Commit Graph

17 Commits

Author SHA1 Message Date
Ingo Molnar
44347d947f Merge branch 'linus' into tracing/core
Merge reason: tracing/core was on a .30-rc1 base and was missing out on
              on a handful of tracing fixes present in .30-rc5-almost.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-07 11:17:34 +02:00
Stuart Bennett
0f9a623dd6 tracing: x86, mmiotrace: only register for die notifier when tracer active
Follow up to afcfe024ae in Linus' tree
("x86: mmiotrace: quieten spurious warning message")

Signed-off-by: Stuart Bennett <stuart@freedesktop.org>
Acked-by: Pekka Paalanen <pq@iki.fi>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1240946271-7083-5-git-send-email-stuart@freedesktop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-29 11:33:34 +02:00
Stuart Bennett
46e91d00b1 tracing: x86, mmiotrace: refactor clearing/restore of page presence
* change function names to clear_* from set_*: in reality we only clear
  and restore page presence, and never unconditionally set present.
  Using clear_*({true, false}, ...) is therefore more honest than
  set_*({false, true}, ...)

* upgrade presence storage to pteval_t: doing user-space tracing will
  require saving and manipulation of the _PAGE_PROTNONE bit, in addition
  to the existing _PAGE_PRESENT changes, and having multiple bools stored
  and passed around does not seem optimal

[ Impact: refactor, clean up mmiotrace code ]

Signed-off-by: Stuart Bennett <stuart@freedesktop.org>
Acked-by: Pekka Paalanen <pq@iki.fi>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1240946271-7083-4-git-send-email-stuart@freedesktop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-29 11:33:33 +02:00
Stuart Bennett
0492e1bb8f tracing: x86, mmiotrace: code consistency/legibility improvement
kmmio_probe being *p and kmmio_fault_page being sometimes *f and
sometimes *p is not helpful.

[ Impact: cleanup ]

Signed-off-by: Stuart Bennett <stuart@freedesktop.org>
Acked-by: Pekka Paalanen <pq@iki.fi>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1240946271-7083-3-git-send-email-stuart@freedesktop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-29 11:33:33 +02:00
Stuart Bennett
33015c8599 tracing: x86, mmiotrace: fix range test
Matching on (addr == (p->addr + p->len)) causes problems when mappings
are adjacent.

[ Impact: fix mmiotrace confusion on adjacent iomaps ]

Signed-off-by: Stuart Bennett <stuart@freedesktop.org>
Acked-by: Pekka Paalanen <pq@iki.fi>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1240946271-7083-2-git-send-email-stuart@freedesktop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-29 11:32:22 +02:00
Stuart Bennett
afcfe024ae x86: mmiotrace: quieten spurious warning message
This message was being incorrectly emitted when using gdb,
so compile it out by default for now; there will be a
better fix in v2.6.30.

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Stuart Bennett <stuart@freedesktop.org>
Acked-by: Pekka Paalanen <pq@iki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-11 21:41:58 +01:00
Stuart Bennett
d0fc63f7bd x86 mmiotrace: fix remove_kmmio_fault_pages()
Impact: fix race+crash in mmiotrace

The list manipulation in remove_kmmio_fault_pages() was broken. If more
than one consecutive kmmio_fault_page was re-added during the grace
period between unregister_kmmio_probe() and remove_kmmio_fault_pages(),
the list manipulation failed to remove pages from the release list.

After a second grace period the pages get into rcu_free_kmmio_fault_pages()
and raise a BUG_ON() kernel crash.

The list manipulation is fixed to properly remove pages from the release
list.

This bug has been present from the very beginning of mmiotrace in the
mainline kernel. It was introduced in 0fd0e3da ("x86: mmiotrace full
patch, preview 1");

An urgent fix for Linus. Tested by Stuart (on 32-bit) and Pekka
(on amd and intel 64-bit systems, nouveau and nvidia proprietary).

Signed-off-by: Stuart Bennett <stuart@freedesktop.org>
Signed-off-by: Pekka Paalanen <pq@iki.fi>
LKML-Reference: <20090308202135.34933feb@daedalus.pq.iki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-08 19:51:23 +01:00
Pekka Paalanen
340430c572 x86 mmiotrace: fix race with release_kmmio_fault_page()
There was a theoretical possibility to a race between arming a page in
post_kmmio_handler() and disarming the page in
release_kmmio_fault_page():

cpu0                             cpu1
------------------------------------------------------------------
mmiotrace shutdown
enter release_kmmio_fault_page
                                 fault on the page
                                 disarm the page
disarm the page
                                 handle the MMIO access
                                 re-arm the page
put the page on release list
remove_kmmio_fault_pages()
                                 fault on the page
                                 page not known to mmiotrace
                                 fall back to do_page_fault()
                                 *KABOOM*

(This scenario also shows the double disarm case which is allowed.)

