Commit fd8aa9095a95 ("xen: optimize xenbus driver for multiple
concurrent xenstore accesses") made a subtle change to the semantic of
xenbus_dev_request_and_reply() and xenbus_transaction_end().
Before on an error response to XS_TRANSACTION_END
xenbus_dev_request_and_reply() would not decrement the active
transaction counter. But xenbus_transaction_end() has always counted the
transaction as finished regardless of the response.
The new behavior is that xenbus_dev_request_and_reply() and
xenbus_transaction_end() will always count the transaction as finished
regardless the response code (handled in xs_request_exit()).
But xenbus_dev_frontend tries to end a transaction on closing of the
device if the XS_TRANSACTION_END failed before. Trying to close the
transaction twice corrupts the reference count. So fix this by also
considering a transaction closed if we have sent XS_TRANSACTION_END once
regardless of the return code.
Cc: <stable(a)vger.kernel.org> # 4.11
Fixes: fd8aa9095a95 ("xen: optimize xenbus driver for multiple concurrent xenstore accesses")
Signed-off-by: Simon Gaiser <simon(a)invisiblethingslab.com>
---
drivers/xen/xenbus/xenbus_dev_frontend.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/xen/xenbus/xenbus_dev_frontend.c b/drivers/xen/xenbus/xenbus_dev_frontend.c
index f3b089b7c0b6..d2edbc79384a 100644
--- a/drivers/xen/xenbus/xenbus_dev_frontend.c
+++ b/drivers/xen/xenbus/xenbus_dev_frontend.c
@@ -365,7 +365,7 @@ void xenbus_dev_queue_reply(struct xb_req_data *req)
if (WARN_ON(rc))
goto out;
}
- } else if (req->msg.type == XS_TRANSACTION_END) {
+ } else if (req->type == XS_TRANSACTION_END) {
trans = xenbus_get_transaction(u, req->msg.tx_id);
if (WARN_ON(!trans))
goto out;
--
2.15.1
From: Huang Ying <huang.ying.caritas(a)gmail.com>
It was reported by Sergey Senozhatsky that if THP (Transparent Huge
Page) and frontswap (via zswap) are both enabled, when memory goes low
so that swap is triggered, segfault and memory corruption will occur
in random user space applications as follow,
kernel: urxvt[338]: segfault at 20 ip 00007fc08889ae0d sp 00007ffc73a7fc40 error 6 in libc-2.26.so[7fc08881a000+1ae000]
#0 0x00007fc08889ae0d _int_malloc (libc.so.6)
#1 0x00007fc08889c2f3 malloc (libc.so.6)
#2 0x0000560e6004bff7 _Z14rxvt_wcstoutf8PKwi (urxvt)
#3 0x0000560e6005e75c n/a (urxvt)
#4 0x0000560e6007d9f1 _ZN16rxvt_perl_interp6invokeEP9rxvt_term9hook_typez (urxvt)
#5 0x0000560e6003d988 _ZN9rxvt_term9cmd_parseEv (urxvt)
#6 0x0000560e60042804 _ZN9rxvt_term6pty_cbERN2ev2ioEi (urxvt)
#7 0x0000560e6005c10f _Z17ev_invoke_pendingv (urxvt)
#8 0x0000560e6005cb55 ev_run (urxvt)
#9 0x0000560e6003b9b9 main (urxvt)
#10 0x00007fc08883af4a __libc_start_main (libc.so.6)
#11 0x0000560e6003f9da _start (urxvt)
After bisection, it was found the first bad commit is
bd4c82c22c367e068 ("mm, THP, swap: delay splitting THP after swapped
out").
The root cause is as follow.
When the pages are written to swap device during swapping out in
swap_writepage(), zswap (fontswap) is tried to compress the pages
instead to improve the performance. But zswap (frontswap) will treat
THP as normal page, so only the head page is saved. After swapping
in, tail pages will not be restored to its original contents, so cause
the memory corruption in the applications.
This is fixed via rejecting to save page in frontswap store functions
if the page is a THP. So that the THP will be swapped out to swap
device.
Another choice is to split THP if frontswap is enabled. But it is
found that the frontswap enabling isn't flexible. For example, if
CONFIG_ZSWAP=y (cannot be module), frontswap will be enabled even if
zswap itself isn't enabled.
Frontswap has multiple backends, to make it easy for one backend to
enable THP support, the THP checking is put in backend frontswap store
functions instead of the general interfaces.
