3 files changed, 40 insertions, 20 deletions

diff --git a/kernel/crash_dump.c b/kernel/crash_dump.c
index 5f85690285d4..69ebf3380bac 100644
--- a/kernel/crash_dump.c
+++ b/kernel/crash_dump.c
@@ -20,8 +20,15 @@ unsigned long saved_max_pfn;
 unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
 
 /*
+ * stores the size of elf header of crash image
+ */
+unsigned long long elfcorehdr_size;
+
+/*
  * elfcorehdr= specifies the location of elf core header stored by the crashed
  * kernel. This option will be passed by kexec loader to the capture kernel.
+ *
+ * Syntax: elfcorehdr=[size[KMG]@]offset[KMG]
  */
 static int __init setup_elfcorehdr(char *arg)
 {
@@ -29,6 +36,10 @@ static int __init setup_elfcorehdr(char *arg)
         if (!arg)
                 return -EINVAL;
         elfcorehdr_addr = memparse(arg, &end);
+        if (*end == '@') {
+                elfcorehdr_size = elfcorehdr_addr;
+                elfcorehdr_addr = memparse(end + 1, &end);
+        }
         return end > arg ? 0 : -EINVAL;
 }
 early_param("elfcorehdr", setup_elfcorehdr);
diff --git a/kernel/kexec.c b/kernel/kexec.c
index 296fbc84d659..dc7bc0829286 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -498,7 +498,7 @@ static struct page *kimage_alloc_crash_control_pages(struct kimage *image,
         while (hole_end <= crashk_res.end) {
                 unsigned long i;
 
-                if (hole_end > KEXEC_CONTROL_MEMORY_LIMIT)
+                if (hole_end > KEXEC_CRASH_CONTROL_MEMORY_LIMIT)
                         break;
                 if (hole_end > crashk_res.end)
                         break;
@@ -999,6 +999,7 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
                         kimage_free(xchg(&kexec_crash_image, NULL));
                         result = kimage_crash_alloc(&image, entry,
                                                      nr_segments, segments);
+                        crash_map_reserved_pages();
                 }
                 if (result)
                         goto out;
@@ -1015,6 +1016,8 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
                                 goto out;
                 }
                 kimage_terminate(image);
+                if (flags & KEXEC_ON_CRASH)
+                        crash_unmap_reserved_pages();
         }
         /* Install the new kernel, and  Uninstall the old */
         image = xchg(dest_image, image);
@@ -1026,6 +1029,18 @@ out:
         return result;
 }
 
+/*
+ * Add and remove page tables for crashkernel memory
+ *
+ * Provide an empty default implementation here -- architecture
+ * code may override this
+ */
+void __weak crash_map_reserved_pages(void)
+{}
+
+void __weak crash_unmap_reserved_pages(void)
+{}
+
 #ifdef CONFIG_COMPAT
 asmlinkage long compat_sys_kexec_load(unsigned long entry,
                                 unsigned long nr_segments,
@@ -1134,14 +1149,16 @@ int crash_shrink_memory(unsigned long new_size)
                 goto unlock;
         }
 
-        start = roundup(start, PAGE_SIZE);
-        end = roundup(start + new_size, PAGE_SIZE);
+        start = roundup(start, KEXEC_CRASH_MEM_ALIGN);
+        end = roundup(start + new_size, KEXEC_CRASH_MEM_ALIGN);
 
+        crash_map_reserved_pages();
         crash_free_reserved_phys_range(end, crashk_res.end);
 
         if ((start == end) && (crashk_res.parent != NULL))
                 release_resource(&crashk_res);
         crashk_res.end = end - 1;
+        crash_unmap_reserved_pages();
 
 unlock:
         mutex_unlock(&kexec_mutex);
@@ -1380,24 +1397,23 @@ int __init parse_crashkernel(char 		 *cmdline,
 }
 
 
-
-void crash_save_vmcoreinfo(void)
+static void update_vmcoreinfo_note(void)
 {
-        u32 *buf;
+        u32 *buf = vmcoreinfo_note;
 
         if (!vmcoreinfo_size)
                 return;
-
-        vmcoreinfo_append_str("CRASHTIME=%ld", get_seconds());
-
-        buf = (u32 *)vmcoreinfo_note;
-
         buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
                               vmcoreinfo_size);
-
         final_note(buf);
 }
 
+void crash_save_vmcoreinfo(void)
+{
+        vmcoreinfo_append_str("CRASHTIME=%ld", get_seconds());
+        update_vmcoreinfo_note();
+}
+
 void vmcoreinfo_append_str(const char *fmt, ...)
 {
         va_list args;
@@ -1483,6 +1499,7 @@ static int __init crash_save_vmcoreinfo_init(void)
         VMCOREINFO_NUMBER(PG_swapcache);
 
         arch_crash_save_vmcoreinfo();
+        update_vmcoreinfo_note();
 
         return 0;
 }
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index c49d66658ec0..ae2719643854 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -153,14 +153,6 @@ extern int pwrsw_enabled;
 extern int unaligned_enabled;
 #endif
 
-#ifdef CONFIG_S390
-#ifdef CONFIG_MATHEMU
-extern int sysctl_ieee_emulation_warnings;
-#endif
-extern int sysctl_userprocess_debug;
-extern int spin_retry;
-#endif
-
 #ifdef CONFIG_IA64
 extern int no_unaligned_warning;
 extern int unaligned_dump_stack;