Commit-ID: 8e1eb3fa009aa7c0b944b3c8b26b07de0efb3200
Gitweb: https://git.kernel.org/tip/8e1eb3fa009aa7c0b944b3c8b26b07de0efb3200
Author: Dan Williams <dan.j.williams(a)intel.com>
AuthorDate: Mon, 5 Feb 2018 17:18:05 -0800
Committer: Ingo Molnar <mingo(a)kernel.org>
CommitDate: Tue, 6 Feb 2018 08:30:27 +0100
x86/entry/64: Clear extra registers beyond syscall arguments, to reduce speculation attack surface
At entry userspace may have (maliciously) populated the extra registers
outside the syscall calling convention with arbitrary values that could
be useful in a speculative execution (Spectre style) attack.
Clear these registers to minimize the kernel's attack surface.
Note, this only clears the extra registers and not the unused
registers for syscalls less than 6 arguments, since those registers are
likely to be clobbered well before their values could be put to use
under speculation.
Note, Linus found that the XOR instructions can be executed with
minimized cost if interleaved with the PUSH instructions, and Ingo's
analysis found that R10 and R11 should be included in the register
clearing beyond the typical 'extra' syscall calling convention
registers.
Suggested-by: Linus Torvalds <torvalds(a)linux-foundation.org>
Reported-by: Andi Kleen <ak(a)linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams(a)intel.com>
Cc: <stable(a)vger.kernel.org>
Cc: Andy Lutomirski <luto(a)kernel.org>
Cc: Borislav Petkov <bp(a)alien8.de>
Cc: Brian Gerst <brgerst(a)gmail.com>
Cc: Denys Vlasenko <dvlasenk(a)redhat.com>
Cc: H. Peter Anvin <hpa(a)zytor.com>
Cc: Josh Poimboeuf <jpoimboe(a)redhat.com>
Cc: Peter Zijlstra <peterz(a)infradead.org>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Link: http://lkml.kernel.org/r/151787988577.7847.16733592218894189003.stgit@dwill…
[ Made small improvements to the changelog and the code comments. ]
Signed-off-by: Ingo Molnar <mingo(a)kernel.org>
---
arch/x86/entry/entry_64.S | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index c752abe..065a71b 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -235,13 +235,26 @@ GLOBAL(entry_SYSCALL_64_after_hwframe)
pushq %r8 /* pt_regs->r8 */
pushq %r9 /* pt_regs->r9 */
pushq %r10 /* pt_regs->r10 */
+ /*
+ * Clear extra registers that a speculation attack might
+ * otherwise want to exploit. Interleave XOR with PUSH
+ * for better uop scheduling:
+ */
+ xorq %r10, %r10 /* nospec r10 */
pushq %r11 /* pt_regs->r11 */
+ xorq %r11, %r11 /* nospec r11 */
pushq %rbx /* pt_regs->rbx */
+ xorl %ebx, %ebx /* nospec rbx */
pushq %rbp /* pt_regs->rbp */
+ xorl %ebp, %ebp /* nospec rbp */
pushq %r12 /* pt_regs->r12 */
+ xorq %r12, %r12 /* nospec r12 */
pushq %r13 /* pt_regs->r13 */
+ xorq %r13, %r13 /* nospec r13 */
pushq %r14 /* pt_regs->r14 */
+ xorq %r14, %r14 /* nospec r14 */
pushq %r15 /* pt_regs->r15 */
+ xorq %r15, %r15 /* nospec r15 */
UNWIND_HINT_REGS
TRACE_IRQS_OFF
From: Russell King <rmk+kernel(a)armlinux.org.uk>
[ Upstream commit f5e64032a799d4f54decc7eb6aafcdffb67f9ad9 ]
When a PHY has the BMCR_PDOWN bit set, it may decide to ignore writes
to other registers, or reset the registers to power-on defaults.
Micrel PHYs do this for their interrupt registers.
The current structure of phylib tries to enable interrupts before
resuming (and releasing) the BMCR_PDOWN bit. This fails, causing
Micrel PHYs to stop working after a suspend/resume sequence if they
are using interrupts.
Fix this by ensuring that the PHY driver resume methods do not take
the phydev->lock mutex themselves, but the callers of phy_resume()
take that lock. This then allows us to move the call to phy_resume()
before we enable interrupts in phy_start().
