Eric DeVolder | 89cde45 | 2023-07-12 12:15:32 -0400 | [diff] [blame] | 1 | # SPDX-License-Identifier: GPL-2.0-only |
| 2 | |
| 3 | menu "Kexec and crash features" |
| 4 | |
| 5 | config CRASH_CORE |
| 6 | bool |
| 7 | |
| 8 | config KEXEC_CORE |
| 9 | select CRASH_CORE |
| 10 | bool |
| 11 | |
| 12 | config KEXEC_ELF |
| 13 | bool |
| 14 | |
| 15 | config HAVE_IMA_KEXEC |
| 16 | bool |
| 17 | |
| 18 | config KEXEC |
| 19 | bool "Enable kexec system call" |
Eric DeVolder | 89cde45 | 2023-07-12 12:15:32 -0400 | [diff] [blame] | 20 | depends on ARCH_SUPPORTS_KEXEC |
| 21 | select KEXEC_CORE |
| 22 | help |
| 23 | kexec is a system call that implements the ability to shutdown your |
| 24 | current kernel, and to start another kernel. It is like a reboot |
| 25 | but it is independent of the system firmware. And like a reboot |
| 26 | you can start any kernel with it, not just Linux. |
| 27 | |
| 28 | The name comes from the similarity to the exec system call. |
| 29 | |
| 30 | It is an ongoing process to be certain the hardware in a machine |
| 31 | is properly shutdown, so do not be surprised if this code does not |
| 32 | initially work for you. As of this writing the exact hardware |
| 33 | interface is strongly in flux, so no good recommendation can be |
| 34 | made. |
| 35 | |
| 36 | config KEXEC_FILE |
| 37 | bool "Enable kexec file based system call" |
| 38 | depends on ARCH_SUPPORTS_KEXEC_FILE |
| 39 | select KEXEC_CORE |
| 40 | help |
| 41 | This is new version of kexec system call. This system call is |
| 42 | file based and takes file descriptors as system call argument |
| 43 | for kernel and initramfs as opposed to list of segments as |
| 44 | accepted by kexec system call. |
| 45 | |
| 46 | config KEXEC_SIG |
| 47 | bool "Verify kernel signature during kexec_file_load() syscall" |
| 48 | depends on ARCH_SUPPORTS_KEXEC_SIG |
| 49 | depends on KEXEC_FILE |
| 50 | help |
| 51 | This option makes the kexec_file_load() syscall check for a valid |
| 52 | signature of the kernel image. The image can still be loaded without |
| 53 | a valid signature unless you also enable KEXEC_SIG_FORCE, though if |
| 54 | there's a signature that we can check, then it must be valid. |
| 55 | |
| 56 | In addition to this option, you need to enable signature |
| 57 | verification for the corresponding kernel image type being |
| 58 | loaded in order for this to work. |
| 59 | |
| 60 | config KEXEC_SIG_FORCE |
| 61 | bool "Require a valid signature in kexec_file_load() syscall" |
| 62 | depends on ARCH_SUPPORTS_KEXEC_SIG_FORCE |
| 63 | depends on KEXEC_SIG |
| 64 | help |
| 65 | This option makes kernel signature verification mandatory for |
| 66 | the kexec_file_load() syscall. |
| 67 | |
| 68 | config KEXEC_IMAGE_VERIFY_SIG |
| 69 | bool "Enable Image signature verification support (ARM)" |
| 70 | default ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG |
| 71 | depends on ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG |
| 72 | depends on KEXEC_SIG |
| 73 | depends on EFI && SIGNED_PE_FILE_VERIFICATION |
| 74 | help |
| 75 | Enable Image signature verification support. |
| 76 | |
| 77 | config KEXEC_BZIMAGE_VERIFY_SIG |
| 78 | bool "Enable bzImage signature verification support" |
| 79 | depends on ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG |
| 80 | depends on KEXEC_SIG |
| 81 | depends on SIGNED_PE_FILE_VERIFICATION |
| 82 | select SYSTEM_TRUSTED_KEYRING |
| 83 | help |
