[PATCH v8 2/7] crash_dump: make dm crypt keys persist for the kdump kernel

[Arnaud Lefebvre]

On Fri, Feb 07, 2025 at 04:08:10PM +0800, Coiby Xu wrote:
>+config CRASH_DM_CRYPT
>+	bool "Support saving crash dump to dm-crypt encrypted volume"
>+	depends on KEXEC_FILE
>+	depends on CRASH_DUMP
>+	depends on DM_CRYPT
>+	help
>+	  With this option enabled, user space can intereact with
>+	  /sys/kernel/config/crash_dm_crypt_keys to make the dm crypt keys
>+	  persistent for the dump-capture kernel.
>+

Maybe also add CONFIG_CONFIGFS_FS option? Without it this series code doesn't compile:

Last build lines:

    GEN     modules.builtin
    MODPOST vmlinux.symvers
    UPD     include/generated/utsversion.h
    CC      init/version-timestamp.o
    KSYMS   .tmp_vmlinux0.kallsyms.S
    AS      .tmp_vmlinux0.kallsyms.o
    LD      .tmp_vmlinux1
  ld: vmlinux.o: in function `config_keys_make_item':
  /usr/src/linux/kernel/crash_dump_dm_crypt.c:250:(.text+0x228028): undefined reference to `config_item_init_type_name'
  ld: vmlinux.o: in function `configfs_dmcrypt_keys_init':
  /usr/src/linux/kernel/crash_dump_dm_crypt.c:442:(.init.text+0x71e5c): undefined reference to `config_group_init'
  ld: /usr/src/linux/kernel/crash_dump_dm_crypt.c:444:(.init.text+0x71e82): undefined reference to `configfs_register_subsystem'
  ld: /usr/src/linux/kernel/crash_dump_dm_crypt.c:454:(.init.text+0x71ef7): undefined reference to `configfs_unregister_subsystem'
  make[2]: *** [scripts/Makefile.vmlinux:77: vmlinux] Error 1
  make[1]: *** [/usr/src/linux/Makefile:1226: vmlinux] Error 2
  make: *** [Makefile:251: __sub-make] Error 2