From: Johannes Berg <johannes@sipsolutions.net>
To: Dmitry Vyukov <dvyukov@google.com>
Cc: David Gow <davidgow@google.com>,
Vincent Whitchurch <vincent.whitchurch@axis.com>,
Patricia Alfonso <trishalfonso@google.com>,
Jeff Dike <jdike@addtoit.com>,
Richard Weinberger <richard@nod.at>,
anton.ivanov@cambridgegreys.com,
Brendan Higgins <brendanhiggins@google.com>,
kasan-dev <kasan-dev@googlegroups.com>,
linux-um@lists.infradead.org, LKML <linux-kernel@vger.kernel.org>,
Daniel Latypov <dlatypov@google.com>
Subject: Re: [RFC PATCH v3] UML: add support for KASAN under x86_64
Date: Fri, 27 May 2022 16:27:55 +0200 [thread overview]
Message-ID: <5eef2f1b43c25447ccca2f50f4964fd77a719b08.camel@sipsolutions.net> (raw)
In-Reply-To: <CACT4Y+aH7LqDUqAyQ7+hkyeZTtkYnMHia73M7=EeAzMYzJ8pQg@mail.gmail.com>
On Fri, 2022-05-27 at 15:52 +0200, Dmitry Vyukov wrote:
> On Fri, 27 May 2022 at 15:27, Johannes Berg <johannes@sipsolutions.net> wrote:
> >
> > On Fri, 2022-05-27 at 15:18 +0200, Dmitry Vyukov wrote:
> > > On Fri, 27 May 2022 at 15:15, Johannes Berg <johannes@sipsolutions.net> wrote:
> > > >
> > > > On Fri, 2022-05-27 at 15:09 +0200, Dmitry Vyukov wrote:
> > > > > > I did note (this is more for kasan-dev@) that the "freed by" is fairly
> > > > > > much useless when using kfree_rcu(), it might be worthwhile to annotate
> > > > > > that somehow, so the stack trace is recorded by kfree_rcu() already,
> > > > > > rather than just showing the RCU callback used for that.
[...]
> Humm... I don't have any explanation based only on this info.
> Generally call_rcu stacks are memorized and I see the call is still there:
> https://elixir.bootlin.com/linux/v5.18/source/kernel/rcu/tree.c#L3595
Oh, that's simple then, UML is !SMP && !PREEMPT so it gets TINY_RCU
instead of TREE_RCU.
Unfortunately, it's not entirely trivial to fix, something like this,
mostly because of header maze (cannot include kasan.h in rcutiny.h):
diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h
index 5fed476f977f..d84e13f2c384 100644
--- a/include/linux/rcutiny.h
+++ b/include/linux/rcutiny.h
@@ -38,7 +38,7 @@ static inline void synchronize_rcu_expedited(void)
*/
extern void kvfree(const void *addr);
-static inline void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
+static inline void __kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
{
if (head) {
call_rcu(head, func);
@@ -51,6 +51,15 @@ static inline void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
kvfree((void *) func);
}
+#ifdef CONFIG_KASAN_GENERIC
+void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func);
+#else
+static inline void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
+{
+ __kvfree_call_rcu(head, func);
+}
+#endif
+
void rcu_qs(void);
static inline void rcu_softirq_qs(void)
diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c
index 340b3f8b090d..aa235f0332ba 100644
--- a/kernel/rcu/tiny.c
+++ b/kernel/rcu/tiny.c
@@ -217,6 +217,18 @@ bool poll_state_synchronize_rcu(unsigned long oldstate)
}
EXPORT_SYMBOL_GPL(poll_state_synchronize_rcu);
+void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
+{
+ if (head) {
+ void *ptr = (void *) head - (unsigned long) func;
+
+ kasan_record_aux_stack_noalloc(ptr);
+ }
+
+ __kvfree_call_rcu(head, func);
+}
+EXPORT_SYMBOL_GPL(kvfree_call_rcu);
+
void __init rcu_init(void)
{
open_softirq(RCU_SOFTIRQ, rcu_process_callbacks);
Or I guess I could copy/paste
#ifdef CONFIG_KASAN_GENERIC
void kasan_record_aux_stack_noalloc(void *ptr);
#else /* CONFIG_KASAN_GENERIC */
static inline void kasan_record_aux_stack_noalloc(void *ptr) {}
#endif /* CONFIG_KASAN_GENERIC */
into rcutiny.h, that'd be smaller, and export the symbol ...
johannes
next prev parent reply other threads:[~2022-05-27 14:28 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-26 0:46 [PATCH] UML: add support for KASAN under x86_64 Patricia Alfonso
2020-02-26 1:19 ` Brendan Higgins
2020-02-26 15:24 ` Dmitry Vyukov
2020-03-06 0:03 ` Patricia Alfonso
2020-03-11 10:32 ` Johannes Berg
2020-03-11 10:46 ` Dmitry Vyukov
2020-03-11 11:18 ` Johannes Berg
2020-03-11 11:40 ` Johannes Berg
2020-03-11 17:34 ` Dmitry Vyukov
2020-03-20 13:39 ` Johannes Berg
2020-03-20 15:18 ` Dmitry Vyukov
2020-03-30 7:43 ` Johannes Berg
2020-03-30 8:38 ` Dmitry Vyukov
2020-03-30 8:41 ` Johannes Berg
2020-03-31 6:14 ` David Gow
2020-03-31 7:43 ` Johannes Berg
2020-03-31 16:39 ` Patricia Alfonso
2020-03-31 16:54 ` Richard Weinberger
2020-03-11 22:32 ` Patricia Alfonso
2020-03-11 22:44 ` Johannes Berg
2022-05-24 10:34 ` Vincent Whitchurch
2022-05-24 10:45 ` Johannes Berg
2022-05-24 19:35 ` David Gow
2022-05-25 11:17 ` Vincent Whitchurch
2022-05-26 1:01 ` [RFC PATCH v3] " David Gow
2022-05-26 9:29 ` Johannes Berg
2022-05-27 5:31 ` Dmitry Vyukov
2022-05-27 7:32 ` Johannes Berg
2022-05-27 10:36 ` Johannes Berg
2022-05-27 13:05 ` Johannes Berg
2022-05-27 13:09 ` Dmitry Vyukov
2022-05-27 13:15 ` Johannes Berg
2022-05-27 13:18 ` Dmitry Vyukov
2022-05-27 13:27 ` Johannes Berg
2022-05-27 13:52 ` Dmitry Vyukov
2022-05-27 14:27 ` Johannes Berg [this message]
2022-05-27 15:46 ` Dmitry Vyukov
2020-03-29 19:06 ` [PATCH] " Richard Weinberger
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=5eef2f1b43c25447ccca2f50f4964fd77a719b08.camel@sipsolutions.net \
--to=johannes@sipsolutions.net \
--cc=anton.ivanov@cambridgegreys.com \
--cc=brendanhiggins@google.com \
--cc=davidgow@google.com \
--cc=dlatypov@google.com \
--cc=dvyukov@google.com \
--cc=jdike@addtoit.com \
--cc=kasan-dev@googlegroups.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-um@lists.infradead.org \
--cc=richard@nod.at \
--cc=trishalfonso@google.com \
--cc=vincent.whitchurch@axis.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).