Re: [PATCH v4 09/10] riscv: kdump: exclude non-dumpable reserved memory regions from vmcore

On 6/30/26 19:12, Pratyush Yadav wrote:

On Tue, Jun 30 2026, Wandun Chen wrote:

quoted

From: Wandun Chen <redacted>

Apply the same non-dumpable reserved memory filtering to RISC-V kdump
as was done for arm64. Use of_reserved_mem_kdump_exclude() to drop
flagged regions from the elfcorehdr PT_LOAD segments, and
of_reserved_mem_kdump_nr_ranges() to pre-size the crash_mem array.

Signed-off-by: Wandun Chen <redacted>
---
 arch/riscv/kernel/machine_kexec_file.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
index 59d4bbc848a8..25359d583bc3 100644
--- a/arch/riscv/kernel/machine_kexec_file.c
+++ b/arch/riscv/kernel/machine_kexec_file.c

@@ -10,6 +10,7 @@
 #include <linux/elf.h>
 #include <linux/slab.h>
 #include <linux/of.h>
+#include <linux/of_reserved_mem.h>
 #include <linux/libfdt.h>
 #include <linux/types.h>
 #include <linux/memblock.h>

@@ -64,6 +65,7 @@ static int prepare_elf_headers(void **addr, unsigned long *sz)
 
 	nr_ranges = 1; /* For exclusion of crashkernel region */
 	walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
+	nr_ranges += of_reserved_mem_kdump_nr_ranges();
 
 	cmem = kmalloc_flex(*cmem, ranges, nr_ranges);
 	if (!cmem)

@@ -77,6 +79,8 @@ static int prepare_elf_headers(void **addr, unsigned long *sz)
 
 	/* Exclude crashkernel region */
 	ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
+	if (!ret)
+		ret = of_reserved_mem_kdump_exclude(cmem);
 	if (!ret)
 		ret = crash_prepare_elf64_headers(cmem, true, addr, sz);

Nit: can you do the usual pattern of if (err) goto err; instead?

Sure, will fix in the next version.

Best regards,
Wandun

So this would look like:

	/* Exclude crashkernel region */
	ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
	if (ret)
		goto out;

	ret = of_reserved_mem_kdump_exclude(cmem);
	if (ret)
		goto out;
        
	ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
out:
	...

With this,

Acked-by: Pratyush Yadav <pratyush@kernel.org>