| 84 | Enable bzImage signature verification support. |
| 85 | |
| 86 | config KEXEC_JUMP |
| 87 | bool "kexec jump" |
| 88 | depends on ARCH_SUPPORTS_KEXEC_JUMP |
| 89 | depends on KEXEC && HIBERNATION |
| 90 | help |
| 91 | Jump between original kernel and kexeced kernel and invoke |
| 92 | code in physical address mode via KEXEC |
| 93 | |
| 94 | config CRASH_DUMP |
| 95 | bool "kernel crash dumps" |
| 96 | depends on ARCH_SUPPORTS_CRASH_DUMP |
| 97 | depends on ARCH_SUPPORTS_KEXEC |
| 98 | select CRASH_CORE |
| 99 | select KEXEC_CORE |
| 100 | select KEXEC |
| 101 | help |
| 102 | Generate crash dump after being started by kexec. |
| 103 | This should be normally only set in special crash dump kernels |
| 104 | which are loaded in the main kernel with kexec-tools into |
| 105 | a specially reserved region and then later executed after |
| 106 | a crash by kdump/kexec. The crash dump kernel must be compiled |
| 107 | to a memory address not used by the main kernel or BIOS using |
| 108 | PHYSICAL_START, or it must be built as a relocatable image |
| 109 | (CONFIG_RELOCATABLE=y). |
| 110 | For more details see Documentation/admin-guide/kdump/kdump.rst |
| 111 | |
| 112 | For s390, this option also enables zfcpdump. |
Costa Shulyupin | c0d2f4c | 2023-08-25 04:30:57 +0300 | [diff] [blame] | 113 | See also <file:Documentation/arch/s390/zfcpdump.rst> |
Eric DeVolder | 89cde45 | 2023-07-12 12:15:32 -0400 | [diff] [blame] | 114 | |
Eric DeVolder | 2472627 | 2023-08-14 17:44:40 -0400 | [diff] [blame] | 115 | config CRASH_HOTPLUG |
| 116 | bool "Update the crash elfcorehdr on system configuration changes" |
| 117 | default y |
| 118 | depends on CRASH_DUMP && (HOTPLUG_CPU || MEMORY_HOTPLUG) |
| 119 | depends on ARCH_SUPPORTS_CRASH_HOTPLUG |
| 120 | help |
| 121 | Enable direct update to the crash elfcorehdr (which contains |
| 122 | the list of CPUs and memory regions to be dumped upon a crash) |
| 123 | in response to hot plug/unplug or online/offline of CPUs or |
| 124 | memory. This is a much more advanced approach than userspace |
| 125 | attempting that. |
| 126 | |
| 127 | If unsure, say Y. |
| 128 | |
| 129 | config CRASH_MAX_MEMORY_RANGES |
| 130 | int "Specify the maximum number of memory regions for the elfcorehdr" |
| 131 | default 8192 |
| 132 | depends on CRASH_HOTPLUG |
| 133 | help |
| 134 | For the kexec_file_load() syscall path, specify the maximum number of |
| 135 | memory regions that the elfcorehdr buffer/segment can accommodate. |
| 136 | These regions are obtained via walk_system_ram_res(); eg. the |
| 137 | 'System RAM' entries in /proc/iomem. |
| 138 | This value is combined with NR_CPUS_DEFAULT and multiplied by |
| 139 | sizeof(Elf64_Phdr) to determine the final elfcorehdr memory buffer/ |
| 140 | segment size. |
| 141 | The value 8192, for example, covers a (sparsely populated) 1TiB system |
| 142 | consisting of 128MiB memblocks, while resulting in an elfcorehdr |
| 143 | memory buffer/segment size under 1MiB. This represents a sane choice |
| 144 | to accommodate both baremetal and virtual machine configurations. |
| 145 | |
Eric DeVolder | a72bbec | 2023-08-14 17:44:44 -0400 | [diff] [blame] | 146 | For the kexec_load() syscall path, CRASH_MAX_MEMORY_RANGES is part of |
| 147 | the computation behind the value provided through the |
| 148 | /sys/kernel/crash_elfcorehdr_size attribute. |
| 149 | |
Eric DeVolder | 89cde45 | 2023-07-12 12:15:32 -0400 | [diff] [blame] | 150 | endmenu |