linux-kernel - [PATCH] mm/shmem: Enclose shmem_mcopy_atomic_pte() with 'CONFIG

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-next>] [day] [month] [year] [list]

Message-ID: <20210316094910.23827-1-sjpark@amazon.com>
Date:   Tue, 16 Mar 2021 10:49:10 +0100
From:   SeongJae Park <sjpark@...zon.com>
To:     <akpm@...ux-foundation.org>
CC:     <hughd@...gle.com>, <axelrasmussen@...gle.com>, <amit@...nel.org>,
        <linux-mm@...ck.org>, <linux-kernel@...r.kernel.org>,
        SeongJae Park <sjpark@...zon.de>
Subject: [PATCH] mm/shmem: Enclose shmem_mcopy_atomic_pte() with 'CONFIG_USERFAULTFD'

From: SeongJae Park <sjpark@...zon.de>

Commit 49eeab03fa0a ("userfaultfd: support minor fault handling for
shmem") introduced shmem_mcopy_atomic_pte().  The function is declared
in 'userfaultfd_k.h' when 'CONFIG_USERFAULTFD' is defined, and defined
as 'BUG()' if the config is unset.  However, the definition of the
function in 'shmem.c' is not protected by the '#ifdef' macro.  As a
result, the build fails when the config is not set.  This commit fixes
the problem.

Fixes: 49eeab03fa0a ("userfaultfd: support minor fault handling for shmem")
Signed-off-by: SeongJae Park <sjpark@...zon.de>

cr https://code.amazon.com/reviews/CR-47204463
---
 mm/shmem.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/shmem.c b/mm/shmem.c
index 547df2b766f7..c0d3abefeb3f 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2359,6 +2359,7 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode
 	return inode;
 }

+#ifdef CONFIG_USERFAULTFD
 int shmem_mcopy_atomic_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd,
 			   struct vm_area_struct *dst_vma,
 			   unsigned long dst_addr, unsigned long src_addr,
@@ -2492,6 +2493,7 @@ int shmem_mcopy_atomic_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd,
 	shmem_inode_unacct_blocks(inode, 1);
 	goto out;
 }
+#endif

 #ifdef CONFIG_TMPFS
 static const struct inode_operations shmem_symlink_inode_operations;
-- 
2.17.1

Amazon Development Center Germany GmbH
Krausenstr. 38
10117 Berlin
Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss
Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B
Sitz: Berlin
Ust-ID: DE 289 237 879