[PATCH] bcm43xx: Remove dead configuration variable CONFIG_947XX
[safe/jmp/linux-2.6] / kernel / kexec.c
index def9c73..2a59c8a 100644 (file)
@@ -6,6 +6,7 @@
  * Version 2.  See the file COPYING for more details.
  */
 
+#include <linux/capability.h>
 #include <linux/mm.h>
 #include <linux/file.h>
 #include <linux/slab.h>
 #include <linux/reboot.h>
 #include <linux/syscalls.h>
 #include <linux/ioport.h>
+#include <linux/hardirq.h>
+#include <linux/elf.h>
+#include <linux/elfcore.h>
+
 #include <asm/page.h>
 #include <asm/uaccess.h>
 #include <asm/io.h>
 #include <asm/system.h>
 #include <asm/semaphore.h>
 
+/* 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",
@@ -32,6 +40,13 @@ struct resource crashk_res = {
        .flags = IORESOURCE_BUSY | IORESOURCE_MEM
 };
 
+int kexec_should_crash(struct task_struct *p)
+{
+       if (in_interrupt() || !p->pid || is_init(p) || panic_on_oops)
+               return 1;
+       return 0;
+}
+
 /*
  * When kexec transitions to the new kernel there is a one-to-one
  * mapping between physical and virtual addresses.  On processors
@@ -78,12 +93,15 @@ struct resource crashk_res = {
  */
 #define KIMAGE_NO_DEST (-1UL)
 
-static int kimage_is_destination_range(
-       struct kimage *image, unsigned long start, unsigned long end);
-static struct page *kimage_alloc_page(struct kimage *image, unsigned int gfp_mask, unsigned long dest);
+static int kimage_is_destination_range(struct kimage *image,
+                                      unsigned long start, unsigned long end);
+static struct page *kimage_alloc_page(struct kimage *image,
+                                      gfp_t gfp_mask,
+                                      unsigned long dest);
 
 static int do_kimage_alloc(struct kimage **rimage, unsigned long entry,
-       unsigned long nr_segments, struct kexec_segment __user *segments)
+                           unsigned long nr_segments,
+                            struct kexec_segment __user *segments)
 {
        size_t segment_bytes;
        struct kimage *image;
@@ -92,11 +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);
-       if (!image) {
+       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;
@@ -136,6 +153,7 @@ static int do_kimage_alloc(struct kimage **rimage, unsigned long entry,
        result = -EADDRNOTAVAIL;
        for (i = 0; i < nr_segments; i++) {
                unsigned long mstart, mend;
+
                mstart = image->segment[i].mem;
                mend   = mstart + image->segment[i].memsz;
                if ((mstart & ~PAGE_MASK) || (mend & ~PAGE_MASK))
@@ -150,12 +168,13 @@ static int do_kimage_alloc(struct kimage **rimage, unsigned long entry,
         * easy explanation as one segment stops on another.
         */
        result = -EINVAL;
-       for(i = 0; i < nr_segments; i++) {
+       for (i = 0; i < nr_segments; i++) {
                unsigned long mstart, mend;
                unsigned long j;
+
                mstart = image->segment[i].mem;
                mend   = mstart + image->segment[i].memsz;
-               for(j = 0; j < i; j++) {
+               for (j = 0; j < i; j++) {
                        unsigned long pstart, pend;
                        pstart = image->segment[j].mem;
                        pend   = pstart + image->segment[j].memsz;
@@ -171,25 +190,25 @@ static int do_kimage_alloc(struct kimage **rimage, unsigned long entry,
         * later on.
         */
        result = -EINVAL;
-       for(i = 0; i < nr_segments; i++) {
+       for (i = 0; i < nr_segments; i++) {
                if (image->segment[i].bufsz > image->segment[i].memsz)
                        goto out;
        }
 
-
        result = 0;
- out:
-       if (result == 0) {
+out:
+       if (result == 0)
                *rimage = image;
-       } else {
+       else
                kfree(image);
-       }
+
        return result;
 
