summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--Documentation/ABI/testing/sysfs-kernel-kexec-kdump10
-rw-r--r--kernel/ksysfs.c21
2 files changed, 31 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-kernel-kexec-kdump b/Documentation/ABI/testing/sysfs-kernel-kexec-kdump
index 96b24565b68e..f6089e38de5f 100644
--- a/Documentation/ABI/testing/sysfs-kernel-kexec-kdump
+++ b/Documentation/ABI/testing/sysfs-kernel-kexec-kdump
@@ -41,3 +41,13 @@ Description: read only
is used by the user space utility kexec to support updating the
in-kernel kdump image during hotplug operations.
User: Kexec tools
+
+What: /sys/kernel/kexec_crash_cma_ranges
+Date: Nov 2025
+Contact: kexec@lists.infradead.org
+Description: read only
+ Provides information about the memory ranges reserved from
+ the Contiguous Memory Allocator (CMA) area that are allocated
+ to the crash (kdump) kernel. It lists the start and end physical
+ addresses of CMA regions assigned for crashkernel use.
+User: kdump service
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c
index eefb67d9883c..0ff2179bc603 100644
--- a/kernel/ksysfs.c
+++ b/kernel/ksysfs.c
@@ -135,6 +135,24 @@ static ssize_t kexec_crash_loaded_show(struct kobject *kobj,
}
KERNEL_ATTR_RO(kexec_crash_loaded);
+#ifdef CONFIG_CRASH_RESERVE
+static ssize_t kexec_crash_cma_ranges_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+
+ ssize_t len = 0;
+ int i;
+
+ for (i = 0; i < crashk_cma_cnt; ++i) {
+ len += sysfs_emit_at(buf, len, "%08llx-%08llx\n",
+ crashk_cma_ranges[i].start,
+ crashk_cma_ranges[i].end);
+ }
+ return len;
+}
+KERNEL_ATTR_RO(kexec_crash_cma_ranges);
+#endif /* CONFIG_CRASH_RESERVE */
+
static ssize_t kexec_crash_size_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
@@ -260,6 +278,9 @@ static struct attribute * kernel_attrs[] = {
#ifdef CONFIG_CRASH_DUMP
&kexec_crash_loaded_attr.attr,
&kexec_crash_size_attr.attr,
+#ifdef CONFIG_CRASH_RESERVE
+ &kexec_crash_cma_ranges_attr.attr,
+#endif
#endif
#endif
#ifdef CONFIG_VMCORE_INFO