Fixed by acquiring kmmio_lock in post_kmmio_handler() and checking
if the page is being released from mmiotrace.

Signed-off-by: Pekka Paalanen <pq@iki.fi>
Cc: Stuart Bennett <stuart@freedesktop.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-02 10:20:37 +01:00
Stuart Bennett
3e39aa156a x86 mmiotrace: improve handling of secondary faults
Upgrade some kmmio.c debug messages to warnings.
Allow secondary faults on probed pages to fall through, and only log
secondary faults that are not due to non-present pages.

Patch edited by Pekka Paalanen.

Signed-off-by: Stuart Bennett <stuart@freedesktop.org>
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-02 10:20:37 +01:00
Pekka Paalanen
0b700a6a25 x86 mmiotrace: split set_page_presence()
From 36772dcb6ffbbb68254cbfc379a103acd2fbfefc Mon Sep 17 00:00:00 2001
From: Pekka Paalanen <pq@iki.fi>
Date: Sat, 28 Feb 2009 21:34:59 +0200

Split set_page_presence() in kmmio.c into two more functions set_pmd_presence()
and set_pte_presence(). Purely code reorganization, no functional changes.

Signed-off-by: Pekka Paalanen <pq@iki.fi>
Cc: Stuart Bennett <stuart@freedesktop.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-02 10:20:36 +01:00
Pekka Paalanen
5359b585fb x86 mmiotrace: fix save/restore page table state
From baa99e2b32449ec7bf147c234adfa444caecac8a Mon Sep 17 00:00:00 2001
From: Pekka Paalanen <pq@iki.fi>
Date: Sun, 22 Feb 2009 20:02:43 +0200

Blindly setting _PAGE_PRESENT in disarm_kmmio_fault_page() overlooks the
possibility, that the page was not present when it was armed.

Make arm_kmmio_fault_page() store the previous page presence in struct
kmmio_fault_page and use it on disarm.

This patch was originally written by Stuart Bennett, but Pekka Paalanen
rewrote it a little different.

Signed-off-by: Pekka Paalanen <pq@iki.fi>
Cc: Stuart Bennett <stuart@freedesktop.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-02 10:20:36 +01:00
Stuart Bennett
e9d54cae8f x86 mmiotrace: WARN_ONCE if dis/arming a page fails
Print a full warning once, if arming or disarming a page fails.

Also, if initial arming fails, do not handle the page further. This
avoids the possibility of a page failing to arm and then later claiming
to have handled any fault on that page.

WARN_ONCE added by Pekka Paalanen.

Signed-off-by: Stuart Bennett <stuart@freedesktop.org>
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-02 10:20:35 +01:00
Ingo Molnar
668a6c3654 - fix mmioftrace + rcu merge interaction
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-25 09:51:43 +02:00
Pekka Paalanen
790e2a290b x86 mmiotrace: page level is unsigned
Fixes some sparse warnings.

Signed-off-by: Pekka Paalanen <pq@iki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-24 11:27:47 +02:00
Pekka Paalanen
87e547fe41 x86 mmiotrace: fix page-unaligned ioremaps
mmiotrace_ioremap() expects to receive the original unaligned map phys address
and size. Also fix {un,}register_kmmio_probe() to deal properly with
unaligned size.

Signed-off-by: Pekka Paalanen <pq@iki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-24 11:27:32 +02:00
Pekka Paalanen
970e6fa038 mmiotrace: code style cleanups
From c2da03771e29159627c5c7b9509ec70bce9f91ee Mon Sep 17 00:00:00 2001
From: Pekka Paalanen <pq@iki.fi>
Date: Mon, 28 Apr 2008 21:25:22 +0300

Signed-off-by: Pekka Paalanen <pq@iki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-24 11:27:28 +02:00
Pekka Paalanen
ff3a3e9ba5 x86 mmiotrace: move files into arch/x86/mm/.
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-24 11:25:37 +02:00