 }
 
 static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry,
-       unsigned long nr_segments, struct kexec_segment __user *segments)
+                               unsigned long nr_segments,
+                               struct kexec_segment __user *segments)
 {
        int result;
        struct kimage *image;
@@ -197,9 +216,9 @@ static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry,
        /* Allocate and initialize a controlling structure */
        image = NULL;
        result = do_kimage_alloc(&image, entry, nr_segments, segments);
-       if (result) {
+       if (result)
                goto out;
-       }
+
        *rimage = image;
 
        /*
@@ -209,7 +228,7 @@ static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry,
         */
        result = -ENOMEM;
        image->control_code_page = kimage_alloc_control_pages(image,
-               get_order(KEXEC_CONTROL_CODE_SIZE));
+                                          get_order(KEXEC_CONTROL_CODE_SIZE));
        if (!image->control_code_page) {
                printk(KERN_ERR "Could not allocate control_code_buffer\n");
                goto out;
@@ -217,16 +236,17 @@ static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry,
 
        result = 0;
  out:
-       if (result == 0) {
+       if (result == 0)
                *rimage = image;
-       } else {
+       else
                kfree(image);
-       }
+
        return result;
 }
 
 static int kimage_crash_alloc(struct kimage **rimage, unsigned long entry,
-       unsigned long nr_segments, struct kexec_segment *segments)
+                               unsigned long nr_segments,
+                               struct kexec_segment __user *segments)
 {
        int result;
        struct kimage *image;
@@ -241,9 +261,8 @@ static int kimage_crash_alloc(struct kimage **rimage, unsigned long entry,
 
        /* Allocate and initialize a controlling structure */
        result = do_kimage_alloc(&image, entry, nr_segments, segments);
-       if (result) {
+       if (result)
                goto out;
-       }
 
        /* Enable the special crash kernel control page
         * allocation policy.
@@ -263,14 +282,14 @@ static int kimage_crash_alloc(struct kimage **rimage, unsigned long entry,
        result = -EADDRNOTAVAIL;
        for (i = 0; i < nr_segments; i++) {
                unsigned long mstart, mend;
+
                mstart = image->segment[i].mem;
-               mend = mstart + image->segment[i].memsz;
+               mend = mstart + image->segment[i].memsz - 1;
                /* Ensure we are within the crash kernel limits */
                if ((mstart < crashk_res.start) || (mend > crashk_res.end))
                        goto out;
        }
 
-
        /*
         * Find a location for the control code buffer, and add
         * the vector of segments so that it's pages will also be
@@ -278,80 +297,83 @@ static int kimage_crash_alloc(struct kimage **rimage, unsigned long entry,
         */
        result = -ENOMEM;
        image->control_code_page = kimage_alloc_control_pages(image,
-               get_order(KEXEC_CONTROL_CODE_SIZE));
+                                          get_order(KEXEC_CONTROL_CODE_SIZE));
        if (!image->control_code_page) {
                printk(KERN_ERR "Could not allocate control_code_buffer\n");
                goto out;
        }
 
        result = 0;
- out:
-       if (result == 0) {
+out:
+       if (result == 0)
                *rimage = image;
-       } else {
+       else
                kfree(image);
-       }
+
        return result;
 }
 
-static int kimage_is_destination_range(
-       struct kimage *image, unsigned long start, unsigned long end)
+static int kimage_is_destination_range(struct kimage *image,
+                                       unsigned long start,
+                                       unsigned long end)
 {
        unsigned long i;
 
        for (i = 0; i < image->nr_segments; i++) {
                unsigned long mstart, mend;
+
                mstart = image->segment[i].mem;
-               mend   = mstart + image->segment[i].memsz;
-               if ((end > mstart) && (start < mend)) {
+               mend = mstart + image->segment[i].memsz;
+               if ((end > mstart) && (start < mend))
                        return 1;
-               }
        }
+
        return 0;
 }
 
