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79365026f8
Commit a72bbec70d ("crash: hotplug support for kexec_load()")
introduced a new kexec flag, `KEXEC_UPDATE_ELFCOREHDR`. Kexec tool uses
this flag to indicate to the kernel that it is safe to modify the
elfcorehdr of the kdump image loaded using the kexec_load system call.
However, it is possible that architectures may need to update kexec
segments other then elfcorehdr. For example, FDT (Flatten Device Tree)
on PowerPC. Introducing a new kexec flag for every new kexec segment
may not be a good solution. Hence, a generic kexec flag bit,
`KEXEC_CRASH_HOTPLUG_SUPPORT`, is introduced to share the CPU/Memory
hotplug support intent between the kexec tool and the kernel for the
kexec_load system call.
Now we have two kexec flags that enables crash hotplug support for
kexec_load system call. First is KEXEC_UPDATE_ELFCOREHDR (only used in
x86), and second is KEXEC_CRASH_HOTPLUG_SUPPORT (for all architectures).
To simplify the process of finding and reporting the crash hotplug
support the following changes are introduced.
1. Define arch specific function to process the kexec flags and
determine crash hotplug support
2. Rename the @update_elfcorehdr member of struct kimage to
@hotplug_support and populate it for both kexec_load and
kexec_file_load syscalls, because architecture can update more than
one kexec segment
3. Let generic function crash_check_hotplug_support report hotplug
support for loaded kdump image based on value of @hotplug_support
To bring the x86 crash hotplug support in line with the above points,
the following changes have been made:
- Introduce the arch_crash_hotplug_support function to process kexec
flags and determine crash hotplug support
- Remove the arch_crash_hotplug_[cpu|memory]_support functions
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240326055413.186534-3-sourabhjain@linux.ibm.com
69 lines
2.1 KiB
C
69 lines
2.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
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#ifndef _UAPILINUX_KEXEC_H
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#define _UAPILINUX_KEXEC_H
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/* kexec system call - It loads the new kernel to boot into.
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* kexec does not sync, or unmount filesystems so if you need
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* that to happen you need to do that yourself.
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*/
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#include <linux/types.h>
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/* kexec flags for different usage scenarios */
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#define KEXEC_ON_CRASH 0x00000001
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#define KEXEC_PRESERVE_CONTEXT 0x00000002
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#define KEXEC_UPDATE_ELFCOREHDR 0x00000004
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#define KEXEC_CRASH_HOTPLUG_SUPPORT 0x00000008
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#define KEXEC_ARCH_MASK 0xffff0000
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/*
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* Kexec file load interface flags.
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* KEXEC_FILE_UNLOAD : Unload already loaded kexec/kdump image.
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* KEXEC_FILE_ON_CRASH : Load/unload operation belongs to kdump image.
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* KEXEC_FILE_NO_INITRAMFS : No initramfs is being loaded. Ignore the initrd
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* fd field.
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*/
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#define KEXEC_FILE_UNLOAD 0x00000001
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#define KEXEC_FILE_ON_CRASH 0x00000002
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#define KEXEC_FILE_NO_INITRAMFS 0x00000004
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#define KEXEC_FILE_DEBUG 0x00000008
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/* These values match the ELF architecture values.
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* Unless there is a good reason that should continue to be the case.
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*/
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#define KEXEC_ARCH_DEFAULT ( 0 << 16)
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#define KEXEC_ARCH_386 ( 3 << 16)
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#define KEXEC_ARCH_68K ( 4 << 16)
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#define KEXEC_ARCH_PARISC (15 << 16)
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#define KEXEC_ARCH_X86_64 (62 << 16)
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#define KEXEC_ARCH_PPC (20 << 16)
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#define KEXEC_ARCH_PPC64 (21 << 16)
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#define KEXEC_ARCH_IA_64 (50 << 16)
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#define KEXEC_ARCH_ARM (40 << 16)
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#define KEXEC_ARCH_S390 (22 << 16)
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#define KEXEC_ARCH_SH (42 << 16)
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#define KEXEC_ARCH_MIPS_LE (10 << 16)
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#define KEXEC_ARCH_MIPS ( 8 << 16)
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#define KEXEC_ARCH_AARCH64 (183 << 16)
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#define KEXEC_ARCH_RISCV (243 << 16)
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#define KEXEC_ARCH_LOONGARCH (258 << 16)
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/* The artificial cap on the number of segments passed to kexec_load. */
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#define KEXEC_SEGMENT_MAX 16
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#ifndef __KERNEL__
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/*
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* This structure is used to hold the arguments that are used when
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* loading kernel binaries.
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*/
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struct kexec_segment {
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const void *buf;
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__kernel_size_t bufsz;
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const void *mem;
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__kernel_size_t memsz;
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};
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#endif /* __KERNEL__ */
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#endif /* _UAPILINUX_KEXEC_H */
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