X-Git-Url: http://git.rot13.org/?a=blobdiff_plain;f=kernel%2Fkexec.c;h=25db14b89e82c529fcb217e311fbebf66c440c60;hb=2f41dddbbd7193fb5cdae0a24db4d378d56885fd;hp=36c5d9cd4cc14b8b0f342600c69b7a653132f1f1;hpb=5dd962494f76fb3ef1196cd420b5d6260d7a3766;p=powerpc.git diff --git a/kernel/kexec.c b/kernel/kexec.c index 36c5d9cd4c..25db14b89e 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -6,6 +6,7 @@ * Version 2. See the file COPYING for more details. */ +#include #include #include #include @@ -19,6 +20,8 @@ #include #include #include +#include +#include #include #include @@ -26,6 +29,9 @@ #include #include +/* Per cpu memory for storing cpu states in case of system crash. */ +note_buf_t* crash_notes; + /* Location of the reserved area for the crash kernel */ struct resource crashk_res = { .name = "Crash kernel", @@ -36,7 +42,7 @@ struct resource crashk_res = { int kexec_should_crash(struct task_struct *p) { - if (in_interrupt() || !p->pid || p->pid == 1 || panic_on_oops) + if (in_interrupt() || !p->pid || is_init(p) || panic_on_oops) return 1; return 0; } @@ -104,11 +110,10 @@ static int do_kimage_alloc(struct kimage **rimage, unsigned long entry, /* Allocate a controlling structure */ result = -ENOMEM; - image = kmalloc(sizeof(*image), GFP_KERNEL); + image = kzalloc(sizeof(*image), GFP_KERNEL); if (!image) goto out; - memset(image, 0, sizeof(*image)); image->head = 0; image->entry = &image->head; image->last_entry = &image->head; @@ -334,7 +339,7 @@ static struct page *kimage_alloc_pages(gfp_t gfp_mask, unsigned int order) if (pages) { unsigned int count, i; pages->mapping = NULL; - pages->private = order; + set_page_private(pages, order); count = 1 << order; for (i = 0; i < count; i++) SetPageReserved(pages + i); @@ -347,7 +352,7 @@ static void kimage_free_pages(struct page *page) { unsigned int order, count, i; - order = page->private; + order = page_private(page); count = 1 << order; for (i = 0; i < count; i++) ClearPageReserved(page + i); @@ -847,6 +852,7 @@ static int kimage_load_crash_segment(struct kimage *image, memset(ptr + uchunk, 0, mchunk - uchunk); } result = copy_from_user(ptr, buf, uchunk); + kexec_flush_icache_page(page); kunmap(page); if (result) { result = (result < 0) ? result : -EIO; @@ -898,14 +904,14 @@ static int kimage_load_segment(struct kimage *image, * kexec does not sync, or unmount filesystems so if you need * that to happen you need to do that yourself. */ -struct kimage *kexec_image = NULL; -static struct kimage *kexec_crash_image = NULL; +struct kimage *kexec_image; +struct kimage *kexec_crash_image; /* * A home grown binary mutex. * Nothing can wait so this mutex is safe to use * in interrupt context :) */ -static int kexec_lock = 0; +static int kexec_lock; asmlinkage long sys_kexec_load(unsigned long entry, unsigned long nr_segments, struct kexec_segment __user *segments, @@ -991,7 +997,8 @@ asmlinkage long sys_kexec_load(unsigned long entry, unsigned long nr_segments, image = xchg(dest_image, image); out: - xchg(&kexec_lock, 0); /* Release the mutex */ + locked = xchg(&kexec_lock, 0); /* Release the mutex */ + BUG_ON(!locked); kimage_free(image); return result; @@ -1038,7 +1045,6 @@ asmlinkage long compat_sys_kexec_load(unsigned long entry, void crash_kexec(struct pt_regs *regs) { - struct kimage *image; int locked; @@ -1052,11 +1058,80 @@ void crash_kexec(struct pt_regs *regs) */ locked = xchg(&kexec_lock, 1); if (!locked) { - image = xchg(&kexec_crash_image, NULL); - if (image) { - machine_crash_shutdown(regs); - machine_kexec(image); + if (kexec_crash_image) { + struct pt_regs fixed_regs; + crash_setup_regs(&fixed_regs, regs); + machine_crash_shutdown(&fixed_regs); + machine_kexec(kexec_crash_image); } - xchg(&kexec_lock, 0); + locked = xchg(&kexec_lock, 0); + BUG_ON(!locked); + } +} + +static u32 *append_elf_note(u32 *buf, char *name, unsigned type, void *data, + size_t data_len) +{ + struct elf_note note; + + note.n_namesz = strlen(name) + 1; + note.n_descsz = data_len; + note.n_type = type; + memcpy(buf, ¬e, sizeof(note)); + buf += (sizeof(note) + 3)/4; + memcpy(buf, name, note.n_namesz); + buf += (note.n_namesz + 3)/4; + memcpy(buf, data, note.n_descsz); + buf += (note.n_descsz + 3)/4; + + return buf; +} + +static void final_note(u32 *buf) +{ + struct elf_note note; + + note.n_namesz = 0; + note.n_descsz = 0; + note.n_type = 0; + memcpy(buf, ¬e, sizeof(note)); +} + +void crash_save_cpu(struct pt_regs *regs, int cpu) +{ + struct elf_prstatus prstatus; + u32 *buf; + + if ((cpu < 0) || (cpu >= NR_CPUS)) + return; + + /* Using ELF notes here is opportunistic. + * I need a well defined structure format + * for the data I pass, and I need tags + * on the data to indicate what information I have + * squirrelled away. ELF notes happen to provide + * all of that, so there is no need to invent something new. + */ + buf = (u32*)per_cpu_ptr(crash_notes, cpu); + if (!buf) + return; + memset(&prstatus, 0, sizeof(prstatus)); + prstatus.pr_pid = current->pid; + 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); +} + +static int __init crash_notes_memory_init(void) +{ + /* Allocate memory for saving cpu registers. */ + crash_notes = alloc_percpu(note_buf_t); + if (!crash_notes) { + printk("Kexec: Memory allocation for saving cpu register" + " states failed\n"); + return -ENOMEM; } + return 0; } +module_init(crash_notes_memory_init)