kmsg: use do_div() to divide 64bit integer

On Tue, May 8, 2012 at 10:02 AM, Stephen Rothwell <sfr@canb.auug.org.au> wrote:
> kernel/built-in.o: In function `devkmsg_read':
> printk.c:(.text+0x27e8): undefined reference to `__udivdi3'
> Most probably the "msg->ts_nsec / 1000" since
> ts_nsec is a u64 and this is a 32 bit build ...

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Kay Sievers <kay@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/printk.c b/kernel/printk.c
index 1ccc6d986cb391e0d0be4aced844231004460ff1..96d4cc8922556ff9aa8b5392f3de626bd4afca1b 100644 (file)
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -407,6 +407,7 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
 {
        struct devkmsg_user *user = file->private_data;
        struct log *msg;
+       u64 ts_usec;
        size_t i;
        size_t len;
        ssize_t ret;
@@ -441,8 +442,10 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
        }
 
        msg = log_from_idx(user->idx);
+       ts_usec = msg->ts_nsec;
+       do_div(ts_usec, 1000);
        len = sprintf(user->buf, "%u,%llu,%llu;",
-                     msg->level, user->seq, msg->ts_nsec / 1000);
+                     msg->level, user->seq, ts_usec);
 
        /* escape non-printable characters */
        for (i = 0; i < msg->text_len; i++) {