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| author | Jason Gunthorpe <jgunthorpe@obsidianresearch.com> | 2016-02-12 20:29:53 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-07-21 07:44:58 +0200 |
| commit | 5ec5771bcb2b4c45771f3f750701ab79dd4cb21a (patch) | |
| tree | 43f7dc57ba5c0ac38e473f2860a03319222dd822 /net/lapb/lapb_timer.c | |
| parent | 5e07de5b5a4ea5c5b56ff73f359a248d97926629 (diff) | |
tpm: Provide strong locking for device removal
commit 4e26195f240d73150e8308ae42874702e3df8d2c upstream.
Add a read/write semaphore around the ops function pointers so
ops can be set to null when the driver un-registers.
Previously the tpm core expected module locking to be enough to
ensure that tpm_unregister could not be called during certain times,
however that hasn't been sufficient for a long time.
Introduce a read/write semaphore around 'ops' so the core can set
it to null when unregistering. This provides a strong fence around
the driver callbacks, guaranteeing to the driver that no callbacks
are running or will run again.
For now the ops_lock is placed very high in the call stack, it could
be pushed down and made more granular in future if necessary.
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/lapb/lapb_timer.c')
0 files changed, 0 insertions, 0 deletions