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2024-03-05misc: open-dice: Convert to platform remove callback returning voidUwe Kleine-König1-3/+2
The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is ignored (apart from emitting a warning) and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new(), which already returns void. Eventually after all drivers are converted, .remove_new() will be renamed to .remove(). Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/8e7179794ffbcaa4ad3d0db50cc4aa03f377fc8c.1708508896.git.u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-31misc: open-dice: Fix spurious lockdep warningWill Deacon1-1/+1
When probing the open-dice driver with PROVE_LOCKING=y, lockdep complains that the mutex in 'drvdata->lock' has a non-static key: | INFO: trying to register non-static key. | The code is fine but needs lockdep annotation, or maybe | you didn't initialize this object before use? | turning off the locking correctness validator. Fix the problem by initialising the mutex memory with mutex_init() instead of __MUTEX_INITIALIZER(). Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Brazdil <dbrazdil@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20240126152410.10148-1-will@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-10mm: replace vma->vm_flags direct modifications with modifier callsSuren Baghdasaryan1-2/+2
Replace direct modifications to vma->vm_flags with calls to modifier functions to be able to track flag changes and to keep vma locking correctness. [akpm@linux-foundation.org: fix drivers/misc/open-dice.c, per Hyeonggon Yoo] Link: https://lkml.kernel.org/r/20230126193752.297968-5-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arjun Roy <arjunroy@google.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: David Rientjes <rientjes@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Laurent Dufour <ldufour@linux.ibm.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Minchan Kim <minchan@google.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Peter Oskolkov <posk@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Punit Agrawal <punit.agrawal@bytedance.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Shakeel Butt <shakeelb@google.com> Cc: Soheil Hassas Yeganeh <soheil@google.com> Cc: Song Liu <songliubraving@fb.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-19drivers/misc/open-dice: don't touch VM_MAYSHAREDavid Hildenbrand1-8/+6
A MAP_SHARED mapping always has VM_MAYSHARE set, and writable (VM_MAYWRITE) MAP_SHARED mappings have VM_SHARED set as well. To identify a MAP_SHARED mapping, it's sufficient to look at VM_MAYSHARE. We cannot have VM_MAYSHARE|VM_WRITE mappings without having VM_SHARED set. Consequently, current code will never actually end up clearing VM_MAYSHARE and that code is confusing, because nobody is supposed to mess with VM_MAYWRITE. Let's clean it up and restructure the code. No functional change intended. Link: https://lkml.kernel.org/r/20230102160856.500584-4-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-02-04misc: open-dice: Add driver to expose DICE data to userspaceDavid Brazdil1-0/+208
Open Profile for DICE is an open protocol for measured boot compatible with the Trusted Computing Group's Device Identifier Composition Engine (DICE) specification. The generated Compound Device Identifier (CDI) certificates represent the hardware/software combination measured by DICE, and can be used for remote attestation and sealing. Add a driver that exposes reserved memory regions populated by firmware with DICE CDIs and exposes them to userspace via a character device. Userspace obtains the memory region's size from read() and calls mmap() to create a mapping of the memory region in its address space. The mapping is not allowed to be write+shared, giving userspace a guarantee that the data were not overwritten by another process. Userspace can also call write(), which triggers a wipe of the DICE data by the driver. Because both the kernel and userspace mappings use write-combine semantics, all clients observe the memory as zeroed after the syscall has returned. Cc: Andrew Scull <ascull@google.com> Cc: Will Deacon <will@kernel.org> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: David Brazdil <dbrazdil@google.com> Link: https://lore.kernel.org/r/20220126231237.529308-3-dbrazdil@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>