On Wed, Jun 07, 2017 at 08:50:45PM -0700, Felix Manlunas wrote: > From: Rick Farrington <ricardo.farring...@cavium.com> > > This patchset addresses issues brought about by low memory conditions > in a VM. These conditions were only seen when VM's were intentionally > created with small amounts of memory (for stress testing). > > 1. Fix GPF in octeon_init_droq(); zero the allocated block 'recv_buf_list'. > This prevents a GPF trying to access an invalid 'recv_buf_list[i]' entry > in octeon_droq_destroy_ring_buffers() if init didn't alloc all entries. > 2. Don't dereference a NULL ptr in octeon_droq_destroy_ring_buffers(). > 3. For defensive programming, zero the allocated block 'oct->droq[0]' in > octeon_setup_output_queues() and 'oct->instr_queue[0]' in > octeon_setup_instr_queues(). >
While these patches are harmless, I don't really understand how allocating the same arrays just with zeros in it can prevent low memory crashes. Once you used v[m,z]alloc, you should expect for failures in these flows and relying on content of that page is not called "solve the bug". Thanks > drivers/net/ethernet/cavium/liquidio/octeon_device.c | 8 ++++---- > drivers/net/ethernet/cavium/liquidio/octeon_droq.c | 6 ++++-- > 2 files changed, 8 insertions(+), 6 deletions(-) > > -- > 1.8.3.1 >
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