-static struct page *kimage_alloc_pages(unsigned int gfp_mask, unsigned int order)
+static struct page *kimage_alloc_pages(gfp_t gfp_mask, unsigned int order)
 {
        struct page *pages;
+
        pages = alloc_pages(gfp_mask, 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++) {
+               for (i = 0; i < count; i++)
                        SetPageReserved(pages + i);
-               }
        }
+
        return pages;
 }
 
 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++) {
+       for (i = 0; i < count; i++)
                ClearPageReserved(page + i);
-       }
        __free_pages(page, order);
 }
 
 static void kimage_free_page_list(struct list_head *list)
 {
        struct list_head *pos, *next;
+
        list_for_each_safe(pos, next, list) {
                struct page *page;
 
                page = list_entry(pos, struct page, lru);
                list_del(&page->lru);
-
                kimage_free_pages(page);
        }
 }
 
-static struct page *kimage_alloc_normal_control_pages(
-       struct kimage *image, unsigned int order)
+static struct page *kimage_alloc_normal_control_pages(struct kimage *image,
+                                                       unsigned int order)
 {
        /* Control pages are special, they are the intermediaries
         * that are needed while we copy the rest of the pages
@@ -378,6 +400,7 @@ static struct page *kimage_alloc_normal_control_pages(
         */
        do {
                unsigned long pfn, epfn, addr, eaddr;
+
                pages = kimage_alloc_pages(GFP_KERNEL, order);
                if (!pages)
                        break;
@@ -386,12 +409,12 @@ static struct page *kimage_alloc_normal_control_pages(
                addr  = pfn << PAGE_SHIFT;
                eaddr = epfn << PAGE_SHIFT;
                if ((epfn >= (KEXEC_CONTROL_MEMORY_LIMIT >> PAGE_SHIFT)) ||
-                       kimage_is_destination_range(image, addr, eaddr))
-               {
+                             kimage_is_destination_range(image, addr, eaddr)) {
                        list_add(&pages->lru, &extra_pages);
                        pages = NULL;
                }
-       } while(!pages);
+       } while (!pages);
+
        if (pages) {
                /* Remember the allocated page... */
                list_add(&pages->lru, &image->control_pages);
@@ -411,12 +434,12 @@ static struct page *kimage_alloc_normal_control_pages(
         * For now it is simpler to just free the pages.
         */
        kimage_free_page_list(&extra_pages);
-       return pages;
 
+       return pages;
 }
 
-static struct page *kimage_alloc_crash_control_pages(
-       struct kimage *image, unsigned int order)
+static struct page *kimage_alloc_crash_control_pages(struct kimage *image,
+                                                     unsigned int order)
 {
        /* Control pages are special, they are the intermediaries
         * that are needed while we copy the rest of the pages
@@ -441,21 +464,22 @@ static struct page *kimage_alloc_crash_control_pages(
         */
        unsigned long hole_start, hole_end, size;
        struct page *pages;
+
        pages = NULL;
        size = (1 << order) << PAGE_SHIFT;
        hole_start = (image->control_page + (size - 1)) & ~(size - 1);
        hole_end   = hole_start + size - 1;
-       while(hole_end <= crashk_res.end) {
+       while (hole_end <= crashk_res.end) {
                unsigned long i;
-               if (hole_end > KEXEC_CONTROL_MEMORY_LIMIT) {
+
+               if (hole_end > KEXEC_CONTROL_MEMORY_LIMIT)
                        break;
-               }
-               if (hole_end > crashk_res.end) {
+               if (hole_end > crashk_res.end)
                        break;
-               }
                /* See if I overlap any of the segments */
-               for(i = 0; i < image->nr_segments; i++) {
+               for (i = 0; i < image->nr_segments; i++) {
                        unsigned long mstart, mend;
+
                        mstart = image->segment[i].mem;
                        mend   = mstart + image->segment[i].memsz - 1;
                        if ((hole_end >= mstart) && (hole_start <= mend)) {
@@ -471,18 +495,19 @@ static struct page *kimage_alloc_crash_control_pages(
                        break;
                }
        }
-       if (pages) {
+       if (pages)
                image->control_page = hole_end;
-       }
+
        return pages;
 }
 
