Hi!
> This patch adds writing support for /dev/oldmem. This can be used to
>
> - Communicate between original kernel and kexeced kernel through write
> to some pages in original kernel.
>
> - Restore the memory contents of hibernated system in kexec based
> hibernation.
>
> Signed-off-by: Huang Ying <ying.huang@xxxxxxxxx>
>
> --- a/arch/x86/kernel/crash_dump_32.c
> +++ b/arch/x86/kernel/crash_dump_32.c
> +ssize_t write_oldmem_page(unsigned long pfn, const char *buf,
> + size_t csize, unsigned long offset, int
> userbuf)
> --- a/drivers/char/mem.c
> +++ b/drivers/char/mem.c
> @@ -348,6 +348,37 @@ static ssize_t read_oldmem(struct file *
> }
> return read;
> }
> +
> +/*
> + * Write memory corresponding to the old kernel.
> + */
> +static ssize_t write_oldmem(struct file *file, const char __user *buf,
> + size_t count, loff_t *ppos)
> +{
...
> + rc = write_oldmem_page(pfn, buf, csize, offset, 1);
I believe this is going to break compilation on non-32bit
machines. Or is crashdump only supported on i386?
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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