wireguard-linux/drivers/s390/crypto/ap_queue.c, branch jd/unified-crypt-queue

s390/ap: remove power management code from ap bus and drivers

2020-03-27T09:22:47Z

The s390 power management support has been removed. So the api registration and the suspend and resume callbacks and all the code related to this for the ap bus and the ap drivers is removed with this patch. Signed-off-by: Harald Freudenberger Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/zcrypt: use fallthrough;

2020-03-25T11:39:37Z

Convert the various uses of fallthrough comments to fallthrough; Done via script Link: https://lore.kernel.org/lkml/b56602fcf79f849e733e7b521bb0e17895d390fa.1582230379.git.joe.com/ Signed-off-by: Joe Perches Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/zcrypt: replace snprintf/sprintf with scnprintf

2020-03-23T12:41:54Z

snprintf() may not always return the correct size of used bytes but instead the length the resulting string would be if it would fit into the buffer. So scnprintf() is the function to use when the real length of the resulting string is needed. Replace all occurrences of snprintf() with scnprintf() where the return code is further processed. Also find and fix some occurrences where sprintf() was used. Suggested-by: Takashi Iwai Signed-off-by: Harald Freudenberger Signed-off-by: Vasily Gorbik

s390/zcrypt: fix card and queue total counter wrap

2020-02-10T11:49:35Z

The internal statistic counters for the total number of requests processed per card and per queue used integers. So they do wrap after a rather huge amount of crypto requests processed. This patch introduces uint64 counters which should hold much longer but still may wrap. The sysfs attributes request_count for card and queue also used only %ld and now display the counter value with %llu. This is not a security relevant fix. The int overflow which happened is not in any way exploitable as a security breach. Signed-off-by: Harald Freudenberger Signed-off-by: Vasily Gorbik

s390/zcrypt: move ap device reset from bus to driver code

2020-01-09T15:59:18Z

This patch moves the reset invocation of an ap device when fresh detected from the ap bus to the probe() function of the driver responsible for this device. The virtualisation of ap devices makes it necessary to remove unconditioned resets on fresh appearing apqn devices. It may be that such a device is already enabled for guest usage. So there may be a race condition between host ap bus and guest ap bus doing the reset. This patch moves the reset from the ap bus to the zcrypt drivers. So if there is no zcrypt driver bound to an ap device - for example the ap device is bound to the vfio device driver - the ap device is untouched passed to the vfio device driver. Signed-off-by: Harald Freudenberger Signed-off-by: Vasily Gorbik

s390/zcrypt: adjust switch fall through comments for -Wimplicit-fallthrough

2019-08-02T11:58:23Z

Silence the following warnings when built with -Wimplicit-fallthrough=3 enabled by default since 5.3-rc2: In file included from ./include/linux/preempt.h:11, from ./include/linux/spinlock.h:51, from ./include/linux/mmzone.h:8, from ./include/linux/gfp.h:6, from ./include/linux/slab.h:15, from drivers/s390/crypto/ap_queue.c:13: drivers/s390/crypto/ap_queue.c: In function 'ap_sm_recv': ./include/linux/list.h:577:2: warning: this statement may fall through [-Wimplicit-fallthrough=] 577 | for (pos = list_first_entry(head, typeof(*pos), member); \ | ^~~ drivers/s390/crypto/ap_queue.c:147:3: note: in expansion of macro 'list_for_each_entry' 147 | list_for_each_entry(ap_msg, &aq->pendingq, list) { | ^~~~~~~~~~~~~~~~~~~ drivers/s390/crypto/ap_queue.c:155:2: note: here 155 | case AP_RESPONSE_NO_PENDING_REPLY: | ^~~~ drivers/s390/crypto/zcrypt_msgtype6.c: In function 'convert_response_ep11_xcrb': drivers/s390/crypto/zcrypt_msgtype6.c:871:6: warning: this statement may fall through [-Wimplicit-fallthrough=] 871 | if (msg->cprbx.cprb_ver_id == 0x04) | ^ drivers/s390/crypto/zcrypt_msgtype6.c:874:2: note: here 874 | default: /* Unknown response type, this should NEVER EVER happen */ | ^~~~~~~ drivers/s390/crypto/zcrypt_msgtype6.c: In function 'convert_response_rng': drivers/s390/crypto/zcrypt_msgtype6.c:901:6: warning: this statement may fall through [-Wimplicit-fallthrough=] 901 | if (msg->cprbx.cprb_ver_id == 0x02) | ^ drivers/s390/crypto/zcrypt_msgtype6.c:907:2: note: here 907 | default: /* Unknown response type, this should NEVER EVER happen */ | ^~~~~~~ drivers/s390/crypto/zcrypt_msgtype6.c: In function 'convert_response_xcrb': drivers/s390/crypto/zcrypt_msgtype6.c:838:6: warning: this statement may fall through [-Wimplicit-fallthrough=] 838 | if (msg->cprbx.cprb_ver_id == 0x02) | ^ drivers/s390/crypto/zcrypt_msgtype6.c:844:2: note: here 844 | default: /* Unknown response type, this should NEVER EVER happen */ | ^~~~~~~ drivers/s390/crypto/zcrypt_msgtype6.c: In function 'convert_response_ica': drivers/s390/crypto/zcrypt_msgtype6.c:801:6: warning: this statement may fall through [-Wimplicit-fallthrough=] 801 | if (msg->cprbx.cprb_ver_id == 0x02) | ^ drivers/s390/crypto/zcrypt_msgtype6.c:808:2: note: here 808 | default: /* Unknown response type, this should NEVER EVER happen */ | ^~~~~~~ Acked-by: Patrick Steuer Signed-off-by: Vasily Gorbik

