steal time is computed, but won't influence scheduler
behaviour
+ nopti [X86-64] Disable kernel page table isolation
+
nolapic [X86-32,APIC] Do not enable or use the local APIC.
nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
pt. [PARIDE]
See Documentation/blockdev/paride.txt.
+ pti= [X86_64]
+ Control user/kernel address space isolation:
+ on - enable
+ off - disable
+ auto - default setting
+
pty.legacy_count=
[KNL] Number of legacy pty's. Overwrites compiled-in
default number.
| Qualcomm Tech. | Falkor v1 | E1003 | QCOM_FALKOR_ERRATUM_1003 |
| Qualcomm Tech. | Falkor v1 | E1009 | QCOM_FALKOR_ERRATUM_1009 |
| Qualcomm Tech. | QDF2400 ITS | E0065 | QCOM_QDF2400_ERRATUM_0065 |
+| Qualcomm Tech. | Falkor v{1,2} | E1041 | QCOM_FALKOR_ERRATUM_1041 |
normal scheduling policy and absolute bandwidth allocation model for
realtime scheduling policy.
+WARNING: cgroup2 doesn't yet support control of realtime processes and
+the cpu controller can only be enabled when all RT processes are in
+the root cgroup. Be aware that system management software may already
+have placed RT processes into nonroot cgroups during the system boot
+process, and these processes may need to be moved to the root cgroup
+before the cpu controller can be enabled.
+
CPU Interface Files
~~~~~~~~~~~~~~~~~~~
at25df321a
at25df641
at26df081a
- en25s64
mr25h128
mr25h256
mr25h10
s25fl008k
s25fl064k
sst25vf040b
- sst25wf040b
m25p40
m25p80
m25p16
compatible = "dlg,da7218";
reg = <0x1a>;
interrupt-parent = <&gpio6>;
- interrupts = <11 IRQ_TYPE_LEVEL_HIGH>;
+ interrupts = <11 IRQ_TYPE_LEVEL_LOW>;
wakeup-source;
VDD-supply = <®_audio>;
reg = <0x1a>;
interrupt-parent = <&gpio6>;
- interrupts = <11 IRQ_TYPE_LEVEL_HIGH>;
+ interrupts = <11 IRQ_TYPE_LEVEL_LOW>;
VDD-supply = <®_audio>;
VDDMIC-supply = <®_audio>;
- "fsl,imx53-ecspi" for SPI compatible with the one integrated on i.MX53 and later Soc
- reg : Offset and length of the register set for the device
- interrupts : Should contain CSPI/eCSPI interrupt
-- cs-gpios : Specifies the gpio pins to be used for chipselects.
- clocks : Clock specifiers for both ipg and per clocks.
- clock-names : Clock names should include both "ipg" and "per"
See the clock consumer binding,
Documentation/devicetree/bindings/clock/clock-bindings.txt
-- dmas: DMA specifiers for tx and rx dma. See the DMA client binding,
- Documentation/devicetree/bindings/dma/dma.txt
-- dma-names: DMA request names should include "tx" and "rx" if present.
-Obsolete properties:
-- fsl,spi-num-chipselects : Contains the number of the chipselect
+Recommended properties:
+- cs-gpios : GPIOs to use as chip selects, see spi-bus.txt. While the native chip
+select lines can be used, they appear to always generate a pulse between each
+word of a transfer. Most use cases will require GPIO based chip selects to
+generate a valid transaction.
Optional properties:
+- num-cs : Number of total chip selects, see spi-bus.txt.
+- dmas: DMA specifiers for tx and rx dma. See the DMA client binding,
+Documentation/devicetree/bindings/dma/dma.txt.
+- dma-names: DMA request names, if present, should include "tx" and "rx".
- fsl,spi-rdy-drctl: Integer, representing the value of DRCTL, the register
controlling the SPI_READY handling. Note that to enable the DRCTL consideration,
the SPI_READY mode-flag needs to be set too.
Valid values are: 0 (disabled), 1 (edge-triggered burst) and 2 (level-triggered burst).
+Obsolete properties:
+- fsl,spi-num-chipselects : Contains the number of the chipselect
+
Example:
ecspi@70010000 {
root of the overlay. Finally the directory is moved to the new
location.
+There are several ways to tune the "redirect_dir" feature.
+
+Kernel config options:
+
+- OVERLAY_FS_REDIRECT_DIR:
+ If this is enabled, then redirect_dir is turned on by default.
+- OVERLAY_FS_REDIRECT_ALWAYS_FOLLOW:
+ If this is enabled, then redirects are always followed by default. Enabling
+ this results in a less secure configuration. Enable this option only when
+ worried about backward compatibility with kernels that have the redirect_dir
+ feature and follow redirects even if turned off.
+
+Module options (can also be changed through /sys/module/overlay/parameters/*):
+
+- "redirect_dir=BOOL":
+ See OVERLAY_FS_REDIRECT_DIR kernel config option above.
+- "redirect_always_follow=BOOL":
+ See OVERLAY_FS_REDIRECT_ALWAYS_FOLLOW kernel config option above.
+- "redirect_max=NUM":
+ The maximum number of bytes in an absolute redirect (default is 256).
+
+Mount options:
+
+- "redirect_dir=on":
+ Redirects are enabled.
+- "redirect_dir=follow":
+ Redirects are not created, but followed.
+- "redirect_dir=off":
+ Redirects are not created and only followed if "redirect_always_follow"
+ feature is enabled in the kernel/module config.
+- "redirect_dir=nofollow":
+ Redirects are not created and not followed (equivalent to "redirect_dir=off"
+ if "redirect_always_follow" feature is not enabled).
+
Non-directories
---------------
+++ /dev/null
-Crossrelease
-============
-
-Started by Byungchul Park <byungchul.park@lge.com>
-
-Contents:
-
- (*) Background
-
- - What causes deadlock
- - How lockdep works
-
- (*) Limitation
-
- - Limit lockdep
- - Pros from the limitation
- - Cons from the limitation
- - Relax the limitation
-
- (*) Crossrelease
-
- - Introduce crossrelease
- - Introduce commit
-
- (*) Implementation
-
- - Data structures
- - How crossrelease works
-
- (*) Optimizations
-
- - Avoid duplication
- - Lockless for hot paths
-
- (*) APPENDIX A: What lockdep does to work aggresively
-
- (*) APPENDIX B: How to avoid adding false dependencies
-
-
-==========
-Background
-==========
-
-What causes deadlock
---------------------
-
-A deadlock occurs when a context is waiting for an event to happen,
-which is impossible because another (or the) context who can trigger the
-event is also waiting for another (or the) event to happen, which is
-also impossible due to the same reason.
-
-For example:
-
- A context going to trigger event C is waiting for event A to happen.
- A context going to trigger event A is waiting for event B to happen.
- A context going to trigger event B is waiting for event C to happen.
-
-A deadlock occurs when these three wait operations run at the same time,
-because event C cannot be triggered if event A does not happen, which in
-turn cannot be triggered if event B does not happen, which in turn
-cannot be triggered if event C does not happen. After all, no event can
-be triggered since any of them never meets its condition to wake up.
-
-A dependency might exist between two waiters and a deadlock might happen
-due to an incorrect releationship between dependencies. Thus, we must
-define what a dependency is first. A dependency exists between them if:
-
- 1. There are two waiters waiting for each event at a given time.
- 2. The only way to wake up each waiter is to trigger its event.
- 3. Whether one can be woken up depends on whether the other can.
-
-Each wait in the example creates its dependency like:
-
- Event C depends on event A.
- Event A depends on event B.
- Event B depends on event C.
-
- NOTE: Precisely speaking, a dependency is one between whether a
- waiter for an event can be woken up and whether another waiter for
- another event can be woken up. However from now on, we will describe
- a dependency as if it's one between an event and another event for
- simplicity.
-
-And they form circular dependencies like:
-
- -> C -> A -> B -
- / \
- \ /
- ----------------
-
- where 'A -> B' means that event A depends on event B.
-
-Such circular dependencies lead to a deadlock since no waiter can meet
-its condition to wake up as described.
-
-CONCLUSION
-
-Circular dependencies cause a deadlock.
-
-
-How lockdep works
------------------
-
-Lockdep tries to detect a deadlock by checking dependencies created by
-lock operations, acquire and release. Waiting for a lock corresponds to
-waiting for an event, and releasing a lock corresponds to triggering an
-event in the previous section.
-
-In short, lockdep does:
-
- 1. Detect a new dependency.
- 2. Add the dependency into a global graph.
- 3. Check if that makes dependencies circular.
- 4. Report a deadlock or its possibility if so.
-
-For example, consider a graph built by lockdep that looks like:
-
- A -> B -
- \
- -> E
- /
- C -> D -
-
- where A, B,..., E are different lock classes.
-
-Lockdep will add a dependency into the graph on detection of a new
-dependency. For example, it will add a dependency 'E -> C' when a new
-dependency between lock E and lock C is detected. Then the graph will be:
-
- A -> B -
- \
- -> E -
- / \
- -> C -> D - \
- / /
- \ /
- ------------------
-
- where A, B,..., E are different lock classes.
-
-This graph contains a subgraph which demonstrates circular dependencies:
-
- -> E -
- / \
- -> C -> D - \
- / /
- \ /
- ------------------
-
- where C, D and E are different lock classes.
-
-This is the condition under which a deadlock might occur. Lockdep
-reports it on detection after adding a new dependency. This is the way
-how lockdep works.
-
-CONCLUSION
-
-Lockdep detects a deadlock or its possibility by checking if circular
-dependencies were created after adding each new dependency.
-
-
-==========
-Limitation
-==========
-
-Limit lockdep
--------------
-
-Limiting lockdep to work on only typical locks e.g. spin locks and
-mutexes, which are released within the acquire context, the
-implementation becomes simple but its capacity for detection becomes
-limited. Let's check pros and cons in next section.
-
-
-Pros from the limitation
-------------------------
-
-Given the limitation, when acquiring a lock, locks in a held_locks
-cannot be released if the context cannot acquire it so has to wait to
-acquire it, which means all waiters for the locks in the held_locks are
-stuck. It's an exact case to create dependencies between each lock in
-the held_locks and the lock to acquire.
-
-For example:
-
- CONTEXT X
- ---------
- acquire A
- acquire B /* Add a dependency 'A -> B' */
- release B
- release A
-
- where A and B are different lock classes.
-
-When acquiring lock A, the held_locks of CONTEXT X is empty thus no
-dependency is added. But when acquiring lock B, lockdep detects and adds
-a new dependency 'A -> B' between lock A in the held_locks and lock B.
-They can be simply added whenever acquiring each lock.
-
-And data required by lockdep exists in a local structure, held_locks
-embedded in task_struct. Forcing to access the data within the context,
-lockdep can avoid racy problems without explicit locks while handling
-the local data.
-
-Lastly, lockdep only needs to keep locks currently being held, to build
-a dependency graph. However, relaxing the limitation, it needs to keep
-even locks already released, because a decision whether they created
-dependencies might be long-deferred.
-
-To sum up, we can expect several advantages from the limitation:
-
- 1. Lockdep can easily identify a dependency when acquiring a lock.
- 2. Races are avoidable while accessing local locks in a held_locks.
- 3. Lockdep only needs to keep locks currently being held.
-
-CONCLUSION
-
-Given the limitation, the implementation becomes simple and efficient.
-
-
-Cons from the limitation
-------------------------
-
-Given the limitation, lockdep is applicable only to typical locks. For
-example, page locks for page access or completions for synchronization
-cannot work with lockdep.
-
-Can we detect deadlocks below, under the limitation?