 
-struct page *kimage_alloc_control_pages(
-       struct kimage *image, unsigned int order)
+struct page *kimage_alloc_control_pages(struct kimage *image,
+                                        unsigned int order)
 {
        struct page *pages = NULL;
-       switch(image->type) {
+
+       switch (image->type) {
        case KEXEC_TYPE_DEFAULT:
                pages = kimage_alloc_normal_control_pages(image, order);
                break;
@@ -490,43 +515,46 @@ struct page *kimage_alloc_control_pages(
                pages = kimage_alloc_crash_control_pages(image, order);
                break;
        }
+
        return pages;
 }
 
 static int kimage_add_entry(struct kimage *image, kimage_entry_t entry)
 {
-       if (*image->entry != 0) {
+       if (*image->entry != 0)
                image->entry++;
-       }
+
        if (image->entry == image->last_entry) {
                kimage_entry_t *ind_page;
                struct page *page;
+
                page = kimage_alloc_page(image, GFP_KERNEL, KIMAGE_NO_DEST);
-               if (!page) {
+               if (!page)
                        return -ENOMEM;
-               }
+
                ind_page = page_address(page);
                *image->entry = virt_to_phys(ind_page) | IND_INDIRECTION;
                image->entry = ind_page;
-               image->last_entry =
-                       ind_page + ((PAGE_SIZE/sizeof(kimage_entry_t)) - 1);
+               image->last_entry = ind_page +
+                                     ((PAGE_SIZE/sizeof(kimage_entry_t)) - 1);
        }
        *image->entry = entry;
        image->entry++;
        *image->entry = 0;
+
        return 0;
 }
 
-static int kimage_set_destination(
-       struct kimage *image, unsigned long destination)
+static int kimage_set_destination(struct kimage *image,
+                                  unsigned long destination)
 {
        int result;
 
        destination &= PAGE_MASK;
        result = kimage_add_entry(image, destination | IND_DESTINATION);
-       if (result == 0) {
+       if (result == 0)
                image->destination = destination;
-       }
+
        return result;
 }
 
@@ -537,9 +565,9 @@ static int kimage_add_page(struct kimage *image, unsigned long page)
 
        page &= PAGE_MASK;
        result = kimage_add_entry(image, page | IND_SOURCE);
-       if (result == 0) {
+       if (result == 0)
                image->destination += PAGE_SIZE;
-       }
+
        return result;
 }
 
@@ -555,10 +583,11 @@ static void kimage_free_extra_pages(struct kimage *image)
 }
 static int kimage_terminate(struct kimage *image)
 {
-       if (*image->entry != 0) {
+       if (*image->entry != 0)
                image->entry++;
-       }
+
        *image->entry = IND_DONE;
+
        return 0;
 }
 
@@ -582,26 +611,24 @@ static void kimage_free(struct kimage *image)
 
        if (!image)
                return;
+
        kimage_free_extra_pages(image);
        for_each_kimage_entry(image, ptr, entry) {
                if (entry & IND_INDIRECTION) {
                        /* Free the previous indirection page */
-                       if (ind & IND_INDIRECTION) {
+                       if (ind & IND_INDIRECTION)
                                kimage_free_entry(ind);
-                       }
                        /* Save this indirection page until we are
                         * done with it.
                         */
                        ind = entry;
                }
-               else if (entry & IND_SOURCE) {
+               else if (entry & IND_SOURCE)
                        kimage_free_entry(entry);
-               }
        }
        /* Free the final indirection page */
-       if (ind & IND_INDIRECTION) {
+       if (ind & IND_INDIRECTION)
                kimage_free_entry(ind);
-       }
 
