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authorSourabh Jain <sourabhjain@linux.ibm.com>2025-11-17 09:21:53 +0530
committerAndrew Morton <akpm@linux-foundation.org>2025-11-20 14:03:44 -0800
commitfdd76c8d6327e616ee61ddd00db16753d722168c (patch)
tree73b8e5a7b007ddf791450c32f219742072ec85d8
parentb1b72ac25f89125d91ef3abd257c3b88ec169962 (diff)
Documentation/ABI: add kexec and kdump sysfs interface
Add an ABI document for following kexec and kdump sysfs interface: - /sys/kernel/kexec_loaded - /sys/kernel/kexec_crash_loaded - /sys/kernel/kexec_crash_size - /sys/kernel/crash_elfcorehdr_size Link: https://lkml.kernel.org/r/20251117035153.1199665-1-sourabhjain@linux.ibm.com Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com> Cc: Aditya Gupta <adityag@linux.ibm.com> Cc: Baoquan he <bhe@redhat.com> Cc: Dave Young <dyoung@redhat.com> Cc: Hari Bathini <hbathini@linux.ibm.com> Cc: Jiri Bohac <jbohac@suse.cz> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mahesh J Salgaonkar <mahesh@linux.ibm.com> Cc: Pingfan Liu <piliu@redhat.com> Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Cc: Shivang Upadhyay <shivangu@linux.ibm.com> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r--Documentation/ABI/testing/sysfs-kernel-kexec-kdump43
1 files changed, 43 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-kernel-kexec-kdump b/Documentation/ABI/testing/sysfs-kernel-kexec-kdump
new file mode 100644
index 000000000000..96b24565b68e
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-kernel-kexec-kdump
@@ -0,0 +1,43 @@
+What: /sys/kernel/kexec_loaded
+Date: Jun 2006
+Contact: kexec@lists.infradead.org
+Description: read only
+ Indicates whether a new kernel image has been loaded
+ into memory using the kexec system call. It shows 1 if
+ a kexec image is present and ready to boot, or 0 if none
+ is loaded.
+User: kexec tools, kdump service
+
+What: /sys/kernel/kexec_crash_loaded
+Date: Jun 2006
+Contact: kexec@lists.infradead.org
+Description: read only
+ Indicates whether a crash (kdump) kernel is currently
+ loaded into memory. It shows 1 if a crash kernel has been
+ successfully loaded for panic handling, or 0 if no crash
+ kernel is present.
+User: Kexec tools, Kdump service
+
+What: /sys/kernel/kexec_crash_size
+Date: Dec 2009
+Contact: kexec@lists.infradead.org
+Description: read/write
+ Shows the amount of memory reserved for loading the crash
+ (kdump) kernel. It reports the size, in bytes, of the
+ crash kernel area defined by the crashkernel= parameter.
+ This interface also allows reducing the crashkernel
+ reservation by writing a smaller value, and the reclaimed
+ space is added back to the system RAM.
+User: Kdump service
+
+What: /sys/kernel/crash_elfcorehdr_size
+Date: Aug 2023
+Contact: kexec@lists.infradead.org
+Description: read only
+ Indicates the preferred size of the memory buffer for the
+ ELF core header used by the crash (kdump) kernel. It defines
+ how much space is needed to hold metadata about the crashed
+ system, including CPU and memory information. This information
+ is used by the user space utility kexec to support updating the
+ in-kernel kdump image during hotplug operations.
+User: Kexec tools