-
-Example 1:
-
- CONTEXT X CONTEXT Y CONTEXT Z
- --------- --------- ----------
- mutex_lock A
- lock_page B
- lock_page B
- mutex_lock A /* DEADLOCK */
- unlock_page B held by X
- unlock_page B
- mutex_unlock A
- mutex_unlock A
-
- where A and B are different lock classes.
-
-No, we cannot.
-
-Example 2:
-
- CONTEXT X CONTEXT Y
- --------- ---------
- mutex_lock A
- mutex_lock A
- wait_for_complete B /* DEADLOCK */
- complete B
- mutex_unlock A
- mutex_unlock A
-
- where A is a lock class and B is a completion variable.
-
-No, we cannot.
-
-CONCLUSION
-
-Given the limitation, lockdep cannot detect a deadlock or its
-possibility caused by page locks or completions.
-
-
-Relax the limitation
---------------------
-
-Under the limitation, things to create dependencies are limited to
-typical locks. However, synchronization primitives like page locks and
-completions, which are allowed to be released in any context, also
-create dependencies and can cause a deadlock. So lockdep should track
-these locks to do a better job. We have to relax the limitation for
-these locks to work with lockdep.
-
-Detecting dependencies is very important for lockdep to work because
-adding a dependency means adding an opportunity to check whether it
-causes a deadlock. The more lockdep adds dependencies, the more it
-thoroughly works. Thus Lockdep has to do its best to detect and add as
-many true dependencies into a graph as possible.
-
-For example, considering only typical locks, lockdep builds a graph like:
-
- A -> B -
- \
- -> E
- /
- C -> D -
-
- where A, B,..., E are different lock classes.
-
-On the other hand, under the relaxation, additional dependencies might
-be created and added. Assuming additional 'FX -> C' and 'E -> GX' are
-added thanks to the relaxation, the graph will be:
-
- A -> B -
- \
- -> E -> GX
- /
- FX -> C -> D -
-
- where A, B,..., E, FX and GX are different lock classes, and a suffix
- 'X' is added on non-typical locks.
-
-The latter graph gives us more chances to check circular dependencies
-than the former. However, it might suffer performance degradation since
-relaxing the limitation, with which design and implementation of lockdep
-can be efficient, might introduce inefficiency inevitably. So lockdep
-should provide two options, strong detection and efficient detection.
-
-Choosing efficient detection:
-
- Lockdep works with only locks restricted to be released within the
- acquire context. However, lockdep works efficiently.
-
-Choosing strong detection:
-
- Lockdep works with all synchronization primitives. However, lockdep
- suffers performance degradation.
-
-CONCLUSION
-
-Relaxing the limitation, lockdep can add additional dependencies giving
-additional opportunities to check circular dependencies.
-
-
-============
-Crossrelease
-============
-
-Introduce crossrelease
-----------------------
-
-In order to allow lockdep to handle additional dependencies by what
-might be released in any context, namely 'crosslock', we have to be able
-to identify those created by crosslocks. The proposed 'crossrelease'
-feature provoides a way to do that.
-
-Crossrelease feature has to do:
-
- 1. Identify dependencies created by crosslocks.
- 2. Add the dependencies into a dependency graph.
-
-That's all. Once a meaningful dependency is added into graph, then
-lockdep would work with the graph as it did. The most important thing
-crossrelease feature has to do is to correctly identify and add true
-dependencies into the global graph.
-
-A dependency e.g. 'A -> B' can be identified only in the A's release
-context because a decision required to identify the dependency can be
-made only in the release context. That is to decide whether A can be
-released so that a waiter for A can be woken up. It cannot be made in
-other than the A's release context.
-
-It's no matter for typical locks because each acquire context is same as
-its release context, thus lockdep can decide whether a lock can be
-released in the acquire context. However for crosslocks, lockdep cannot
-make the decision in the acquire context but has to wait until the
-release context is identified.
-
-Therefore, deadlocks by crosslocks cannot be detected just when it
-happens, because those cannot be identified until the crosslocks are
-released. However, deadlock possibilities can be detected and it's very
-worth. See 'APPENDIX A' section to check why.
-
-CONCLUSION
-
-Using crossrelease feature, lockdep can work with what might be released
-in any context, namely crosslock.
-
-
-Introduce commit
-----------------
-
-Since crossrelease defers the work adding true dependencies of
-crosslocks until they are actually released, crossrelease has to queue
-all acquisitions which might create dependencies with the crosslocks.
-Then it identifies dependencies using the queued data in batches at a
-proper time. We call it 'commit'.
-
-There are four types of dependencies:
-
-1. TT type: 'typical lock A -> typical lock B'
-
- Just when acquiring B, lockdep can see it's in the A's release
- context. So the dependency between A and B can be identified
- immediately. Commit is unnecessary.
-
-2. TC type: 'typical lock A -> crosslock BX'
-
- Just when acquiring BX, lockdep can see it's in the A's release
- context. So the dependency between A and BX can be identified
- immediately. Commit is unnecessary, too.
-
-3. CT type: 'crosslock AX -> typical lock B'
-
- When acquiring B, lockdep cannot identify the dependency because
- there's no way to know if it's in the AX's release context. It has
- to wait until the decision can be made. Commit is necessary.
-
-4. CC type: 'crosslock AX -> crosslock BX'
-
- When acquiring BX, lockdep cannot identify the dependency because
- there's no way to know if it's in the AX's release context. It has
- to wait until the decision can be made. Commit is necessary.
- But, handling CC type is not implemented yet. It's a future work.
-
-Lockdep can work without commit for typical locks, but commit step is
-necessary once crosslocks are involved. Introducing commit, lockdep
-performs three steps. What lockdep does in each step is:
-
-1. Acquisition: For typical locks, lockdep does what it originally did
- and queues the lock so that CT type dependencies can be checked using
- it at the commit step. For crosslocks, it saves data which will be
- used at the commit step and increases a reference count for it.
-
-2. Commit: No action is reauired for typical locks. For crosslocks,
- lockdep adds CT type dependencies using the data saved at the
- acquisition step.
-
-3. Release: No changes are required for typical locks. When a crosslock
- is released, it decreases a reference count for it.
-
-CONCLUSION
-
-Crossrelease introduces commit step to handle dependencies of crosslocks
-in batches at a proper time.
-
-
-==============
-Implementation
-==============
-
-Data structures
----------------
-
-Crossrelease introduces two main data structures.
-
-1. hist_lock
-
- This is an array embedded in task_struct, for keeping lock history so
- that dependencies can be added using them at the commit step. Since
- it's local data, it can be accessed locklessly in the owner context.
- The array is filled at the acquisition step and consumed at the
- commit step. And it's managed in circular manner.
-
-2. cross_lock
-
- One per lockdep_map exists. This is for keeping data of crosslocks
- and used at the commit step.
-
-
-How crossrelease works
-----------------------
-
-It's the key of how crossrelease works, to defer necessary works to an
-appropriate point in time and perform in at once at the commit step.
-Let's take a look with examples step by step, starting from how lockdep
-works without crossrelease for typical locks.
-
- acquire A /* Push A onto held_locks */
- acquire B /* Push B onto held_locks and add 'A -> B' */
- acquire C /* Push C onto held_locks and add 'B -> C' */
- release C /* Pop C from held_locks */
- release B /* Pop B from held_locks */
- release A /* Pop A from held_locks */
-
- where A, B and C are different lock classes.
-
- NOTE: This document assumes that readers already understand how
- lockdep works without crossrelease thus omits details. But there's
- one thing to note. Lockdep pretends to pop a lock from held_locks
- when releasing it. But it's subtly different from the original pop
- operation because lockdep allows other than the top to be poped.
-
-In this case, lockdep adds 'the top of held_locks -> the lock to acquire'
-dependency every time acquiring a lock.
-
-After adding 'A -> B', a dependency graph will be:
-
- A -> B
-
- where A and B are different lock classes.
-
-And after adding 'B -> C', the graph will be:
-
- A -> B -> C
-
- where A, B and C are different lock classes.
-
-Let's performs commit step even for typical locks to add dependencies.
-Of course, commit step is not necessary for them, however, it would work
-well because this is a more general way.
-
- acquire A
- /*
- * Queue A into hist_locks
- *
- * In hist_locks: A
- * In graph: Empty
- */
-
- acquire B
- /*
- * Queue B into hist_locks
- *
- * In hist_locks: A, B
- * In graph: Empty
- */
-
- acquire C
- /*
- * Queue C into hist_locks
- *
- * In hist_locks: A, B, C
- * In graph: Empty
- */
-
- commit C
- /*
- * Add 'C -> ?'
- * Answer the following to decide '?'
- * What has been queued since acquire C: Nothing
- *
- * In hist_locks: A, B, C
- * In graph: Empty
- */
-
- release C
-
- commit B
- /*
- * Add 'B -> ?'
- * Answer the following to decide '?'
- * What has been queued since acquire B: C
- *
- * In hist_locks: A, B, C
- * In graph: 'B -> C'
- */
-
- release B
-
- commit A
- /*
- * Add 'A -> ?'
- * Answer the following to decide '?'
- * What has been queued since acquire A: B, C
- *
- * In hist_locks: A, B, C
- * In graph: 'B -> C', 'A -> B', 'A -> C'
- */
-
- release A
-
- where A, B and C are different lock classes.
-
-In this case, dependencies are added at the commit step as described.
-
-After commits for A, B and C, the graph will be:
-
- A -> B -> C
-
- where A, B and C are different lock classes.
-
- NOTE: A dependency 'A -> C' is optimized out.
-
-We can see the former graph built without commit step is same as the
-latter graph built using commit steps. Of course the former way leads to
-earlier finish for building the graph, which means we can detect a
-deadlock or its possibility sooner. So the former way would be prefered
-when possible. But we cannot avoid using the latter way for crosslocks.
-
-Let's look at how commit steps work for crosslocks. In this case, the
-commit step is performed only on crosslock AX as real. And it assumes
-that the AX release context is different from the AX acquire context.
-
- BX RELEASE CONTEXT BX ACQUIRE CONTEXT
- ------------------ ------------------
- acquire A
- /*
- * Push A onto held_locks
- * Queue A into hist_locks
- *
- * In held_locks: A
- * In hist_locks: A
- * In graph: Empty
- */
-
- acquire BX
- /*
- * Add 'the top of held_locks -> BX'
- *
- * In held_locks: A
- * In hist_locks: A
- * In graph: 'A -> BX'
- */
-
- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- It must be guaranteed that the following operations are seen after
- acquiring BX globally. It can be done by things like barrier.
- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
- acquire C
- /*
- * Push C onto held_locks
- * Queue C into hist_locks
- *
- * In held_locks: C
- * In hist_locks: C
- * In graph: 'A -> BX'
- */
-
- release C
- /*
- * Pop C from held_locks
- *
- * In held_locks: Empty
- * In hist_locks: C
- * In graph: 'A -> BX'
- */
- acquire D
- /*
- * Push D onto held_locks
- * Queue D into hist_locks
- * Add 'the top of held_locks -> D'
- *
- * In held_locks: A, D
- * In hist_locks: A, D
- * In graph: 'A -> BX', 'A -> D'
- */
- acquire E
- /*
- * Push E onto held_locks
- * Queue E into hist_locks
- *
- * In held_locks: E
- * In hist_locks: C, E
- * In graph: 'A -> BX', 'A -> D'
- */
-
- release E
- /*
- * Pop E from held_locks
- *
- * In held_locks: Empty
- * In hist_locks: D, E
- * In graph: 'A -> BX', 'A -> D'
- */
- release D
- /*
- * Pop D from held_locks
- *
- * In held_locks: A
- * In hist_locks: A, D
- * In graph: 'A -> BX', 'A -> D'
- */
- commit BX
- /*
- * Add 'BX -> ?'
