[PATCH v5 7/8] crash_core: replace for_each_mem_range() with for_each_mem_region()

Wandun Chen <[email protected]> Thu, 6 Aug 2026 17:35:18 +0800
Newsgroups dev.linux.lists.iommu,dev.linux.lists.loongarch,org.infradead.lists.kexec,org.infradead.lists.linux-arm-kernel,org.infradead.lists.linux-riscv,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-kernel,org.kvack.linux-mm
Message-ID <[email protected]>
From: Wandun Chen <[email protected]>

for_each_mem_range() skips MEMBLOCK_NOMAP regions implicitly. Switch the
weak defaults to for_each_mem_region(), which exposes struct
memblock_region and per-region flags, and filter NOMAP regions explicitly
via the new crash_should_skip_region() helper. This prepares for a
subsequent patch to extend the skip filter.

No functional change.

Signed-off-by: Wandun Chen <[email protected]>
Tested-by: Meijing Zhao <[email protected]>
---
 kernel/crash_core.c | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 77285ae3ce60..fb78b7814f18 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -269,6 +269,12 @@ int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,
 	return 0;
 }
 
+/* Exclude NOMAP regions from the vmcore. */
+static bool crash_should_skip_region(struct memblock_region *reg)
+{
+	return memblock_is_nomap(reg);
+}
+
 static struct crash_mem *alloc_cmem(unsigned int nr_ranges)
 {
 	struct crash_mem *cmem;
@@ -284,22 +290,25 @@ static struct crash_mem *alloc_cmem(unsigned int nr_ranges)
 unsigned int __weak arch_get_system_nr_ranges(void)
 {
 	unsigned int nr_ranges = 2 + crashk_cma_cnt; /* crashk_res + crashk_low_res, +CMA splits */
-	phys_addr_t start, end;
-	u64 i;
+	struct memblock_region *reg;
 
-	for_each_mem_range(i, &start, &end)
+	for_each_mem_region(reg) {
+		if (crash_should_skip_region(reg))
+			continue;
 		nr_ranges++;
+	}
 	return nr_ranges;
 }
 
 int __weak arch_crash_populate_cmem(struct crash_mem *cmem)
 {
-	phys_addr_t start, end;
-	u64 i;
+	struct memblock_region *reg;
 
-	for_each_mem_range(i, &start, &end) {
-		cmem->ranges[cmem->nr_ranges].start = start;
-		cmem->ranges[cmem->nr_ranges].end = end - 1;
+	for_each_mem_region(reg) {
+		if (crash_should_skip_region(reg))
+			continue;
+		cmem->ranges[cmem->nr_ranges].start = reg->base;
+		cmem->ranges[cmem->nr_ranges].end = reg->base + reg->size - 1;
 		cmem->nr_ranges++;
 	}
 	return 0;
-- 
2.43.0