Fixes: bd4c82c22c367e068 ("mm, THP, swap: delay splitting THP after swapped out")
Reported-by: Sergey Senozhatsky <sergey.senozhatsky(a)gmail.com>
Tested-by: Sergey Senozhatsky <sergey.senozhatsky(a)gmail.com>
Suggested-by: Minchan Kim <minchan(a)kernel.org> # put THP checking in backend
Signed-off-by: "Huang, Ying" <ying.huang(a)intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk(a)oracle.com>
Cc: Dan Streetman <ddstreet(a)ieee.org>
Cc: Seth Jennings <sjenning(a)redhat.com>
Cc: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp>
Cc: Shaohua Li <shli(a)kernel.org>
Cc: Michal Hocko <mhocko(a)suse.com>
Cc: Johannes Weiner <hannes(a)cmpxchg.org>
Cc: Mel Gorman <mgorman(a)techsingularity.net>
Cc: Shakeel Butt <shakeelb(a)google.com>
Cc: Boris Ostrovsky <boris.ostrovsky(a)oracle.com>
Cc: Juergen Gross <jgross(a)suse.com>
Cc: stable(a)vger.kernel.org # 4.14
Changelog:
v3:
- Fix via checking THP in frontswap backend as suggested by Minchan.
v2:
- Move frontswap check into swapfile.c to avoid to make vmscan.c
depends on frontswap as suggested by Minchan.
---
drivers/xen/tmem.c | 4 ++++
mm/zswap.c | 6 ++++++
2 files changed, 10 insertions(+)
diff --git a/drivers/xen/tmem.c b/drivers/xen/tmem.c
index bf13d1ec51f3..04e7b3b29bac 100644
--- a/drivers/xen/tmem.c
+++ b/drivers/xen/tmem.c
@@ -284,6 +284,10 @@ static int tmem_frontswap_store(unsigned type, pgoff_t offset,
int pool = tmem_frontswap_poolid;
int ret;
+ /* THP isn't supported */
+ if (PageTransHuge(page))
+ return -1;
+
if (pool < 0)
return -1;
if (ind64 != ind)
diff --git a/mm/zswap.c b/mm/zswap.c
index c004aa4fd3f4..61a5c41972db 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -1007,6 +1007,12 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset,
u8 *src, *dst;
struct zswap_header zhdr = { .swpentry = swp_entry(type, offset) };
+ /* THP isn't supported */
+ if (PageTransHuge(page)) {
+ ret = -EINVAL;
+ goto reject;
+ }
+
if (!zswap_enabled || !tree) {
ret = -ENODEV;
goto reject;
--
2.15.1
Some other drivers may be waiting for our extcon to show-up (exiting their
probe methods with -EPROBE_DEFER until we show up).
These drivers will typically get the cable state directly after getting
the extcon, this commit changes the int3496 code to process the id-pin
before registering the extcon, so that other drivers see the correct state
right away.
Fixes: 2f556bdb9f2e ("extcon: int3496: Add Intel INT3496 ACPI ... driver")
Cc: stable(a)vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede(a)redhat.com>
---
drivers/extcon/extcon-intel-int3496.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/extcon/extcon-intel-int3496.c b/drivers/extcon/extcon-intel-int3496.c
index c8691b5a9cb0..b23ee9d993a3 100644
--- a/drivers/extcon/extcon-intel-int3496.c
+++ b/drivers/extcon/extcon-intel-int3496.c
@@ -131,6 +131,10 @@ static int int3496_probe(struct platform_device *pdev)
if (IS_ERR(data->gpio_usb_mux))
dev_info(dev, "can't request USB MUX GPIO\n");
+ /* process id-pin first so that we start with the right status */
+ queue_delayed_work(system_wq, &data->work, 0);
+ flush_delayed_work(&data->work);
+
/* register extcon device */
data->edev = devm_extcon_dev_allocate(dev, int3496_cable);
if (IS_ERR(data->edev))
@@ -153,9 +157,6 @@ static int int3496_probe(struct platform_device *pdev)
return ret;
}
- /* queue initial processing of id-pin */
- queue_delayed_work(system_wq, &data->work, 0);
-
platform_set_drvdata(pdev, data);
return 0;
--
2.14.3
Apparently using the manual Maud/Naud mode does not work on KBL. The
details on the failure mode are scarce, except that there's no audio,
and there is obviously no idea on the root cause either. It is also
unknown whether the failure can be reproduced on newer platforms in some
scenarios.
