Re: [PATCH v2 0/6] remove dead NULL checks after GFP_NOFAIL allocations and fix xive use-after-free

[Andrew Morton]

On Fri, 24 Jul 2026 10:28:45 +0800 Gou Hao <gouhao@xxxxxxxxxxxxx> wrote:

> This is a code cleanup series that removes unreachable
> NULL checks (and associated error handling) that follow allocations
> using __GFP_NOFAIL, which guarantees non-NULL return.

Sigh.

Back when Linux ran on an abacus, I added __GFP_NOFAIL because four or
five sites (file systems) were infinitely looping on alloc_pages until
it succeeded.  I figured we should move this operation into the page
allocator so we could easily find those sites and fix them to Not Do
That.

I made it very clear (changelog and code comments) that no new code
should use __GFP_NOFAIL.  How did that work out?

hp2:/usr/src/linux-7.2-rc4> grep -r __GFP_NOFAIL | wc -l
241

So much lameness!   My immediate reaction to your patchset is "No.  Fix
the damn code instead".  But I've resoundingly lost that fight.


Thanks, I'll scoop up the entire series.  If individual patches pop up
in linux-next then I'll drop the mm.git copies.



AI review has a shower of possible pre-existing issues.  I'm seeing
use-after-free, double-free, leak, system hang, NULL pointer
dereference, usual stuff :(

They're in powerpc and cxgb4, if maintainers are interested.

	https://sashiko.dev/#/patchset/20260724022851.466017-1-gouhao@xxxxxxxxxxxxx