Hi Eric,
On Wed, Jul 05, 2023 at 10:20:03AM -0400, 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.
NOTE: The original Kconfig has a KEXEC_SIG which depends on
MODULE_SIG_FORMAT. However, attempts to keep the MODULE_SIG_FORMAT
dependency (using the strategy outlined in this series, and other
techniques) results in 'error: recursive dependency detected'
on CRYPTO.
Per Alexander Gordeev <agordeev@xxxxxxxxxxxxx>: "the MODULE_SIG_FORMAT
dependency was introduced with [git commit below] and in fact was not
necessary, since s390 did/does not use mod_check_sig() anyway.
commit c8424e776b09 ("MODSIGN: Export module signature definitions")
MODULE_SIG_FORMAT is needed to select SYSTEM_DATA_VERIFICATION. But
SYSTEM_DATA_VERIFICATION is also selected by FS_VERITY*, so dropping
MODULE_SIG_FORMAT does not hurt."
Therefore, the solution is to drop the MODULE_SIG_FORMAT dependency
from KEXEC_SIG. Still results in equivalent .config files for s390.
Signed-off-by: Eric DeVolder <eric.devolder@xxxxxxxxxx>
Acked-by: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
---
arch/s390/Kconfig | 65 ++++++++++++++---------------------------------
1 file changed, 19 insertions(+), 46 deletions(-)
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 5b39918b7042..5d4fbbfdd1cd 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -244,6 +244,25 @@ config PGTABLE_LEVELS
source "kernel/livepatch/Kconfig"
+config ARCH_DEFAULT_KEXEC
+ def_bool y
+
+config ARCH_SUPPORTS_KEXEC
+ def_bool y
+
+config ARCH_SUPPORTS_KEXEC_FILE
+ def_bool CRYPTO && CRYPTO_SHA256 && CRYPTO_SHA256_S390
+
+config ARCH_HAS_KEXEC_PURGATORY
+ def_bool KEXEC_FILE
+
+config ARCH_SUPPORTS_CRASH_DUMP
+ def_bool y
+ help
+ Refer to <file:Documentation/s390/zfcpdump.rst> for more details on this.
+ This option also enables s390 zfcpdump.
+ See also <file:Documentation/s390/zfcpdump.rst>
+
menu "Processor type and features"
config HAVE_MARCH_Z10_FEATURES
@@ -482,36 +501,6 @@ config SCHED_TOPOLOGY
source "kernel/Kconfig.hz"
-config KEXEC
- def_bool y
- select KEXEC_CORE
-
-config KEXEC_FILE
- bool "kexec file based system call"
- select KEXEC_CORE
- depends on CRYPTO
- depends on CRYPTO_SHA256
- depends on CRYPTO_SHA256_S390
- help
- Enable the kexec file based system call. In contrast to the normal
- kexec system call this system call takes file descriptors for the
- kernel and initramfs as arguments.
-
-config ARCH_HAS_KEXEC_PURGATORY
- def_bool y
- depends on KEXEC_FILE
-
-config KEXEC_SIG
- bool "Verify kernel signature during kexec_file_load() syscall"
- depends on KEXEC_FILE && MODULE_SIG_FORMAT
- help
- This option makes kernel signature verification mandatory for
- the kexec_file_load() syscall.
-
- In addition to that option, you need to enable signature
- verification for the corresponding kernel image type being
- loaded in order for this to work.
-
config KERNEL_NOBP
def_bool n
prompt "Enable modified branch prediction for the kernel by default"
@@ -733,22 +722,6 @@ config VFIO_AP
endmenu
-menu "Dump support"
-
-config CRASH_DUMP
- bool "kernel crash dumps"
- select KEXEC
- help
- Generate crash dump after being started by kexec.
- Crash dump kernels are loaded in the main kernel with kexec-tools
- into a specially reserved region and then later executed after
- a crash by kdump/kexec.
- Refer to <file:Documentation/s390/zfcpdump.rst> for more details on this.
