linux-kernel - [PATCH v10 14/18] mm/debug: print vm

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250213224655.1680278-15-surenb@google.com>
Date: Thu, 13 Feb 2025 14:46:51 -0800
From: Suren Baghdasaryan <surenb@...gle.com>
To: akpm@...ux-foundation.org
Cc: peterz@...radead.org, willy@...radead.org, liam.howlett@...cle.com, 
	lorenzo.stoakes@...cle.com, david.laight.linux@...il.com, mhocko@...e.com, 
	vbabka@...e.cz, hannes@...xchg.org, mjguzik@...il.com, oliver.sang@...el.com, 
	mgorman@...hsingularity.net, david@...hat.com, peterx@...hat.com, 
	oleg@...hat.com, dave@...olabs.net, paulmck@...nel.org, brauner@...nel.org, 
	dhowells@...hat.com, hdanton@...a.com, hughd@...gle.com, 
	lokeshgidra@...gle.com, minchan@...gle.com, jannh@...gle.com, 
	shakeel.butt@...ux.dev, souravpanda@...gle.com, pasha.tatashin@...een.com, 
	klarasmodin@...il.com, richard.weiyang@...il.com, corbet@....net, 
	linux-doc@...r.kernel.org, linux-mm@...ck.org, linux-kernel@...r.kernel.org, 
	kernel-team@...roid.com, surenb@...gle.com
Subject: [PATCH v10 14/18] mm/debug: print vm_refcnt state when dumping the vma

vm_refcnt encodes a number of useful states:
- whether vma is attached or detached
- the number of current vma readers
- presence of a vma writer
Let's include it in the vma dump.

Signed-off-by: Suren Baghdasaryan <surenb@...gle.com>
Acked-by: Vlastimil Babka <vbabka@...e.cz>
---
Changes since v9 [1]:
- Minimized duplicate code, per Lorenzo Stoakes

[1] https://lore.kernel.org/all/20250111042604.3230628-14-surenb@google.com/

 mm/debug.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/mm/debug.c b/mm/debug.c
index e1282b85a877..2d1bd67d957b 100644
--- a/mm/debug.c
+++ b/mm/debug.c
@@ -181,11 +181,17 @@ void dump_vma(const struct vm_area_struct *vma)
 	pr_emerg("vma %px start %px end %px mm %px\n"
 		"prot %lx anon_vma %px vm_ops %px\n"
 		"pgoff %lx file %px private_data %px\n"
+#ifdef CONFIG_PER_VMA_LOCK
+		"refcnt %x\n"
+#endif
 		"flags: %#lx(%pGv)\n",
 		vma, (void *)vma->vm_start, (void *)vma->vm_end, vma->vm_mm,
 		(unsigned long)pgprot_val(vma->vm_page_prot),
 		vma->anon_vma, vma->vm_ops, vma->vm_pgoff,
 		vma->vm_file, vma->vm_private_data,
+#ifdef CONFIG_PER_VMA_LOCK
+		refcount_read(&vma->vm_refcnt),
+#endif
 		vma->vm_flags, &vma->vm_flags);
 }
 EXPORT_SYMBOL(dump_vma);
-- 
2.48.1.601.g30ceb7b040-goog