        /* Handle any machine specific cleanup */
        machine_kexec_cleanup(image);
@@ -611,26 +638,28 @@ static void kimage_free(struct kimage *image)
        kfree(image);
 }
 
-static kimage_entry_t *kimage_dst_used(struct kimage *image, unsigned long page)
+static kimage_entry_t *kimage_dst_used(struct kimage *image,
+                                       unsigned long page)
 {
        kimage_entry_t *ptr, entry;
        unsigned long destination = 0;
 
        for_each_kimage_entry(image, ptr, entry) {
-               if (entry & IND_DESTINATION) {
+               if (entry & IND_DESTINATION)
                        destination = entry & PAGE_MASK;
-               }
                else if (entry & IND_SOURCE) {
-                       if (page == destination) {
+                       if (page == destination)
                                return ptr;
-                       }
                        destination += PAGE_SIZE;
                }
        }
-       return 0;
+
+       return NULL;
 }
 
-static struct page *kimage_alloc_page(struct kimage *image, unsigned int gfp_mask, unsigned long destination)
+static struct page *kimage_alloc_page(struct kimage *image,
+                                       gfp_t gfp_mask,
+                                       unsigned long destination)
 {
        /*
         * Here we implement safeguards to ensure that a source page
@@ -670,11 +699,11 @@ static struct page *kimage_alloc_page(struct kimage *image, unsigned int gfp_mas
 
                /* Allocate a page, if we run out of memory give up */
                page = kimage_alloc_pages(gfp_mask, 0);
-               if (!page) {
-                       return 0;
-               }
+               if (!page)
+                       return NULL;
                /* If the page cannot be used file it away */
-               if (page_to_pfn(page) > (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {
+               if (page_to_pfn(page) >
+                               (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {
                        list_add(&page->lru, &image->unuseable_pages);
                        continue;
                }
@@ -685,7 +714,8 @@ static struct page *kimage_alloc_page(struct kimage *image, unsigned int gfp_mas
                        break;
 
                /* If the page is not a destination page use it */
-               if (!kimage_is_destination_range(image, addr, addr + PAGE_SIZE))
+               if (!kimage_is_destination_range(image, addr,
+                                                 addr + PAGE_SIZE))
                        break;
 
                /*
@@ -718,16 +748,17 @@ static struct page *kimage_alloc_page(struct kimage *image, unsigned int gfp_mas
                        list_add(&page->lru, &image->dest_pages);
                }
        }
+
        return page;
 }
 
 static int kimage_load_normal_segment(struct kimage *image,
-       struct kexec_segment *segment)
+                                        struct kexec_segment *segment)
 {
        unsigned long maddr;
        unsigned long ubytes, mbytes;
        int result;
-       unsigned char *buf;
+       unsigned char __user *buf;
 
        result = 0;
        buf = segment->buf;
@@ -736,34 +767,36 @@ static int kimage_load_normal_segment(struct kimage *image,
        maddr = segment->mem;
 
        result = kimage_set_destination(image, maddr);
-       if (result < 0) {
+       if (result < 0)
                goto out;
-       }
-       while(mbytes) {
+
+       while (mbytes) {
                struct page *page;
                char *ptr;
                size_t uchunk, mchunk;
+
                page = kimage_alloc_page(image, GFP_HIGHUSER, maddr);
                if (page == 0) {
                        result  = -ENOMEM;
                        goto out;
                }
-               result = kimage_add_page(image, page_to_pfn(page) << PAGE_SHIFT);
-               if (result < 0) {
+               result = kimage_add_page(image, page_to_pfn(page)
+                                                               << PAGE_SHIFT);
+               if (result < 0)
                        goto out;
-               }
+
                ptr = kmap(page);
                /* Start with a clear page */
                memset(ptr, 0, PAGE_SIZE);
                ptr += maddr & ~PAGE_MASK;
                mchunk = PAGE_SIZE - (maddr & ~PAGE_MASK);
-               if (mchunk > mbytes) {
+               if (mchunk > mbytes)
                        mchunk = mbytes;
-               }
+
                uchunk = mchunk;
-               if (uchunk > ubytes) {
+               if (uchunk > ubytes)
                        uchunk = ubytes;
-               }
+
                result = copy_from_user(ptr, buf, uchunk);
                kunmap(page);
                if (result) {
@@ -775,12 +808,12 @@ static int kimage_load_normal_segment(struct kimage *image,
                buf    += mchunk;
                mbytes -= mchunk;
        }
- out:
+out:
        return result;
 }
 
