[PATCH linux-next 3/3] arch, crash: move arch_crash_save_vmcoreinfo() out to file vmcore_info.c

[Baoquan He]

Nathan reported below building error:

=====
$ curl -LSso .config https://git.alpinelinux.org/aports/plain/community/linux-edge/config-edge.armv7
$ make -skj"$(nproc)" ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- olddefconfig all
..
arm-linux-gnueabi-ld: arch/arm/kernel/machine_kexec.o: in function `arch_crash_save_vmcoreinfo':
machine_kexec.c:(.text+0x488): undefined reference to `vmcoreinfo_append_str'
====

On architecutres, like arm, s390, ppc, sh, function
arch_crash_save_vmcoreinfo() is located in machine_kexec.c and it can
only be compiled in when CONFIG_KEXEC_CORE=y.

That's not right because arch_crash_save_vmcoreinfo() is used to export
arch specific vmcoreinfo. CONFIG_VMCORE_INFO is supposed to control its
compiling in. However, CONFIG_VMVCORE_INFO could be independent of
CONFIG_KEXEC_CORE, e.g CONFIG_PROC_KCORE=y will select CONFIG_VMVCORE_INFO.
Or CONFIG_KEXEC/CONFIG_KEXEC_FILE is set while CONFIG_CRASH_DUMP is
not set, it will report linking error.

So, on arm, s390, ppc and sh, move arch_crash_save_vmcoreinfo out to
a new file vmcore_info.c. Let CONFIG_VMCORE_INFO decide if compiling in
arch_crash_save_vmcoreinfo().

Reported-by: Nathan Chancellor <nathan@xxxxxxxxxx>
Closes: https://lore.kernel.org/all/20240126045551.GA126645@dev-arch.thelio-3990X/T/#u
Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
---
 arch/arm/kernel/Makefile         |  1 +
 arch/arm/kernel/machine_kexec.c  |  7 -------
 arch/arm/kernel/vmcore_info.c    | 10 ++++++++++
 arch/powerpc/kexec/Makefile      |  1 +
 arch/powerpc/kexec/core.c        | 28 --------------------------
 arch/powerpc/kexec/vmcore_info.c | 34 ++++++++++++++++++++++++++++++++
 arch/s390/kernel/Makefile        |  1 +
 arch/s390/kernel/machine_kexec.c | 15 --------------
 arch/s390/kernel/vmcore_info.c   | 23 +++++++++++++++++++++
 arch/sh/kernel/Makefile          |  1 +
 arch/sh/kernel/machine_kexec.c   | 11 -----------
 arch/sh/kernel/vmcore_info.c     | 17 ++++++++++++++++
 12 files changed, 88 insertions(+), 61 deletions(-)
 create mode 100644 arch/arm/kernel/vmcore_info.c
 create mode 100644 arch/powerpc/kexec/vmcore_info.c
 create mode 100644 arch/s390/kernel/vmcore_info.c
 create mode 100644 arch/sh/kernel/vmcore_info.c

diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index 771264d4726a..6a9de826ffd3 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -60,6 +60,7 @@ 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_CORE)	+= machine_kexec.o relocate_kernel.o
+obj-$(CONFIG_VMCORE_INFO)	+= vmcore_info.o
 # Main staffs in KPROBES are in arch/arm/probes/ .
 obj-$(CONFIG_KPROBES)		+= patch.o insn.o
 obj-$(CONFIG_OABI_COMPAT)	+= sys_oabi-compat.o
diff --git a/arch/arm/kernel/machine_kexec.c b/arch/arm/kernel/machine_kexec.c
index 5d07cf9e0044..80ceb5bd2680 100644
--- a/arch/arm/kernel/machine_kexec.c
+++ b/arch/arm/kernel/machine_kexec.c
@@ -198,10 +198,3 @@ void machine_kexec(struct kimage *image)
 
 	soft_restart(reboot_entry_phys);
 }
-
-void arch_crash_save_vmcoreinfo(void)
-{
-#ifdef CONFIG_ARM_LPAE
-	VMCOREINFO_CONFIG(ARM_LPAE);
-#endif
-}
diff --git a/arch/arm/kernel/vmcore_info.c b/arch/arm/kernel/vmcore_info.c
new file mode 100644
index 000000000000..1437aba47787
--- /dev/null
+++ b/arch/arm/kernel/vmcore_info.c
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/vmcore_info.h>
+
+void arch_crash_save_vmcoreinfo(void)
+{
+#ifdef CONFIG_ARM_LPAE
+	VMCOREINFO_CONFIG(ARM_LPAE);
+#endif
+}
diff --git a/arch/powerpc/kexec/Makefile b/arch/powerpc/kexec/Makefile
index 0c2abe7f9908..91e96f5168b7 100644
--- a/arch/powerpc/kexec/Makefile
+++ b/arch/powerpc/kexec/Makefile
@@ -8,6 +8,7 @@ obj-y				+= core.o crash.o core_$(BITS).o
 obj-$(CONFIG_PPC32)		+= relocate_32.o
 
 obj-$(CONFIG_KEXEC_FILE)	+= file_load.o ranges.o file_load_$(BITS).o elf_$(BITS).o
+obj-$(CONFIG_VMCORE_INFO)	+= vmcore_info.o
 
