Merge branch 'master' into upstream

[sfrench/cifs-2.6.git] / kernel / kexec.c

diff --git a/kernel/kexec.c b/kernel/kexec.c
index 2c95848fbce8261463e54833d60d68573e9fb9b8..fcdd5d2bc3f4b47b57854c41a1cec882939c02ed 100644 (file)
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -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>
@@ -26,6 +27,9 @@
 #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",
@@ -36,7 +40,7 @@ struct resource crashk_res = {
 
 int kexec_should_crash(struct task_struct *p)
 {
-       if (in_interrupt() || !p->pid || p->pid == 1 || panic_on_oops)
+       if (in_interrupt() || !p->pid || is_init(p) || panic_on_oops)
                return 1;
        return 0;
 }
@@ -898,14 +902,14 @@ 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,
@@ -991,7 +995,8 @@ asmlinkage long sys_kexec_load(unsigned long entry, unsigned long nr_segments,
        image = xchg(dest_image, image);
 
 out:
-       xchg(&kexec_lock, 0); /* Release the mutex */
+       locked = xchg(&kexec_lock, 0); /* Release the mutex */
+       BUG_ON(!locked);
        kimage_free(image);
 
        return result;
@@ -1038,7 +1043,6 @@ asmlinkage long compat_sys_kexec_load(unsigned long entry,
 
 void crash_kexec(struct pt_regs *regs)
 {
-       struct kimage *image;
        int locked;
 
 
@@ -1052,11 +1056,26 @@ void crash_kexec(struct pt_regs *regs)
         */
        locked = xchg(&kexec_lock, 1);
        if (!locked) {
-               image = xchg(&kexec_crash_image, NULL);
-               if (image) {
-                       machine_crash_shutdown(regs);
-                       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 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)