linux/drivers/misc/mic, branch v4.20

misc: mic/scif: fix copy-paste error in scif_create_remote_lookup

2018-11-27T08:00:38Z

gcc '-Wunused-but-set-variable' warning: drivers/misc/mic/scif/scif_rma.c: In function 'scif_create_remote_lookup': drivers/misc/mic/scif/scif_rma.c:373:25: warning: variable 'vmalloc_num_pages' set but not used [-Wunused-but-set-variable] 'vmalloc_num_pages' should be used to determine if the address is within the vmalloc range. Fixes: ba612aa8b487 ("misc: mic: SCIF memory registration and unregistration") Signed-off-by: YueHaibing Cc: stable Signed-off-by: Greg Kroah-Hartman

misc: mic: scif: remove set but not used variables 'src_dma_addr, dst_dma_addr'

2018-10-15T18:47:40Z

Fixes gcc '-Wunused-but-set-variable' warning: drivers/misc/mic/scif/scif_dma.c: In function 'scif_rma_list_dma_copy_wrapper': drivers/misc/mic/scif/scif_dma.c:1558:27: warning: variable 'dst_dma_addr' set but not used [-Wunused-but-set-variable] drivers/misc/mic/scif/scif_dma.c:1558:13: warning: variable 'src_dma_addr' set but not used [-Wunused-but-set-variable] They never used since introduction in commit 7cc31cd27752 ("misc: mic: SCIF DMA and CPU copy interface") Signed-off-by: YueHaibing Signed-off-by: Greg Kroah-Hartman

misc: mic: fix a DMA pool free failure

2018-10-15T18:47:40Z

In _scif_prog_signal(), the boolean variable 'x100' is used to indicate whether the MIC Coprocessor is X100. If 'x100' is true, the status descriptor will be used to write the value to the destination. Otherwise, a DMA pool will be allocated for this purpose. Specifically, if the DMA pool is allocated successfully, two memory addresses will be returned. One is for the CPU and the other is for the device to access the DMA pool. The former is stored to the variable 'status' and the latter is stored to the variable 'src'. After the allocation, the address in 'src' is saved to 'status->src_dma_addr', which is actually in the DMA pool, and 'src' is then modified. Later on, if an error occurs, the execution flow will transfer to the label 'dma_fail', which will check 'x100' and free up the allocated DMA pool if 'x100' is false. The point here is that 'status->src_dma_addr' is used for freeing up the DMA pool. As mentioned before, 'status->src_dma_addr' is in the DMA pool. And thus, the device is able to modify this data. This can potentially cause failures when freeing up the DMA pool because of the modified device address. This patch avoids the above issue by using the variable 'src' (with necessary calculation) to free up the DMA pool. Signed-off-by: Wenwen Wang Signed-off-by: Greg Kroah-Hartman

misc: mic: scif: remove redundant check on ret < 0

2018-10-11T10:12:55Z

The check for ret < 0 is redundant as any places prior to this point where ret is set to an error value the code will exit out of the loop to the error exit label 'err'. Remove this redundant dead code. Detected by CoverityScan, CID#1339528 ("Logically dead code") Signed-off-by: Colin Ian King Signed-off-by: Greg Kroah-Hartman

misc: mic: scif: Remove unused variable

2018-09-25T18:21:02Z

Clang warns when a variable is assigned to itself. drivers/misc/mic/scif/scif_dma.c:1577:12: warning: explicitly assigning value of variable of type 'bool' (aka '_Bool') to itself [-Wself-assign] dst_local = dst_local; ~~~~~~~~~ ^ ~~~~~~~~~ 1 warning generated. This is usually done to avoid an unused variable warning, which is the case here. dst_local is used nowhere in this function, which has been the case since the initial code drop in commit 7cc31cd27752 ("misc: mic: SCIF DMA and CPU copy interface") in 2015. Just remove the variable, it can be added back if it was intended to be used. Link: https://github.com/ClangBuiltLinux/linux/issues/107 Signed-off-by: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman

mm, oom: distinguish blockable mode for mmu notifiers

2018-08-22T17:52:44Z

There are several blockable mmu notifiers which might sleep in mmu_notifier_invalidate_range_start and that is a problem for the oom_reaper because it needs to guarantee a forward progress so it cannot depend on any sleepable locks. Currently we simply back off and mark an oom victim with blockable mmu notifiers as done after a short sleep. That can result in selecting a new oom victim prematurely because the previous one still hasn't torn its memory down yet. We can do much better though. Even if mmu notifiers use sleepable locks there is no reason to automatically assume those locks are held. Moreover majority of notifiers only care about a portion of the address space and there is absolutely zero reason to fail when we are unmapping an unrelated range. Many notifiers do really block and wait for HW which is harder to handle and we have to bail out though. This patch handles the low hanging fruit. __mmu_notifier_invalidate_range_start gets a blockable flag and callbacks are not allowed to sleep if the flag is set to false. This is achieved by using trylock instead of the sleepable lock for most callbacks and continue as long as we do not block down the call chain. I think we can improve that even further because there is a common pattern to do a range lookup first and then do something about that. The first part can be done without a sleeping lock in most cases AFAICS. The oom_reaper end then simply retries if there is at least one notifier which couldn't make any progress in !blockable mode. A retry loop is already implemented to wait for the mmap_sem and this is basically the same thing. The simplest way for driver developers to test this code path is to wrap userspace code which uses these notifiers into a memcg and set the hard limit to hit the oom. This can be done e.g. after the test faults in all the mmu notifier managed memory and set the hard limit to something really small. Then we are looking for a proper process tear down. [akpm@linux-foundation.org: coding style fixes] [akpm@linux-foundation.org: minor code simplification] Link: http://lkml.kernel.org/r/20180716115058.5559-1-mhocko@kernel.org Signed-off-by: Michal Hocko Acked-by: Christian König # AMD notifiers Acked-by: Leon Romanovsky # mlx and umem_odp Reported-by: David Rientjes Cc: "David (ChunMing) Zhou" Cc: Paolo Bonzini Cc: Alex Deucher Cc: David Airlie Cc: Jani Nikula Cc: Joonas Lahtinen Cc: Rodrigo Vivi Cc: Doug Ledford Cc: Jason Gunthorpe Cc: Mike Marciniszyn Cc: Dennis Dalessandro Cc: Sudeep Dutt Cc: Ashutosh Dixit Cc: Dimitri Sivanich Cc: Boris Ostrovsky Cc: Juergen Gross Cc: "Jérôme Glisse" Cc: Andrea Arcangeli Cc: Felix Kuehling Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

misc: mic: SCIF Fix scif_get_new_port() error handling

2018-08-05T14:29:11Z

There are only 2 callers of scif_get_new_port() and both appear to get the error handling wrong. Both treat zero returns as error, but it actually returns negative error codes and >= 0 on success. Fixes: e9089f43c9a7 ("misc: mic: SCIF open close bind and listen APIs") Signed-off-by: Dan Carpenter Signed-off-by: Greg Kroah-Hartman

misc: mic: fix passing the current time

2018-07-07T15:44:52Z

I noticed that the mic driver passes a 'struct timespec64' as part of a message into an attached device, where it is used to set the current system time. This won't actually work if one of the two sides runs a 32-bit kernel and the other runs a 64-bit kernel, since the structure layout is different between the two. I found this while replacing calls to the deprecated do_settimeofday64() interface with the modern ktime_get_real_ts() variant, but it seems appropriate to address both at the same time here. To make sure we have a sane structure, let's define our own structure using the layout of the 64-bit kernel. Signed-off-by: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman

misc: mic: mark expected switch fall-through

2018-07-07T15:38:57Z

In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. Signed-off-by: Gustavo A. R. Silva Signed-off-by: Greg Kroah-Hartman

misc: mic: Release reference count and memory for VOP device

2018-03-15T17:12:01Z

Never directly free @dev after calling device_register(), even if it returned an error! Always use put_device() to give up the reference initialized. Release allocated memory for vop device in vop_release_dev(). Signed-off-by: Arvind Yadav Signed-off-by: Greg Kroah-Hartman