Merge tag 'mm-nonmm-stable-2024-03-14-09-36' of git://git.kernel.org/pub/scm/linux...

[linux-block.git] / kernel / kexec_core.c

diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index ce3429e7972ccd8be3f2d5df97fe10f939bf2107..0e96f6b243447368674fd343b6fb90343e79df43 100644 (file)
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -750,22 +750,24 @@ static int kimage_load_normal_segment(struct kimage *image,
                                PAGE_SIZE - (maddr & ~PAGE_MASK));
                uchunk = min(ubytes, mchunk);
 
-               /* 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);
+               if (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);
+                       ubytes -= uchunk;
+                       if (image->file_mode)
+                               kbuf += uchunk;
+                       else
+                               buf += uchunk;
+               }
                kunmap_local(ptr);
                if (result) {
                        result = -EFAULT;
                        goto out;
                }
-               ubytes -= uchunk;
                maddr  += mchunk;
-               if (image->file_mode)
-                       kbuf += mchunk;
-               else
-                       buf += mchunk;
                mbytes -= mchunk;
 
                cond_resched();
@@ -817,11 +819,18 @@ static int kimage_load_crash_segment(struct kimage *image,
                        memset(ptr + uchunk, 0, mchunk - 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);
+               if (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);
+                       ubytes -= uchunk;
+                       if (image->file_mode)
+                               kbuf += uchunk;
+                       else
+                               buf += uchunk;
+               }
                kexec_flush_icache_page(page);
                kunmap_local(ptr);
                arch_kexec_pre_free_pages(page_address(page), 1);
@@ -829,12 +838,7 @@ static int kimage_load_crash_segment(struct kimage *image,
                        result = -EFAULT;
                        goto out;
                }
-               ubytes -= uchunk;
                maddr  += mchunk;
-               if (image->file_mode)
-                       kbuf += mchunk;
-               else
-                       buf += mchunk;
                mbytes -= mchunk;
 
                cond_resched();