Signed-off-by: Russell King <rmk+kernel(a)armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew(a)lunn.ch>
Signed-off-by: David S. Miller <davem(a)davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin(a)microsoft.com>
---
drivers/net/phy/at803x.c | 4 ----
drivers/net/phy/phy.c | 9 +++------
drivers/net/phy/phy_device.c | 10 ++++++----
3 files changed, 9 insertions(+), 14 deletions(-)
diff --git a/drivers/net/phy/at803x.c b/drivers/net/phy/at803x.c
index 5f93e6add563..e911e4990b20 100644
--- a/drivers/net/phy/at803x.c
+++ b/drivers/net/phy/at803x.c
@@ -239,14 +239,10 @@ static int at803x_resume(struct phy_device *phydev)
{
int value;
- mutex_lock(&phydev->lock);
-
value = phy_read(phydev, MII_BMCR);
value &= ~(BMCR_PDOWN | BMCR_ISOLATE);
phy_write(phydev, MII_BMCR, value);
- mutex_unlock(&phydev->lock);
-
return 0;
}
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 2b1e67bc1e73..ed10d1fc8f59 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -828,7 +828,6 @@ EXPORT_SYMBOL(phy_stop);
*/
void phy_start(struct phy_device *phydev)
{
- bool do_resume = false;
int err = 0;
mutex_lock(&phydev->lock);
@@ -841,6 +840,9 @@ void phy_start(struct phy_device *phydev)
phydev->state = PHY_UP;
break;
case PHY_HALTED:
+ /* if phy was suspended, bring the physical link up again */
+ phy_resume(phydev);
+
/* make sure interrupts are re-enabled for the PHY */
if (phydev->irq != PHY_POLL) {
err = phy_enable_interrupts(phydev);
@@ -849,17 +851,12 @@ void phy_start(struct phy_device *phydev)
}
phydev->state = PHY_RESUMING;
- do_resume = true;
break;
default:
break;
}
mutex_unlock(&phydev->lock);
- /* if phy was suspended, bring the physical link up again */
- if (do_resume)
- phy_resume(phydev);
-
phy_trigger_machine(phydev, true);
}
EXPORT_SYMBOL(phy_start);
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 67f25ac29025..b15b31ca2618 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -135,7 +135,9 @@ static int mdio_bus_phy_resume(struct device *dev)
if (!mdio_bus_phy_may_suspend(phydev))
goto no_resume;
+ mutex_lock(&phydev->lock);
ret = phy_resume(phydev);
+ mutex_unlock(&phydev->lock);
if (ret < 0)
return ret;
@@ -1026,7 +1028,9 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,
if (err)
goto error;
+ mutex_lock(&phydev->lock);
phy_resume(phydev);
+ mutex_unlock(&phydev->lock);
phy_led_triggers_register(phydev);
return err;
@@ -1157,6 +1161,8 @@ int phy_resume(struct phy_device *phydev)
struct phy_driver *phydrv = to_phy_driver(phydev->mdio.dev.driver);
int ret = 0;
+ WARN_ON(!mutex_is_locked(&phydev->lock));
+
if (phydev->drv && phydrv->resume)
ret = phydrv->resume(phydev);
@@ -1639,13 +1645,9 @@ int genphy_resume(struct phy_device *phydev)
{
int value;
- mutex_lock(&phydev->lock);
-
value = phy_read(phydev, MII_BMCR);
phy_write(phydev, MII_BMCR, value & ~BMCR_PDOWN);
- mutex_unlock(&phydev->lock);
-
return 0;
}
EXPORT_SYMBOL(genphy_resume);
--
2.11.0
On Tue, Feb 06, 2018 at 06:48:53AM +0000, Harsh Shandilya wrote:
> On Tue 6 Feb, 2018, 12:09 AM Greg Kroah-Hartman, <gregkh(a)linuxfoundation.org>
> wrote:
>
> > This is the start of the stable review cycle for the 3.18.94 release.
> > There are 36 patches in this series, all will be posted as a response
> > to this one. If anyone has any issues with these being applied, please
> > let me know.
> >
> > Responses should be made by Wed Feb 7 18:23:41 UTC 2018.
> > Anything received after that time might be too late.
> >
> > The whole patch series can be found in one patch at:
> >
> > kernel.org/pub/linux/kernel/v3.x/stable-review/patch-3.18.94-rc1.gz
> > or in the git tree and branch at:
> > git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
> > linux-3.18.y
> > and the diffstat can be found below.
