Searched hist:b00b6289 (Results 1 – 1 of 1) sorted by relevance
/openbmc/linux/arch/powerpc/platforms/powernv/ |
H A D | vas-window.c | b00b6289 Thu Feb 08 03:18:38 CST 2018 Nicholas Piggin <npiggin@gmail.com> powerpc/vas: Don't set uses_vas for kernel windows
cp_abort is only required for user windows, because kernel context must not be preempted between a copy/paste pair.
Without this patch, the init task gets used_vas set when it runs the nx842_powernv_init initcall, which opens windows for kernel usage.
used_vas is then never cleared anywhere, so it gets propagated into all other tasks. It's a property of the address space, so it should really be cleared when a new mm is created (or in dup_mmap if the mmaps are marked as VM_DONTCOPY). For now we seem to have no such driver, so leave that for another patch.
Fixes: 6c8e6bb2a52d ("powerpc/vas: Add support for user receive window") Cc: stable@vger.kernel.org # v4.15+ Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> b00b6289 Thu Feb 08 03:18:38 CST 2018 Nicholas Piggin <npiggin@gmail.com> powerpc/vas: Don't set uses_vas for kernel windows cp_abort is only required for user windows, because kernel context must not be preempted between a copy/paste pair. Without this patch, the init task gets used_vas set when it runs the nx842_powernv_init initcall, which opens windows for kernel usage. used_vas is then never cleared anywhere, so it gets propagated into all other tasks. It's a property of the address space, so it should really be cleared when a new mm is created (or in dup_mmap if the mmaps are marked as VM_DONTCOPY). For now we seem to have no such driver, so leave that for another patch. Fixes: 6c8e6bb2a52d ("powerpc/vas: Add support for user receive window") Cc: stable@vger.kernel.org # v4.15+ Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
|