[PATCH v3 12/21] vmcore: allocate per-cpu crash_notes objects on page-size boundary

[HATAYAMA Daisuke]

To satisfy mmap()'s page-size boundary requirement, allocate per-cpu
crash_notes objects on page-size boundary.

/proc/vmcore on the 2nd kernel checks if each note objects is
allocated on page-size boundary. If there's some object not satisfying
the page-size boundary requirement, /proc/vmcore doesn't provide
mmap() interface.

Signed-off-by: HATAYAMA Daisuke <d.hatayama at jp.fujitsu.com>
---

 kernel/kexec.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/kernel/kexec.c b/kernel/kexec.c
index bddd3d7..d1f365e 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -1234,7 +1234,8 @@ void crash_save_cpu(struct pt_regs *regs, int cpu)
 static int __init crash_notes_memory_init(void)
 {
 	/* Allocate memory for saving cpu registers. */
-	crash_notes = alloc_percpu(note_buf_t);
+	crash_notes = __alloc_percpu(roundup(sizeof(note_buf_t), PAGE_SIZE),
+				     PAGE_SIZE);
 	if (!crash_notes) {
 		printk("Kexec: Memory allocation for saving cpu register"
 		" states failed\n");