 static int kimage_load_crash_segment(struct kimage *image,
-       struct kexec_segment *segment)
+                                       struct kexec_segment *segment)
 {
        /* For crash dumps kernels we simply copy the data from
         * user space to it's destination.
@@ -789,17 +822,18 @@ static int kimage_load_crash_segment(struct kimage *image,
        unsigned long maddr;
        unsigned long ubytes, mbytes;
        int result;
-       unsigned char *buf;
+       unsigned char __user *buf;
 
        result = 0;
        buf = segment->buf;
        ubytes = segment->bufsz;
        mbytes = segment->memsz;
        maddr = segment->mem;
-       while(mbytes) {
+       while (mbytes) {
                struct page *page;
                char *ptr;
                size_t uchunk, mchunk;
+
                page = pfn_to_page(maddr >> PAGE_SHIFT);
                if (page == 0) {
                        result  = -ENOMEM;
@@ -808,9 +842,9 @@ static int kimage_load_crash_segment(struct kimage *image,
                ptr = kmap(page);
                ptr += maddr & ~PAGE_MASK;
                mchunk = PAGE_SIZE - (maddr & ~PAGE_MASK);
-               if (mchunk > mbytes) {
+               if (mchunk > mbytes)
                        mchunk = mbytes;
-               }
+
                uchunk = mchunk;
                if (uchunk > ubytes) {
                        uchunk = ubytes;
@@ -818,6 +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;
@@ -828,15 +863,16 @@ static int kimage_load_crash_segment(struct kimage *image,
                buf    += mchunk;
                mbytes -= mchunk;
        }
- out:
+out:
        return result;
 }
 
 static int kimage_load_segment(struct kimage *image,
-       struct kexec_segment *segment)
+                               struct kexec_segment *segment)
 {
        int result = -ENOMEM;
-       switch(image->type) {
+
+       switch (image->type) {
        case KEXEC_TYPE_DEFAULT:
                result = kimage_load_normal_segment(image, segment);
                break;
@@ -844,6 +880,7 @@ static int kimage_load_segment(struct kimage *image,
                result = kimage_load_crash_segment(image, segment);
                break;
        }
+
        return result;
 }
 
@@ -867,18 +904,18 @@ 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,
-       unsigned long flags)
+asmlinkage long sys_kexec_load(unsigned long entry, unsigned long nr_segments,
+                               struct kexec_segment __user *segments,
+                               unsigned long flags)
 {
        struct kimage **dest_image, *image;
        int locked;
@@ -898,9 +935,7 @@ asmlinkage long sys_kexec_load(unsigned long entry,
        /* Verify we are on the appropriate architecture */
        if (((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH) &&
                ((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH_DEFAULT))
-       {
                return -EINVAL;
-       }
 