- * What has been queued since acquire BX: C, E
- *
- * In held_locks: Empty
- * In hist_locks: D, E
- * In graph: 'A -> BX', 'A -> D',
- * 'BX -> C', 'BX -> E'
- */
-
- release BX
- /*
- * In held_locks: Empty
- * In hist_locks: D, E
- * In graph: 'A -> BX', 'A -> D',
- * 'BX -> C', 'BX -> E'
- */
- release A
- /*
- * Pop A from held_locks
- *
- * In held_locks: Empty
- * In hist_locks: A, D
- * In graph: 'A -> BX', 'A -> D',
- * 'BX -> C', 'BX -> E'
- */
-
- where A, BX, C,..., E are different lock classes, and a suffix 'X' is
- added on crosslocks.
-
-Crossrelease considers all acquisitions after acqiuring BX are
-candidates which might create dependencies with BX. True dependencies
-will be determined when identifying the release context of BX. Meanwhile,
-all typical locks are queued so that they can be used at the commit step.
-And then two dependencies 'BX -> C' and 'BX -> E' are added at the
-commit step when identifying the release context.
-
-The final graph will be, with crossrelease:
-
- -> C
- /
- -> BX -
- / \
- A - -> E
- \
- -> D
-
- where A, BX, C,..., E are different lock classes, and a suffix 'X' is
- added on crosslocks.
-
-However, the final graph will be, without crossrelease:
-
- A -> D
-
- where A and D are different lock classes.
-
-The former graph has three more dependencies, 'A -> BX', 'BX -> C' and
-'BX -> E' giving additional opportunities to check if they cause
-deadlocks. This way lockdep can detect a deadlock or its possibility
-caused by crosslocks.
-
-CONCLUSION
-
-We checked how crossrelease works with several examples.
-
-
-=============
-Optimizations
-=============
-
-Avoid duplication
------------------
-
-Crossrelease feature uses a cache like what lockdep already uses for
-dependency chains, but this time it's for caching CT type dependencies.
-Once that dependency is cached, the same will never be added again.
-
-
-Lockless for hot paths
-----------------------
-
-To keep all locks for later use at the commit step, crossrelease adopts
-a local array embedded in task_struct, which makes access to the data
-lockless by forcing it to happen only within the owner context. It's
-like how lockdep handles held_locks. Lockless implmentation is important
-since typical locks are very frequently acquired and released.
-
-
-=================================================
-APPENDIX A: What lockdep does to work aggresively
-=================================================
-
-A deadlock actually occurs when all wait operations creating circular
-dependencies run at the same time. Even though they don't, a potential
-deadlock exists if the problematic dependencies exist. Thus it's
-meaningful to detect not only an actual deadlock but also its potential
-possibility. The latter is rather valuable. When a deadlock occurs
-actually, we can identify what happens in the system by some means or
-other even without lockdep. However, there's no way to detect possiblity
-without lockdep unless the whole code is parsed in head. It's terrible.
-Lockdep does the both, and crossrelease only focuses on the latter.
-
-Whether or not a deadlock actually occurs depends on several factors.
-For example, what order contexts are switched in is a factor. Assuming
-circular dependencies exist, a deadlock would occur when contexts are
-switched so that all wait operations creating the dependencies run
-simultaneously. Thus to detect a deadlock possibility even in the case
-that it has not occured yet, lockdep should consider all possible
-combinations of dependencies, trying to:
-
-1. Use a global dependency graph.
-
- Lockdep combines all dependencies into one global graph and uses them,
- regardless of which context generates them or what order contexts are
- switched in. Aggregated dependencies are only considered so they are
- prone to be circular if a problem exists.
-
-2. Check dependencies between classes instead of instances.
-
- What actually causes a deadlock are instances of lock. However,
- lockdep checks dependencies between classes instead of instances.
- This way lockdep can detect a deadlock which has not happened but
- might happen in future by others but the same class.
-
-3. Assume all acquisitions lead to waiting.
-
- Although locks might be acquired without waiting which is essential
- to create dependencies, lockdep assumes all acquisitions lead to
- waiting since it might be true some time or another.
-
-CONCLUSION
-
-Lockdep detects not only an actual deadlock but also its possibility,
-and the latter is more valuable.
-
-
-==================================================
-APPENDIX B: How to avoid adding false dependencies
-==================================================
-
-Remind what a dependency is. A dependency exists if:
-
- 1. There are two waiters waiting for each event at a given time.
- 2. The only way to wake up each waiter is to trigger its event.
- 3. Whether one can be woken up depends on whether the other can.
-
-For example:
-
- acquire A
- acquire B /* A dependency 'A -> B' exists */
- release B
- release A
-
- where A and B are different lock classes.
-
-A depedency 'A -> B' exists since:
-
- 1. A waiter for A and a waiter for B might exist when acquiring B.
- 2. Only way to wake up each is to release what it waits for.
- 3. Whether the waiter for A can be woken up depends on whether the
- other can. IOW, TASK X cannot release A if it fails to acquire B.
-
-For another example:
-
- TASK X TASK Y
- ------ ------
- acquire AX
- acquire B /* A dependency 'AX -> B' exists */
- release B
- release AX held by Y
-
- where AX and B are different lock classes, and a suffix 'X' is added
- on crosslocks.
-
-Even in this case involving crosslocks, the same rule can be applied. A
-depedency 'AX -> B' exists since:
-
- 1. A waiter for AX and a waiter for B might exist when acquiring B.
- 2. Only way to wake up each is to release what it waits for.
- 3. Whether the waiter for AX can be woken up depends on whether the
- other can. IOW, TASK X cannot release AX if it fails to acquire B.
-
-Let's take a look at more complicated example:
-
- TASK X TASK Y
- ------ ------
- acquire B
- release B
- fork Y
- acquire AX
- acquire C /* A dependency 'AX -> C' exists */
- release C
- release AX held by Y
-
- where AX, B and C are different lock classes, and a suffix 'X' is
- added on crosslocks.
-
-Does a dependency 'AX -> B' exist? Nope.
-
-Two waiters are essential to create a dependency. However, waiters for
-AX and B to create 'AX -> B' cannot exist at the same time in this
-example. Thus the dependency 'AX -> B' cannot be created.
-
-It would be ideal if the full set of true ones can be considered. But
-we can ensure nothing but what actually happened. Relying on what
-actually happens at runtime, we can anyway add only true ones, though
-they might be a subset of true ones. It's similar to how lockdep works
-for typical locks. There might be more true dependencies than what
-lockdep has detected in runtime. Lockdep has no choice but to rely on
-what actually happens. Crossrelease also relies on it.
-
-CONCLUSION
-
-Relying on what actually happens, lockdep can avoid adding false
-dependencies.
original compressor. Once all pages are removed from an old zpool, the zpool
and its compressor are freed.
+Some of the pages in zswap are same-value filled pages (i.e. contents of the
+page have same value or repetitive pattern). These pages include zero-filled
+pages and they are handled differently. During store operation, a page is
+checked if it is a same-value filled page before compressing it. If true, the
+compressed length of the page is set to zero and the pattern or same-filled
+value is stored.
+
+Same-value filled pages identification feature is enabled by default and can be
+disabled at boot time by setting the "same_filled_pages_enabled" attribute to 0,
+e.g. zswap.same_filled_pages_enabled=0. It can also be enabled and disabled at
+runtime using the sysfs "same_filled_pages_enabled" attribute, e.g.
+
+echo 1 > /sys/module/zswap/parameters/same_filled_pages_enabled
+
+When zswap same-filled page identification is disabled at runtime, it will stop
+checking for the same-value filled pages during store operation. However, the
+existing pages which are marked as same-value filled pages remain stored
+unchanged in zswap until they are either loaded or invalidated.
+
A debugfs interface is provided for various statistic about pool size, number
-of pages stored, and various counters for the reasons pages are rejected.
+of pages stored, same-value filled pages and various counters for the reasons
+pages are rejected.
-<previous description obsolete, deleted>
-
Virtual memory map with 4 level page tables:
0000000000000000 - 00007fffffffffff (=47 bits) user space, different per mm
... unused hole ...
ffffec0000000000 - fffffbffffffffff (=44 bits) kasan shadow memory (16TB)
... unused hole ...
+fffffe0000000000 - fffffe7fffffffff (=39 bits) LDT remap for PTI
+fffffe8000000000 - fffffeffffffffff (=39 bits) cpu_entry_area mapping
ffffff0000000000 - ffffff7fffffffff (=39 bits) %esp fixup stacks
... unused hole ...
ffffffef00000000 - fffffffeffffffff (=64 GB) EFI region mapping space
... unused hole ...
ffffffff80000000 - ffffffff9fffffff (=512 MB) kernel text mapping, from phys 0
-ffffffffa0000000 - ffffffffff5fffff (=1526 MB) module mapping space (variable)
-ffffffffff600000 - ffffffffffdfffff (=8 MB) vsyscalls
+ffffffffa0000000 - [fixmap start] (~1526 MB) module mapping space (variable)
+[fixmap start] - ffffffffff5fffff kernel-internal fixmap range
+ffffffffff600000 - ffffffffff600fff (=4 kB) legacy vsyscall ABI
ffffffffffe00000 - ffffffffffffffff (=2 MB) unused hole
Virtual memory map with 5 level page tables:
hole caused by [56:63] sign extension
ff00000000000000 - ff0fffffffffffff (=52 bits) guard hole, reserved for hypervisor
ff10000000000000 - ff8fffffffffffff (=55 bits) direct mapping of all phys. memory
-ff90000000000000 - ff91ffffffffffff (=49 bits) hole
-ff92000000000000 - ffd1ffffffffffff (=54 bits) vmalloc/ioremap space
+ff90000000000000 - ff9fffffffffffff (=52 bits) LDT remap for PTI
+ffa0000000000000 - ffd1ffffffffffff (=54 bits) vmalloc/ioremap space (12800 TB)
ffd2000000000000 - ffd3ffffffffffff (=49 bits) hole
ffd4000000000000 - ffd5ffffffffffff (=49 bits) virtual memory map (512TB)
... unused hole ...
ffdf000000000000 - fffffc0000000000 (=53 bits) kasan shadow memory (8PB)
... unused hole ...
+fffffe8000000000 - fffffeffffffffff (=39 bits) cpu_entry_area mapping
ffffff0000000000 - ffffff7fffffffff (=39 bits) %esp fixup stacks
... unused hole ...
ffffffef00000000 - fffffffeffffffff (=64 GB) EFI region mapping space
... unused hole ...
ffffffff80000000 - ffffffff9fffffff (=512 MB) kernel text mapping, from phys 0
-ffffffffa0000000 - ffffffffff5fffff (=1526 MB) module mapping space
-ffffffffff600000 - ffffffffffdfffff (=8 MB) vsyscalls
+ffffffffa0000000 - [fixmap start] (~1526 MB) module mapping space
+[fixmap start] - ffffffffff5fffff kernel-internal fixmap range
+ffffffffff600000 - ffffffffff600fff (=4 kB) legacy vsyscall ABI
ffffffffffe00000 - ffffffffffffffff (=2 MB) unused hole
Architecture defines a 64-bit virtual address. Implementations can support
less. Currently supported are 48- and 57-bit virtual addresses. Bits 63
-through to the most-significant implemented bit are set to either all ones
-or all zero. This causes hole between user space and kernel addresses.
+through to the most-significant implemented bit are sign extended.
+This causes hole between user space and kernel addresses if you interpret them
+as unsigned.
The direct mapping covers all memory in the system up to the highest
memory address (this means in some cases it can also include PCI memory
the processes using the page fault handler, with init_top_pgt as
reference.
-Current X86-64 implementations support up to 46 bits of address space (64 TB),
-which is our current limit. This expands into MBZ space in the page tables.
-
We map EFI runtime services in the 'efi_pgd' PGD in a 64Gb large virtual
memory window (this size is arbitrary, it can be raised later if needed).
