On Wed, Nov 23, 2011 at 9:18 PM, Michael Holzheu <holzheu at linux.vnet.ibm.com> wrote: > From: Michael Holzheu <holzheu at linux.vnet.ibm.com> > > Currently it is possible to set the crash_size via the sysfs > /sys/kernel/kexec_crash_size even if no crash kernel memory has > been defined with the "crashkernel" parameter. In this case > "crashk_res" is not initialized and crashk_res.start = crashk_res.end = 0. > Unfortunately resource_size(&crashk_res) returns 1 in this case. > This breaks the s390 implementation of crash_(un)map_reserved_pages(). > > To fix the problem the correct "old_size" is now calculated in > crash_shrink_memory(). "old_size is set to "0" if crashk_res is > not initialized. With this change crash_shrink_memory() will do nothing, > when "crashk_res" is not initialized. It will return "0" for > "echo 0 > /sys/kernel/kexec_crash_size" and -EINVAL for > "echo [not zero] > /sys/kernel/kexec_crash_size". > > In addition to that this patch also simplifies the "ret = -EINVAL" > vs. "ret = 0" logic as suggested by Simon Horman. > > Cc: Simon Horman <horms at verge.net.au> > Signed-off-by: Michael Holzheu <holzheu at linux.vnet.ibm.com> Reviewed-by: WANG Cong <xiyou.wangcong at gmail.com> Thanks.
