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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/kexec/crash_elfcorehdr_size - /sys/kernel/kexec/crash_cma_ranges Link: https://lkml.kernel.org/r/20251118114507.1769455-4-sourabhjain@linux.ibm.com Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com> Acked-by: Baoquan He <bhe@redhat.com> Cc: Aditya Gupta <adityag@linux.ibm.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>
62 lines
2.2 KiB
Plaintext
62 lines
2.2 KiB
Plaintext
What: /sys/kernel/kexec/*
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Date: Nov 2025
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Contact: kexec@lists.infradead.org
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Description:
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The /sys/kernel/kexec/* directory contains sysfs files
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that provide information about the configuration status
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of kexec and kdump.
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What: /sys/kernel/kexec/loaded
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Date: Nov 2025
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Contact: kexec@lists.infradead.org
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Description: read only
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Indicates whether a new kernel image has been loaded
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into memory using the kexec system call. It shows 1 if
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a kexec image is present and ready to boot, or 0 if none
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is loaded.
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User: kexec tools, kdump service
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What: /sys/kernel/kexec/crash_loaded
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Date: Nov 2025
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Contact: kexec@lists.infradead.org
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Description: read only
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Indicates whether a crash (kdump) kernel is currently
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loaded into memory. It shows 1 if a crash kernel has been
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successfully loaded for panic handling, or 0 if no crash
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kernel is present.
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User: Kexec tools, Kdump service
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What: /sys/kernel/kexec/crash_size
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Date: Nov 2025
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Contact: kexec@lists.infradead.org
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Description: read/write
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Shows the amount of memory reserved for loading the crash
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(kdump) kernel. It reports the size, in bytes, of the
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crash kernel area defined by the crashkernel= parameter.
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This interface also allows reducing the crashkernel
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reservation by writing a smaller value, and the reclaimed
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space is added back to the system RAM.
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User: Kdump service
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What: /sys/kernel/kexec/crash_elfcorehdr_size
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Date: Nov 2025
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Contact: kexec@lists.infradead.org
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Description: read only
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Indicates the preferred size of the memory buffer for the
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ELF core header used by the crash (kdump) kernel. It defines
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how much space is needed to hold metadata about the crashed
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system, including CPU and memory information. This information
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is used by the user space utility kexec to support updating the
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in-kernel kdump image during hotplug operations.
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User: Kexec tools
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What: /sys/kernel/kexec/crash_cma_ranges
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Date: Nov 2025
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Contact: kexec@lists.infradead.org
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Description: read only
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Provides information about the memory ranges reserved from
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the Contiguous Memory Allocator (CMA) area that are allocated
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to the crash (kdump) kernel. It lists the start and end physical
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addresses of CMA regions assigned for crashkernel use.
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User: kdump service
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