diff options
Diffstat (limited to 'kernel/kexec_core.c')
| -rw-r--r-- | kernel/kexec_core.c | 91 |
1 files changed, 44 insertions, 47 deletions
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index 5a5d192a89ac..ca2743f9c634 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -46,7 +46,7 @@ #include <crypto/hash.h> #include "kexec_internal.h" -DEFINE_MUTEX(kexec_mutex); +atomic_t __kexec_lock = ATOMIC_INIT(0); /* Per cpu memory for storing cpu states in case of system crash. */ note_buf_t __percpu *crash_notes; @@ -81,7 +81,7 @@ int kexec_should_crash(struct task_struct *p) if (crash_kexec_post_notifiers) return 0; /* - * There are 4 panic() calls in do_exit() path, each of which + * There are 4 panic() calls in make_task_dead() path, each of which * corresponds to each of these 4 conditions. */ if (in_interrupt() || !p->pid || is_global_init(p) || panic_on_oops) @@ -591,11 +591,6 @@ static void kimage_free_extra_pages(struct kimage *image) } -int __weak machine_kexec_post_load(struct kimage *image) -{ - return 0; -} - void kimage_terminate(struct kimage *image) { if (*image->entry != 0) @@ -768,7 +763,6 @@ static struct page *kimage_alloc_page(struct kimage *image, kimage_free_pages(old_page); continue; } - addr = old_addr; page = old_page; break; } @@ -788,7 +782,6 @@ static int kimage_load_normal_segment(struct kimage *image, unsigned char __user *buf = NULL; unsigned char *kbuf = NULL; - result = 0; if (image->file_mode) kbuf = segment->kbuf; else @@ -816,7 +809,7 @@ static int kimage_load_normal_segment(struct kimage *image, if (result < 0) goto out; - ptr = kmap(page); + ptr = kmap_local_page(page); /* Start with a clear page */ clear_page(ptr); ptr += maddr & ~PAGE_MASK; @@ -829,7 +822,7 @@ static int kimage_load_normal_segment(struct kimage *image, memcpy(ptr, kbuf, uchunk); else result = copy_from_user(ptr, buf, uchunk); - kunmap(page); + kunmap_local(ptr); if (result) { result = -EFAULT; goto out; @@ -880,7 +873,7 @@ static int kimage_load_crash_segment(struct kimage *image, goto out; } arch_kexec_post_alloc_pages(page_address(page), 1, 0); - ptr = kmap(page); + ptr = kmap_local_page(page); ptr += maddr & ~PAGE_MASK; mchunk = min_t(size_t, mbytes, PAGE_SIZE - (maddr & ~PAGE_MASK)); @@ -896,7 +889,7 @@ static int kimage_load_crash_segment(struct kimage *image, else result = copy_from_user(ptr, buf, uchunk); kexec_flush_icache_page(page); - kunmap(page); + kunmap_local(ptr); arch_kexec_pre_free_pages(page_address(page), 1); if (result) { result = -EFAULT; @@ -936,6 +929,28 @@ int kimage_load_segment(struct kimage *image, struct kimage *kexec_image; struct kimage *kexec_crash_image; int kexec_load_disabled; +#ifdef CONFIG_SYSCTL +static struct ctl_table kexec_core_sysctls[] = { + { + .procname = "kexec_load_disabled", + .data = &kexec_load_disabled, + .maxlen = sizeof(int), + .mode = 0644, + /* only handle a transition from default "0" to "1" */ + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ONE, + .extra2 = SYSCTL_ONE, + }, + { } +}; + +static int __init kexec_core_sysctl_init(void) +{ + register_sysctl_init("kernel", kexec_core_sysctls); + return 0; +} +late_initcall(kexec_core_sysctl_init); +#endif /* * No panic_cpu check version of crash_kexec(). This function is called @@ -944,7 +959,7 @@ int kexec_load_disabled; */ void __noclone __crash_kexec(struct pt_regs *regs) { - /* Take the kexec_mutex here to prevent sys_kexec_load + /* Take the kexec_lock here to prevent sys_kexec_load * running on one cpu from replacing the crash kernel * we are using after a panic on a different cpu. * @@ -952,7 +967,7 @@ void __noclone __crash_kexec(struct pt_regs *regs) * of memory the xchg(&kexec_crash_image) would be * sufficient. But since I reuse the memory... */ - if (mutex_trylock(&kexec_mutex)) { + if (kexec_trylock()) { if (kexec_crash_image) { struct pt_regs fixed_regs; @@ -961,7 +976,7 @@ void __noclone __crash_kexec(struct pt_regs *regs) machine_crash_shutdown(&fixed_regs); machine_kexec(kexec_crash_image); } - mutex_unlock(&kexec_mutex); + kexec_unlock(); } } STACK_FRAME_NON_STANDARD(__crash_kexec); @@ -989,24 +1004,18 @@ void crash_kexec(struct pt_regs *regs) } } -size_t crash_get_memory_size(void) +ssize_t crash_get_memory_size(void) { - size_t size = 0; + ssize_t size = 0; + + if (!kexec_trylock()) + return -EBUSY; - mutex_lock(&kexec_mutex); if (crashk_res.end != crashk_res.start) size = resource_size(&crashk_res); - mutex_unlock(&kexec_mutex); - return size; -} -void __weak crash_free_reserved_phys_range(unsigned long begin, - unsigned long end) -{ - unsigned long addr; - - for (addr = begin; addr < end; addr += PAGE_SIZE) - free_reserved_page(boot_pfn_to_page(addr >> PAGE_SHIFT)); + kexec_unlock(); + return size; } int crash_shrink_memory(unsigned long new_size) @@ -1016,7 +1025,8 @@ int crash_shrink_memory(unsigned long new_size) unsigned long old_size; struct resource *ram_res; - mutex_lock(&kexec_mutex); + if (!kexec_trylock()) + return -EBUSY; if (kexec_crash_image) { ret = -ENOENT; @@ -1054,7 +1064,7 @@ int crash_shrink_memory(unsigned long new_size) insert_resource(&iomem_resource, ram_res); unlock: - mutex_unlock(&kexec_mutex); + kexec_unlock(); return ret; } @@ -1078,7 +1088,7 @@ void crash_save_cpu(struct pt_regs *regs, int cpu) return; memset(&prstatus, 0, sizeof(prstatus)); prstatus.common.pr_pid = current->pid; - elf_core_copy_kernel_regs(&prstatus.pr_reg, regs); + elf_core_copy_regs(&prstatus.pr_reg, regs); buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS, &prstatus, sizeof(prstatus)); final_note(buf); @@ -1126,7 +1136,7 @@ int kernel_kexec(void) { int error = 0; - if (!mutex_trylock(&kexec_mutex)) + if (!kexec_trylock()) return -EBUSY; if (!kexec_image) { error = -EINVAL; @@ -1202,19 +1212,6 @@ int kernel_kexec(void) #endif Unlock: - mutex_unlock(&kexec_mutex); + kexec_unlock(); return error; } - -/* - * Protection mechanism for crashkernel reserved memory after - * the kdump kernel is loaded. - * - * Provide an empty default implementation here -- architecture - * code may override this - */ -void __weak arch_kexec_protect_crashkres(void) -{} - -void __weak arch_kexec_unprotect_crashkres(void) -{} |