Re: kern/54395: earmv7hf binaries trigger kernel panic on aarch64

[Valery Ushakov <uwe%stderr.spb.ru@localhost>]

The following reply was made to PR kern/54395; it has been noted by GNATS.

From: Valery Ushakov <uwe%stderr.spb.ru@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: kern/54395: earmv7hf binaries trigger kernel panic on aarch64
Date: Tue, 1 Oct 2019 15:36:58 +0300

 On Mon, Jul 22, 2019 at 04:05:00 +0000, rokuyama.rk%gmail.com@localhost wrote:
 
 > >Fix:
 > As described above, this is not MD, but MI bug. uvm_findspace() assumes
 > that hint is not modified by uvm_map_space_avail(). But this is not true
 > when alignment is required but hint is not aligned properly.
 > 
 > To fix this, align hint at the beginning of uvm_findspace(). Then,
 > inconsistent does not occur:
 > 
 > http://www.netbsd.org/~rin/uvm_map_20190722.patch
 
 +#define ALIGN_VA(va, align, topdown) do { \
 +	if ((align) != 0 && ((va) & ((align) - 1)) != 0) { \
 +		if (topdown) \
 +			(va) &= ~((align) - 1); \
 
 Use roundown2() here?
 
 +		else \
 +			(va) = roundup(va, align); \
 
 Use roundup2() here instead, which avoids multiplication?
 
 
 We don't seem to have a convenience macro for testing power of 2
 alignment to use in the test though.
 
 -uwe