- This option also enables s390 zfcpdump.
- See also <file:Documentation/s390/zfcpdump.rst>
-
-endmenu
-
config CCW
def_bool y
--
2.31.1
I just bisected the following build failure visible with 'ARCH=s390
allnoconfig' to this change as commit 842ce0e1dafa ("s390/kexec:
refactor for kernel/Kconfig.kexec") in -next.
arch/s390/kernel/machine_kexec.c:120:37: warning: 'struct kimage' declared inside parameter
list will not be visible outside of this definition or declaration
120 | static bool kdump_csum_valid(struct kimage *image)
| ^~~~~~
arch/s390/kernel/machine_kexec.c:188:34: warning: 'struct kimage' declared inside parameter
list will not be visible outside of this definition or declaration
188 | int machine_kexec_prepare(struct kimage *image)
| ^~~~~~
arch/s390/kernel/machine_kexec.c: In function 'machine_kexec_prepare':
arch/s390/kernel/machine_kexec.c:192:18: error: invalid use of undefined type 'struct kimage'
192 | if (image->type == KEXEC_TYPE_CRASH)
| ^~
arch/s390/kernel/machine_kexec.c:192:28: error: 'KEXEC_TYPE_CRASH' undeclared (first use in
this function); did you mean 'KEXEC_ON_CRASH'?
192 | if (image->type == KEXEC_TYPE_CRASH)
| ^~~~~~~~~~~~~~~~
| KEXEC_ON_CRASH
arch/s390/kernel/machine_kexec.c:192:28: note: each undeclared identifier is reported only once
for each function it appears in
arch/s390/kernel/machine_kexec.c:196:18: error: invalid use of undefined type 'struct kimage'
196 | if (image->type != KEXEC_TYPE_DEFAULT)
| ^~
arch/s390/kernel/machine_kexec.c:196:28: error: 'KEXEC_TYPE_DEFAULT' undeclared (first use in
this function); did you mean 'KEXEC_ARCH_DEFAULT'?
196 | if (image->type != KEXEC_TYPE_DEFAULT)
| ^~~~~~~~~~~~~~~~~~
| KEXEC_ARCH_DEFAULT
In file included from arch/s390/include/asm/thread_info.h:31,
from include/linux/thread_info.h:60,
from arch/s390/include/asm/preempt.h:6,
from include/linux/preempt.h:79,
from arch/s390/include/asm/percpu.h:5,
from include/linux/irqflags.h:18,
from include/linux/rcupdate.h:26,
from include/linux/rculist.h:11,
from include/linux/pid.h:5,
from include/linux/sched.h:14,
from include/linux/ratelimit.h:6,
from include/linux/dev_printk.h:16,
from include/linux/device.h:15,
from arch/s390/kernel/machine_kexec.c:9:
arch/s390/kernel/machine_kexec.c:200:48: error: invalid use of undefined type 'struct kimage'
200 | reboot_code_buffer = page_to_virt(image->control_code_page);
| ^~
arch/s390/include/asm/page.h:186:58: note: in definition of macro '__va'
186 | #define __va(x) ((void *)(unsigned long)(x))
| ^
arch/s390/include/asm/page.h:194:38: note: in expansion of macro 'pfn_to_phys'
194 | #define pfn_to_virt(pfn) __va(pfn_to_phys(pfn))
| ^~~~~~~~~~~
arch/s390/include/asm/page.h:199:33: note: in expansion of macro 'pfn_to_virt'
199 | #define page_to_virt(page) pfn_to_virt(page_to_pfn(page))
| ^~~~~~~~~~~
include/asm-generic/memory_model.h:64:21: note: in expansion of macro '__page_to_pfn'
64 | #define page_to_pfn __page_to_pfn
| ^~~~~~~~~~~~~
arch/s390/kernel/machine_kexec.c:200:30: note: in expansion of macro 'page_to_virt'
200 | reboot_code_buffer = page_to_virt(image->control_code_page);
| ^~~~~~~~~~~~
arch/s390/kernel/machine_kexec.c: At top level:
arch/s390/kernel/machine_kexec.c:207:35: warning: 'struct kimage' declared inside parameter
list will not be visible outside of this definition or declaration
207 | void machine_kexec_cleanup(struct kimage *image)
| ^~~~~~
arch/s390/kernel/machine_kexec.c: In function '__do_machine_kexec':
