On 12/19/18 9:04 AM, Eugeniy Paltsev wrote:

Just curious: isn't that enough to use GFP_NOWAIT instead
of GFP_KERNEL when we allocate page in show_regs()?

As I can see x86 use print_vma_addr() in their show_signal_msg()
function which allocate page with __get_free_page(GFP_NOWAIT);

I'm not sure if lockdep will be happy with it still.

At any rate, as explained in changelog, this still has merit, since the buffer is
only needed for nested d_path calls, which are better served with a smaller
on-stack buffer. For cases such as kernel crash, we want lesser code/traces in
fault path to sift thru !

-Vineet