diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h index cb1320ebbc23..ae5482a2f0ca 100644 --- a/arch/x86/include/asm/kexec.h +++ b/arch/x86/include/asm/kexec.h @@ -210,15 +210,8 @@ extern void kdump_nmi_shootdown_cpus(void); void arch_crash_handle_hotplug_event(struct kimage *image, void *arg); #define arch_crash_handle_hotplug_event arch_crash_handle_hotplug_event -#ifdef CONFIG_HOTPLUG_CPU -int arch_crash_hotplug_cpu_support(void); -#define crash_hotplug_cpu_support arch_crash_hotplug_cpu_support -#endif - -#ifdef CONFIG_MEMORY_HOTPLUG -int arch_crash_hotplug_memory_support(void); -#define crash_hotplug_memory_support arch_crash_hotplug_memory_support -#endif +int arch_crash_hotplug_support(struct kimage *image, unsigned long kexec_flags); +#define arch_crash_hotplug_support arch_crash_hotplug_support unsigned int arch_crash_get_elfcorehdr_size(void); #define crash_get_elfcorehdr_size arch_crash_get_elfcorehdr_size diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c index 2a682fe86352..f06501445cd9 100644 --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c @@ -402,20 +402,26 @@ int crash_load_segments(struct kimage *image) #undef pr_fmt #define pr_fmt(fmt) "crash hp: " fmt -/* These functions provide the value for the sysfs crash_hotplug nodes */ -#ifdef CONFIG_HOTPLUG_CPU -int arch_crash_hotplug_cpu_support(void) +int arch_crash_hotplug_support(struct kimage *image, unsigned long kexec_flags) { - return crash_check_update_elfcorehdr(); -} -#endif -#ifdef CONFIG_MEMORY_HOTPLUG -int arch_crash_hotplug_memory_support(void) -{ - return crash_check_update_elfcorehdr(); -} +#ifdef CONFIG_KEXEC_FILE + if (image->file_mode) + return 1; #endif + /* + * Initially, crash hotplug support for kexec_load was added + * with the KEXEC_UPDATE_ELFCOREHDR flag. Later, this + * functionality was expanded to accommodate multiple kexec + * segment updates, leading to the introduction of the + * KEXEC_CRASH_HOTPLUG_SUPPORT kexec flag bit. Consequently, + * when the kexec tool sends either of these flags, it indicates + * that the required kexec segment (elfcorehdr) is excluded from + * the SHA calculation. + */ + return (kexec_flags & KEXEC_UPDATE_ELFCOREHDR || + kexec_flags & KEXEC_CRASH_HOTPLUG_SUPPORT); +} unsigned int arch_crash_get_elfcorehdr_size(void) { diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 56fba44ba391..c61ecb0c2ae2 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -306,7 +306,7 @@ static ssize_t crash_hotplug_show(struct device *dev, struct device_attribute *attr, char *buf) { - return sysfs_emit(buf, "%d\n", crash_hotplug_cpu_support()); + return sysfs_emit(buf, "%d\n", crash_check_hotplug_support()); } static DEVICE_ATTR_ADMIN_RO(crash_hotplug); #endif diff --git a/drivers/base/memory.c b/drivers/base/memory.c index c0436f46cfb7..67858eeb92ed 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -535,7 +535,7 @@ static DEVICE_ATTR_RW(auto_online_blocks); static ssize_t crash_hotplug_show(struct device *dev, struct device_attribute *attr, char *buf) { - return sysfs_emit(buf, "%d\n", crash_hotplug_memory_support()); + return sysfs_emit(buf, "%d\n", crash_check_hotplug_support()); } static DEVICE_ATTR_RO(crash_hotplug); #endif diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h index 647e928efee8..44305336314e 100644 --- a/include/linux/crash_core.h +++ b/include/linux/crash_core.h @@ -40,14 +40,13 @@ static inline void arch_kexec_unprotect_crashkres(void) { } static inline void arch_crash_handle_hotplug_event(struct kimage *image, void *arg) { } #endif -int crash_check_update_elfcorehdr(void); +int crash_check_hotplug_support(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; } +#ifndef arch_crash_hotplug_support +static inline int arch_crash_hotplug_support(struct kimage *image, unsigned long kexec_flags) +{ + return 0; +} #endif #ifndef crash_get_elfcorehdr_size diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 060835bb82d5..5b93a5767413 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -319,8 +319,10 @@ struct kimage { /* If set, we are using file mode kexec syscall */ unsigned int file_mode:1; #ifdef CONFIG_CRASH_HOTPLUG - /* If set, allow changes to elfcorehdr of kexec_load'd image */ - unsigned int update_elfcorehdr:1; + /* If set, it is safe to update kexec segments that are + * excluded from SHA calculation. + */ + unsigned int hotplug_support:1; #endif #ifdef ARCH_HAS_KIMAGE_ARCH @@ -391,9 +393,10 @@ bool kexec_load_permitted(int kexec_image_type); /* List of defined/legal kexec flags */ #ifndef CONFIG_KEXEC_JUMP -#define KEXEC_FLAGS (KEXEC_ON_CRASH | KEXEC_UPDATE_ELFCOREHDR) +#define KEXEC_FLAGS (KEXEC_ON_CRASH | KEXEC_UPDATE_ELFCOREHDR | KEXEC_CRASH_HOTPLUG_SUPPORT) #else -#define KEXEC_FLAGS (KEXEC_ON_CRASH | KEXEC_PRESERVE_CONTEXT | KEXEC_UPDATE_ELFCOREHDR) +#define KEXEC_FLAGS (KEXEC_ON_CRASH | KEXEC_PRESERVE_CONTEXT | KEXEC_UPDATE_ELFCOREHDR | \ + KEXEC_CRASH_HOTPLUG_SUPPORT) #endif /* List of defined/legal kexec file flags */ diff --git a/include/uapi/linux/kexec.h b/include/uapi/linux/kexec.h index c17bb096ea68..5ae1741ea8ea 100644 --- a/include/uapi/linux/kexec.h +++ b/include/uapi/linux/kexec.h @@ -13,6 +13,7 @@ #define KEXEC_ON_CRASH 0x00000001 #define KEXEC_PRESERVE_CONTEXT 0x00000002 #define KEXEC_UPDATE_ELFCOREHDR 0x00000004 +#define KEXEC_CRASH_HOTPLUG_SUPPORT 0x00000008 #define KEXEC_ARCH_MASK 0xffff0000 /* diff --git a/kernel/crash_core.c b/kernel/crash_core.c index 70fa8111a9d6..394db3ebe835 100644 --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -493,10 +493,10 @@ static DEFINE_MUTEX(__crash_hotplug_lock); /* * This routine utilized when the crash_hotplug sysfs node is read. - * It reflects the kernel's ability/permission to update the crash - * elfcorehdr directly. + * It reflects the kernel's ability/permission to update the kdump + * image directly. */ -int crash_check_update_elfcorehdr(void) +int crash_check_hotplug_support(void) { int rc = 0; @@ -508,10 +508,7 @@ int crash_check_update_elfcorehdr(void) return 0; } if (kexec_crash_image) { - if (kexec_crash_image->file_mode) - rc = 1; - else - rc = kexec_crash_image->update_elfcorehdr; + rc = kexec_crash_image->hotplug_support; } /* Release lock now that update complete */ kexec_unlock(); @@ -552,8 +549,8 @@ static void crash_handle_hotplug_event(unsigned int hp_action, unsigned int cpu, image = kexec_crash_image; - /* Check that updating elfcorehdr is permitted */ - if (!(image->file_mode || image->update_elfcorehdr)) + /* Check that kexec segments update is permitted */ + if (!image->hotplug_support) goto out; if (hp_action == KEXEC_CRASH_HP_ADD_CPU || diff --git a/kernel/kexec.c b/kernel/kexec.c index bab542fc1463..a6b3f96bb50c 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -135,8 +135,8 @@ static int do_kexec_load(unsigned long entry, unsigned long nr_segments, image->preserve_context = 1; #ifdef CONFIG_CRASH_HOTPLUG - if (flags & KEXEC_UPDATE_ELFCOREHDR) - image->update_elfcorehdr = 1; + if ((flags & KEXEC_ON_CRASH) && arch_crash_hotplug_support(image, flags)) + image->hotplug_support = 1; #endif ret = machine_kexec_prepare(image); diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index 2d1db05fbf04..3d64290d24c9 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -376,6 +376,11 @@ SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd, if (ret) goto out; +#ifdef CONFIG_CRASH_HOTPLUG + if ((flags & KEXEC_FILE_ON_CRASH) && arch_crash_hotplug_support(image, flags)) + image->hotplug_support = 1; +#endif + ret = machine_kexec_prepare(image); if (ret) goto out;