> >
> > thanks,
> >
> > greg k-h
> >
>
> Builds and boots on the OnePlus 3T, no regressions noticed.
Yeah! That device is the only reason I keep this tree alive :)
thanks for testing and letting me know.
greg k-h
This is a note to let you know that I've just added the patch titled
um: Fix out-of-tree build
to the 3.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
um-fix-out-of-tree-build.patch
and it can be found in the queue-3.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable(a)vger.kernel.org> know about it.
>From 0b5aedfe0e6654ec54f35109e1929a1cf7fc4cdd Mon Sep 17 00:00:00 2001
From: Richard Weinberger <richard(a)nod.at>
Date: Sun, 28 Jun 2015 22:55:26 +0200
Subject: um: Fix out-of-tree build
From: Richard Weinberger <richard(a)nod.at>
commit 0b5aedfe0e6654ec54f35109e1929a1cf7fc4cdd upstream.
Commit 30b11ee9a (um: Remove copy&paste code from init.h)
uncovered an issue wrt. out-of-tree builds.
For out-of-tree builds, we must not rely on relative paths.
Before 30b11ee9a it worked by chance as no host code included
generated header files.
Acked-by: Randy Dunlap <rdunlap(a)infradead.org>
Signed-off-by: Richard Weinberger <richard(a)nod.at>
Cc: Guenter Roeck <linux(a)roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/um/Makefile | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/um/Makefile
+++ b/arch/um/Makefile
@@ -70,8 +70,8 @@ KBUILD_AFLAGS += $(ARCH_INCLUDE)
USER_CFLAGS = $(patsubst $(KERNEL_DEFINES),,$(patsubst -I%,,$(KBUILD_CFLAGS))) \
$(ARCH_INCLUDE) $(MODE_INCLUDE) $(filter -I%,$(CFLAGS)) \
- -D_FILE_OFFSET_BITS=64 -idirafter include \
- -D__KERNEL__ -D__UM_HOST__
+ -D_FILE_OFFSET_BITS=64 -idirafter $(srctree)/include \
+ -idirafter $(obj)/include -D__KERNEL__ -D__UM_HOST__
#This will adjust *FLAGS accordingly to the platform.
include $(srctree)/$(ARCH_DIR)/Makefile-os-$(OS)
Patches currently in stable-queue which might be from richard(a)nod.at are
queue-3.18/um-stop-abusing-__kernel__.patch
queue-3.18/um-link-vmlinux-with-no-pie.patch
queue-3.18/um-remove-copy-paste-code-from-init.h.patch
queue-3.18/um-fix-out-of-tree-build.patch
When a request is preempted, it is unsubmitted from the HW queue and
removed from the active list of breadcrumbs. In the process, this
however triggers the signaler and it may see the clear rbtree with the
old, and still valid, seqno. This confuses the signaler into action and
signaling the fence.
Fixes: d6a2289d9d6b ("drm/i915: Remove the preempted request from the execution queue")
Signed-off-by: Chris Wilson <chris(a)chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin(a)linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen(a)linux.intel.com>
Cc: <stable(a)vger.kernel.org> # v4.12+
---
drivers/gpu/drm/i915/intel_breadcrumbs.c | 20 ++++----------------
1 file changed, 4 insertions(+), 16 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_breadcrumbs.c b/drivers/gpu/drm/i915/intel_breadcrumbs.c
index efbc627a2a25..b955f7d7bd0f 100644
--- a/drivers/gpu/drm/i915/intel_breadcrumbs.c
+++ b/drivers/gpu/drm/i915/intel_breadcrumbs.c
@@ -588,29 +588,16 @@ void intel_engine_remove_wait(struct intel_engine_cs *engine,
spin_unlock_irq(&b->rb_lock);
}
-static bool signal_valid(const struct drm_i915_gem_request *request)
-{
- return intel_wait_check_request(&request->signaling.wait, request);
-}
-
static bool signal_complete(const struct drm_i915_gem_request *request)
{
if (!request)
return false;
- /* If another process served as the bottom-half it may have already
- * signalled that this wait is already completed.
- */
- if (intel_wait_complete(&request->signaling.wait))
- return signal_valid(request);
-
- /* Carefully check if the request is complete, giving time for the
+ /*
+ * Carefully check if the request is complete, giving time for the
* seqno to be visible or if the GPU hung.