        /* Put an artificial cap on the number
         * of segments passed to kexec_load.
@@ -920,58 +955,60 @@ asmlinkage long sys_kexec_load(unsigned long entry,
         * KISS: always take the mutex.
         */
        locked = xchg(&kexec_lock, 1);
-       if (locked) {
+       if (locked)
                return -EBUSY;
-       }
+
        dest_image = &kexec_image;
-       if (flags & KEXEC_ON_CRASH) {
+       if (flags & KEXEC_ON_CRASH)
                dest_image = &kexec_crash_image;
-       }
        if (nr_segments > 0) {
                unsigned long i;
+
                /* Loading another kernel to reboot into */
-               if ((flags & KEXEC_ON_CRASH) == 0) {
-                       result = kimage_normal_alloc(&image, entry, nr_segments, segments);
-               }
+               if ((flags & KEXEC_ON_CRASH) == 0)
+                       result = kimage_normal_alloc(&image, entry,
+                                                       nr_segments, segments);
                /* Loading another kernel to switch to if this one crashes */
                else if (flags & KEXEC_ON_CRASH) {
                        /* Free any current crash dump kernel before
                         * we corrupt it.
                         */
                        kimage_free(xchg(&kexec_crash_image, NULL));
-                       result = kimage_crash_alloc(&image, entry, nr_segments, segments);
+                       result = kimage_crash_alloc(&image, entry,
+                                                    nr_segments, segments);
                }
-               if (result) {
+               if (result)
                        goto out;
-               }
+
                result = machine_kexec_prepare(image);
-               if (result) {
+               if (result)
                        goto out;
-               }
-               for(i = 0; i < nr_segments; i++) {
+
+               for (i = 0; i < nr_segments; i++) {
                        result = kimage_load_segment(image, &image->segment[i]);
-                       if (result) {
+                       if (result)
                                goto out;
-                       }
                }
                result = kimage_terminate(image);
-               if (result) {
+               if (result)
                        goto out;
-               }
        }
        /* Install the new kernel, and  Uninstall the old */
        image = xchg(dest_image, image);
 
- out:
-       xchg(&kexec_lock, 0); /* Release the mutex */
+out:
+       locked = xchg(&kexec_lock, 0); /* Release the mutex */
+       BUG_ON(!locked);
        kimage_free(image);
+
        return result;
 }
 
 #ifdef CONFIG_COMPAT
 asmlinkage long compat_sys_kexec_load(unsigned long entry,
-       unsigned long nr_segments, struct compat_kexec_segment __user *segments,
-       unsigned long flags)
+                               unsigned long nr_segments,
+                               struct compat_kexec_segment __user *segments,
+                               unsigned long flags)
 {
        struct compat_kexec_segment in;
        struct kexec_segment out, __user *ksegments;
@@ -980,20 +1017,17 @@ asmlinkage long compat_sys_kexec_load(unsigned long entry,
        /* Don't allow clients that don't understand the native
         * architecture to do anything.
         */
-       if ((flags & KEXEC_ARCH_MASK) == KEXEC_ARCH_DEFAULT) {
+       if ((flags & KEXEC_ARCH_MASK) == KEXEC_ARCH_DEFAULT)
                return -EINVAL;
-       }
 
-       if (nr_segments > KEXEC_SEGMENT_MAX) {
+       if (nr_segments > KEXEC_SEGMENT_MAX)
                return -EINVAL;
-       }
 
        ksegments = compat_alloc_user_space(nr_segments * sizeof(out));
        for (i=0; i < nr_segments; i++) {
                result = copy_from_user(&in, &segments[i], sizeof(in));
-               if (result) {
+               if (result)
                        return -EFAULT;
-               }
 
                out.buf   = compat_ptr(in.buf);
                out.bufsz = in.bufsz;
@@ -1001,18 +1035,16 @@ asmlinkage long compat_sys_kexec_load(unsigned long entry,
                out.memsz = in.memsz;
 
                result = copy_to_user(&ksegments[i], &out, sizeof(out));
-               if (result) {
+               if (result)
                        return -EFAULT;
-               }
        }
 
        return sys_kexec_load(entry, nr_segments, ksegments, flags);
 }
 #endif
 
-void crash_kexec(void)
+void crash_kexec(struct pt_regs *regs)
 {
-       struct kimage *image;
        int locked;
 
 
@@ -1026,11 +1058,80 @@ void crash_kexec(void)
         */
        locked = xchg(&kexec_lock, 1);
        if (!locked) {
-               image = xchg(&kexec_crash_image, NULL);
-               if (image) {
-                       machine_crash_shutdown();
-                       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, &note, 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, &note, 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, "CORE", 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)