linux-kernel - [PATCH v5 21/37] mm/page_ext: enable early_page_ext when CONFIG_MEM_ALLOC_PROFILING

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: <20240306182440.2003814-22-surenb@google.com>
Date: Wed,  6 Mar 2024 10:24:19 -0800
From: Suren Baghdasaryan <surenb@...gle.com>
To: akpm@...ux-foundation.org
Cc: kent.overstreet@...ux.dev, mhocko@...e.com, vbabka@...e.cz, 
	hannes@...xchg.org, roman.gushchin@...ux.dev, mgorman@...e.de, 
	dave@...olabs.net, willy@...radead.org, liam.howlett@...cle.com, 
	penguin-kernel@...ove.sakura.ne.jp, corbet@....net, void@...ifault.com, 
	peterz@...radead.org, juri.lelli@...hat.com, catalin.marinas@....com, 
	will@...nel.org, arnd@...db.de, tglx@...utronix.de, mingo@...hat.com, 
	dave.hansen@...ux.intel.com, x86@...nel.org, peterx@...hat.com, 
	david@...hat.com, axboe@...nel.dk, mcgrof@...nel.org, masahiroy@...nel.org, 
	nathan@...nel.org, dennis@...nel.org, jhubbard@...dia.com, tj@...nel.org, 
	muchun.song@...ux.dev, rppt@...nel.org, paulmck@...nel.org, 
	pasha.tatashin@...een.com, yosryahmed@...gle.com, yuzhao@...gle.com, 
	dhowells@...hat.com, hughd@...gle.com, andreyknvl@...il.com, 
	keescook@...omium.org, ndesaulniers@...gle.com, vvvvvv@...gle.com, 
	gregkh@...uxfoundation.org, ebiggers@...gle.com, ytcoode@...il.com, 
	vincent.guittot@...aro.org, dietmar.eggemann@....com, rostedt@...dmis.org, 
	bsegall@...gle.com, bristot@...hat.com, vschneid@...hat.com, cl@...ux.com, 
	penberg@...nel.org, iamjoonsoo.kim@....com, 42.hyeyoo@...il.com, 
	glider@...gle.com, elver@...gle.com, dvyukov@...gle.com, shakeelb@...gle.com, 
	songmuchun@...edance.com, jbaron@...mai.com, aliceryhl@...gle.com, 
	rientjes@...gle.com, minchan@...gle.com, kaleshsingh@...gle.com, 
	surenb@...gle.com, kernel-team@...roid.com, linux-doc@...r.kernel.org, 
	linux-kernel@...r.kernel.org, iommu@...ts.linux.dev, 
	linux-arch@...r.kernel.org, linux-fsdevel@...r.kernel.org, linux-mm@...ck.org, 
	linux-modules@...r.kernel.org, kasan-dev@...glegroups.com, 
	cgroups@...r.kernel.org
Subject: [PATCH v5 21/37] mm/page_ext: enable early_page_ext when CONFIG_MEM_ALLOC_PROFILING_DEBUG=y

For all page allocations to be tagged, page_ext has to be initialized
before the first page allocation. Early tasks allocate their stacks
using page allocator before alloc_node_page_ext() initializes page_ext
area, unless early_page_ext is enabled. Therefore these allocations will
generate a warning when CONFIG_MEM_ALLOC_PROFILING_DEBUG is enabled.
Enable early_page_ext whenever CONFIG_MEM_ALLOC_PROFILING_DEBUG=y to
ensure page_ext initialization prior to any page allocation. This will
have all the negative effects associated with early_page_ext, such as
possible longer boot time, therefore we enable it only when debugging
with CONFIG_MEM_ALLOC_PROFILING_DEBUG enabled and not universally for
CONFIG_MEM_ALLOC_PROFILING.

Signed-off-by: Suren Baghdasaryan <surenb@...gle.com>
Reviewed-by: Vlastimil Babka <vbabka@...e.cz>
---
 mm/page_ext.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/mm/page_ext.c b/mm/page_ext.c
index 3c58fe8a24df..e7d8f1a5589e 100644
--- a/mm/page_ext.c
+++ b/mm/page_ext.c
@@ -95,7 +95,16 @@ unsigned long page_ext_size;
 
 static unsigned long total_usage;
 
+#ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG
+/*
+ * To ensure correct allocation tagging for pages, page_ext should be available
+ * before the first page allocation. Otherwise early task stacks will be
+ * allocated before page_ext initialization and missing tags will be flagged.
+ */
+bool early_page_ext __meminitdata = true;
+#else
 bool early_page_ext __meminitdata;
+#endif
 static int __init setup_early_page_ext(char *str)
 {
 	early_page_ext = true;
-- 
2.44.0.278.ge034bb2e1d-goog