Re: [PATCH v2 1/3] module: Rename module_alloc() to text_alloc() and move to kernel proper

+++ Jarkko Sakkinen [24/07/20 10:36 +0300]:

On Thu, Jul 23, 2020 at 03:42:09PM +0300, Ard Biesheuvel wrote:

quoted

On Thu, 23 Jul 2020 at 04:52, Jarkko Sakkinen
[off-list ref] wrote:

quoted

On Thu, Jul 16, 2020 at 06:49:09PM +0200, Christophe Leroy wrote:

quoted

Jarkko Sakkinen [off-list ref] a écrit :

quoted

Rename module_alloc() to text_alloc() and module_memfree() to
text_memfree(), and move them to kernel/text.c, which is unconditionally
compiled to the kernel proper. This allows kprobes, ftrace and bpf to
allocate space for executable code without requiring to compile the modules
support (CONFIG_MODULES=y) in.

You are not changing enough in powerpc to have this work.
On powerpc 32 bits (6xx), when STRICT_KERNEL_RWX is selected, the vmalloc
space is set to NX (no exec) at segment level (ie by 256Mbytes zone) unless
CONFIG_MODULES is selected.

Christophe

This has been deduced down to:

https://lore.kernel.org/lkml/20200717030422.679972-1-jarkko.sakkinen@linux.intel.com/ (local)

I.e. not intruding PPC anymore :-)

Ok, so after the elaborate discussion we had between Jessica, Russell,
Peter, Will, Mark, you and myself, where we pointed out that
a) a single text_alloc() abstraction for bpf, kprobes and ftrace does
not fit other architectures very well, and
b) that module_alloc() is not suitable as a default to base text_alloc() on,

In the latest iteration (v5) it is conditionally available only if arch
defines and fallback has been removed.

quoted

you went ahead and implemented that anyway, but only cc'ing Peter,
akpm, Masami and the mm list this time?

No problems with that. Actually each patch gets everything that
get_maintainer.pl gives with a cc cmd script, not just the ones
explicitly listed in the patch.

Should I explicitly CC you to the next version? I'm happy to grow
the list when requested.

Yes, please CC everybody that was part of the discussion last time
especially during v2, and please use a consistent CC list for the
whole patchset. It is difficult to review when you only receive patch
1 out of 6 with no mention of text_alloc() anywhere and without being
CC'd on the cover letter.

Jessica