The mappings are not part of any other kernel PGD and are only available
Note that if CONFIG_RANDOMIZE_MEMORY is enabled, the direct mapping of all
physical memory, vmalloc/ioremap space and virtual memory map are randomized.
Their order is preserved but their base will be offset early at boot time.
-
--Andi Kleen, Jul 2004
F: include/uapi/linux/bfs_fs.h
BLACKFIN ARCHITECTURE
-M: Steven Miao <realmz6@gmail.com>
L: adi-buildroot-devel@lists.sourceforge.net (moderated for non-subscribers)
T: git git://git.code.sf.net/p/adi-linux/code
W: http://blackfin.uclinux.org
-S: Supported
+S: Orphan
F: arch/blackfin/
BLACKFIN EMAC DRIVER
L: adi-buildroot-devel@lists.sourceforge.net (moderated for non-subscribers)
W: http://blackfin.uclinux.org
-S: Supported
+S: Orphan
F: drivers/net/ethernet/adi/
BLACKFIN MEDIA DRIVER
-M: Scott Jiang <scott.jiang.linux@gmail.com>
L: adi-buildroot-devel@lists.sourceforge.net (moderated for non-subscribers)
W: http://blackfin.uclinux.org/
-S: Supported
+S: Orphan
F: drivers/media/platform/blackfin/
F: drivers/media/i2c/adv7183*
F: drivers/media/i2c/vs6624*
BLACKFIN RTC DRIVER
L: adi-buildroot-devel@lists.sourceforge.net (moderated for non-subscribers)
W: http://blackfin.uclinux.org
-S: Supported
+S: Orphan
F: drivers/rtc/rtc-bfin.c
BLACKFIN SDH DRIVER
L: adi-buildroot-devel@lists.sourceforge.net (moderated for non-subscribers)
W: http://blackfin.uclinux.org
-S: Supported
+S: Orphan
F: drivers/mmc/host/bfin_sdh.c
BLACKFIN SERIAL DRIVER
L: adi-buildroot-devel@lists.sourceforge.net (moderated for non-subscribers)
W: http://blackfin.uclinux.org
-S: Supported
+S: Orphan
F: drivers/tty/serial/bfin_uart.c
BLACKFIN WATCHDOG DRIVER
L: adi-buildroot-devel@lists.sourceforge.net (moderated for non-subscribers)
W: http://blackfin.uclinux.org
-S: Supported
+S: Orphan
F: drivers/watchdog/bfin_wdt.c
BLINKM RGB LED DRIVER
FCOE SUBSYSTEM (libfc, libfcoe, fcoe)
M: Johannes Thumshirn <jth@kernel.org>
-L: fcoe-devel@open-fcoe.org
+L: linux-scsi@vger.kernel.org
W: www.Open-FCoE.org
S: Supported
F: drivers/scsi/libfc/
SYNOPSYS DESIGNWARE ENTERPRISE ETHERNET DRIVER
M: Jie Deng <jiedeng@synopsys.com>
+M: Jose Abreu <Jose.Abreu@synopsys.com>
L: netdev@vger.kernel.org
S: Supported
F: drivers/net/ethernet/synopsys/
VERSION = 4
PATCHLEVEL = 15
SUBLEVEL = 0
-EXTRAVERSION = -rc3
+EXTRAVERSION = -rc5
NAME = Fearless Coyote
# *DOCUMENTATION*
# disable invalid "can't wrap" optimizations for signed / pointers
KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
+# Make sure -fstack-check isn't enabled (like gentoo apparently did)
+KBUILD_CFLAGS += $(call cc-option,-fno-stack-check,)
+
# conserve stack if available
KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
switch0port10: port@10 {
reg = <10>;
label = "dsa";
- phy-mode = "xgmii";
+ phy-mode = "xaui";
link = <&switch1port10>;
};
};
switch1port10: port@10 {
reg = <10>;
label = "dsa";
- phy-mode = "xgmii";
+ phy-mode = "xaui";
link = <&switch0port10>;
};
};
.pushsection .text.fixup,"ax"
.align 4
9001: mov r4, #-EFAULT
+#ifdef CONFIG_CPU_SW_DOMAIN_PAN
+ ldr r5, [sp, #9*4] @ *err_ptr
+#else
ldr r5, [sp, #8*4] @ *err_ptr
+#endif
str r4, [r5]
ldmia sp, {r1, r2} @ retrieve dst, len
add r2, r2, r1
If unsure, say Y.
-
config SOCIONEXT_SYNQUACER_PREITS
bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
default y
a 128kB offset to be applied to the target address in this commands.
If unsure, say Y.
+
+config QCOM_FALKOR_ERRATUM_E1041
+ bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
+ default y
+ help
+ Falkor CPU may speculatively fetch instructions from an improper
+ memory location when MMU translation is changed from SCTLR_ELn[M]=1
+ to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
+
+ If unsure, say Y.
+
endmenu
#endif
.endm
+/**
+ * Errata workaround prior to disable MMU. Insert an ISB immediately prior
+ * to executing the MSR that will change SCTLR_ELn[M] from a value of 1 to 0.
+ */
+ .macro pre_disable_mmu_workaround
+#ifdef CONFIG_QCOM_FALKOR_ERRATUM_E1041
+ isb
+#endif
+ .endm
+
#endif /* __ASM_ASSEMBLER_H */
#define FTR_VISIBLE true /* Feature visible to the user space */
#define FTR_HIDDEN false /* Feature is hidden from the user */
+#define FTR_VISIBLE_IF_IS_ENABLED(config) \
+ (IS_ENABLED(config) ? FTR_VISIBLE : FTR_HIDDEN)
+
struct arm64_ftr_bits {
bool sign; /* Value is signed ? */
bool visible;
#define BRCM_CPU_PART_VULCAN 0x516
#define QCOM_CPU_PART_FALKOR_V1 0x800
+#define QCOM_CPU_PART_FALKOR 0xC00
#define MIDR_CORTEX_A53 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A53)
#define MIDR_CORTEX_A57 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A57)
#define MIDR_THUNDERX_81XX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX_81XX)
#define MIDR_THUNDERX_83XX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX_83XX)
#define MIDR_QCOM_FALKOR_V1 MIDR_CPU_MODEL(ARM_CPU_IMP_QCOM, QCOM_CPU_PART_FALKOR_V1)
+#define MIDR_QCOM_FALKOR MIDR_CPU_MODEL(ARM_CPU_IMP_QCOM, QCOM_CPU_PART_FALKOR)
#ifndef __ASSEMBLY__
#include <asm/cmpxchg.h>
#include <asm/fixmap.h>
#include <linux/mmdebug.h>
+#include <linux/mm_types.h>
+#include <linux/sched.h>
extern void __pte_error(const char *file, int line, unsigned long val);
extern void __pmd_error(const char *file, int line, unsigned long val);
static inline pte_t pte_mkclean(pte_t pte)
{
- return clear_pte_bit(pte, __pgprot(PTE_DIRTY));
+ pte = clear_pte_bit(pte, __pgprot(PTE_DIRTY));
+ pte = set_pte_bit(pte, __pgprot(PTE_RDONLY));
+
+ return pte;
}
static inline pte_t pte_mkdirty(pte_t pte)
{
- return set_pte_bit(pte, __pgprot(PTE_DIRTY));
+ pte = set_pte_bit(pte, __pgprot(PTE_DIRTY));
+
+ if (pte_write(pte))
+ pte = clear_pte_bit(pte, __pgprot(PTE_RDONLY));
+
+ return pte;
}
static inline pte_t pte_mkold(pte_t pte)
}
}
-struct mm_struct;
-struct vm_area_struct;
-
extern void __sync_icache_dcache(pte_t pteval, unsigned long addr);
/*
* hardware updates of the pte (ptep_set_access_flags safely changes
* valid ptes without going through an invalid entry).
*/
- if (pte_valid(*ptep) && pte_valid(pte)) {
+ if (IS_ENABLED(CONFIG_DEBUG_VM) && pte_valid(*ptep) && pte_valid(pte) &&
+ (mm == current->active_mm || atomic_read(&mm->mm_users) > 1)) {
VM_WARN_ONCE(!pte_young(pte),
"%s: racy access flag clearing: 0x%016llx -> 0x%016llx",
__func__, pte_val(*ptep), pte_val(pte));
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
/*
- * ptep_set_wrprotect - mark read-only while preserving the hardware update of
- * the Access Flag.
+ * ptep_set_wrprotect - mark read-only while trasferring potential hardware
+ * dirty status (PTE_DBM && !PTE_RDONLY) to the software PTE_DIRTY bit.
*/
#define __HAVE_ARCH_PTEP_SET_WRPROTECT
static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
{
pte_t old_pte, pte;
- /*
- * ptep_set_wrprotect() is only called on CoW mappings which are
- * private (!VM_SHARED) with the pte either read-only (!PTE_WRITE &&
- * PTE_RDONLY) or writable and software-dirty (PTE_WRITE &&
- * !PTE_RDONLY && PTE_DIRTY); see is_cow_mapping() and
- * protection_map[]. There is no race with the hardware update of the
- * dirty state: clearing of PTE_RDONLY when PTE_WRITE (a.k.a. PTE_DBM)
- * is set.
- */
- VM_WARN_ONCE(pte_write(*ptep) && !pte_dirty(*ptep),
- "%s: potential race with hardware DBM", __func__);
pte = READ_ONCE(*ptep);
do {
old_pte = pte;
+ /*
+ * If hardware-dirty (PTE_WRITE/DBM bit set and PTE_RDONLY
+ * clear), set the PTE_DIRTY bit.
+ */
+ if (pte_hw_dirty(pte))
+ pte = pte_mkdirty(pte);
pte = pte_wrprotect(pte);
pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep),
pte_val(old_pte), pte_val(pte));
mrs x12, sctlr_el1
ldr x13, =SCTLR_ELx_FLAGS
bic x12, x12, x13
+ pre_disable_mmu_workaround
msr sctlr_el1, x12
isb
};
static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = {
- ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_SVE_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
+ FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_SVE_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_GIC_SHIFT, 4, 0),
S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_ASIMD_SHIFT, 4, ID_AA64PFR0_ASIMD_NI),
S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_FP_SHIFT, 4, ID_AA64PFR0_FP_NI),
mrs x0, sctlr_el2
bic x0, x0, #1 << 0 // clear SCTLR.M
bic x0, x0, #1 << 2 // clear SCTLR.C
+ pre_disable_mmu_workaround
msr sctlr_el2, x0
isb
b 2f
mrs x0, sctlr_el1
bic x0, x0, #1 << 0 // clear SCTLR.M
bic x0, x0, #1 << 2 // clear SCTLR.C
+ pre_disable_mmu_workaround
msr sctlr_el1, x0
isb
2:
local_bh_disable();
- current->thread.fpsimd_state = *state;
+ current->thread.fpsimd_state.user_fpsimd = state->user_fpsimd;
if (system_supports_sve() && test_thread_flag(TIF_SVE))
fpsimd_to_sve(current);
* to take into account by discarding the current kernel mapping and
* creating a new one.