arch/s390/kernel/machine_kexec.c:243:40: error: invalid use of undefined type 'struct kimage'
243 | data_mover = page_to_phys(image->control_code_page);
| ^~
arch/s390/include/asm/page.h:189:35: note: in definition of macro 'pfn_to_phys'
189 | #define pfn_to_phys(pfn) ((pfn) << PAGE_SHIFT)
| ^~~
include/asm-generic/memory_model.h:64:21: note: in expansion of macro '__page_to_pfn'
64 | #define page_to_pfn __page_to_pfn
| ^~~~~~~~~~~~~
arch/s390/kernel/machine_kexec.c:243:22: note: in expansion of macro 'page_to_phys'
243 | data_mover = page_to_phys(image->control_code_page);
| ^~~~~~~~~~~~
arch/s390/kernel/machine_kexec.c:244:36: error: invalid use of undefined type 'struct kimage'
244 | entry = virt_to_phys(&image->head);
| ^~
In file included from arch/s390/kernel/machine_kexec.c:27:
arch/s390/kernel/machine_kexec.c:252:40: error: invalid use of undefined type 'struct kimage'
252 | unsigned long, image->start,
| ^~
arch/s390/include/asm/stacktrace.h:101:32: note: in definition of macro 'CALL_LARGS_2'
101 | long arg2 = (long)(t2)(a2)
| ^~
arch/s390/include/asm/stacktrace.h:216:9: note: in expansion of macro 'CALL_LARGS_3'
216 | CALL_LARGS_##nr(__VA_ARGS__); \
| ^~~~~~~~~~~
arch/s390/kernel/machine_kexec.c:250:9: note: in expansion of macro 'call_nodat'
250 | call_nodat(3, void, (relocate_kernel_t)data_mover,
| ^~~~~~~~~~
In file included from include/linux/irqflags.h:15:
arch/s390/kernel/machine_kexec.c:252:40: error: invalid use of undefined type 'struct kimage'
252 | unsigned long, image->start,
| ^~
include/linux/typecheck.h:11:16: note: in definition of macro 'typecheck'
11 | typeof(x) __dummy2; \
| ^
arch/s390/include/asm/stacktrace.h:136:9: note: in expansion of macro 'CALL_TYPECHECK_2'
136 | CALL_TYPECHECK_2(__VA_ARGS__); \
| ^~~~~~~~~~~~~~~~
arch/s390/include/asm/stacktrace.h:219:9: note: in expansion of macro 'CALL_TYPECHECK_3'
219 | CALL_TYPECHECK_##nr(__VA_ARGS__); \
| ^~~~~~~~~~~~~~~
arch/s390/kernel/machine_kexec.c:250:9: note: in expansion of macro 'call_nodat'
250 | call_nodat(3, void, (relocate_kernel_t)data_mover,
| ^~~~~~~~~~
include/linux/typecheck.h:12:25: warning: comparison of distinct pointer types lacks a cast
12 | (void)(&__dummy == &__dummy2); \
| ^~
arch/s390/include/asm/stacktrace.h:134:9: note: in expansion of macro 'typecheck'
134 | typecheck(t, a)
| ^~~~~~~~~
arch/s390/include/asm/stacktrace.h:136:9: note: in expansion of macro 'CALL_TYPECHECK_2'
136 | CALL_TYPECHECK_2(__VA_ARGS__); \
| ^~~~~~~~~~~~~~~~
arch/s390/include/asm/stacktrace.h:219:9: note: in expansion of macro 'CALL_TYPECHECK_3'
219 | CALL_TYPECHECK_##nr(__VA_ARGS__); \
| ^~~~~~~~~~~~~~~
arch/s390/kernel/machine_kexec.c:250:9: note: in expansion of macro 'call_nodat'
250 | call_nodat(3, void, (relocate_kernel_t)data_mover,
| ^~~~~~~~~~
arch/s390/kernel/machine_kexec.c: At top level:
arch/s390/kernel/machine_kexec.c:278:27: warning: 'struct kimage' declared inside parameter
list will not be visible outside of this definition or declaration
278 | void machine_kexec(struct kimage *image)
| ^~~~~~
arch/s390/kernel/machine_kexec.c: In function 'machine_kexec':
arch/s390/kernel/machine_kexec.c:280:18: error: invalid use of undefined type 'struct kimage'
280 | if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
| ^~
arch/s390/kernel/machine_kexec.c:280:28: error: 'KEXEC_TYPE_CRASH' undeclared (first use in
this function); did you mean 'KEXEC_ON_CRASH'?