*/
- if (__i915_request_irq_complete(request))
- return true;
-
- return false;
+ return __i915_request_irq_complete(request);
}
static struct drm_i915_gem_request *to_signaler(struct rb_node *rb)
@@ -712,6 +699,7 @@ static int intel_breadcrumbs_signaler(void *arg)
&request->fence.flags)) {
local_bh_disable();
dma_fence_signal(&request->fence);
+ GEM_BUG_ON(!i915_gem_request_completed(request));
local_bh_enable(); /* kick start the tasklets */
}
--
2.15.1
On Mon, Feb 05, 2018 at 11:41:54AM +0000, Mark Brown wrote:
>On Sat, Feb 03, 2018 at 06:00:42PM +0000, Sasha Levin wrote:
>> From: Abhijeet Kumar <abhijeet.kumar(a)intel.com>
>>
>> [ Upstream commit d070f7c703ef26e3db613f24206823f916272fc6 ]
>>
>> In skylake platform, we hear a loud pop noise(0 dB) at start of
>> audio capture power up sequence. This patch removes the pop noise
>> from the recording by adding a delay before enabling ADC.
>
>> switch (event) {
>> case SND_SOC_DAPM_POST_PMU:
>> + msleep(125);
>> regmap_update_bits(nau8825->regmap, NAU8825_REG_ENA_CTRL,
>
>This is another one of these where I'm not convinced that backporting to
>stable isn't going to introduce regressions - it will fix problems on
>some systems but if someone really cares about a startup pop and has
>arranged to do something like discard the start of the audio where the
>pop occurs then this may cut off even more and cause them to miss
>things.
It might cause regressions for users who worked around the issue, but it
may also fix the issue for users who didn't. I think that in general
we'd rather have mainline and stable trees have the same bugs and
breakage - we don't want surprises when users jump around between
kernels.
--
Thanks,
Sasha
From: Laurent Pinchart <laurent.pinchart+renesas(a)ideasonboard.com>
commit 641307df71fe77d7b38a477067495ede05d47295 upstream.
When stopping the CRTC the driver must disable all planes and wait for
the change to take effect at the next vblank. Merely calling
drm_crtc_wait_one_vblank() is not enough, as the function doesn't
include any mechanism to handle the race with vblank interrupts.
Replace the drm_crtc_wait_one_vblank() call with a manual mechanism that
handles the vblank interrupt race.
Cc: stable(a)vger.kernel.org
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas(a)ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas(a)ideasonboard.com>
Signed-off-by: thongsyho <thong.ho.px(a)rvc.renesas.com>
Signed-off-by: Nhan Nguyen <nhan.nguyen.yb(a)renesas.com>
---
drivers/gpu/drm/rcar-du/rcar_du_crtc.c | 54 ++++++++++++++++++++++++++++++----
drivers/gpu/drm/rcar-du/rcar_du_crtc.h | 8 +++++
2 files changed, 56 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
index 25bdab6..6fab079 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
@@ -371,6 +371,31 @@ static void rcar_du_crtc_start(struct rcar_du_crtc *rcrtc)
rcrtc->started = true;
}
+static void rcar_du_crtc_disable_planes(struct rcar_du_crtc *rcrtc)
+{
+ struct rcar_du_device *rcdu = rcrtc->group->dev;
+ struct drm_crtc *crtc = &rcrtc->crtc;
+ u32 status;
+ /* Make sure vblank interrupts are enabled. */
+ drm_crtc_vblank_get(crtc);
+ /*
+ * Disable planes and calculate how many vertical blanking interrupts we
+ * have to wait for. If a vertical blanking interrupt has been triggered
+ * but not processed yet, we don't know whether it occurred before or
+ * after the planes got disabled. We thus have to wait for two vblank
+ * interrupts in that case.
