linux-kernel - [PATCH v4 3/5] bitmap: Add bitmap_alloc(), bitmap_zalloc() and bitmap

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: <20180630201750.2588-4-andriy.shevchenko@linux.intel.com>
Date:   Sat, 30 Jun 2018 23:17:48 +0300
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Alasdair Kergon <agk@...hat.com>,
        Mike Snitzer <snitzer@...hat.com>, dm-devel@...hat.com,
        Shaohua Li <shli@...nel.org>, linux-raid@...r.kernel.org,
        Dmitry Torokhov <dmitry.torokhov@...il.com>,
        linux-input@...r.kernel.org,
        Andrew Morton <akpm@...ux-foundation.org>,
        Yury Norov <ynorov@...iumnetworks.com>,
        linux-kernel@...r.kernel.org, mika.westerberg@...ux.intel.com,
        Joe Perches <joe@...ches.com>
Cc:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Subject: [PATCH v4 3/5] bitmap: Add bitmap_alloc(), bitmap_zalloc() and bitmap_free()

A lot of code become ugly because of open coding allocations for bitmaps.

Introduce three helpers to allow users be more clear of intention
and keep their code neat.

Note, due to multiple circular dependencies we may not provide
the helpers as inliners. For now we keep them exported and, perhaps,
at some point in the future we will sort out header inclusion and
inheritance.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
---
 include/linux/bitmap.h |  8 ++++++++
 lib/bitmap.c           | 19 +++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index 1ee46f492267..acf5e8df3504 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -104,6 +104,14 @@
  * contain all bit positions from 0 to 'bits' - 1.
  */
 
+/*
+ * Allocation and deallocation of bitmap.
+ * Provided in lib/bitmap.c to avoid circular dependency.
+ */
+extern unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags);
+extern unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags);
+extern void bitmap_free(const unsigned long *bitmap);
+
 /*
  * lib/bitmap.c provides these functions:
  */
diff --git a/lib/bitmap.c b/lib/bitmap.c
index 33e95cd359a2..09acf2fd6a35 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -13,6 +13,7 @@
 #include <linux/bitops.h>
 #include <linux/bug.h>
 #include <linux/kernel.h>
+#include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/uaccess.h>
 
@@ -1125,6 +1126,24 @@ void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int n
 EXPORT_SYMBOL(bitmap_copy_le);
 #endif
 
+unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags)
+{
+	return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long), flags);
+}
+EXPORT_SYMBOL(bitmap_alloc);
+
+unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags)
+{
+	return bitmap_alloc(nbits, flags | __GFP_ZERO);
+}
+EXPORT_SYMBOL(bitmap_zalloc);
+
+void bitmap_free(const unsigned long *bitmap)
+{
+	kfree(bitmap);
+}
+EXPORT_SYMBOL(bitmap_free);
+
 #if BITS_PER_LONG == 64
 /**
  * bitmap_from_arr32 - copy the contents of u32 array of bits to bitmap
-- 
2.18.0