280 | if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
| ^~~~~~~~~~~~~~~~
| KEXEC_ON_CRASH
arch/s390/kernel/machine_kexec.c:280:66: error: passing argument 1 of 'kdump_csum_valid' from
incompatible pointer type [-Werror=incompatible-pointer-types]
280 | if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
| ^~~~~
| |
| struct kimage *
arch/s390/kernel/machine_kexec.c:120:45: note: expected 'struct kimage *' but argument is of
type 'struct kimage *'
120 | static bool kdump_csum_valid(struct kimage *image)
| ~~~~~~~~~~~~~~~^~~~~
cc1: some warnings being treated as errors
I don't think this change is equivalent for s390, which had
config KEXEC
def_bool y
select KEXEC_CORE
but it is now the equivalent of
config KEXEC
bool "Enable kexec system call"
default y
which enables KEXEC by default but it also allows KEXEC to be disabled
for s390 now, because it is a user-visible symbol, not one that is
unconditionally enabled no matter what. If s390 can tolerate KEXEC being
user selectable, then I assume the fix is just adjusting
arch/s390/kernel/Makefile to only build the machine_kexec files when
CONFIG_KEXEC_CORE is set:
diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index 6b2a051e1f8a..a06b39da95f0 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -37,10 +37,10 @@ CFLAGS_unwind_bc.o += -fno-optimize-sibling-calls
obj-y := head64.o traps.o time.o process.o earlypgm.o early.o setup.o idle.o vtime.o
obj-y += processor.o syscall.o ptrace.o signal.o cpcmd.o ebcdic.o nmi.o
obj-y += debug.o irq.o ipl.o dis.o diag.o vdso.o cpufeature.o
-obj-y += sysinfo.o lgr.o os_info.o machine_kexec.o
+obj-y += sysinfo.o lgr.o os_info.o
obj-y += runtime_instr.o cache.o fpu.o dumpstack.o guarded_storage.o sthyi.o
obj-y += entry.o reipl.o relocate_kernel.o kdebugfs.o alternative.o
-obj-y += nospec-branch.o ipl_vmparm.o machine_kexec_reloc.o unwind_bc.o
+obj-y += nospec-branch.o ipl_vmparm.o unwind_bc.o
obj-y += smp.o text_amode31.o stacktrace.o abs_lowcore.o
extra-y += vmlinux.lds
@@ -66,6 +66,7 @@ obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
obj-$(CONFIG_UPROBES) += uprobes.o
obj-$(CONFIG_JUMP_LABEL) += jump_label.o
+obj-$(CONFIG_KEXEC_CORE) += machine_kexec.o machine_kexec_reloc.o
obj-$(CONFIG_KEXEC_FILE) += machine_kexec_file.o kexec_image.o
obj-$(CONFIG_KEXEC_FILE) += kexec_elf.o
Otherwise, the prompt for KEXEC could be made conditional on some ARCH
symbol so that architectures can opt out of it.