*/
+ pre_disable_mmu_workaround
msr sctlr_el1, x20 // disable the MMU
isb
bl __create_page_tables // recreate kernel mapping
#include <linux/perf_event.h>
#include <linux/ptrace.h>
#include <linux/smp.h>
+#include <linux/uaccess.h>
#include <asm/compat.h>
#include <asm/current.h>
#include <asm/traps.h>
#include <asm/cputype.h>
#include <asm/system_misc.h>
-#include <asm/uaccess.h>
/* Breakpoint currently in use for each BRP. */
static DEFINE_PER_CPU(struct perf_event *, bp_on_reg[ARM_MAX_BRP]);
mrs x0, sctlr_el2
ldr x1, =SCTLR_ELx_FLAGS
bic x0, x0, x1
+ pre_disable_mmu_workaround
msr sctlr_el2, x0
isb
1:
mrs x5, sctlr_el2
ldr x6, =SCTLR_ELx_FLAGS
bic x5, x5, x6 // Clear SCTL_M and etc
+ pre_disable_mmu_workaround
msr sctlr_el2, x5
isb
{
u64 reg;
+ /* Clear pmscr in case of early return */
+ *pmscr_el1 = 0;
+
/* SPE present on this CPU? */
if (!cpuid_feature_extract_unsigned_field(read_sysreg(id_aa64dfr0_el1),
ID_AA64DFR0_PMSVER_SHIFT))
.check_wx = true,
};
- walk_pgd(&st, &init_mm, 0);
+ walk_pgd(&st, &init_mm, VA_START);
note_page(&st, 0, 0, 0);
if (st.wx_pages || st.uxn_pages)
pr_warn("Checked W+X mappings: FAILED, %lu W+X pages found, %lu non-UXN pages found\n",
{
struct siginfo info;
const struct fault_info *inf;
- int ret = 0;
inf = esr_to_fault_info(esr);
pr_err("Synchronous External Abort: %s (0x%08x) at 0x%016lx\n",
if (interrupts_enabled(regs))
nmi_enter();
- ret = ghes_notify_sea();
+ ghes_notify_sea();
if (interrupts_enabled(regs))
nmi_exit();
info.si_addr = (void __user *)addr;
arm64_notify_die("", regs, &info, esr);
- return ret;
+ return 0;
}
static const struct fault_info fault_info[] = {
reserve_elfcorehdr();
+ high_memory = __va(memblock_end_of_DRAM() - 1) + 1;
+
dma_contiguous_reserve(arm64_dma_phys_limit);
memblock_allow_resize();
sparse_init();
zone_sizes_init(min, max);
- high_memory = __va((max << PAGE_SHIFT) - 1) + 1;
memblock_dump_all();
}
while ((nuline = strchr(s, '\n')) != NULL) {
if (nuline != s)
pdc_iodc_print(s, nuline - s);
- pdc_iodc_print("\r\n", 2);
- s = nuline + 1;
+ pdc_iodc_print("\r\n", 2);
+ s = nuline + 1;
}
if (*s != '\0')
pdc_iodc_print(s, strlen(s));
/* thread information allocation */
+#ifdef CONFIG_IRQSTACKS
+#define THREAD_SIZE_ORDER 2 /* PA-RISC requires at least 16k stack */
+#else
#define THREAD_SIZE_ORDER 3 /* PA-RISC requires at least 32k stack */
+#endif
+
/* Be sure to hunt all references to this down when you change the size of
* the kernel stack */
#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
STREG %r19,PT_SR7(%r16)
intr_return:
- /* NOTE: Need to enable interrupts incase we schedule. */
- ssm PSW_SM_I, %r0
-
/* check for reschedule */
mfctl %cr30,%r1
LDREG TI_FLAGS(%r1),%r19 /* sched.h: TIF_NEED_RESCHED */
LDREG PT_IASQ1(%r16), %r20
cmpib,COND(=),n 0,%r20,intr_restore /* backward */
+ /* NOTE: We need to enable interrupts if we have to deliver
+ * signals. We used to do this earlier but it caused kernel
+ * stack overflows. */
+ ssm PSW_SM_I, %r0
+
copy %r0, %r25 /* long in_syscall = 0 */
#ifdef CONFIG_64BIT
ldo -16(%r30),%r29 /* Reference param save area */
cmpib,COND(=) 0, %r20, intr_do_preempt
nop
+ /* NOTE: We need to enable interrupts if we schedule. We used
+ * to do this earlier but it caused kernel stack overflows. */
+ ssm PSW_SM_I, %r0
+
#ifdef CONFIG_64BIT
ldo -16(%r30),%r29 /* Reference param save area */
#endif
__INITRODATA
+ .align 4
.export os_hpmc_size
os_hpmc_size:
.word .os_hpmc_end-.os_hpmc
#include <linux/slab.h>
#include <linux/kallsyms.h>
#include <linux/sort.h>
-#include <linux/sched.h>
#include <linux/uaccess.h>
#include <asm/assembly.h>
#include <linux/preempt.h>
#include <linux/init.h>
-#include <asm/processor.h>
#include <asm/delay.h>
-
#include <asm/special_insns.h> /* for mfctl() */
#include <asm/processor.h> /* for boot_cpu_data */
#endif
}
-static inline void arch_dup_mmap(struct mm_struct *oldmm,
- struct mm_struct *mm)
+static inline int arch_dup_mmap(struct mm_struct *oldmm,
+ struct mm_struct *mm)
{
+ return 0;
}
#ifndef CONFIG_PPC_BOOK3S_64
printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
regs->nip, regs->link, regs->ctr);
- printk("REGS: %p TRAP: %04lx %s (%s)\n",
+ printk("REGS: %px TRAP: %04lx %s (%s)\n",
regs, regs->trap, print_tainted(), init_utsname()->release);
printk("MSR: "REG" ", regs->msr);
print_msr_bits(regs->msr);
/* Return the per-cpu state for state saving/migration */
return (u64)xc->cppr << KVM_REG_PPC_ICP_CPPR_SHIFT |
- (u64)xc->mfrr << KVM_REG_PPC_ICP_MFRR_SHIFT;
+ (u64)xc->mfrr << KVM_REG_PPC_ICP_MFRR_SHIFT |
+ (u64)0xff << KVM_REG_PPC_ICP_PPRI_SHIFT;
}
int kvmppc_xive_set_icp(struct kvm_vcpu *vcpu, u64 icpval)
/*
* Restore P and Q. If the interrupt was pending, we
- * force both P and Q, which will trigger a resend.
+ * force Q and !P, which will trigger a resend.
*
* That means that a guest that had both an interrupt
* pending (queued) and Q set will restore with only
* is perfectly fine as coalescing interrupts that haven't
* been presented yet is always allowed.
*/
- if (val & KVM_XICS_PRESENTED || val & KVM_XICS_PENDING)
+ if (val & KVM_XICS_PRESENTED && !(val & KVM_XICS_PENDING))
state->old_p = true;
if (val & KVM_XICS_QUEUED || val & KVM_XICS_PENDING)
state->old_q = true;
func = (u8 *) __bpf_call_base + imm;
/* Save skb pointer if we need to re-cache skb data */
- if (bpf_helper_changes_pkt_data(func))
+ if ((ctx->seen & SEEN_SKB) &&
+ bpf_helper_changes_pkt_data(func))
PPC_BPF_STL(3, 1, bpf_jit_stack_local(ctx));
bpf_jit_emit_func_call(image, ctx, (u64)func);
PPC_MR(b2p[BPF_REG_0], 3);
/* refresh skb cache */
- if (bpf_helper_changes_pkt_data(func)) {
+ if ((ctx->seen & SEEN_SKB) &&
+ bpf_helper_changes_pkt_data(func)) {
/* reload skb pointer to r3 */
PPC_BPF_LL(3, 1, bpf_jit_stack_local(ctx));
bpf_jit_emit_skb_loads(image, ctx);
int ret;
__u64 target;
- if (is_kernel_addr(addr))
- return branch_target((unsigned int *)addr);
+ if (is_kernel_addr(addr)) {
+ if (probe_kernel_read(&instr, (void *)addr, sizeof(instr)))
+ return 0;
+
+ return branch_target(&instr);
+ }
/* Userspace: need copy instruction here then translate it */
pagefault_disable();
if (!cpumask_test_and_clear_cpu(cpu, &nest_imc_cpumask))
return 0;
+ /*
+ * Check whether nest_imc is registered. We could end up here if the
+ * cpuhotplug callback registration fails. i.e, callback invokes the
+ * offline path for all successfully registered nodes. At this stage,
+ * nest_imc pmu will not be registered and we should return here.
+ *
+ * We return with a zero since this is not an offline failure. And
+ * cpuhp_setup_state() returns the actual failure reason to the caller,
+ * which in turn will call the cleanup routine.
+ */
+ if (!nest_pmus)
+ return 0;
+
/*
* Now that this cpu is one of the designated,
* find a next cpu a) which is online and b) in same chip.
if (nest_pmus == 1) {
cpuhp_remove_state(CPUHP_AP_PERF_POWERPC_NEST_IMC_ONLINE);
kfree(nest_imc_refc);
+ kfree(per_nest_pmu_arr);
}
if (nest_pmus > 0)
kfree(pmu_ptr->attr_groups[IMC_EVENT_ATTR]->attrs);
kfree(pmu_ptr->attr_groups[IMC_EVENT_ATTR]);
kfree(pmu_ptr);
- kfree(per_nest_pmu_arr);
return;
}
ret = nest_pmu_cpumask_init();
if (ret) {
mutex_unlock(&nest_init_lock);
+ kfree(nest_imc_refc);
+ kfree(per_nest_pmu_arr);
goto err_free;
}
}
#define smp_rmb() RISCV_FENCE(r,r)
#define smp_wmb() RISCV_FENCE(w,w)
+/*
+ * This is a very specific barrier: it's currently only used in two places in
+ * the kernel, both in the scheduler. See include/linux/spinlock.h for the two
+ * orderings it guarantees, but the "critical section is RCsc" guarantee
+ * mandates a barrier on RISC-V. The sequence looks like:
+ *
+ * lr.aq lock
+ * sc lock <= LOCKED
+ * smp_mb__after_spinlock()
+ * // critical section
+ * lr lock
+ * sc.rl lock <= UNLOCKED
+ *
+ * The AQ/RL pair provides a RCpc critical section, but there's not really any
+ * way we can take advantage of that here because the ordering is only enforced
+ * on that one lock. Thus, we're just doing a full fence.
