From: Cong Wang <xiyou.wangcong@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>,
Cong Wang <xiyou.wangcong@gmail.com>,
Prarit Bhargava <prarit@redhat.com>,
Arnd Bergmann <arnd@arndb.de>,
Greg Kroah-Hartman <greg@kroah.com>,
Dave Young <dyoung@redhat.com>
Subject: [PATCH 2/2] lkdtm: avoid calling sleeping functions in interrupt context
Date: Wed, 1 Feb 2012 14:58:20 +0800 [thread overview]
Message-ID: <1328079501-24746-2-git-send-email-xiyou.wangcong@gmail.com> (raw)
In-Reply-To: <1328079501-24746-1-git-send-email-xiyou.wangcong@gmail.com>
lkdtm_do_action() could be called in interrupt context,
but it also calls sleeping functions like schedule(),
kmalloc(GFP_KERNEL) etc., for such cases, avoid calling them
if we are in interrupt context.
BTW, check the return value of kmalloc().
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
---
drivers/misc/lkdtm.c | 15 +++++++++++++--
1 files changed, 13 insertions(+), 2 deletions(-)
diff --git a/drivers/misc/lkdtm.c b/drivers/misc/lkdtm.c
index afdef2e..63b23a4 100644
--- a/drivers/misc/lkdtm.c
+++ b/drivers/misc/lkdtm.c
@@ -311,22 +311,31 @@ static void lkdtm_do_action(enum ctype which)
}
case CT_OVERWRITE_ALLOCATION: {
size_t len = 1020;
- u32 *data = kmalloc(len, GFP_KERNEL);
+ u32 *data = kmalloc(len, GFP_ATOMIC);
+ if (!data)
+ break;
data[1024 / sizeof(u32)] = 0x12345678;
kfree(data);
break;
}
case CT_WRITE_AFTER_FREE: {
size_t len = 1024;
- u32 *data = kmalloc(len, GFP_KERNEL);
+ u32 *data;
+ if (in_interrupt())
+ break;
+ data = kmalloc(len, GFP_KERNEL);
+ if (!data)
+ break;
kfree(data);
schedule();
memset(data, 0x78, len);
break;
}
case CT_SOFTLOCKUP:
+ if (in_interrupt())
+ break;
preempt_disable();
for (;;)
cpu_relax();
@@ -337,6 +346,8 @@ static void lkdtm_do_action(enum ctype which)
cpu_relax();
break;
case CT_HUNG_TASK:
+ if (in_interrupt())
+ break;
set_current_state(TASK_UNINTERRUPTIBLE);
schedule();
break;
--
1.7.7.6
next prev parent reply other threads:[~2012-02-01 6:59 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-01 6:58 [PATCH 1/2] lkdtm: use atomic_t to replace count_lock Cong Wang
2012-02-01 6:58 ` Cong Wang [this message]
2012-02-01 15:27 ` Arnd Bergmann
2012-02-02 13:33 ` Cong Wang
2012-02-02 13:44 ` Arnd Bergmann
2012-02-02 14:27 ` Cong Wang
2012-02-02 14:55 ` Arnd Bergmann
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1328079501-24746-2-git-send-email-xiyou.wangcong@gmail.com \
--to=xiyou.wangcong@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=arnd@arndb.de \
--cc=dyoung@redhat.com \
--cc=greg@kroah.com \
--cc=linux-kernel@vger.kernel.org \
--cc=prarit@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).