On 7/5/23 10:05, Arnd Bergmann wrote:
On Wed, Jul 5, 2023, at 16:19, Eric DeVolder wrote:
The kexec and crash kernel options are provided in the common
kernel/Kconfig.kexec. Utilize the common options and provide
the ARCH_SUPPORTS_ and ARCH_SELECTS_ entries to recreate the
equivalent set of KEXEC and CRASH options.
Signed-off-by: Eric DeVolder <eric.devolder@xxxxxxxxxx>
+config ARCH_SUPPORTS_KEXEC
+ def_bool (!SMP || PM_SLEEP_SMP) && MMU
config ATAGS_PROC
bool "Export atags in procfs"
@@ -1668,17 +1656,8 @@ config ATAGS_PROC
Should the atags used to boot the kernel be exported in an "atags"
file in procfs. Useful with kexec.
-config CRASH_DUMP
- bool "Build kdump crash kernel (EXPERIMENTAL)"
- help
- Generate crash dump after being started by kexec. This should
- be normally only set in special crash dump kernels which are
- loaded in the main kernel with kexec-tools into a specially
- reserved region and then later executed after a crash by
- kdump/kexec. The crash dump kernel must be compiled to a
- memory address not used by the main kernel
-
- For more details see Documentation/admin-guide/kdump/kdump.rst
+config ARCH_SUPPORTS_CRASH_DUMP
+ def_bool y
I see this is now in linux-next, and it caused a few randconfig
build issues, these never happened in the past:
Arnd,
Thanks for looking at this!
I received randconfig errors from Andrew Morton's machinery. When investigating I
found that randconfig was able to specify CRASH_DUMP without KEXEC, and that lead
to problems. I believe this situation existed prior to this series as well.
Specifically CRASH_DUMP does not have a dependency on KEXEC, or select (only s390
has this hole closed).
For CRASH_DUMP, this series now selects KEXEC to close this gap, which is what a
sane config would have (ie both CRASH_DUMP and KEXEC).
Do you think the changes outlined below are still needed?
eric
* The #ifdef CONFIG_KEXEC check in arch/arm/include/asm/kexec.h
needs to be changed to CONFIG_KEXEC_CORE:
include/linux/kexec.h:41:2: error: #error KEXEC_SOURCE_MEMORY_LIMIT not defined
same thing on m68k
* ARCH_SUPPORTS_CRASH_DUMP needs the same dependency as ARCH_SUPPORTS_KEXEC,
otherwise we seem to run into an obscure assembler error building the kdump
core on architectures that do not support kdump:
/tmp/ccpYl6w9.s:1546: Error: selected processor does not support requested special purpose register -- `mrs r2,cpsr'
* Most architectures build machine_kexec.o only when KEXEC is enabled,
this also needs to be changed to KEXEC_CORE:
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -59,7 +59,7 @@ obj-$(CONFIG_FUNCTION_TRACER) += entry-ftrace.o
obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o insn.o patch.o
obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o insn.o patch.o
obj-$(CONFIG_JUMP_LABEL) += jump_label.o insn.o patch.o
-obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o
+obj-$(CONFIG_KEXEC_CORE) += machine_kexec.o relocate_kernel.o
# Main staffs in KPROBES are in arch/arm/probes/ .
obj-$(CONFIG_KPROBES) += patch.o insn.o
obj-$(CONFIG_OABI_COMPAT) += sys_oabi-compat.o
Arnd