+ */
+#define smp_mb__after_spinlock() RISCV_FENCE(rw,rw)
+
#include <asm-generic/barrier.h>
#endif /* __ASSEMBLY__ */
#include <asm/tlbflush.h>
#include <asm/thread_info.h>
-#ifdef CONFIG_HVC_RISCV_SBI
-#include <asm/hvc_riscv_sbi.h>
-#endif
-
#ifdef CONFIG_DUMMY_CONSOLE
struct screen_info screen_info = {
.orig_video_lines = 30,
void __init setup_arch(char **cmdline_p)
{
-#if defined(CONFIG_HVC_RISCV_SBI)
- if (likely(early_console == NULL)) {
- early_console = &riscv_sbi_early_console_dev;
- register_console(early_console);
- }
-#endif
-
#ifdef CONFIG_CMDLINE_BOOL
#ifdef CONFIG_CMDLINE_OVERRIDE
strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
bool local = (flags & SYS_RISCV_FLUSH_ICACHE_LOCAL) != 0;
/* Check the reserved flags. */
- if (unlikely(flags & !SYS_RISCV_FLUSH_ICACHE_ALL))
+ if (unlikely(flags & ~SYS_RISCV_FLUSH_ICACHE_ALL))
return -EINVAL;
flush_icache_mm(mm, local);
return pud;
}
-#define pud_write pud_write
-static inline int pud_write(pud_t pud)
-{
- return (pud_val(pud) & _REGION3_ENTRY_WRITE) != 0;
-}
-
static inline pud_t pud_mkclean(pud_t pud)
{
if (pud_large(pud)) {
return retval;
}
+ groups_sort(group_info);
retval = set_current_groups(group_info);
put_group_info(group_info);
#define SEEN_LITERAL 8 /* code uses literals */
#define SEEN_FUNC 16 /* calls C functions */
#define SEEN_TAIL_CALL 32 /* code uses tail calls */
-#define SEEN_SKB_CHANGE 64 /* code changes skb data */
-#define SEEN_REG_AX 128 /* code uses constant blinding */
+#define SEEN_REG_AX 64 /* code uses constant blinding */
#define SEEN_STACK (SEEN_FUNC | SEEN_MEM | SEEN_SKB)
/*
EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0,
REG_15, 152);
}
- if (jit->seen & SEEN_SKB)
+ if (jit->seen & SEEN_SKB) {
emit_load_skb_data_hlen(jit);
- if (jit->seen & SEEN_SKB_CHANGE)
/* stg %b1,ST_OFF_SKBP(%r0,%r15) */
EMIT6_DISP_LH(0xe3000000, 0x0024, BPF_REG_1, REG_0, REG_15,
STK_OFF_SKBP);
+ }
}
/*
EMIT2(0x0d00, REG_14, REG_W1);
/* lgr %b0,%r2: load return value into %b0 */
EMIT4(0xb9040000, BPF_REG_0, REG_2);
- if (bpf_helper_changes_pkt_data((void *)func)) {
- jit->seen |= SEEN_SKB_CHANGE;
+ if ((jit->seen & SEEN_SKB) &&
+ bpf_helper_changes_pkt_data((void *)func)) {
/* lg %b1,ST_OFF_SKBP(%r15) */
EMIT6_DISP_LH(0xe3000000, 0x0004, BPF_REG_1, REG_0,
REG_15, STK_OFF_SKBP);
.previous
ENTRY(__arch_hweight64)
- sethi %hi(__sw_hweight16), %g1
- jmpl %g1 + %lo(__sw_hweight16), %g0
+ sethi %hi(__sw_hweight64), %g1
+ jmpl %g1 + %lo(__sw_hweight64), %g0
nop
ENDPROC(__arch_hweight64)
EXPORT_SYMBOL(__arch_hweight64)
if (!printk_ratelimit())
return;
- printk("%s%s[%d]: segfault at %lx ip %p (rpc %p) sp %p error %x",
+ printk("%s%s[%d]: segfault at %lx ip %px (rpc %px) sp %px error %x",
task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
tsk->comm, task_pid_nr(tsk), address,
(void *)regs->pc, (void *)regs->u_regs[UREG_I7],
if (!printk_ratelimit())
return;
- printk("%s%s[%d]: segfault at %lx ip %p (rpc %p) sp %p error %x",
+ printk("%s%s[%d]: segfault at %lx ip %px (rpc %px) sp %px error %x",
task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
tsk->comm, task_pid_nr(tsk), address,
(void *)regs->tpc, (void *)regs->u_regs[UREG_I7],
if (!(pmd_val(pmd) & _PAGE_VALID))
return 0;
- if (!pmd_access_permitted(pmd, write))
+ if (write && !pmd_write(pmd))
return 0;
refs = 0;
if (!(pud_val(pud) & _PAGE_VALID))
return 0;
- if (!pud_access_permitted(pud, write))
+ if (write && !pud_write(pud))
return 0;
refs = 0;
u8 *func = ((u8 *)__bpf_call_base) + imm;
ctx->saw_call = true;
+ if (ctx->saw_ld_abs_ind && bpf_helper_changes_pkt_data(func))
+ emit_reg_move(bpf2sparc[BPF_REG_1], L7, ctx);
emit_call((u32 *)func, ctx);
emit_nop(ctx);
emit_reg_move(O0, bpf2sparc[BPF_REG_0], ctx);
- if (bpf_helper_changes_pkt_data(func) && ctx->saw_ld_abs_ind)
- load_skb_regs(ctx, bpf2sparc[BPF_REG_6]);
+ if (ctx->saw_ld_abs_ind && bpf_helper_changes_pkt_data(func))
+ load_skb_regs(ctx, L7);
break;
}
generic-y += barrier.h
+generic-y += bpf_perf_event.h
generic-y += bug.h
generic-y += clkdev.h
generic-y += current.h
/*
* Needed since we do not use the asm-generic/mm_hooks.h:
*/
-static inline void arch_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
+static inline int arch_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
{
uml_setup_stubs(mm);
+ return 0;
}
extern void arch_exit_mmap(struct mm_struct *mm);
static inline void arch_unmap(struct mm_struct *mm,
if (!printk_ratelimit())
return;
- printk("%s%s[%d]: segfault at %lx ip %p sp %p error %x",
+ printk("%s%s[%d]: segfault at %lx ip %px sp %px error %x",
task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
tsk->comm, task_pid_nr(tsk), FAULT_ADDRESS(*fi),
(void *)UPT_IP(regs), (void *)UPT_SP(regs),
} \
} while (0)
-static inline void arch_dup_mmap(struct mm_struct *oldmm,
- struct mm_struct *mm)
+static inline int arch_dup_mmap(struct mm_struct *oldmm,
+ struct mm_struct *mm)
{
+ return 0;
}
static inline void arch_unmap(struct mm_struct *mm,
config NR_CPUS
int "Maximum number of CPUs" if SMP && !MAXSMP
range 2 8 if SMP && X86_32 && !X86_BIGSMP
- range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
+ range 2 64 if SMP && X86_32 && X86_BIGSMP
+ range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK && X86_64
range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
default "1" if !SMP
default "8192" if MAXSMP
config UNWINDER_GUESS
bool "Guess unwinder"
depends on EXPERT
+ depends on !STACKDEPOT
---help---
This option enables the "guess" unwinder for unwinding kernel stack
traces. It scans the stack and reports every kernel text address it
ifdef CONFIG_X86_64
vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/pagetable.o
vmlinux-objs-y += $(obj)/mem_encrypt.o
+ vmlinux-objs-y += $(obj)/pgtable_64.o
endif
$(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone
leaq boot_stack_end(%rbx), %rsp
#ifdef CONFIG_X86_5LEVEL
- /* Check if 5-level paging has already enabled */
- movq %cr4, %rax
- testl $X86_CR4_LA57, %eax
- jnz lvl5
+ /*
+ * Check if we need to enable 5-level paging.
+ * RSI holds real mode data and need to be preserved across
+ * a function call.
+ */
+ pushq %rsi
+ call l5_paging_required
+ popq %rsi
+
+ /* If l5_paging_required() returned zero, we're done here. */
+ cmpq $0, %rax
+ je lvl5
/*
* At this point we are in long mode with 4-level paging enabled,
}
}
+static bool l5_supported(void)
+{
+ /* Check if leaf 7 is supported. */
+ if (native_cpuid_eax(0) < 7)
+ return 0;
+
+ /* Check if la57 is supported. */
+ return native_cpuid_ecx(7) & (1 << (X86_FEATURE_LA57 & 31));
+}
+
#if CONFIG_X86_NEED_RELOCS
static void handle_relocations(void *output, unsigned long output_len,
unsigned long virt_addr)
console_init();
debug_putstr("early console in extract_kernel\n");
+ if (IS_ENABLED(CONFIG_X86_5LEVEL) && !l5_supported()) {
+ error("This linux kernel as configured requires 5-level paging\n"
+ "This CPU does not support the required 'cr4.la57' feature\n"
+ "Unable to boot - please use a kernel appropriate for your CPU\n");
+ }
+
free_mem_ptr = heap; /* Heap */
free_mem_end_ptr = heap + BOOT_HEAP_SIZE;
*/
#undef CONFIG_AMD_MEM_ENCRYPT
+/* No PAGE_TABLE_ISOLATION support needed either: */
+#undef CONFIG_PAGE_TABLE_ISOLATION
+
#include "misc.h"
/* These actually do the work of building the kernel identity maps. */
--- /dev/null
+#include <asm/processor.h>
+
+/*
+ * __force_order is used by special_insns.h asm code to force instruction
+ * serialization.
+ *
+ * It is not referenced from the code, but GCC < 5 with -fPIE would fail
+ * due to an undefined symbol. Define it to make these ancient GCCs work.
+ */
+unsigned long __force_order;
+
+int l5_paging_required(void)
+{
+ /* Check if leaf 7 is supported. */
+
+ if (native_cpuid_eax(0) < 7)
+ return 0;
+
+ /* Check if la57 is supported. */
+ if (!(native_cpuid_ecx(7) & (1 << (X86_FEATURE_LA57 & 31))))
+ return 0;
+
+ /* Check if 5-level paging has already been enabled. */
+ if (native_read_cr4() & X86_CR4_LA57)
+ return 0;
+
+ return 1;
+}
# Make sure the files actually exist
verify "$FBZIMAGE"
-verify "$MTOOLSRC"
genbzdisk() {
+ verify "$MTOOLSRC"
mformat a:
syslinux $FIMAGE
echo "$KCMDLINE" | mcopy - a:syslinux.cfg
}
genfdimage144() {
+ verify "$MTOOLSRC"
dd if=/dev/zero of=$FIMAGE bs=1024 count=1440 2> /dev/null
mformat v:
syslinux $FIMAGE
}
genfdimage288() {
+ verify "$MTOOLSRC"
dd if=/dev/zero of=$FIMAGE bs=1024 count=2880 2> /dev/null
mformat w:
syslinux $FIMAGE
salsa20_ivsetup(ctx, walk.iv);
- if (likely(walk.nbytes == nbytes))
- {
- salsa20_encrypt_bytes(ctx, walk.src.virt.addr,
- walk.dst.virt.addr, nbytes);
- return blkcipher_walk_done(desc, &walk, 0);
- }
-
while (walk.nbytes >= 64) {
salsa20_encrypt_bytes(ctx, walk.src.virt.addr,
walk.dst.virt.addr,
/* SPDX-License-Identifier: GPL-2.0 */
#include <linux/jump_label.h>
#include <asm/unwind_hints.h>
+#include <asm/cpufeatures.h>
+#include <asm/page_types.h>
+#include <asm/percpu.h>
+#include <asm/asm-offsets.h>
+#include <asm/processor-flags.h>
/*
#endif
.endm
+#ifdef CONFIG_PAGE_TABLE_ISOLATION
+
+/*
+ * PAGE_TABLE_ISOLATION PGDs are 8k. Flip bit 12 to switch between the two
+ * halves:
+ */
+#define PTI_SWITCH_PGTABLES_MASK (1<<PAGE_SHIFT)
+#define PTI_SWITCH_MASK (PTI_SWITCH_PGTABLES_MASK|(1<<X86_CR3_PTI_SWITCH_BIT))
+
+.macro SET_NOFLUSH_BIT reg:req
+ bts $X86_CR3_PCID_NOFLUSH_BIT, \reg
+.endm
+
+.macro ADJUST_KERNEL_CR3 reg:req
+ ALTERNATIVE "", "SET_NOFLUSH_BIT \reg", X86_FEATURE_PCID
+ /* Clear PCID and "PAGE_TABLE_ISOLATION bit", point CR3 at kernel pagetables: */
+ andq $(~PTI_SWITCH_MASK), \reg
+.endm
+
+.macro SWITCH_TO_KERNEL_CR3 scratch_reg:req
+ ALTERNATIVE "jmp .Lend_\@", "", X86_FEATURE_PTI
+ mov %cr3, \scratch_reg
+ ADJUST_KERNEL_CR3 \scratch_reg
+ mov \scratch_reg, %cr3
+.Lend_\@:
+.endm
+
+#define THIS_CPU_user_pcid_flush_mask \
+ PER_CPU_VAR(cpu_tlbstate) + TLB_STATE_user_pcid_flush_mask
+
+.macro SWITCH_TO_USER_CR3_NOSTACK scratch_reg:req scratch_reg2:req
+ ALTERNATIVE "jmp .Lend_\@", "", X86_FEATURE_PTI
+ mov %cr3, \scratch_reg
+
+ ALTERNATIVE "jmp .Lwrcr3_\@", "", X86_FEATURE_PCID
+
+ /*
+ * Test if the ASID needs a flush.
