From: Kees Cook <keescook@chromium.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Kees Cook <keescook@chromium.org>,
stable@vger.kernel.org,
Elena Reshetova <elena.reshetova@intel.com>,
x86@kernel.org, Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Alexander Potapenko <glider@google.com>,
Alexander Popov <alex.popov@linux.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Jann Horn <jannh@google.com>,
kernel-hardening@lists.openwall.com,
linux-hardening@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, Vlastimil Babka <vbabka@suse.cz>,
David Hildenbrand <david@redhat.com>,
Mike Rapoport <rppt@linux.ibm.com>,
Andrew Morton <akpm@linux-foundation.org>,
Jonathan Corbet <corbet@lwn.net>,
Randy Dunlap <rdunlap@infradead.org>
Subject: [PATCH v5 1/7] mm: Restore init_on_* static branch defaults
Date: Tue, 9 Mar 2021 13:42:55 -0800 [thread overview]
Message-ID: <20210309214301.678739-2-keescook@chromium.org> (raw)
In-Reply-To: <20210309214301.678739-1-keescook@chromium.org>
Choosing the initial state of static branches changes the assembly layout
(if the condition is expected to be likely, inline, or unlikely, out of
line via a jump). The _TRUE/_FALSE defines for CONFIG_INIT_ON_*_DEFAULT_ON
were accidentally removed. These need to stay so that the CONFIG controls
the pessimization of the resulting static branch NOP/JMP locations.
Fixes: 04013513cc84 ("mm, page_alloc: do not rely on the order of page_poison and init_on_alloc/free parameters")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
include/linux/mm.h | 8 ++++++++
mm/page_alloc.c | 8 ++++++++
2 files changed, 16 insertions(+)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 77e64e3eac80..b3317d91ee8e 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2871,7 +2871,11 @@ static inline void kernel_poison_pages(struct page *page, int numpages) { }
static inline void kernel_unpoison_pages(struct page *page, int numpages) { }
#endif
+#ifdef CONFIG_INIT_ON_ALLOC_DEFAULT_ON
+DECLARE_STATIC_KEY_TRUE(init_on_alloc);
+#else
DECLARE_STATIC_KEY_FALSE(init_on_alloc);
+#endif
static inline bool want_init_on_alloc(gfp_t flags)
{
if (static_branch_unlikely(&init_on_alloc))
@@ -2879,7 +2883,11 @@ static inline bool want_init_on_alloc(gfp_t flags)
return flags & __GFP_ZERO;
}
+#ifdef CONFIG_INIT_ON_FREE_DEFAULT_ON
+DECLARE_STATIC_KEY_TRUE(init_on_free);
+#else
DECLARE_STATIC_KEY_FALSE(init_on_free);
+#endif
static inline bool want_init_on_free(void)
{
return static_branch_unlikely(&init_on_free);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 3e4b29ee2b1e..f2d474a844cf 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -167,10 +167,18 @@ unsigned long totalcma_pages __read_mostly;
int percpu_pagelist_fraction;
gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
+#ifdef CONFIG_INIT_ON_ALLOC_DEFAULT_ON
+DEFINE_STATIC_KEY_TRUE(init_on_alloc);
+#else
DEFINE_STATIC_KEY_FALSE(init_on_alloc);
+#endif
EXPORT_SYMBOL(init_on_alloc);
+#ifdef CONFIG_INIT_ON_FREE_DEFAULT_ON
+DEFINE_STATIC_KEY_TRUE(init_on_free);
+#else
DEFINE_STATIC_KEY_FALSE(init_on_free);
+#endif
EXPORT_SYMBOL(init_on_free);
static bool _init_on_alloc_enabled_early __read_mostly
--
2.25.1
next prev parent reply other threads:[~2021-03-09 21:43 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-09 21:42 [PATCH v5 0/7] Optionally randomize kernel stack offset each syscall Kees Cook
2021-03-09 21:42 ` Kees Cook [this message]
2021-03-10 23:56 ` [PATCH v5 1/7] mm: Restore init_on_* static branch defaults Andrew Morton
2021-03-15 17:28 ` Kees Cook
2021-03-09 21:42 ` [PATCH v5 2/7] jump_label: Provide CONFIG-driven build state defaults Kees Cook
2021-03-09 21:42 ` [PATCH v5 3/7] init_on_alloc: Unpessimize default-on builds Kees Cook
2021-03-10 12:52 ` Andrey Konovalov
2021-03-10 21:03 ` Kees Cook
2021-03-09 21:42 ` [PATCH v5 4/7] stack: Optionally randomize kernel stack offset each syscall Kees Cook
2021-03-09 21:42 ` [PATCH v5 5/7] x86/entry: Enable random_kstack_offset support Kees Cook
2021-03-09 21:43 ` [PATCH v5 6/7] arm64: entry: " Kees Cook
2021-03-09 21:43 ` [PATCH v5 7/7] lkdtm: Add REPORT_STACK for checking stack offsets Kees Cook
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