s390/zcrypt: fix possible deadlock situation on ap queue remove

2019-04-10T15:46:24Z

With commit 01396a374c3d ("s390/zcrypt: revisit ap device remove procedure") the ap queue remove is now a two stage process. However, a del_timer_sync() call may trigger the timer function which may try to lock the very same spinlock as is held by the function just initiating the del_timer_sync() call. This could end up in a deadlock situation. Very unlikely but possible as you need to remove an ap queue at the exact sime time when a timeout of a request occurs. Signed-off-by: Harald Freudenberger Reported-by: Pierre Morel Fixes: commit 01396a374c3d ("s390/zcrypt: revisit ap device remove procedure") Signed-off-by: Martin Schwidefsky

s390/zcrypt: revisit ap device remove procedure

2019-03-06T08:34:03Z

Working with the vfio-ap driver let to some revisit of the way how an ap (queue) device is removed from the driver. With the current implementation all the cleanup was done before the driver even got notified about the removal. Now the ap queue removal is done in 3 steps: 1) A preparation step, all ap messages within the queue are flushed and so the driver does 'receive' them. Also a new state AP_STATE_REMOVE assigned to the queue makes sure there are no new messages queued in. 2) Now the driver's remove function is invoked and the driver should do the job of cleaning up it's internal administration lists or whatever. After 2) is done it is guaranteed, that the driver is not invoked any more. On the other hand the driver has to make sure that the APQN is not accessed any more after step 2 is complete. 3) Now the ap bus code does the job of total cleanup of the APQN. A reset with zero is triggered and the state of the queue goes to AP_STATE_UNBOUND. After step 3) is complete, the ap queue has no pending messages and the APQN is cleared and so there are no requests and replies lingering around in the firmware queue for this APQN. Also the interrupts are disabled. After these remove steps the ap queue device may be assigned to another driver. Stress testing this remove/probe procedure showed a problem with the correct module reference counting. The actual receive of an reply in the driver is done asynchronous with completions. So with a driver change on an ap queue the message flush triggers completions but the threads waiting for the completions may run at a time where the queue already has the new driver assigned. So the module_put() at receive time needs to be done on the driver module which queued the ap message. This change is also part of this patch. Signed-off-by: Harald Freudenberger Reviewed-by: Ingo Franzki Signed-off-by: Martin Schwidefsky

s390/zcrypt: use new state UNBOUND during queue driver rebind

2019-02-13T07:27:44Z

When an alternate driver (vfio-ap) has bound an ap queue and this binding is revised the ap queue device is in an intermittent state not bound to any driver. The internal state variable covered this with the state AP_STATE_BORKED which is also used to reflect broken devices. When now an ap bus scan runs such a device is destroyed and on the next scan reconstructed. So a stress test with high frequency switching the queue driver between the default and the vfio-ap driver hit this gap and the queue was removed until the next ap bus scan. This fix now introduces another state for the in-between condition for a queue momentary not bound to a driver and so the ap bus scan function skips this device instead of removing it. Also some very slight but maybe helpful debug feature messages come with this patch - in particular a message showing that a broken card/queue device will get removed. Signed-off-by: Harald Freudenberger Reviewed-by: Ingo Franzki Signed-off-by: Martin Schwidefsky

s390/zcrypt: make sysfs reset attribute trigger queue reset

2018-12-13T09:42:26Z

Until now there is no way to reset a AP queue or card. Driving a card or queue offline and online again does only toggle the 'software' online state. The only way to trigger a (hardware) reset is by running hot-unplug/hot-plug for example on the HMC. This patch makes the queue reset attribute in sysfs writable. Writing into this attribute triggers a reset on the AP queue's state machine. So the AP queue is flushed and state machine runs through the initial states which cause a reset (PQAP(RAPQ)) and a re-registration to interrupts (PQAP(AQIC)) if available. The reset sysfs attribute is writable by root only. So only an administrator is allowed to initiate a reset of AP queues. Please note that the queue's counter values are left untouched by the reset. Signed-off-by: Harald Freudenberger Signed-off-by: Martin Schwidefsky