+ */
+ spin_lock_irq(&rcrtc->vblank_lock);
+ rcar_du_group_write(rcrtc->group, rcrtc->index % 2 ? DS2PR : DS1PR, 0);
+ status = rcar_du_crtc_read(rcrtc, DSSR);
+ rcrtc->vblank_count = status & DSSR_VBK ? 2 : 1;
+ spin_unlock_irq(&rcrtc->vblank_lock);
+ if (!wait_event_timeout(rcrtc->vblank_wait, rcrtc->vblank_count == 0,
+ msecs_to_jiffies(100)))
+ dev_warn(rcdu->dev, "vertical blanking timeout\n");
+ drm_crtc_vblank_put(crtc);
+}
+
static void rcar_du_crtc_stop(struct rcar_du_crtc *rcrtc)
{
struct drm_crtc *crtc = &rcrtc->crtc;
@@ -379,17 +404,16 @@ static void rcar_du_crtc_stop(struct rcar_du_crtc *rcrtc)
return;
/* Disable all planes and wait for the change to take effect. This is
- * required as the DSnPR registers are updated on vblank, and no vblank
- * will occur once the CRTC is stopped. Disabling planes when starting
- * the CRTC thus wouldn't be enough as it would start scanning out
- * immediately from old frame buffers until the next vblank.
+ * required as the plane enable registers are updated on vblank, and no
+ * vblank will occur once the CRTC is stopped. Disabling planes when
+ * starting the CRTC thus wouldn't be enough as it would start scanning
+ * out immediately from old frame buffers until the next vblank.
*
* This increases the CRTC stop delay, especially when multiple CRTCs
* are stopped in one operation as we now wait for one vblank per CRTC.
* Whether this can be improved needs to be researched.
*/
- rcar_du_group_write(rcrtc->group, rcrtc->index % 2 ? DS2PR : DS1PR, 0);
- drm_crtc_wait_one_vblank(crtc);
+ rcar_du_crtc_disable_planes(rcrtc);
/* Disable vertical blanking interrupt reporting. We first need to wait
* for page flip completion before stopping the CRTC as userspace
@@ -528,10 +552,26 @@ static irqreturn_t rcar_du_crtc_irq(int irq, void *arg)
irqreturn_t ret = IRQ_NONE;
u32 status;
+ spin_lock(&rcrtc->vblank_lock);
+
status = rcar_du_crtc_read(rcrtc, DSSR);
rcar_du_crtc_write(rcrtc, DSRCR, status & DSRCR_MASK);
if (status & DSSR_VBK) {
+ /*
+ * Wake up the vblank wait if the counter reaches 0. This must
+ * be protected by the vblank_lock to avoid races in
+ * rcar_du_crtc_disable_planes().
+ */
+ if (rcrtc->vblank_count) {
+ if (--rcrtc->vblank_count == 0)
+ wake_up(&rcrtc->vblank_wait);
+ }
+ }
+
+ spin_unlock(&rcrtc->vblank_lock);
+
+ if (status & DSSR_VBK) {
drm_handle_vblank(rcrtc->crtc.dev, rcrtc->index);
rcar_du_crtc_finish_page_flip(rcrtc);
ret = IRQ_HANDLED;
@@ -585,6 +625,8 @@ int rcar_du_crtc_create(struct rcar_du_group *rgrp, unsigned int index)
}
init_waitqueue_head(&rcrtc->flip_wait);
+ init_waitqueue_head(&rcrtc->vblank_wait);
+ spin_lock_init(&rcrtc->vblank_lock);
rcrtc->group = rgrp;
rcrtc->mmio_offset = mmio_offsets[index];
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.h b/drivers/gpu/drm/rcar-du/rcar_du_crtc.h
index 2bbe3f5..be22ce3 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.h
+++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.h
@@ -15,6 +15,7 @@
#define __RCAR_DU_CRTC_H__
#include <linux/mutex.h>
+#include <linux/spinlock.h>
#include <linux/wait.h>
#include <drm/drmP.h>
@@ -32,6 +33,9 @@ struct rcar_du_group;
* @started: whether the CRTC has been started and is running
* @event: event to post when the pending page flip completes
* @flip_wait: wait queue used to signal page flip completion
+ * @vblank_lock: protects vblank_wait and vblank_count
+ * @vblank_wait: wait queue used to signal vertical blanking
+ * @vblank_count: number of vertical blanking interrupts to wait for
* @outputs: bitmask of the outputs (enum rcar_du_output) driven by this CRTC
* @enabled: whether the CRTC is enabled, used to control system resume
* @group: CRTC group this CRTC belongs to
@@ -48,6 +52,10 @@ struct rcar_du_crtc {
struct drm_pending_vblank_event *event;
wait_queue_head_t flip_wait;
+ spinlock_t vblank_lock;
+ wait_queue_head_t vblank_wait;
+ unsigned int vblank_count;
+
unsigned int outputs;
bool enabled;
--
1.9.1