arm64: userspace broken with jemalloc 4.0.0

[Jason Evans]

On Aug 29, 2015, at 3:05 PM, Julien Grall <julien.grall at citrix.com> wrote:
> I've built the latest freebsd master (r287263) for arm64 today. While
> trying to use the userspace I hit some ASSERT in jemalloc:
> 
> # ls
> <jemalloc>: /usr/src/freebsd/lib/libc/../../contrib/jemalloc/include/jemalloc/internal/arena.h:571: Failed assertion: "pageind >= map_bias"
> pid 21 (ls), uid 0: exited on signal 6
> Abort trap
> 
> It's happening every time with the command "ls".
> 
> I tried to use the previous version of jemalloc (i.e reverting
> all the patches up to "Update jemalloc to version 4.0.0" included)
> and everything is working.
> 
> Note that I'm using Freebsd as a Xen ARM guest although the only
> difference is the version of jemalloc (4.0.0 vs 3.6.0).
> 
> Does anyone using arm64 have seen a similar ASSERT?
> 
> BTW, is there any way to rebuild only the libc rather than doing
> make buildworld everytime I modified the jemalloc code?

What is the page size on arm64?  If it's greater than 8 KiB, I know what the problem is and have a patch that I've already tested and can integrate tomorrow when I'm awake enough not fat-finger it.

	https://github.com/jemalloc/jemalloc/commit/5ef33a9f2b9f4fb56553529f7b31f4f5f57ce014

Thanks,
Jason