On Wed, Mar 28, 2018 at 1:51 PM, Thomas Gleixner <[email protected]> wrote: > To get rid of the variable length arrays on stack in the RS decoder it's > necessary to allocate the decoder buffers per control structure instance. > > All usage sites have been checked for potential parallel decoder usage and > fixed where necessary. Kees confirmed that the pstore decoding is strictly > single threaded so there should be no surprises.
For posterity: pstore ecc decode happens during probe and during read. The read (pstore_get_backend_records()) has an explicit read_mutex. I was pondering, though, since we have a common control structure now, maybe we should just add a spinlock too to avoid future surprises? > Allocate them in the rs control structure sized depending on the number of > roots for the chosen codec and adapt the decoder code to make use of them. > > Document the fact that decode operations based on a particular rs control > instance cannot run in parallel and the caller has to ensure that as it's > not possible to provide a proper locking construct which fits all use > cases. > > Signed-off-by: Thomas Gleixner <[email protected]> Regardless: Acked-by: Kees Cook <[email protected]> Thanks for doing this! -Kees -- Kees Cook Pixel Security