 # Disable GCOV, KCOV & sanitizers in odd or sensitive code
 GCOV_PROFILE_core_$(BITS).o := n
diff --git a/arch/powerpc/kexec/core.c b/arch/powerpc/kexec/core.c
index 27fa9098a5b7..3ff4411ed496 100644
--- a/arch/powerpc/kexec/core.c
+++ b/arch/powerpc/kexec/core.c
@@ -53,34 +53,6 @@ void machine_kexec_cleanup(struct kimage *image)
 {
 }
 
-void arch_crash_save_vmcoreinfo(void)
-{
-
-#ifdef CONFIG_NUMA
-	VMCOREINFO_SYMBOL(node_data);
-	VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
-#endif
-#ifndef CONFIG_NUMA
-	VMCOREINFO_SYMBOL(contig_page_data);
-#endif
-#if defined(CONFIG_PPC64) && defined(CONFIG_SPARSEMEM_VMEMMAP)
-	VMCOREINFO_SYMBOL(vmemmap_list);
-	VMCOREINFO_SYMBOL(mmu_vmemmap_psize);
-	VMCOREINFO_SYMBOL(mmu_psize_defs);
-	VMCOREINFO_STRUCT_SIZE(vmemmap_backing);
-	VMCOREINFO_OFFSET(vmemmap_backing, list);
-	VMCOREINFO_OFFSET(vmemmap_backing, phys);
-	VMCOREINFO_OFFSET(vmemmap_backing, virt_addr);
-	VMCOREINFO_STRUCT_SIZE(mmu_psize_def);
-	VMCOREINFO_OFFSET(mmu_psize_def, shift);
-#endif
-	VMCOREINFO_SYMBOL(cur_cpu_spec);
-	VMCOREINFO_OFFSET(cpu_spec, cpu_features);
-	VMCOREINFO_OFFSET(cpu_spec, mmu_features);
-	vmcoreinfo_append_str("NUMBER(RADIX_MMU)=%d\n", early_radix_enabled());
-	vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
-}
-
 /*
  * Do not allocate memory (or fail in any way) in machine_kexec().
  * We are past the point of no return, committed to rebooting now.
diff --git a/arch/powerpc/kexec/vmcore_info.c b/arch/powerpc/kexec/vmcore_info.c
new file mode 100644
index 000000000000..c15f0adaaab5
--- /dev/null
+++ b/arch/powerpc/kexec/vmcore_info.c
@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/vmcore_info.h>
+#include <asm/pgalloc.h>
+
+void arch_crash_save_vmcoreinfo(void)
+{
+
+#ifdef CONFIG_NUMA
+	VMCOREINFO_SYMBOL(node_data);
+	VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
+#endif
+#ifndef CONFIG_NUMA
+	VMCOREINFO_SYMBOL(contig_page_data);
+#endif
+#if defined(CONFIG_PPC64) && defined(CONFIG_SPARSEMEM_VMEMMAP)
+	VMCOREINFO_SYMBOL(vmemmap_list);
+	VMCOREINFO_SYMBOL(mmu_vmemmap_psize);
+	VMCOREINFO_SYMBOL(mmu_psize_defs);
+	VMCOREINFO_STRUCT_SIZE(vmemmap_backing);
+	VMCOREINFO_OFFSET(vmemmap_backing, list);
+	VMCOREINFO_OFFSET(vmemmap_backing, phys);
+	VMCOREINFO_OFFSET(vmemmap_backing, virt_addr);
+	VMCOREINFO_STRUCT_SIZE(mmu_psize_def);
+	VMCOREINFO_OFFSET(mmu_psize_def, shift);
+#endif
+	VMCOREINFO_SYMBOL(cur_cpu_spec);
+	VMCOREINFO_OFFSET(cpu_spec, cpu_features);
+	VMCOREINFO_OFFSET(cpu_spec, mmu_features);
+	vmcoreinfo_append_str("NUMBER(RADIX_MMU)=%d\n", early_radix_enabled());
+	vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
+}
+
+
diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index 7a562b4199c8..fa029d0dc28f 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -64,6 +64,7 @@ obj-$(CONFIG_FUNCTION_TRACER)	+= ftrace.o
 obj-$(CONFIG_FUNCTION_TRACER)	+= mcount.o
 obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
 obj-$(CONFIG_KEXEC_CORE)	+= machine_kexec.o relocate_kernel.o
+obj-$(CONFIG_VMCORE_INFO)	+= vmcore_info.o
 obj-$(CONFIG_UPROBES)		+= uprobes.o
 obj-$(CONFIG_JUMP_LABEL)	+= jump_label.o
 
diff --git a/arch/s390/kernel/machine_kexec.c b/arch/s390/kernel/machine_kexec.c
index aa22ffc16bcd..10277a460204 100644
--- a/arch/s390/kernel/machine_kexec.c
+++ b/arch/s390/kernel/machine_kexec.c
@@ -209,21 +209,6 @@ void machine_kexec_cleanup(struct kimage *image)
 {
 }
 
