: Wandun Chen <chenwandun@lixiang•com>
Prepare for storing /memreserve/ entries in the reserved_mem array.
alloc_reserved_mem_array is skipped if the device tree lacks a
/reserved-memory node, pointer 'reserved_mem' continues to reference
the reserved_mem_array which lives in __initdata, storing
/memreserve/ entries into reserved_mem_array would result in metadata
loss, and an out-of-bounds memory access will occur if the device
tree contains more than MAX_RESERVED_REGIONS /memreserve/ entries.
So split alloc_reserved_mem_array() from fdt_scan_reserved_mem_late(),
and call alloc_reserved_mem_array() whether or not there is a
/reserved-memory node.
No functional change.
The actual /memreserve/ population is added in a follow-up patch.
Signed-off-by: Wandun Chen <chenwandun@lixiang•com>
---
drivers/of/fdt.c | 7 +++++--
drivers/of/of_private.h | 1 +
drivers/of/of_reserved_mem.c | 6 +-----
3 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 82f7327c59ea..83a2a474831e 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -1284,8 +1284,11 @@ void __init unflatten_device_tree(void)
{
void *fdt = initial_boot_params;
- /* Save the statically-placed regions in the reserved_mem array */
- fdt_scan_reserved_mem_late();
+ /* Attempt dynamic allocation of a new reserved_mem array */
+ if (fdt && alloc_reserved_mem_array()) {
+ /* Save the statically-placed regions in the reserved_mem array */
+ fdt_scan_reserved_mem_late();
+ }
/* Populate an empty root node when bootloader doesn't provide one */
if (!fdt) {
diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
index 0ae16da066e2..50e5a533e059 100644
--- a/drivers/of/of_private.h
+++ b/drivers/of/of_private.h
@@ -187,6 +187,7 @@ static inline struct device_node *__of_get_dma_parent(const struct device_node *
int fdt_scan_reserved_mem(void);
void __init fdt_scan_reserved_mem_late(void);
+bool __init alloc_reserved_mem_array(void);
bool of_fdt_device_is_available(const void *blob, unsigned long node);
diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index 05defc91e901..888dcb6bdce5 100644
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c
@@ -69,7 +69,7 @@ static int __init early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
* the initial static array is copied over to this new array and
* the new array is used from this point on.
*/
-static bool __init alloc_reserved_mem_array(void)
+bool __init alloc_reserved_mem_array(void)
{
struct reserved_mem *new_array;
size_t alloc_size, copy_size, memset_size;
@@ -272,10 +272,6 @@ void __init fdt_scan_reserved_mem_late(void)
return;
}
- /* Attempt dynamic allocation of a new reserved_mem array */
- if (!alloc_reserved_mem_array())
- return;
-
if (__reserved_mem_check_root(node)) {
pr_err("Reserved memory: unsupported node format, ignoring\n");
return;
--
2.43.0
next prev parent reply other threads:[~2026-05-27 3:30 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 ` Wandun Chen [this message]
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 ` [PATCH v3 08/11] of: reserved_mem: add kdump helpers to exclude non-dumpable regions Wandun Chen
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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