From: David Gow <davidgow@google.com>
To: Vincent Whitchurch <vincent.whitchurch@axis.com>,
Johannes Berg <johannes@sipsolutions.net>,
Patricia Alfonso <trishalfonso@google.com>,
Jeff Dike <jdike@addtoit.com>,
Richard Weinberger <richard@nod.at>,
anton.ivanov@cambridgegreys.com,
Dmitry Vyukov <dvyukov@google.com>,
Brendan Higgins <brendanhiggins@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Andrey Konovalov <andreyknvl@gmail.com>,
Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: David Gow <davidgow@google.com>,
kasan-dev <kasan-dev@googlegroups.com>,
linux-um@lists.infradead.org, LKML <linux-kernel@vger.kernel.org>,
Daniel Latypov <dlatypov@google.com>,
linux-mm@kvack.org
Subject: [PATCH v2 1/2] mm: Add PAGE_ALIGN_DOWN macro
Date: Fri, 27 May 2022 11:55:59 -0700 [thread overview]
Message-ID: <20220527185600.1236769-1-davidgow@google.com> (raw)
This is just the same as PAGE_ALIGN(), but rounds the address down, not
up.
Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: David Gow <davidgow@google.com>
---
Note: there is no v1 of this patch, it's just part of v2 of the
UML/KASAN series.
There are almost certainly lots of places where this macro should be
used: just look for ALIGN_DOWN(..., PAGE_SIZE). I haven't gone through
to try to replace them all.
---
include/linux/mm.h | 3 +++
1 file changed, 3 insertions(+)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index e34edb775334..e68731f0ef20 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -221,6 +221,9 @@ int overcommit_policy_handler(struct ctl_table *, int, void *, size_t *,
/* to align the pointer to the (next) page boundary */
#define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE)
+/* to align the pointer to the (prev) page boundary */
+#define PAGE_ALIGN_DOWN(addr) ALIGN_DOWN(addr, PAGE_SIZE)
+
/* test whether an address (unsigned long or pointer) is aligned to PAGE_SIZE */
#define PAGE_ALIGNED(addr) IS_ALIGNED((unsigned long)(addr), PAGE_SIZE)
--
2.36.1.124.g0e6072fb45-goog
next reply other threads:[~2022-05-27 18:56 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-27 18:55 David Gow [this message]
2022-05-27 18:56 ` [PATCH v2 2/2] UML: add support for KASAN under x86_64 David Gow
2022-05-27 20:14 ` Johannes Berg
2022-05-29 17:55 ` Johannes Berg
2022-06-30 7:53 ` David Gow
2022-05-29 17:04 ` Johannes Berg
2022-06-30 7:53 ` David Gow
2022-05-30 18:03 ` Andrey Konovalov
2022-06-30 7:54 ` David Gow
2022-05-30 0:06 ` [PATCH v2 1/2] mm: Add PAGE_ALIGN_DOWN macro Andrew Morton
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