| Message ID | e13b7014857ea296285ee5cfcdaaada9007f6978.1634638695.git.leonro@nvidia.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Jason Gunthorpe |
| Headers | show |
| Series | [RESEND,rdma-rc] RDMA/mlx5: Add dummy umem to IB_MR_TYPE_DM | expand |
On Tue, Oct 19, 2021 at 01:23:13PM +0300, Leon Romanovsky wrote: > From: Alaa Hleihel <alaa@nvidia.com> > > After the cited patch, and for the case of IB_MR_TYPE_DM that doesn't > have a umem (even though it is a user MR), function mlx5_free_priv_descs() > will think that it's a kernel MR, leading to wrongly accessing mr->descs > that will get wrong values in the union which leads to attempting to > release resources that were not allocated in the first place. > > For example: > DMA-API: mlx5_core 0000:08:00.1: device driver tries to free DMA memory it has not allocated [device address=0x0000000000000000] [size=0 bytes] > WARNING: CPU: 8 PID: 1021 at kernel/dma/debug.c:961 check_unmap+0x54f/0x8b0 > RIP: 0010:check_unmap+0x54f/0x8b0 > Call Trace: > debug_dma_unmap_page+0x57/0x60 > mlx5_free_priv_descs+0x57/0x70 [mlx5_ib] > mlx5_ib_dereg_mr+0x1fb/0x3d0 [mlx5_ib] > ib_dereg_mr_user+0x60/0x140 [ib_core] > uverbs_destroy_uobject+0x59/0x210 [ib_uverbs] > uobj_destroy+0x3f/0x80 [ib_uverbs] > ib_uverbs_cmd_verbs+0x435/0xd10 [ib_uverbs] > ? uverbs_finalize_object+0x50/0x50 [ib_uverbs] > ? lock_acquire+0xc4/0x2e0 > ? lock_acquired+0x12/0x380 > ? lock_acquire+0xc4/0x2e0 > ? lock_acquire+0xc4/0x2e0 > ? ib_uverbs_ioctl+0x7c/0x140 [ib_uverbs] > ? lock_release+0x28a/0x400 > ib_uverbs_ioctl+0xc0/0x140 [ib_uverbs] > ? ib_uverbs_ioctl+0x7c/0x140 [ib_uverbs] > __x64_sys_ioctl+0x7f/0xb0 > do_syscall_64+0x38/0x90 > > Fix it by adding a dummy umem to IB_MR_TYPE_DM MRs. > > Fixes: f18ec4223117 ("RDMA/mlx5: Use a union inside mlx5_ib_mr") > Signed-off-by: Alaa Hleihel <alaa@nvidia.com> > Signed-off-by: Leon Romanovsky <leonro@nvidia.com> > RESEND: https://lore.kernel.org/all/9c6478b70dc23cfec3a7bfc345c30ff817e7e799.1631660866.git.leonro@nvidia.com > > Our request to drop that original patch was because mr-->umem pointer is checked > in rereg flow for the DM MRs with expectation to have NULL there. However DM is > blocked for the rereg path in the commit 5ccbf63f87a3 ("IB/uverbs: Prevent > reregistration of DM_MR to regular MR"), and the checks in mlx5_ib are redundant. That logic in the core code is bogus and should be deleted. It is perfeclty fine to use rereg to change the access flags on a DM MR and mlx5 now implements that. So let's not go down a path that blocks it. Like this instead: diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h index e636e954f6bf2a..4a7a56ed740b9b 100644 --- a/drivers/infiniband/hw/mlx5/mlx5_ib.h +++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h @@ -664,7 +664,6 @@ struct mlx5_ib_mr { /* User MR data */ struct mlx5_cache_ent *cache_ent; - struct ib_umem *umem; /* This is zero'd when the MR is allocated */ union { @@ -676,7 +675,7 @@ struct mlx5_ib_mr { struct list_head list; }; - /* Used only by kernel MRs (umem == NULL) */ + /* Used only by kernel MRs */ struct { void *descs; void *descs_alloc; @@ -697,8 +696,9 @@ struct mlx5_ib_mr { int data_length; }; - /* Used only by User MRs (umem != NULL) */ + /* Used only by User MRs */ struct { + struct ib_umem *umem; unsigned int page_shift; /* Current access_flags */ int access_flags; diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c index 221f0949794e35..997d133d00369d 100644 --- a/drivers/infiniband/hw/mlx5/mr.c +++ b/drivers/infiniband/hw/mlx5/mr.c @@ -1904,19 +1904,19 @@ mlx5_alloc_priv_descs(struct ib_device *device, return ret; } -static void -mlx5_free_priv_descs(struct mlx5_ib_mr *mr) +static void mlx5_free_priv_descs(struct mlx5_ib_mr *mr) { - if (!mr->umem && mr->descs) { - struct ib_device *device = mr->ibmr.device; - int size = mr->max_descs * mr->desc_size; - struct mlx5_ib_dev *dev = to_mdev(device); + struct ib_device *device = mr->ibmr.device; + int size = mr->max_descs * mr->desc_size; + struct mlx5_ib_dev *dev = to_mdev(device); - dma_unmap_single(&dev->mdev->pdev->dev, mr->desc_map, size, - DMA_TO_DEVICE); - kfree(mr->descs_alloc); - mr->descs = NULL; - } + if (!mr->descs) + return; + + dma_unmap_single(&dev->mdev->pdev->dev, mr->desc_map, size, + DMA_TO_DEVICE); + kfree(mr->descs_alloc); + mr->descs = NULL; } int mlx5_ib_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata) @@ -1978,7 +1978,7 @@ int mlx5_ib_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata) return rc; } - if (mr->umem) { + if (udata && mr->umem) { bool is_odp = is_odp_mr(mr); if (!is_odp) @@ -1992,7 +1992,8 @@ int mlx5_ib_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata) if (mr->cache_ent) { mlx5_mr_cache_free(dev, mr); } else { - mlx5_free_priv_descs(mr); + if (!udata) + mlx5_free_priv_descs(mr); kfree(mr); } return 0; @@ -2079,7 +2080,6 @@ static struct mlx5_ib_mr *mlx5_ib_alloc_pi_mr(struct ib_pd *pd, if (err) goto err_free_in; - mr->umem = NULL; kfree(in); return mr; @@ -2206,7 +2206,6 @@ static struct ib_mr *__mlx5_ib_alloc_mr(struct ib_pd *pd, } mr->ibmr.device = pd->device; - mr->umem = NULL; switch (mr_type) { case IB_MR_TYPE_MEM_REG:
On Mon, Oct 25, 2021 at 02:31:50PM -0300, Jason Gunthorpe wrote: > On Tue, Oct 19, 2021 at 01:23:13PM +0300, Leon Romanovsky wrote: > > From: Alaa Hleihel <alaa@nvidia.com> > > > > After the cited patch, and for the case of IB_MR_TYPE_DM that doesn't > > have a umem (even though it is a user MR), function mlx5_free_priv_descs() > > will think that it's a kernel MR, leading to wrongly accessing mr->descs > > that will get wrong values in the union which leads to attempting to > > release resources that were not allocated in the first place. > > > > For example: > > DMA-API: mlx5_core 0000:08:00.1: device driver tries to free DMA memory it has not allocated [device address=0x0000000000000000] [size=0 bytes] > > WARNING: CPU: 8 PID: 1021 at kernel/dma/debug.c:961 check_unmap+0x54f/0x8b0 > > RIP: 0010:check_unmap+0x54f/0x8b0 > > Call Trace: > > debug_dma_unmap_page+0x57/0x60 > > mlx5_free_priv_descs+0x57/0x70 [mlx5_ib] > > mlx5_ib_dereg_mr+0x1fb/0x3d0 [mlx5_ib] > > ib_dereg_mr_user+0x60/0x140 [ib_core] > > uverbs_destroy_uobject+0x59/0x210 [ib_uverbs] > > uobj_destroy+0x3f/0x80 [ib_uverbs] > > ib_uverbs_cmd_verbs+0x435/0xd10 [ib_uverbs] > > ? uverbs_finalize_object+0x50/0x50 [ib_uverbs] > > ? lock_acquire+0xc4/0x2e0 > > ? lock_acquired+0x12/0x380 > > ? lock_acquire+0xc4/0x2e0 > > ? lock_acquire+0xc4/0x2e0 > > ? ib_uverbs_ioctl+0x7c/0x140 [ib_uverbs] > > ? lock_release+0x28a/0x400 > > ib_uverbs_ioctl+0xc0/0x140 [ib_uverbs] > > ? ib_uverbs_ioctl+0x7c/0x140 [ib_uverbs] > > __x64_sys_ioctl+0x7f/0xb0 > > do_syscall_64+0x38/0x90 > > > > Fix it by adding a dummy umem to IB_MR_TYPE_DM MRs. > > > > Fixes: f18ec4223117 ("RDMA/mlx5: Use a union inside mlx5_ib_mr") > > Signed-off-by: Alaa Hleihel <alaa@nvidia.com> > > Signed-off-by: Leon Romanovsky <leonro@nvidia.com> > > RESEND: https://lore.kernel.org/all/9c6478b70dc23cfec3a7bfc345c30ff817e7e799.1631660866.git.leonro@nvidia.com > > > > Our request to drop that original patch was because mr-->umem pointer is checked > > in rereg flow for the DM MRs with expectation to have NULL there. However DM is > > blocked for the rereg path in the commit 5ccbf63f87a3 ("IB/uverbs: Prevent > > reregistration of DM_MR to regular MR"), and the checks in mlx5_ib are redundant. > > That logic in the core code is bogus and should be deleted. > > It is perfeclty fine to use rereg to change the access flags on a DM > MR and mlx5 now implements that. > > So let's not go down a path