[prev in list] [next in list] [prev in thread] [next in thread]
List: git-commits-head
Subject: shm: fix shmctl(SHM_INFO) lockup with !CONFIG_SHMEM
From: Linux Kernel Mailing List <linux-kernel () vger ! kernel ! org>
Date: 2009-02-05 22:59:45
Message-ID: 200902052259.n15Mxjnt009290 () hera ! kernel ! org
[Download RAW message or body]
Gitweb: http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=a68e61e8ff2d46327a37b69056998b47745db6fa
Commit: a68e61e8ff2d46327a37b69056998b47745db6fa
Parent: 1f5e31d7e55ac7fbd4ec5e5b20c8868b0e4564c9
Author: Tony Battersby <tonyb@cybernetics.com>
AuthorDate: Wed Feb 4 15:12:04 2009 -0800
Committer: Linus Torvalds <torvalds@linux-foundation.org>
CommitDate: Thu Feb 5 12:56:47 2009 -0800
shm: fix shmctl(SHM_INFO) lockup with !CONFIG_SHMEM
shm_get_stat() assumes that the inode is a "struct shmem_inode_info",
which is incorrect for !CONFIG_SHMEM (see fs/ramfs/inode.c:
ramfs_get_inode() vs. mm/shmem.c: shmem_get_inode()).
This bad assumption can cause shmctl(SHM_INFO) to lockup when
shm_get_stat() tries to spin_lock(&info->lock). Users of !CONFIG_SHMEM
may encounter this lockup simply by invoking the 'ipcs' command.
Reported by Jiri Olsa back in February 2008:
http://lkml.org/lkml/2008/2/29/74
Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Reported-by: Jiri Olsa <olsajiri@gmail.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: <stable@kernel.org> [2.6.everything]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
ipc/shm.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/ipc/shm.c b/ipc/shm.c
index c0a021f..f8f69fa 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -565,11 +565,15 @@ static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
struct hstate *h = hstate_file(shp->shm_file);
*rss += pages_per_huge_page(h) * mapping->nrpages;
} else {
+#ifdef CONFIG_SHMEM
struct shmem_inode_info *info = SHMEM_I(inode);
spin_lock(&info->lock);
*rss += inode->i_mapping->nrpages;
*swp += info->swapped;
spin_unlock(&info->lock);
+#else
+ *rss += inode->i_mapping->nrpages;
+#endif
}
total++;
--
To unsubscribe from this list: send the line "unsubscribe git-commits-head" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
[prev in list] [next in list] [prev in thread] [next in thread]
Configure |
About |
News |
Add a list |
Sponsored by KoreLogic