diff options
Diffstat (limited to 'kernel/kexec.c')
-rw-r--r-- | kernel/kexec.c | 302 |
1 files changed, 160 insertions, 142 deletions
diff --git a/kernel/kexec.c b/kernel/kexec.c index 277f22a..7843548 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -87,12 +87,15 @@ int kexec_should_crash(struct task_struct *p) */ #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, + unsigned int 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; @@ -102,9 +105,9 @@ 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) { + if (!image) goto out; - } + memset(image, 0, sizeof(*image)); image->head = 0; image->entry = &image->head; @@ -145,6 +148,7 @@ 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)) @@ -159,12 +163,13 @@ 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; @@ -180,25 +185,25 @@ 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; @@ -206,9 +211,9 @@ 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; /* @@ -218,7 +223,7 @@ 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; @@ -226,16 +231,17 @@ 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 *segments) { int result; struct kimage *image; @@ -250,9 +256,8 @@ 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. @@ -272,6 +277,7 @@ 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 - 1; /* Ensure we are within the crash kernel limits */ @@ -279,7 +285,6 @@ static int kimage_crash_alloc(struct kimage **rimage, unsigned long entry, goto out; } - /* * Find a location for the control code buffer, and add * the vector of segments so that it's pages will also be @@ -287,80 +292,84 @@ 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(unsigned int 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; 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; 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 @@ -387,6 +396,7 @@ 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; @@ -395,12 +405,12 @@ 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); @@ -420,12 +430,12 @@ 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 @@ -450,21 +460,22 @@ 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)) { @@ -480,18 +491,19 @@ 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; @@ -499,43 +511,46 @@ 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; } @@ -546,9 +561,9 @@ 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; } @@ -564,10 +579,11 @@ 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; } @@ -591,26 +607,24 @@ 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); @@ -620,26 +634,28 @@ 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; } -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, + unsigned int gfp_mask, + unsigned long destination) { /* * Here we implement safeguards to ensure that a source page @@ -679,11 +695,11 @@ 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) { + if (!page) return 0; - } /* 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; } @@ -694,7 +710,8 @@ 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; /* @@ -727,11 +744,12 @@ 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; @@ -745,34 +763,36 @@ 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) { @@ -784,12 +804,12 @@ 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. @@ -805,10 +825,11 @@ static int kimage_load_crash_segment(struct kimage *image, 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; @@ -817,9 +838,9 @@ 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; @@ -837,15 +858,16 @@ 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; @@ -853,6 +875,7 @@ static int kimage_load_segment(struct kimage *image, result = kimage_load_crash_segment(image, segment); break; } + return result; } @@ -885,9 +908,9 @@ static struct kimage *kexec_crash_image = NULL; */ static int kexec_lock = 0; -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; @@ -907,9 +930,7 @@ 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. @@ -929,58 +950,59 @@ 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: +out: xchg(&kexec_lock, 0); /* Release the mutex */ 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; @@ -989,20 +1011,17 @@ 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; @@ -1010,9 +1029,8 @@ 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); |