Re: [bug report] bad error return in walk_hugetlb_range()

[Dan Carpenter <dan.carpenter@linaro.org>]

On Tue, Oct 07, 2025 at 12:13:40PM +0200, David Hildenbrand wrote:
> On 04.10.25 08:22, Dan Carpenter wrote:
> > This is really old code.  I think it's a bug in hugetlb.
> > 
> > 	drivers/gpu/drm/xe/xe_gt_pagefault.c:353 pf_queue_work_func()
> > 	warn: passing positive error code 's32min-(-12),(-10)-(-1),1' to 'ERR_PTR'
> > 

Thanks, David.  Yeah.  You're right.  My apologies.  I tracked down the
confusion and this warning is actually because Smatch thinks that
hmm_range_fault() propogates the positive returns from walk_page_range().
But actually walk_page_range() only returns positive with certain flags.

Someone explained this to me in Jun and I said I would silence the
warning but I forgot...  Ugh...  Sorry.  :(

https://lore.kernel.org/all/aECCaCP3BGGGUUa0@stanley.mountain/

I have done it now, below.

regards,
dan carpenter

From fb706e39230f6f2bc6d68a18837171ea4c1fecc6 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@linaro.org>
Date: Tue, 7 Oct 2025 14:37:51 +0300
Subject: [PATCH] db/kernel.delete_returns: hmm_range_fault() can't return 1

This is pretty tricky code to read.  It doesn't return 1.  This leads to
error pointer warnings.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 smatch_data/db/kernel.delete.return_states | 1 +
 1 file changed, 1 insertion(+)

diff --git a/smatch_data/db/kernel.delete.return_states b/smatch_data/db/kernel.delete.return_states
index a1b3553a9f03..cfdf252e472c 100644
--- a/smatch_data/db/kernel.delete.return_states
+++ b/smatch_data/db/kernel.delete.return_states
@@ -30,3 +30,4 @@ ubi_find_or_add_av 0
 xe_migrate_copy 0
 scmi_get_or_create_handler 0
 alloc_frame_masks 0
+hmm_range_fault 1
-- 
2.51.0