On Tue, Sep 08, 2020 at 09:53:11PM +0200, Pavel Machek wrote:
Hi!
On machines with much memory (> 2 TByte) and log_mtts_per_seg == 0, a max_order of 31 will be passed to mlx_buddy_init(), which results in s = BITS_TO_LONGS(1 << 31) becoming a negative value, leading to kvmalloc_array() failure when it is converted to size_t.
mlx4_core 0000:b1:00.0: Failed to initialize memory region table, aborting mlx4_core: probe of 0000:b1:00.0 failed with error -12
Fix this issue by changing the left shifting operand from a signed literal to an unsigned one.
Will we still have problems with > 4 TByte machines?
AFAIK we're safe since max_buddy is calculated as such
/* In drivers/net/ethernet/mellanox/mlx4/mr.c */ err = mlx4_buddy_init(&mr_table->mtt_buddy, ilog2((u32)dev->caps.num_mtts / (1 << log_mtts_per_seg)));
Also, num_mtts is capped at 2^31
/* In drivers/net/ethernet/mellanox/mlx4/profile.c */ /* * We want to scale the number of MTTs with the size of the * system memory, since it makes sense to register a lot of * memory on a system with a lot of memory. As a heuristic, * make sure we have enough MTTs to cover twice the system * memory (with PAGE_SIZE entries). * * This number has to be a power of two and fit into 32 bits * due to device limitations, so cap this at 2^31 as well. * That limits us to 8TB of memory registration per HCA with * 4KB pages, which is probably OK for the next few months. */ si_meminfo(&si); request->num_mtt = roundup_pow_of_two(max_t(unsigned, request->num_mtt, min(1UL << (31 - log_mtts_per_seg), (si.totalram << 1) >> log_mtts_per_seg)));
Best, Shung-Hsi Yu
Should the computation be done in u64?
Best regards, Pavel
Fixes: 225c7b1feef1 ("IB/mlx4: Add a driver Mellanox ConnectX InfiniBand adapters") Signed-off-by: Shung-Hsi Yu shung-hsi.yu@suse.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org
+++ b/drivers/net/ethernet/mellanox/mlx4/mr.c @@ -114,7 +114,7 @@ static int mlx4_buddy_init(struct mlx4_buddy *buddy, int max_order) goto err_out; for (i = 0; i <= buddy->max_order; ++i) {
s = BITS_TO_LONGS(1 << (buddy->max_order - i));
s = BITS_TO_LONGS(1UL << (buddy->max_order - i));-- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html