-void arch_crash_save_vmcoreinfo(void)
-{
-	struct lowcore *abs_lc;
-
-	VMCOREINFO_SYMBOL(lowcore_ptr);
-	VMCOREINFO_SYMBOL(high_memory);
-	VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
-	vmcoreinfo_append_str("SAMODE31=%lx\n", (unsigned long)__samode31);
-	vmcoreinfo_append_str("EAMODE31=%lx\n", (unsigned long)__eamode31);
-	vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
-	abs_lc = get_abs_lowcore();
-	abs_lc->vmcore_info = paddr_vmcoreinfo_note();
-	put_abs_lowcore(abs_lc);
-}
-
 void machine_shutdown(void)
 {
 }
diff --git a/arch/s390/kernel/vmcore_info.c b/arch/s390/kernel/vmcore_info.c
new file mode 100644
index 000000000000..eccb6b20b505
--- /dev/null
+++ b/arch/s390/kernel/vmcore_info.c
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/vmcore_info.h>
+#include <asm/abs_lowcore.h>
+#include <linux/mm.h>
+#include <asm/setup.h>
+
+void arch_crash_save_vmcoreinfo(void)
+{
+	struct lowcore *abs_lc;
+
+	VMCOREINFO_SYMBOL(lowcore_ptr);
+	VMCOREINFO_SYMBOL(high_memory);
+	VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
+	vmcoreinfo_append_str("SAMODE31=%lx\n", (unsigned long)__samode31);
+	vmcoreinfo_append_str("EAMODE31=%lx\n", (unsigned long)__eamode31);
+	vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
+	abs_lc = get_abs_lowcore();
+	abs_lc->vmcore_info = paddr_vmcoreinfo_note();
+	put_abs_lowcore(abs_lc);
+}
+
+
diff --git a/arch/sh/kernel/Makefile b/arch/sh/kernel/Makefile
index 2d7e70537de0..ba917008d63e 100644
--- a/arch/sh/kernel/Makefile
+++ b/arch/sh/kernel/Makefile
@@ -34,6 +34,7 @@ obj-$(CONFIG_SH_STANDARD_BIOS)	+= sh_bios.o
 obj-$(CONFIG_KGDB)		+= kgdb.o
 obj-$(CONFIG_MODULES)		+= sh_ksyms_32.o module.o
 obj-$(CONFIG_KEXEC_CORE)	+= machine_kexec.o relocate_kernel.o
+obj-$(CONFIG_VMCORE_INFO)	+= vmcore_info.o
 obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
 obj-$(CONFIG_STACKTRACE)	+= stacktrace.o
 obj-$(CONFIG_IO_TRAPPED)	+= io_trapped.o
diff --git a/arch/sh/kernel/machine_kexec.c b/arch/sh/kernel/machine_kexec.c
index 8daa8a6e6fa6..8321b31d2e19 100644
--- a/arch/sh/kernel/machine_kexec.c
+++ b/arch/sh/kernel/machine_kexec.c
@@ -137,17 +137,6 @@ void machine_kexec(struct kimage *image)
 	__ftrace_enabled_restore(save_ftrace_enabled);
 }
 
-void arch_crash_save_vmcoreinfo(void)
-{
-#ifdef CONFIG_NUMA
-	VMCOREINFO_SYMBOL(node_data);
-	VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
-#endif
-#ifdef CONFIG_X2TLB
-	VMCOREINFO_CONFIG(X2TLB);
-#endif
-}
-
 void __init reserve_crashkernel(void)
 {
 	unsigned long long crash_size, crash_base;
diff --git a/arch/sh/kernel/vmcore_info.c b/arch/sh/kernel/vmcore_info.c
new file mode 100644
index 000000000000..04c4387e6315
--- /dev/null
+++ b/arch/sh/kernel/vmcore_info.c
@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/vmcore_info.h>
+#include <linux/mm.h>
+
+void arch_crash_save_vmcoreinfo(void)
+{
+#ifdef CONFIG_NUMA
+	VMCOREINFO_SYMBOL(node_data);
+	VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
+#endif
+#ifdef CONFIG_X2TLB
+	VMCOREINFO_CONFIG(X2TLB);
+#endif
+}
+
+
-- 
2.41.0