From: Xi Wang wangxi11@huawei.com
[ Upstream commit 60c3becfd1a138fdcfe48f2a5ef41ef0078d481e ]
When run perftest in many times, the system will report a BUG as follows:
BUG: Bad rss-counter state mm:(____ptrval____) idx:0 val:-1 BUG: Bad rss-counter state mm:(____ptrval____) idx:1 val:1
We tested with different kernel version and found it started from the the following commit:
commit d10bcf947a3e ("RDMA/umem: Combine contiguous PAGE_SIZE regions in SGEs")
In this commit, the sg->offset is always 0 when sg_set_page() is called in ib_umem_get() and the drivers are not allowed to change the sgl, otherwise it will get bad page descriptor when unfolding SGEs in __ib_umem_release() as sg_page_count() will get wrong result while sgl->offset is not 0.
However, there is a weird sgl usage in the current hns driver, the driver modified sg->offset after calling ib_umem_get(), which caused we iterate past the wrong number of pages in for_each_sg_page iterator.
This patch fixes it by correcting the non-standard sgl usage found in the hns_roce_db_map_user() function.
Fixes: d10bcf947a3e ("RDMA/umem: Combine contiguous PAGE_SIZE regions in SGEs") Fixes: 0425e3e6e0c7 ("RDMA/hns: Support flush cqe for hip08 in kernel space") Link: https://lore.kernel.org/r/1562808737-45723-1-git-send-email-oulijun@huawei.c... Signed-off-by: Xi Wang wangxi11@huawei.com Signed-off-by: Jason Gunthorpe jgg@mellanox.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/infiniband/hw/hns/hns_roce_db.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/drivers/infiniband/hw/hns/hns_roce_db.c b/drivers/infiniband/hw/hns/hns_roce_db.c index 0c6c1fe87705c..d60453e98db7c 100644 --- a/drivers/infiniband/hw/hns/hns_roce_db.c +++ b/drivers/infiniband/hw/hns/hns_roce_db.c @@ -12,13 +12,15 @@ int hns_roce_db_map_user(struct hns_roce_ucontext *context, struct ib_udata *udata, unsigned long virt, struct hns_roce_db *db) { + unsigned long page_addr = virt & PAGE_MASK; struct hns_roce_user_db_page *page; + unsigned int offset; int ret = 0;
mutex_lock(&context->page_mutex);
list_for_each_entry(page, &context->page_list, list) - if (page->user_virt == (virt & PAGE_MASK)) + if (page->user_virt == page_addr) goto found;
page = kmalloc(sizeof(*page), GFP_KERNEL); @@ -28,8 +30,8 @@ int hns_roce_db_map_user(struct hns_roce_ucontext *context, }
refcount_set(&page->refcount, 1); - page->user_virt = (virt & PAGE_MASK); - page->umem = ib_umem_get(udata, virt & PAGE_MASK, PAGE_SIZE, 0, 0); + page->user_virt = page_addr; + page->umem = ib_umem_get(udata, page_addr, PAGE_SIZE, 0, 0); if (IS_ERR(page->umem)) { ret = PTR_ERR(page->umem); kfree(page); @@ -39,10 +41,9 @@ int hns_roce_db_map_user(struct hns_roce_ucontext *context, list_add(&page->list, &context->page_list);
found: - db->dma = sg_dma_address(page->umem->sg_head.sgl) + - (virt & ~PAGE_MASK); - page->umem->sg_head.sgl->offset = virt & ~PAGE_MASK; - db->virt_addr = sg_virt(page->umem->sg_head.sgl); + offset = virt - page_addr; + db->dma = sg_dma_address(page->umem->sg_head.sgl) + offset; + db->virt_addr = sg_virt(page->umem->sg_head.sgl) + offset; db->u.user_page = page; refcount_inc(&page->refcount);