crash: split crash dumping code out from kexec_core.c

Currently, KEXEC_CORE select CRASH_CORE automatically because crash codes need be built in to avoid compiling error when building kexec code even though the crash dumping functionality is not enabled. E.g -------------------- CONFIG_CRASH_CORE=y CONFIG_KEXEC_CORE=y CONFIG_KEXEC=y CONFIG_KEXEC_FILE=y --------------------- After splitting out crashkernel reservation code and vmcoreinfo exporting code, there's only crash related code left in kernel/crash_core.c. Now move crash related codes from kexec_core.c to crash_core.c and only build it in when CONFIG_CRASH_DUMP=y. And also wrap up crash codes inside CONFIG_CRASH_DUMP ifdeffery scope, or replace inappropriate CONFIG_KEXEC_CORE ifdef with CONFIG_CRASH_DUMP ifdef in generic kernel files. With these changes, crash_core codes are abstracted from kexec codes and can be disabled at all if only kexec reboot feature is wanted. Link: https://lkml.kernel.org/r/20240124051254.67105-5-bhe@redhat.com Signed-off-by: Baoquan He <bhe@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Hari Bathini <hbathini@linux.ibm.com> Cc: Pingfan Liu <piliu@redhat.com> Cc: Klara Modin <klarasmodin@gmail.com> Cc: Michael Kelley <mhklinux@outlook.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Yang Li <yang.lee@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mariux64 · Feb 24, 2024 · 02aff84 · 02aff84
1 parent 2c44b67
commit 02aff84
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Showing 10 changed files with 359 additions and 292 deletions.
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
@@ -144,7 +144,7 @@ static DEVICE_ATTR(release, S_IWUSR, NULL, cpu_release_store);
 #endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
 #endif /* CONFIG_HOTPLUG_CPU */
 
-#ifdef CONFIG_KEXEC_CORE
+#ifdef CONFIG_CRASH_DUMP
 #include <linux/kexec.h>
 
 static ssize_t crash_notes_show(struct device *dev,
@@ -189,14 +189,14 @@ static const struct attribute_group crash_note_cpu_attr_group = {
 #endif
 
 static const struct attribute_group *common_cpu_attr_groups[] = {
-#ifdef CONFIG_KEXEC_CORE
+#ifdef CONFIG_CRASH_DUMP
 	&crash_note_cpu_attr_group,
 #endif
 	NULL
 };
 
 static const struct attribute_group *hotplugable_cpu_attr_groups[] = {
-#ifdef CONFIG_KEXEC_CORE
+#ifdef CONFIG_CRASH_DUMP
 	&crash_note_cpu_attr_group,
 #endif
 	NULL

diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h
@@ -6,6 +6,48 @@
 #include <linux/elfcore.h>
 #include <linux/elf.h>
 
+struct kimage;
+
+#ifdef CONFIG_CRASH_DUMP
+
+int crash_shrink_memory(unsigned long new_size);
+ssize_t crash_get_memory_size(void);
+
+#ifndef arch_kexec_protect_crashkres
+/*
+ * Protection mechanism for crashkernel reserved memory after
+ * the kdump kernel is loaded.
+ *
+ * Provide an empty default implementation here -- architecture
+ * code may override this
+ */
+static inline void arch_kexec_protect_crashkres(void) { }
+#endif
+
+#ifndef arch_kexec_unprotect_crashkres
+static inline void arch_kexec_unprotect_crashkres(void) { }
+#endif
+
+
+
+#ifndef arch_crash_handle_hotplug_event
+static inline void arch_crash_handle_hotplug_event(struct kimage *image) { }
+#endif
+
+int crash_check_update_elfcorehdr(void);
+
+#ifndef crash_hotplug_cpu_support
+static inline int crash_hotplug_cpu_support(void) { return 0; }
+#endif
+
+#ifndef crash_hotplug_memory_support
+static inline int crash_hotplug_memory_support(void) { return 0; }
+#endif
+
+#ifndef crash_get_elfcorehdr_size
+static inline unsigned int crash_get_elfcorehdr_size(void) { return 0; }
+#endif
+
 /* Alignment required for elf header segment */
 #define ELF_CORE_HEADER_ALIGN   4096
 
@@ -31,4 +73,23 @@ struct kexec_segment;
 #define KEXEC_CRASH_HP_REMOVE_MEMORY		4
 #define KEXEC_CRASH_HP_INVALID_CPU		-1U
 
+extern void __crash_kexec(struct pt_regs *regs);
+extern void crash_kexec(struct pt_regs *regs);
+int kexec_should_crash(struct task_struct *p);
+int kexec_crash_loaded(void);
+void crash_save_cpu(struct pt_regs *regs, int cpu);
+extern int kimage_crash_copy_vmcoreinfo(struct kimage *image);
+
+#else /* !CONFIG_CRASH_DUMP*/
+struct pt_regs;
+struct task_struct;
+struct kimage;
+static inline void __crash_kexec(struct pt_regs *regs) { }
+static inline void crash_kexec(struct pt_regs *regs) { }
+static inline int kexec_should_crash(struct task_struct *p) { return 0; }
+static inline int kexec_crash_loaded(void) { return 0; }
+static inline void crash_save_cpu(struct pt_regs *regs, int cpu) {};
+static inline int kimage_crash_copy_vmcoreinfo(struct kimage *image) { return 0; };
+#endif /* CONFIG_CRASH_DUMP*/
+
 #endif /* LINUX_CRASH_CORE_H */
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
@@ -15,7 +15,6 @@
 
 #if !defined(__ASSEMBLY__)
 
-#include <linux/crash_core.h>
 #include <linux/vmcore_info.h>
 #include <linux/crash_reserve.h>
 #include <asm/io.h>
@@ -33,6 +32,7 @@ extern note_buf_t __percpu *crash_notes;
 #include <linux/module.h>
 #include <linux/highmem.h>
 #include <asm/kexec.h>
+#include <linux/crash_core.h>
 
 /* Verify architecture specific macros are defined */
 
@@ -380,13 +380,6 @@ extern struct page *kimage_alloc_control_pages(struct kimage *image,
 static inline int machine_kexec_post_load(struct kimage *image) { return 0; }
 #endif
 
-extern void __crash_kexec(struct pt_regs *);
-extern void crash_kexec(struct pt_regs *);
-int kexec_should_crash(struct task_struct *);
-int kexec_crash_loaded(void);
-void crash_save_cpu(struct pt_regs *regs, int cpu);
-extern int kimage_crash_copy_vmcoreinfo(struct kimage *image);
-
 extern struct kimage *kexec_image;
 extern struct kimage *kexec_crash_image;
 
@@ -410,24 +403,6 @@ bool kexec_load_permitted(int kexec_image_type);
 /* flag to track if kexec reboot is in progress */
 extern bool kexec_in_progress;
 
-int crash_shrink_memory(unsigned long new_size);
-ssize_t crash_get_memory_size(void);
-
-#ifndef arch_kexec_protect_crashkres
-/*
- * Protection mechanism for crashkernel reserved memory after
- * the kdump kernel is loaded.
- *
- * Provide an empty default implementation here -- architecture
- * code may override this
- */
-static inline void arch_kexec_protect_crashkres(void) { }
-#endif
-
-#ifndef arch_kexec_unprotect_crashkres
-static inline void arch_kexec_unprotect_crashkres(void) { }
-#endif
-
 #ifndef page_to_boot_pfn
 static inline unsigned long page_to_boot_pfn(struct page *page)
 {
@@ -484,24 +459,6 @@ static inline int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, g
 static inline void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages) { }
 #endif
 
-#ifndef arch_crash_handle_hotplug_event
-static inline void arch_crash_handle_hotplug_event(struct kimage *image) { }
-#endif
-
-int crash_check_update_elfcorehdr(void);
-
-#ifndef crash_hotplug_cpu_support
-static inline int crash_hotplug_cpu_support(void) { return 0; }
-#endif
-
-#ifndef crash_hotplug_memory_support
-static inline int crash_hotplug_memory_support(void) { return 0; }
-#endif
-
-#ifndef crash_get_elfcorehdr_size
-static inline unsigned int crash_get_elfcorehdr_size(void) { return 0; }
-#endif
-
 extern bool kexec_file_dbg_print;
 
 #define kexec_dprintk(fmt, ...)					\

diff --git a/init/initramfs.c b/init/initramfs.c
@@ -642,7 +642,7 @@ void __weak __init free_initrd_mem(unsigned long start, unsigned long end)
 			"initrd");
 }
 
-#ifdef CONFIG_KEXEC_CORE
+#ifdef CONFIG_CRASH_RESERVE
 static bool __init kexec_free_initrd(void)
 {
 	unsigned long crashk_start = (unsigned long)__va(crashk_res.start);

diff --git a/kernel/Makefile b/kernel/Makefile
@@ -70,7 +70,8 @@ obj-$(CONFIG_KALLSYMS_SELFTEST) += kallsyms_selftest.o
 obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o
 obj-$(CONFIG_VMCORE_INFO) += vmcore_info.o elfcorehdr.o
 obj-$(CONFIG_CRASH_RESERVE) += crash_reserve.o
-obj-$(CONFIG_KEXEC_CORE) += kexec_core.o crash_core.o
+obj-$(CONFIG_KEXEC_CORE) += kexec_core.o
+obj-$(CONFIG_CRASH_DUMP) += crash_core.o
 obj-$(CONFIG_KEXEC) += kexec.o
 obj-$(CONFIG_KEXEC_FILE) += kexec_file.o
 obj-$(CONFIG_KEXEC_ELF) += kexec_elf.o