kernel/linux.git/drivers/hwtracing/stm, branch linux-4.4.y

stm class: Fix a double free of stm_source_device

2019-09-06T08:18:17+00:00

commit 961b6ffe0e2c403b09a8efe4a2e986b3c415391a upstream. In the error path of stm_source_register_device(), the kfree is unnecessary, as the put_device() before it ends up calling stm_source_device_release() to free stm_source_device, leading to a double free at the outer kfree() call. Remove it. Signed-off-by: Ding Xiang Signed-off-by: Alexander Shishkin Fixes: 7bd1d4093c2fa ("stm class: Introduce an abstraction for System Trace Module devices") Link: https://lore.kernel.org/linux-arm-kernel/1563354988-23826-1-git-send-email-dingxiang@cmss.chinamobile.com/ Cc: stable@vger.kernel.org # v4.4+ Link: https://lore.kernel.org/r/20190821074955.3925-2-alexander.shishkin@linux.intel.com Signed-off-by: Greg Kroah-Hartman

stm class: Fix channel free in stm output free path

2019-06-11T10:23:44+00:00

commit ee496da4c3915de3232b5f5cd20e21ae3e46fe8d upstream. Number of free masters is not set correctly in stm free path. Fix this by properly adding the number of output channels before setting them to 0 in stm_output_disclaim(). Currently it is equivalent to doing nothing since master->nr_free is incremented by 0. Fixes: 7bd1d4093c2f ("stm class: Introduce an abstraction for System Trace Module devices") Signed-off-by: Tingwei Zhang Signed-off-by: Sai Prakash Ranjan Cc: stable@vger.kernel.org # v4.4 Signed-off-by: Alexander Shishkin Signed-off-by: Greg Kroah-Hartman

stm class: Hide STM-specific options if STM is disabled

2019-04-03T04:23:29+00:00

[ Upstream commit 4a2e2b19f96acfc037a9773c7729d133ce1e7e3b ] If STM=n, it doesn't make sense to ask about STM_DUMMY and STM_SOURCE_CONSOLE support, which are not even built when enabled anyway. Hence hide these options if STM=n. Reported-by: Linus Torvalds Signed-off-by: Geert Uytterhoeven Signed-off-by: Alexander Shishkin Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

stm class: Fix stm device initialization order

2019-04-03T04:23:24+00:00

[ Upstream commit 389b6699a2aa0b457aa69986e9ddf39f3b4030fd ] Currently, stm_register_device() makes the device visible and then proceeds to initializing spinlocks and other properties, which leaves a window when the device can already be opened but is not yet fully operational. Fix this by reversing the initialization order. Reported-by: Alan Cox Signed-off-by: Alexander Shishkin Reviewed-by: Laurent Fert Signed-off-by: Sasha Levin

stm class: Do not leak the chrdev in error path

2019-04-03T04:23:24+00:00

[ Upstream commit cbe4a61d1ddc4790d950ca8c33ef79ee68ef5e2b ] Currently, the error path of stm_register_device() forgets to unregister the chrdev. Fix this. Reported-by: Alan Cox Signed-off-by: Alexander Shishkin Reviewed-by: Laurent Fert Signed-off-by: Sasha Levin

stm class: Fix a race in unlinking

2019-04-03T04:23:22+00:00

[ Upstream commit b4ca34aaf78ed0cdfc15956d377064104257a437 ] There is a window in stm_source_link_drop(), during which the source's link may change before locks are acquired. When this happens, it throws a warning, since this is not an expected scenario. This patch handles the race in such a way that if the link appears to have changed by the time we took the locks, it will release them and repeat the whole unlinking procedure from the beginning, unless the other contender beat us to it. Signed-off-by: Alexander Shishkin Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

stm class: Fix unbalanced module/device refcounting

2019-04-03T04:23:22+00:00

[ Upstream commit f7c81c7176c72c7899390754b4b038a64b296e4d ] STM code takes references to the stm device and its module for the duration of the character device's existence or the stm_source link. Dropping these references is not well balanced everywhere, which may lead to leaks. This patch balances the acquisition and releasing of these two references and annotates each site so that it's easier to verify correctness by reading the code. Signed-off-by: Alexander Shishkin Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

stm class: Guard output assignment against concurrency

2019-04-03T04:23:22+00:00

[ Upstream commit cde4ad8368840e414ecf67db258fe1dabaa5fd2e ] It is possible to concurrently assign the same output (a character device writer or an stm_source device) to different stm devices, which sets off a strategically placed warning in stm_output_assign(). To avoid this, use a spinlock to serialize (un)assignments between outputs and stm devices. Signed-off-by: Alexander Shishkin Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

stm class: Fix unlocking braino in the error path

2019-04-03T04:23:22+00:00

[ Upstream commit 1810f2c44817c74ca3d05d1e3981e3a2e2ceb6f5 ] If an illegal attempt is made to unlink stm source device from an stm device, the stm device's link spinlock mistakenly remains locked. While this really shouldn't happen (there's a warning in place), the locking should remain in order so that we can still recover from this situation if it indeed does happen. This patch unifies the unlocking in the exit path of __stm_source_link_drop() to fix this. Reported-by: Laurent Fert Signed-off-by: Alexander Shishkin Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

stm class: Support devices with multiple instances

2019-04-03T04:23:22+00:00

[ Upstream commit 59be422e4ce10e3d49d4c9407a80fab8a9b7bc84 ] By convention, the name of the stm policy directory in configfs consists of the device name to which it applies and the actual policy name, separated by a dot. Now, some devices already have dots in their names that separate name of the actual device from its instance identifier. Such devices will result in two (or more, who can tell) dots in the policy directory name. Existing policy code, however, will treat the first dot as the one that separates device name from policy name, therefore failing the above case. This patch makes the last dot in the directory name be the separator, thus prohibiting dots from being used in policy names. Suggested-by: Chunyan Zhang Signed-off-by: Alexander Shishkin Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin