Commit 02aff848 authored by Baoquan He's avatar Baoquan He Committed by Andrew Morton
Browse files

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: default avatarBaoquan 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: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 2c44b67e

drivers/base/cpu.c

+3 −3
Original line number Diff line number Diff line
@@ -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

include/linux/crash_core.h

+61 −0
Original line number Diff line number Diff line
@@ -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 */

include/linux/kexec.h

+1 −44
Original line number Diff line number Diff line
@@ -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, ...)					\

init/initramfs.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

kernel/Makefile

+2 −1
Original line number Diff line number Diff line
@@ -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