+ */
+ movq \scratch_reg, \scratch_reg2
+ andq $(0x7FF), \scratch_reg /* mask ASID */
+ bt \scratch_reg, THIS_CPU_user_pcid_flush_mask
+ jnc .Lnoflush_\@
+
+ /* Flush needed, clear the bit */
+ btr \scratch_reg, THIS_CPU_user_pcid_flush_mask
+ movq \scratch_reg2, \scratch_reg
+ jmp .Lwrcr3_\@
+
+.Lnoflush_\@:
+ movq \scratch_reg2, \scratch_reg
+ SET_NOFLUSH_BIT \scratch_reg
+
+.Lwrcr3_\@:
+ /* Flip the PGD and ASID to the user version */
+ orq $(PTI_SWITCH_MASK), \scratch_reg
+ mov \scratch_reg, %cr3
+.Lend_\@:
+.endm
+
+.macro SWITCH_TO_USER_CR3_STACK scratch_reg:req
+ pushq %rax
+ SWITCH_TO_USER_CR3_NOSTACK scratch_reg=\scratch_reg scratch_reg2=%rax
+ popq %rax
+.endm
+
+.macro SAVE_AND_SWITCH_TO_KERNEL_CR3 scratch_reg:req save_reg:req
+ ALTERNATIVE "jmp .Ldone_\@", "", X86_FEATURE_PTI
+ movq %cr3, \scratch_reg
+ movq \scratch_reg, \save_reg
+ /*
+ * Is the "switch mask" all zero? That means that both of
+ * these are zero:
+ *
+ * 1. The user/kernel PCID bit, and
+ * 2. The user/kernel "bit" that points CR3 to the
+ * bottom half of the 8k PGD
+ *
+ * That indicates a kernel CR3 value, not a user CR3.
+ */
+ testq $(PTI_SWITCH_MASK), \scratch_reg
+ jz .Ldone_\@
+
+ ADJUST_KERNEL_CR3 \scratch_reg
+ movq \scratch_reg, %cr3
+
+.Ldone_\@:
+.endm
+
+.macro RESTORE_CR3 scratch_reg:req save_reg:req
+ ALTERNATIVE "jmp .Lend_\@", "", X86_FEATURE_PTI
+
+ ALTERNATIVE "jmp .Lwrcr3_\@", "", X86_FEATURE_PCID
+
+ /*
+ * KERNEL pages can always resume with NOFLUSH as we do
+ * explicit flushes.
+ */
+ bt $X86_CR3_PTI_SWITCH_BIT, \save_reg
+ jnc .Lnoflush_\@
+
+ /*
+ * Check if there's a pending flush for the user ASID we're
+ * about to set.
+ */
+ movq \save_reg, \scratch_reg
+ andq $(0x7FF), \scratch_reg
+ bt \scratch_reg, THIS_CPU_user_pcid_flush_mask
+ jnc .Lnoflush_\@
+
+ btr \scratch_reg, THIS_CPU_user_pcid_flush_mask
+ jmp .Lwrcr3_\@
+
+.Lnoflush_\@:
+ SET_NOFLUSH_BIT \save_reg
+
+.Lwrcr3_\@:
+ /*
+ * The CR3 write could be avoided when not changing its value,
+ * but would require a CR3 read *and* a scratch register.
+ */
+ movq \save_reg, %cr3
+.Lend_\@:
+.endm
+
+#else /* CONFIG_PAGE_TABLE_ISOLATION=n: */
+
+.macro SWITCH_TO_KERNEL_CR3 scratch_reg:req
+.endm
+.macro SWITCH_TO_USER_CR3_NOSTACK scratch_reg:req scratch_reg2:req
+.endm
+.macro SWITCH_TO_USER_CR3_STACK scratch_reg:req
+.endm
+.macro SAVE_AND_SWITCH_TO_KERNEL_CR3 scratch_reg:req save_reg:req
+.endm
+.macro RESTORE_CR3 scratch_reg:req save_reg:req
+.endm
+
+#endif
+
#endif /* CONFIG_X86_64 */
/*
movl %esp, %eax # pt_regs pointer
/* Are we currently on the SYSENTER stack? */
- PER_CPU(cpu_tss + CPU_TSS_SYSENTER_stack + SIZEOF_SYSENTER_stack, %ecx)
- subl %eax, %ecx /* ecx = (end of SYSENTER_stack) - esp */
- cmpl $SIZEOF_SYSENTER_stack, %ecx
+ movl PER_CPU_VAR(cpu_entry_area), %ecx
+ addl $CPU_ENTRY_AREA_entry_stack + SIZEOF_entry_stack, %ecx
+ subl %eax, %ecx /* ecx = (end of entry_stack) - esp */
+ cmpl $SIZEOF_entry_stack, %ecx
jb .Ldebug_from_sysenter_stack
TRACE_IRQS_OFF
movl %esp, %eax # pt_regs pointer
/* Are we currently on the SYSENTER stack? */
- PER_CPU(cpu_tss + CPU_TSS_SYSENTER_stack + SIZEOF_SYSENTER_stack, %ecx)
- subl %eax, %ecx /* ecx = (end of SYSENTER_stack) - esp */
- cmpl $SIZEOF_SYSENTER_stack, %ecx
+ movl PER_CPU_VAR(cpu_entry_area), %ecx
+ addl $CPU_ENTRY_AREA_entry_stack + SIZEOF_entry_stack, %ecx
+ subl %eax, %ecx /* ecx = (end of entry_stack) - esp */
+ cmpl $SIZEOF_entry_stack, %ecx
jb .Lnmi_from_sysenter_stack
/* Not on SYSENTER stack. */
#include <asm/segment.h>
#include <asm/cache.h>
#include <asm/errno.h>
-#include "calling.h"
#include <asm/asm-offsets.h>
#include <asm/msr.h>
#include <asm/unistd.h>
#include <asm/frame.h>
#include <linux/err.h>
+#include "calling.h"
+
.code64
.section .entry.text, "ax"
* with them due to bugs in both AMD and Intel CPUs.
*/
+ .pushsection .entry_trampoline, "ax"
+
+/*
+ * The code in here gets remapped into cpu_entry_area's trampoline. This means
+ * that the assembler and linker have the wrong idea as to where this code
+ * lives (and, in fact, it's mapped more than once, so it's not even at a
+ * fixed address). So we can't reference any symbols outside the entry
+ * trampoline and expect it to work.
+ *
+ * Instead, we carefully abuse %rip-relative addressing.
+ * _entry_trampoline(%rip) refers to the start of the remapped) entry
+ * trampoline. We can thus find cpu_entry_area with this macro:
+ */
+
+#define CPU_ENTRY_AREA \
+ _entry_trampoline - CPU_ENTRY_AREA_entry_trampoline(%rip)
+
+/* The top word of the SYSENTER stack is hot and is usable as scratch space. */
+#define RSP_SCRATCH CPU_ENTRY_AREA_entry_stack + \
+ SIZEOF_entry_stack - 8 + CPU_ENTRY_AREA
+
+ENTRY(entry_SYSCALL_64_trampoline)
+ UNWIND_HINT_EMPTY
+ swapgs
+
+ /* Stash the user RSP. */
+ movq %rsp, RSP_SCRATCH
+
+ /* Note: using %rsp as a scratch reg. */
+ SWITCH_TO_KERNEL_CR3 scratch_reg=%rsp
+
+ /* Load the top of the task stack into RSP */
+ movq CPU_ENTRY_AREA_tss + TSS_sp1 + CPU_ENTRY_AREA, %rsp
+
+ /* Start building the simulated IRET frame. */
+ pushq $__USER_DS /* pt_regs->ss */
+ pushq RSP_SCRATCH /* pt_regs->sp */
+ pushq %r11 /* pt_regs->flags */
+ pushq $__USER_CS /* pt_regs->cs */
+ pushq %rcx /* pt_regs->ip */
+
+ /*
+ * x86 lacks a near absolute jump, and we can't jump to the real
+ * entry text with a relative jump. We could push the target
+ * address and then use retq, but this destroys the pipeline on
+ * many CPUs (wasting over 20 cycles on Sandy Bridge). Instead,
+ * spill RDI and restore it in a second-stage trampoline.
+ */
+ pushq %rdi
+ movq $entry_SYSCALL_64_stage2, %rdi
+ jmp *%rdi
+END(entry_SYSCALL_64_trampoline)
+
+ .popsection
+
+ENTRY(entry_SYSCALL_64_stage2)
+ UNWIND_HINT_EMPTY
+ popq %rdi
+ jmp entry_SYSCALL_64_after_hwframe
+END(entry_SYSCALL_64_stage2)
+
ENTRY(entry_SYSCALL_64)
UNWIND_HINT_EMPTY
/*
*/
swapgs
+ /*
+ * This path is not taken when PAGE_TABLE_ISOLATION is disabled so it
+ * is not required to switch CR3.
+ */
movq %rsp, PER_CPU_VAR(rsp_scratch)
movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp
popq %rsi /* skip rcx */
popq %rdx
popq %rsi
+
+ /*
+ * Now all regs are restored except RSP and RDI.
+ * Save old stack pointer and switch to trampoline stack.
+ */
+ movq %rsp, %rdi
+ movq PER_CPU_VAR(cpu_tss_rw + TSS_sp0), %rsp
+
+ pushq RSP-RDI(%rdi) /* RSP */
+ pushq (%rdi) /* RDI */
+
+ /*
+ * We are on the trampoline stack. All regs except RDI are live.
+ * We can do future final exit work right here.
+ */
+ SWITCH_TO_USER_CR3_STACK scratch_reg=%rdi
+
popq %rdi
- movq RSP-ORIG_RAX(%rsp), %rsp
+ popq %rsp
USERGS_SYSRET64
END(entry_SYSCALL_64)
.macro DEBUG_ENTRY_ASSERT_IRQS_OFF
#ifdef CONFIG_DEBUG_ENTRY
- pushfq
- testl $X86_EFLAGS_IF, (%rsp)
+ pushq %rax
+ SAVE_FLAGS(CLBR_RAX)
+ testl $X86_EFLAGS_IF, %eax
jz .Lokay_\@
ud2
.Lokay_\@:
- addq $8, %rsp
+ popq %rax
#endif
.endm
/* 0(%rsp): ~(interrupt number) */
.macro interrupt func
cld
+
+ testb $3, CS-ORIG_RAX(%rsp)
+ jz 1f
+ SWAPGS
+ call switch_to_thread_stack
+1:
+
ALLOC_PT_GPREGS_ON_STACK
SAVE_C_REGS
SAVE_EXTRA_REGS
jz 1f
/*
- * IRQ from user mode. Switch to kernel gsbase and inform context
- * tracking that we're in kernel mode.
- */
- SWAPGS
-
- /*
+ * IRQ from user mode.
+ *
* We need to tell lockdep that IRQs are off. We can't do this until
* we fix gsbase, and we should do it before enter_from_user_mode
* (which can take locks). Since TRACE_IRQS_OFF idempotent,
ud2
1:
#endif
- SWAPGS
POP_EXTRA_REGS
- POP_C_REGS
- addq $8, %rsp /* skip regs->orig_ax */
+ popq %r11
+ popq %r10
+ popq %r9
+ popq %r8
+ popq %rax
+ popq %rcx
+ popq %rdx
+ popq %rsi
+
+ /*
+ * The stack is now user RDI, orig_ax, RIP, CS, EFLAGS, RSP, SS.
+ * Save old stack pointer and switch to trampoline stack.
+ */
+ movq %rsp, %rdi
+ movq PER_CPU_VAR(cpu_tss_rw + TSS_sp0), %rsp
+
+ /* Copy the IRET frame to the trampoline stack. */
+ pushq 6*8(%rdi) /* SS */
+ pushq 5*8(%rdi) /* RSP */
+ pushq 4*8(%rdi) /* EFLAGS */
+ pushq 3*8(%rdi) /* CS */
+ pushq 2*8(%rdi) /* RIP */
+
+ /* Push user RDI on the trampoline stack. */
+ pushq (%rdi)
+
+ /*
+ * We are on the trampoline stack. All regs except RDI are live.
