diff options
Diffstat (limited to 'kernel/crash_core.c')
| -rw-r--r-- | kernel/crash_core.c | 68 |
1 files changed, 38 insertions, 30 deletions
diff --git a/kernel/crash_core.c b/kernel/crash_core.c index 78b5dc7cee3a..335b8425dd4b 100644 --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -4,6 +4,8 @@ * Copyright (C) 2002-2004 Eric Biederman <ebiederm@xmission.com> */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + #include <linux/buildid.h> #include <linux/init.h> #include <linux/utsname.h> @@ -434,7 +436,7 @@ void crash_save_cpu(struct pt_regs *regs, int cpu) memset(&prstatus, 0, sizeof(prstatus)); prstatus.common.pr_pid = current->pid; elf_core_copy_regs(&prstatus.pr_reg, regs); - buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS, + buf = append_elf_note(buf, NN_PRSTATUS, NT_PRSTATUS, &prstatus, sizeof(prstatus)); final_note(buf); } @@ -493,25 +495,23 @@ 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; crash_hotplug_lock(); /* Obtain lock while reading crash information */ if (!kexec_trylock()) { - pr_info("kexec_trylock() failed, elfcorehdr may be inaccurate\n"); + if (!kexec_in_progress) + pr_info("kexec_trylock() failed, kdump image may be inaccurate\n"); crash_hotplug_unlock(); 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(); @@ -521,27 +521,35 @@ int crash_check_update_elfcorehdr(void) } /* - * To accurately reflect hot un/plug changes of cpu and memory resources - * (including onling and offlining of those resources), the elfcorehdr - * (which is passed to the crash kernel via the elfcorehdr= parameter) - * must be updated with the new list of CPUs and memories. + * To accurately reflect hot un/plug changes of CPU and Memory resources + * (including onling and offlining of those resources), the relevant + * kexec segments must be updated with latest CPU and Memory resources. + * + * Architectures must ensure two things for all segments that need + * updating during hotplug events: + * + * 1. Segments must be large enough to accommodate a growing number of + * resources. + * 2. Exclude the segments from SHA verification. * - * In order to make changes to elfcorehdr, two conditions are needed: - * First, the segment containing the elfcorehdr must be large enough - * to permit a growing number of resources; the elfcorehdr memory size - * is based on NR_CPUS_DEFAULT and CRASH_MAX_MEMORY_RANGES. - * Second, purgatory must explicitly exclude the elfcorehdr from the - * list of segments it checks (since the elfcorehdr changes and thus - * would require an update to purgatory itself to update the digest). + * For example, on most architectures, the elfcorehdr (which is passed + * to the crash kernel via the elfcorehdr= parameter) must include the + * new list of CPUs and memory. To make changes to the elfcorehdr, it + * should be large enough to permit a growing number of CPU and Memory + * resources. One can estimate the elfcorehdr memory size based on + * NR_CPUS_DEFAULT and CRASH_MAX_MEMORY_RANGES. The elfcorehdr is + * excluded from SHA verification by default if the architecture + * supports crash hotplug. */ -static void crash_handle_hotplug_event(unsigned int hp_action, unsigned int cpu) +static void crash_handle_hotplug_event(unsigned int hp_action, unsigned int cpu, void *arg) { struct kimage *image; crash_hotplug_lock(); /* Obtain lock while changing crash information */ if (!kexec_trylock()) { - pr_info("kexec_trylock() failed, elfcorehdr may be inaccurate\n"); + if (!kexec_in_progress) + pr_info("kexec_trylock() failed, kdump image may be inaccurate\n"); crash_hotplug_unlock(); return; } @@ -552,8 +560,8 @@ 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 || @@ -596,7 +604,7 @@ static void crash_handle_hotplug_event(unsigned int hp_action, unsigned int cpu) image->hp_action = hp_action; /* Now invoke arch-specific update handler */ - arch_crash_handle_hotplug_event(image); + arch_crash_handle_hotplug_event(image, arg); /* No longer handling a hotplug event */ image->hp_action = KEXEC_CRASH_HP_NONE; @@ -612,17 +620,17 @@ out: crash_hotplug_unlock(); } -static int crash_memhp_notifier(struct notifier_block *nb, unsigned long val, void *v) +static int crash_memhp_notifier(struct notifier_block *nb, unsigned long val, void *arg) { switch (val) { case MEM_ONLINE: crash_handle_hotplug_event(KEXEC_CRASH_HP_ADD_MEMORY, - KEXEC_CRASH_HP_INVALID_CPU); + KEXEC_CRASH_HP_INVALID_CPU, arg); break; case MEM_OFFLINE: crash_handle_hotplug_event(KEXEC_CRASH_HP_REMOVE_MEMORY, - KEXEC_CRASH_HP_INVALID_CPU); + KEXEC_CRASH_HP_INVALID_CPU, arg); break; } return NOTIFY_OK; @@ -635,13 +643,13 @@ static struct notifier_block crash_memhp_nb = { static int crash_cpuhp_online(unsigned int cpu) { - crash_handle_hotplug_event(KEXEC_CRASH_HP_ADD_CPU, cpu); + crash_handle_hotplug_event(KEXEC_CRASH_HP_ADD_CPU, cpu, NULL); return 0; } static int crash_cpuhp_offline(unsigned int cpu) { - crash_handle_hotplug_event(KEXEC_CRASH_HP_REMOVE_CPU, cpu); + crash_handle_hotplug_event(KEXEC_CRASH_HP_REMOVE_CPU, cpu, NULL); return 0; } |