1 files changed, 37 insertions, 9 deletions

diff --git a/kernel/kexec.c b/kernel/kexec.c
index 0926f2a3ed03..f18c780f9716 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -548,6 +548,7 @@ kimage_file_alloc_init(struct kimage **rimage, int kernel_fd,
 {
         int ret;
         struct kimage *image;
+        bool kexec_on_panic = flags & KEXEC_FILE_ON_CRASH;
 
         image = do_kimage_alloc_init();
         if (!image)
@@ -555,6 +556,12 @@ kimage_file_alloc_init(struct kimage **rimage, int kernel_fd,
 
         image->file_mode = 1;
 
+        if (kexec_on_panic) {
+                /* Enable special crash kernel control page alloc policy. */
+                image->control_page = crashk_res.start;
+                image->type = KEXEC_TYPE_CRASH;
+        }
+
         ret = kimage_file_prepare_segments(image, kernel_fd, initrd_fd,
                                            cmdline_ptr, cmdline_len, flags);
         if (ret)
@@ -572,10 +579,12 @@ kimage_file_alloc_init(struct kimage **rimage, int kernel_fd,
                 goto out_free_post_load_bufs;
         }
 
-        image->swap_page = kimage_alloc_control_pages(image, 0);
-        if (!image->swap_page) {
-                pr_err(KERN_ERR "Could not allocate swap buffer\n");
-                goto out_free_control_pages;
+        if (!kexec_on_panic) {
+                image->swap_page = kimage_alloc_control_pages(image, 0);
+                if (!image->swap_page) {
+                        pr_err(KERN_ERR "Could not allocate swap buffer\n");
+                        goto out_free_control_pages;
+                }
         }
 
         *rimage = image;
@@ -1113,10 +1122,14 @@ static int kimage_load_crash_segment(struct kimage *image,
         unsigned long maddr;
         size_t ubytes, mbytes;
         int result;
-        unsigned char __user *buf;
+        unsigned char __user *buf = NULL;
+        unsigned char *kbuf = NULL;
 
         result = 0;
-        buf = segment->buf;
+        if (image->file_mode)
+                kbuf = segment->kbuf;
+        else
+                buf = segment->buf;
         ubytes = segment->bufsz;
         mbytes = segment->memsz;
         maddr = segment->mem;
@@ -1139,7 +1152,12 @@ static int kimage_load_crash_segment(struct kimage *image,
                         /* Zero the trailing part of the page */
                         memset(ptr + uchunk, 0, mchunk - uchunk);
                 }
-                result = copy_from_user(ptr, buf, uchunk);
+
+                /* For file based kexec, source pages are in kernel memory */
+                if (image->file_mode)
+                        memcpy(ptr, kbuf, uchunk);
+                else
+                        result = copy_from_user(ptr, buf, uchunk);
                 kexec_flush_icache_page(page);
                 kunmap(page);
                 if (result) {
@@ -1148,7 +1166,10 @@ static int kimage_load_crash_segment(struct kimage *image,
                 }
                 ubytes -= uchunk;
                 maddr  += mchunk;
-                buf += mchunk;
+                if (image->file_mode)
+                        kbuf += mchunk;
+                else
+                        buf += mchunk;
                 mbytes -= mchunk;
         }
 out:
@@ -2127,7 +2148,14 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz,
         kbuf->top_down = top_down;
 
         /* Walk the RAM ranges and allocate a suitable range for the buffer */
-        ret = walk_system_ram_res(0, -1, kbuf, locate_mem_hole_callback);
+        if (image->type == KEXEC_TYPE_CRASH)
+                ret = walk_iomem_res("Crash kernel",
+                                     IORESOURCE_MEM | IORESOURCE_BUSY,
+                                     crashk_res.start, crashk_res.end, kbuf,
+                                     locate_mem_hole_callback);
+        else
+                ret = walk_system_ram_res(0, -1, kbuf,
+                                          locate_mem_hole_callback);
         if (ret != 1) {
                 /* A suitable memory range could not be found for buffer */
                 return -EADDRNOTAVAIL;