Re: armv8 does not respect personality ADDR_LIMIT_3GB

2021-10-08 Thread Arnd Bergmann
On Thu, Oct 7, 2021 at 10:28 PM Lennart Sorensen wrote: > On Wed, Oct 06, 2021 at 02:08:49PM -0400, Camm Maguire wrote: > > I also get the impression in my searching for stuff about this problem, > that 3/4 of the things I find about wanting to do this are gcl related. > I guess it may be the only

Re: armv8 does not respect personality ADDR_LIMIT_3GB

2021-10-07 Thread Lennart Sorensen
On Wed, Oct 06, 2021 at 02:08:49PM -0400, Camm Maguire wrote: > Greetings, and thanks for your reply > > On Tue, 5 Oct 2021 15:01:59 -0400, Len Sorensen wrote: > > >>From what I could find, some programs allocate their own stack early in > >execution and can hence put it where they want which I g

Re: armv8 does not respect personality ADDR_LIMIT_3GB

2021-10-06 Thread Camm Maguire
Greetings, and thanks for your reply On Tue, 5 Oct 2021 15:01:59 -0400, Len Sorensen wrote: >>From what I could find, some programs allocate their own stack early in >execution and can hence put it where they want which I guess would free >up some known address space range. Potentially. With ad

Re: armv8 does not respect personality ADDR_LIMIT_3GB

2021-10-05 Thread Adrian Bunk
On Tue, Oct 05, 2021 at 03:23:53PM -0400, Camm Maguire wrote: >... > Fair enough, but *Debian* ships a given compiled kernel fixing this > parameter, no? That is the target for the distribution and > apps/packages. Most x86 users use our kernel, but not on arm. On x86 nearly all hardware support

Re: armv8 does not respect personality ADDR_LIMIT_3GB

2021-10-05 Thread Arnd Bergmann
On Tue, Oct 5, 2021 at 7:37 PM Camm Maguire wrote: > > Greetings, and thank you so much for your very detailed, clear, and > comprehensive reply! > > PER_LINUX_32GB and/or a userspace interface to set the address space > layout would be nice, but my chief concern is that whatever the kernel > prov

Re: armv8 does not respect personality ADDR_LIMIT_3GB

2021-10-05 Thread Lennart Sorensen
On Tue, Oct 05, 2021 at 04:17:51PM -0400, Jeffrey Walton wrote: > On Tue, Oct 5, 2021 at 4:00 PM Lennart Sorensen > wrote: > > > > ... > > This fixnum idea in gcl is broken. It must go away. Pointers are for > > addresses and nothing else. > > +1. Tagged pointers caused a lot of problems portin

Re: armv8 does not respect personality ADDR_LIMIT_3GB

2021-10-05 Thread Jeffrey Walton
On Tue, Oct 5, 2021 at 4:00 PM Lennart Sorensen wrote: > > ... > This fixnum idea in gcl is broken. It must go away. Pointers are for > addresses and nothing else. +1. Tagged pointers caused a lot of problems porting some packages to Aarch64. Tagged pointers were blocking a number of web relate

Re: armv8 does not respect personality ADDR_LIMIT_3GB

2021-10-05 Thread Lennart Sorensen
On Tue, Oct 05, 2021 at 03:23:53PM -0400, Camm Maguire wrote: > Greetings! > > Fair enough, but *Debian* ships a given compiled kernel fixing this > parameter, no? That is the target for the distribution and > apps/packages. Users compiling their own kernel can expect > incompatibilities. Debia

Re: armv8 does not respect personality ADDR_LIMIT_3GB

2021-10-05 Thread Camm Maguire
Greetings! Fair enough, but *Debian* ships a given compiled kernel fixing this parameter, no? That is the target for the distribution and apps/packages. Users compiling their own kernel can expect incompatibilities. Take care, Adrian Bunk writes: > On Tue, Oct 05, 2021 at 01:37:49PM -0400, C

Re: armv8 does not respect personality ADDR_LIMIT_3GB

2021-10-05 Thread Adrian Bunk
On Tue, Oct 05, 2021 at 01:37:49PM -0400, Camm Maguire wrote: >... > To me it seems that the 64bit kernel, if it > offers a compatibility mode, should match whatever the contemporaneous > 32bit kernel behavior is, making this a bug in the compatibility mode. >... You are expecting compatibility wi

Re: armv8 does not respect personality ADDR_LIMIT_3GB

2021-10-05 Thread Lennart Sorensen
On Tue, Oct 05, 2021 at 01:37:49PM -0400, Camm Maguire wrote: > Greetings, and thank you so much for your very detailed, clear, and > comprehensive reply! > > PER_LINUX_32GB and/or a userspace interface to set the address space > layout would be nice, but my chief concern is that whatever the kern

Re: armv8 does not respect personality ADDR_LIMIT_3GB

2021-10-05 Thread Camm Maguire
Greetings, and thank you so much for your very detailed, clear, and comprehensive reply! PER_LINUX_32GB and/or a userspace interface to set the address space layout would be nice, but my chief concern is that whatever the kernel provides to userspace be the same on all machines purporting to be of

Re: armv8 does not respect personality ADDR_LIMIT_3GB

2021-10-05 Thread Arnd Bergmann
On Mon, Oct 4, 2021 at 7:38 PM Camm Maguire wrote: > > Greetings! There seems to be a subarchitecture within the current 32bit > Debian arm universes and buildds. armv8 processors will leave the C > stack start at 0x even when personality ADDR_LIMIT_3GB is set, > whereas on armv7 the add

armv8 does not respect personality ADDR_LIMIT_3GB

2021-10-04 Thread Camm Maguire
Greetings! There seems to be a subarchitecture within the current 32bit Debian arm universes and buildds. armv8 processors will leave the C stack start at 0x even when personality ADDR_LIMIT_3GB is set, whereas on armv7 the address starts at 0xbfff, as on other 32bit linux machines.