+ * We can do future final exit work right here.
+ */
+
+ SWITCH_TO_USER_CR3_STACK scratch_reg=%rdi
+
+ /* Restore RDI. */
+ popq %rdi
+ SWAPGS
INTERRUPT_RETURN
*/
pushq %rdi /* Stash user RDI */
- SWAPGS
+ SWAPGS /* to kernel GS */
+ SWITCH_TO_KERNEL_CR3 scratch_reg=%rdi /* to kernel CR3 */
+
movq PER_CPU_VAR(espfix_waddr), %rdi
movq %rax, (0*8)(%rdi) /* user RAX */
movq (1*8)(%rsp), %rax /* user RIP */
/* Now RAX == RSP. */
andl $0xffff0000, %eax /* RAX = (RSP & 0xffff0000) */
- popq %rdi /* Restore user RDI */
/*
* espfix_stack[31:16] == 0. The page tables are set up such that
* still points to an RO alias of the ESPFIX stack.
*/
orq PER_CPU_VAR(espfix_stack), %rax
- SWAPGS
+
+ SWITCH_TO_USER_CR3_STACK scratch_reg=%rdi
+ SWAPGS /* to user GS */
+ popq %rdi /* Restore user RDI */
+
movq %rax, %rsp
UNWIND_HINT_IRET_REGS offset=8
/*
* Exception entry points.
*/
-#define CPU_TSS_IST(x) PER_CPU_VAR(cpu_tss) + (TSS_ist + ((x) - 1) * 8)
+#define CPU_TSS_IST(x) PER_CPU_VAR(cpu_tss_rw) + (TSS_ist + ((x) - 1) * 8)
+
+/*
+ * Switch to the thread stack. This is called with the IRET frame and
+ * orig_ax on the stack. (That is, RDI..R12 are not on the stack and
+ * space has not been allocated for them.)
+ */
+ENTRY(switch_to_thread_stack)
+ UNWIND_HINT_FUNC
+
+ pushq %rdi
+ /* Need to switch before accessing the thread stack. */
+ SWITCH_TO_KERNEL_CR3 scratch_reg=%rdi
+ movq %rsp, %rdi
+ movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp
+ UNWIND_HINT sp_offset=16 sp_reg=ORC_REG_DI
+
+ pushq 7*8(%rdi) /* regs->ss */
+ pushq 6*8(%rdi) /* regs->rsp */
+ pushq 5*8(%rdi) /* regs->eflags */
+ pushq 4*8(%rdi) /* regs->cs */
+ pushq 3*8(%rdi) /* regs->ip */
+ pushq 2*8(%rdi) /* regs->orig_ax */
+ pushq 8(%rdi) /* return address */
+ UNWIND_HINT_FUNC
+
+ movq (%rdi), %rdi
+ ret
+END(switch_to_thread_stack)
.macro idtentry sym do_sym has_error_code:req paranoid=0 shift_ist=-1
ENTRY(\sym)
ALLOC_PT_GPREGS_ON_STACK
- .if \paranoid
- .if \paranoid == 1
+ .if \paranoid < 2
testb $3, CS(%rsp) /* If coming from userspace, switch stacks */
- jnz 1f
+ jnz .Lfrom_usermode_switch_stack_\@
.endif
+
+ .if \paranoid
call paranoid_entry
.else
call error_entry
jmp error_exit
.endif
- .if \paranoid == 1
+ .if \paranoid < 2
/*
- * Paranoid entry from userspace. Switch stacks and treat it
+ * Entry from userspace. Switch stacks and treat it
* as a normal entry. This means that paranoid handlers
* run in real process context if user_mode(regs).
*/
-1:
+.Lfrom_usermode_switch_stack_\@:
call error_entry
-
- movq %rsp, %rdi /* pt_regs pointer */
- call sync_regs
- movq %rax, %rsp /* switch stack */
-
movq %rsp, %rdi /* pt_regs pointer */
.if \has_error_code
js 1f /* negative -> in kernel */
SWAPGS
xorl %ebx, %ebx
-1: ret
+
+1:
+ SAVE_AND_SWITCH_TO_KERNEL_CR3 scratch_reg=%rax save_reg=%r14
+
+ ret
END(paranoid_entry)
/*
testl %ebx, %ebx /* swapgs needed? */
jnz .Lparanoid_exit_no_swapgs
TRACE_IRQS_IRETQ
+ RESTORE_CR3 scratch_reg=%rbx save_reg=%r14
SWAPGS_UNSAFE_STACK
jmp .Lparanoid_exit_restore
.Lparanoid_exit_no_swapgs:
* from user mode due to an IRET fault.
*/
SWAPGS
+ /* We have user CR3. Change to kernel CR3. */
+ SWITCH_TO_KERNEL_CR3 scratch_reg=%rax
.Lerror_entry_from_usermode_after_swapgs:
+ /* Put us onto the real thread stack. */
+ popq %r12 /* save return addr in %12 */
+ movq %rsp, %rdi /* arg0 = pt_regs pointer */
+ call sync_regs
+ movq %rax, %rsp /* switch stack */
+ ENCODE_FRAME_POINTER
+ pushq %r12
+
/*
* We need to tell lockdep that IRQs are off. We can't do this until
* we fix gsbase, and we should do it before enter_from_user_mode
* .Lgs_change's error handler with kernel gsbase.
*/
SWAPGS
+ SWITCH_TO_KERNEL_CR3 scratch_reg=%rax
jmp .Lerror_entry_done
.Lbstep_iret:
.Lerror_bad_iret:
/*
- * We came from an IRET to user mode, so we have user gsbase.
- * Switch to kernel gsbase:
+ * We came from an IRET to user mode, so we have user
+ * gsbase and CR3. Switch to kernel gsbase and CR3:
*/
SWAPGS
+ SWITCH_TO_KERNEL_CR3 scratch_reg=%rax
/*
* Pretend that the exception came from user mode: set up pt_regs
/*
* Runs on exception stack. Xen PV does not go through this path at all,
* so we can use real assembly here.
+ *
+ * Registers:
+ * %r14: Used to save/restore the CR3 of the interrupted context
+ * when PAGE_TABLE_ISOLATION is in use. Do not clobber.
*/
ENTRY(nmi)
UNWIND_HINT_IRET_REGS
swapgs
cld
+ SWITCH_TO_KERNEL_CR3 scratch_reg=%rdx
movq %rsp, %rdx
movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp
UNWIND_HINT_IRET_REGS base=%rdx offset=8
movq $-1, %rsi
call do_nmi
+ RESTORE_CR3 scratch_reg=%r15 save_reg=%r14
+
testl %ebx, %ebx /* swapgs needed? */
jnz nmi_restore
nmi_swapgs:
*/
ENTRY(entry_SYSENTER_compat)
/* Interrupts are off on entry. */
- SWAPGS_UNSAFE_STACK
+ SWAPGS
+
+ /* We are about to clobber %rsp anyway, clobbering here is OK */
+ SWITCH_TO_KERNEL_CR3 scratch_reg=%rsp
+
movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp
/*
pushq $0 /* pt_regs->r14 = 0 */
pushq $0 /* pt_regs->r15 = 0 */
+ /*
+ * We just saved %rdi so it is safe to clobber. It is not
+ * preserved during the C calls inside TRACE_IRQS_OFF anyway.
+ */
+ SWITCH_TO_KERNEL_CR3 scratch_reg=%rdi
+
/*
* User mode is traced as though IRQs are on, and SYSENTER
* turned them off.
* when the system call started, which is already known to user
* code. We zero R8-R10 to avoid info leaks.
*/
+ movq RSP-ORIG_RAX(%rsp), %rsp
+
+ /*
+ * The original userspace %rsp (RSP-ORIG_RAX(%rsp)) is stored
+ * on the process stack which is not mapped to userspace and
+ * not readable after we SWITCH_TO_USER_CR3. Delay the CR3
+ * switch until after after the last reference to the process
+ * stack.
+ *
+ * %r8/%r9 are zeroed before the sysret, thus safe to clobber.
+ */
+ SWITCH_TO_USER_CR3_NOSTACK scratch_reg=%r8 scratch_reg2=%r9
+
xorq %r8, %r8
xorq %r9, %r9
xorq %r10, %r10
- movq RSP-ORIG_RAX(%rsp), %rsp
swapgs
sysretl
END(entry_SYSCALL_compat)
*/
movl %eax, %eax
- /* Construct struct pt_regs on stack (iret frame is already on stack) */
pushq %rax /* pt_regs->orig_ax */
+
+ /* switch to thread stack expects orig_ax to be pushed */
+ call switch_to_thread_stack
+
pushq %rdi /* pt_regs->di */
pushq %rsi /* pt_regs->si */
pushq %rdx /* pt_regs->dx */
#include <asm/unistd.h>
#include <asm/fixmap.h>
#include <asm/traps.h>
+#include <asm/paravirt.h>
#define CREATE_TRACE_POINTS
#include "vsyscall_trace.h"
WARN_ON_ONCE(address != regs->ip);
+ /* This should be unreachable in NATIVE mode. */
+ if (WARN_ON(vsyscall_mode == NATIVE))
+ return false;
+
if (vsyscall_mode == NONE) {
warn_bad_vsyscall(KERN_INFO, regs,
"vsyscall attempted with vsyscall=none");
return vsyscall_mode != NONE && (addr & PAGE_MASK) == VSYSCALL_ADDR;
}
+/*
+ * The VSYSCALL page is the only user-accessible page in the kernel address
+ * range. Normally, the kernel page tables can have _PAGE_USER clear, but
+ * the tables covering VSYSCALL_ADDR need _PAGE_USER set if vsyscalls
+ * are enabled.
+ *
+ * Some day we may create a "minimal" vsyscall mode in which we emulate
+ * vsyscalls but leave the page not present. If so, we skip calling
+ * this.
+ */
+void __init set_vsyscall_pgtable_user_bits(pgd_t *root)
+{
+ pgd_t *pgd;
+ p4d_t *p4d;
+ pud_t *pud;
+ pmd_t *pmd;
+
+ pgd = pgd_offset_pgd(root, VSYSCALL_ADDR);
+ set_pgd(pgd, __pgd(pgd_val(*pgd) | _PAGE_USER));
+ p4d = p4d_offset(pgd, VSYSCALL_ADDR);
+#if CONFIG_PGTABLE_LEVELS >= 5
+ p4d->p4d |= _PAGE_USER;
+#endif
+ pud = pud_offset(p4d, VSYSCALL_ADDR);
+ set_pud(pud, __pud(pud_val(*pud) | _PAGE_USER));
+ pmd = pmd_offset(pud, VSYSCALL_ADDR);
+ set_pmd(pmd, __pmd(pmd_val(*pmd) | _PAGE_USER));
+}
+
void __init map_vsyscall(void)
{
extern char __vsyscall_page;
unsigned long physaddr_vsyscall = __pa_symbol(&__vsyscall_page);
- if (vsyscall_mode != NONE)
+ if (vsyscall_mode != NONE) {
__set_fixmap(VSYSCALL_PAGE, physaddr_vsyscall,
vsyscall_mode == NATIVE
? PAGE_KERNEL_VSYSCALL
: PAGE_KERNEL_VVAR);
+ set_vsyscall_pgtable_user_bits(swapper_pg_dir);
+ }
BUILD_BUG_ON((unsigned long)__fix_to_virt(VSYSCALL_PAGE) !=
(unsi
git.samba.org / sfrench / cifs-2.6.git / commitdiff