The problem was introduced when switching from automatic mode to manual
mode in commit 6014ac122ed0 ("drm/i915/audio: set proper N/M in
modeset"). Instead of reverting that, disable the feature on KBL as a
workaround.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104093
Reported-by: Quanxian Wang <quanxian.wang(a)intel.com>
Fixes: 6014ac122ed0 ("drm/i915/audio: set proper N/M in modeset")
Cc: <stable(a)vger.kernel.org> # v4.10+
Cc: Keqiao Zhang <keqiao.zhang(a)intel.com>
Cc: Ville Syrjälä <ville.syrjala(a)linux.intel.com>
Cc: Mengdong Lin <mengdong.lin(a)intel.com>
Cc: Libin Yang <libin.yang(a)linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi(a)intel.com>
Cc: Quanxian Wang <quanxian.wang(a)intel.com>
Cc: Wang Zhijun <zhijunx.wang(a)intel.com>
Cc: Cui Yueping <yuepingx.cui(a)intel.com>
Cc: Alice Liu <alice.liu(a)intel.com>
Cc: intel-gfx(a)lists.freedesktop.org
Signed-off-by: Jani Nikula <jani.nikula(a)intel.com>
---
UNTESTED. Please provide Tested-by's on the affected KBLs, but *also* on
CFL, CNL, etc.
---
drivers/gpu/drm/i915/intel_audio.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_audio.c b/drivers/gpu/drm/i915/intel_audio.c
index 522d54fecb53..b7634cff12b6 100644
--- a/drivers/gpu/drm/i915/intel_audio.c
+++ b/drivers/gpu/drm/i915/intel_audio.c
@@ -294,12 +294,19 @@ hsw_dp_audio_config_update(struct intel_encoder *encoder,
struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
enum port port = encoder->port;
enum pipe pipe = crtc->pipe;
- const struct dp_aud_n_m *nm;
+ const struct dp_aud_n_m *nm = NULL;
int rate;
u32 tmp;
rate = acomp ? acomp->aud_sample_rate[port] : 0;
- nm = audio_config_dp_get_n_m(crtc_state, rate);
+
+ /*
+ * FIXME: For reasons still unknown, there seem to be issues with the
+ * manual Maud/Naud mode on KBL.
+ */
+ if (!IS_KABYLAKE(dev_priv))
+ nm = audio_config_dp_get_n_m(crtc_state, rate);
+
if (nm)
DRM_DEBUG_KMS("using Maud %u, Naud %u\n", nm->m, nm->n);
else
--
2.11.0
Hi,
not sure whether this is the best list to ask for that, but maybe
somebody from -stable interested people has hit similar problem..
if it's not appropriate list to ask/report, please let me know
since we started rolling to 4.14.x kernels, we've experienced multiple
KVM guest panics (with 4.14 on hosts)
We've first hit it with 4.14.12, yesterday I had similar problem with 4.14.16.
backtraces can be observed here:
http://nik.lbox.cz/download/guest-panic-host-4.14.12.pnghttp://nik.lbox.cz/download/guest-panic-host-4.14.16.png
sorry I don't have anything more complete
they are a bit different, but there are some similarities (ie double_fault)
also important to note, both are from different host systems.
after reverting hosts to 4.4, crashes are gone.
my question is, did anyone hit similar problem? Is this something
know, maybe fixed in 4.14.17? (I'll give 4.14.17 try anyways I suppose)
(or latest git?)
could it be related to page table isolation enabled hosts?
btw hosts are running x86_64 centos 7, guests are either centos 6
or centos 7
If I could provide any further info, let me know
BR
nik
--
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-------------------------------------
The patch titled
Subject: mm, swap, frontswap: fix THP swap if frontswap enabled
has been added to the -mm tree. Its filename is
mm-swap-frontswap-fix-thp-swap-if-frontswap-enabled-v3.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-swap-frontswap-fix-thp-swap-if-…
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-swap-frontswap-fix-thp-swap-if-…
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Huang Ying <huang.ying.caritas(a)gmail.com>
Subject: mm, swap, frontswap: fix THP swap if frontswap enabled
It was reported by Sergey Senozhatsky that if THP (Transparent Huge Page)
and frontswap (via zswap) are both enabled, when memory goes low so that
swap is triggered, segfault and memory corruption will occur in random
user space applications as follow,
kernel: urxvt[338]: segfault at 20 ip 00007fc08889ae0d sp 00007ffc73a7fc40 error 6 in libc-2.26.so[7fc08881a000+1ae000]
#0 0x00007fc08889ae0d _int_malloc (libc.so.6)
#1 0x00007fc08889c2f3 malloc (libc.so.6)
#2 0x0000560e6004bff7 _Z14rxvt_wcstoutf8PKwi (urxvt)
#3 0x0000560e6005e75c n/a (urxvt)
#4 0x0000560e6007d9f1 _ZN16rxvt_perl_interp6invokeEP9rxvt_term9hook_typez (urxvt)
#5 0x0000560e6003d988 _ZN9rxvt_term9cmd_parseEv (urxvt)
#6 0x0000560e60042804 _ZN9rxvt_term6pty_cbERN2ev2ioEi (urxvt)
#7 0x0000560e6005c10f _Z17ev_invoke_pendingv (urxvt)
#8 0x0000560e6005cb55 ev_run (urxvt)
#9 0x0000560e6003b9b9 main (urxvt)
#10 0x00007fc08883af4a __libc_start_main (libc.so.6)
#11 0x0000560e6003f9da _start (urxvt)
After bisection, it was found the first bad commit is bd4c82c22c367e068
("mm, THP, swap: delay splitting THP after swapped out").
The root cause is as follows:
When the pages are written to swap device during swapping out in
swap_writepage(), zswap (fontswap) is tried to compress the pages to
improve performance. But zswap (frontswap) will treat THP as a normal
page, so only the head page is saved. After swapping in, tail pages will
not be restored to their original contents, causing memory corruption in
the applications.
This is fixed by refusing to save page in the frontswap store functions if
the page is a THP. So that the THP will be swapped out to swap device.
Another choice is to split THP if frontswap is enabled. But it is found
that the frontswap enabling isn't flexible. For example, if
CONFIG_ZSWAP=y (cannot be module), frontswap will be enabled even if zswap
itself isn't enabled.
Frontswap has multiple backends, to make it easy for one backend to enable
THP support, the THP checking is put in backend frontswap store functions
instead of the general interfaces.
Link: http://lkml.kernel.org/r/20180209084947.22749-1-ying.huang@intel.com
Fixes: bd4c82c22c367e068 ("mm, THP, swap: delay splitting THP after swapped out")
Signed-off-by: "Huang, Ying" <ying.huang(a)intel.com>
Reported-by: Sergey Senozhatsky <sergey.senozhatsky(a)gmail.com>
Suggested-by: Minchan Kim <minchan(a)kernel.org> [put THP checking in backend]
Cc: Konrad Rzeszutek Wilk <konrad.wilk(a)oracle.com>
Cc: Dan Streetman <ddstreet(a)ieee.org>
Cc: Seth Jennings <sjenning(a)redhat.com>
Cc: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp>
Cc: Shaohua Li <shli(a)kernel.org>
Cc: Michal Hocko <mhocko(a)suse.com>
Cc: Johannes Weiner <hannes(a)cmpxchg.org>
Cc: Mel Gorman <mgorman(a)techsingularity.net>
Cc: Shakeel Butt <shakeelb(a)google.com>
Cc: Boris Ostrovsky <boris.ostrovsky(a)oracle.com>
Cc: Juergen Gross <jgross(a)suse.com>
Cc: <stable(a)vger.kernel.org> [4.14]
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
drivers/xen/tmem.c | 4 ++++
mm/zswap.c | 6 ++++++
2 files changed, 10 insertions(+)
diff -puN drivers/xen/tmem.c~mm-swap-frontswap-fix-thp-swap-if-frontswap-enabled-v3 drivers/xen/tmem.c
--- a/drivers/xen/tmem.c~mm-swap-frontswap-fix-thp-swap-if-frontswap-enabled-v3
+++ a/drivers/xen/tmem.c
@@ -284,6 +284,10 @@ static int tmem_frontswap_store(unsigned
int pool = tmem_frontswap_poolid;
int ret;
+ /* THP isn't supported */
+ if (PageTransHuge(page))
+ return -1;
+
if (pool < 0)
return -1;
if (ind64 != ind)
diff -puN mm/zswap.c~mm-swap-frontswap-fix-thp-swap-if-frontswap-enabled-v3 mm/zswap.c
--- a/mm/zswap.c~mm-swap-frontswap-fix-thp-swap-if-frontswap-enabled-v3
+++ a/mm/zswap.c
@@ -1007,6 +1007,12 @@ static int zswap_frontswap_store(unsigne
u8 *src, *dst;
struct zswap_header zhdr = { .swpentry = swp_entry(type, offset) };
+ /* THP isn't supported */
+ if (PageTransHuge(page)) {
+ ret = -EINVAL;
+ goto reject;
+ }
+
if (!zswap_enabled || !tree) {
ret = -ENODEV;
goto reject;
_
Patches currently in -mm which might be from huang.ying.caritas(a)gmail.com are
mm-swap-frontswap-fix-thp-swap-if-frontswap-enabled-v3.patch