that blocks it. > > Like this instead: Thanks, let's give a try. > > diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h > index e636e954f6bf2a..4a7a56ed740b9b 100644 > --- a/drivers/infiniband/hw/mlx5/mlx5_ib.h > +++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h > @@ -664,7 +664,6 @@ struct mlx5_ib_mr { > > /* User MR data */ > struct mlx5_cache_ent *cache_ent; > - struct ib_umem *umem; > > /* This is zero'd when the MR is allocated */ > union { > @@ -676,7 +675,7 @@ struct mlx5_ib_mr { > struct list_head list; > }; > > - /* Used only by kernel MRs (umem == NULL) */ > + /* Used only by kernel MRs */ > struct { > void *descs; > void *descs_alloc; > @@ -697,8 +696,9 @@ struct mlx5_ib_mr { > int data_length; > }; > > - /* Used only by User MRs (umem != NULL) */ > + /* Used only by User MRs */ > struct { > + struct ib_umem *umem; > unsigned int page_shift; > /* Current access_flags */ > int access_flags; > diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c > index 221f0949794e35..997d133d00369d 100644 > --- a/drivers/infiniband/hw/mlx5/mr.c > +++ b/drivers/infiniband/hw/mlx5/mr.c > @@ -1904,19 +1904,19 @@ mlx5_alloc_priv_descs(struct ib_device *device, > return ret; > } > > -static void > -mlx5_free_priv_descs(struct mlx5_ib_mr *mr) > +static void mlx5_free_priv_descs(struct mlx5_ib_mr *mr) > { > - if (!mr->umem && mr->descs) { > - struct ib_device *device = mr->ibmr.device; > - int size = mr->max_descs * mr->desc_size; > - struct mlx5_ib_dev *dev = to_mdev(device); > + struct ib_device *device = mr->ibmr.device; > + int size = mr->max_descs * mr->desc_size; > + struct mlx5_ib_dev *dev = to_mdev(device); > > - dma_unmap_single(&dev->mdev->pdev->dev, mr->desc_map, size, > - DMA_TO_DEVICE); > - kfree(mr->descs_alloc); > - mr->descs = NULL; > - } > + if (!mr->descs) > + return; > + > + dma_unmap_single(&dev->mdev->pdev->dev, mr->desc_map, size, > + DMA_TO_DEVICE); > + kfree(mr->descs_alloc); > + mr->descs = NULL; > } > > int mlx5_ib_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata) > @@ -1978,7 +1978,7 @@ int mlx5_ib_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata) > return rc; > } > > - if (mr->umem) { > + if (udata && mr->umem) { > bool is_odp = is_odp_mr(mr); > > if (!is_odp) > @@ -1992,7 +1992,8 @@ int mlx5_ib_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata) > if (mr->cache_ent) { > mlx5_mr_cache_free(dev, mr); > } else { > - mlx5_free_priv_descs(mr); > + if (!udata) > + mlx5_free_priv_descs(mr); > kfree(mr); > } > return 0; > @@ -2079,7 +2080,6 @@ static struct mlx5_ib_mr *mlx5_ib_alloc_pi_mr(struct ib_pd *pd, > if (err) > goto err_free_in; > > - mr->umem = NULL; > kfree(in); > > return mr; > @@ -2206,7 +2206,6 @@ static struct ib_mr *__mlx5_ib_alloc_mr(struct ib_pd *pd, > } > > mr->ibmr.device = pd->device; > - mr->umem = NULL; > > switch (mr_type) { > case IB_MR_TYPE_MEM_REG:
diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index 86d479772fbc..a2f9c922bdd9 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -260,6 +260,27 @@ struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr, } EXPORT_SYMBOL(ib_umem_get); +/** + * ib_umem_get_dummy - Create an empty umem + * + * @device: IB device to connect UMEM + */ +struct ib_umem *ib_umem_get_dummy(struct ib_device *device) +{ + struct ib_umem *umem; + + umem = kzalloc(sizeof(*umem), GFP_KERNEL); + if (!umem) + return ERR_PTR(-ENOMEM); + + umem->ibdev = device; + umem->owning_mm = current->mm; + mmgrab(umem->owning_mm); + + return umem; +} +EXPORT_SYMBOL(ib_umem_get_dummy); + /** * ib_umem_release - release memory pinned with ib_umem_get * @umem: umem struct to release diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c index 3be36ebbf67a..6fbc281a8881 100644 --- a/drivers/infiniband/hw/mlx5/mr.c +++ b/drivers/infiniband/hw/mlx5/mr.c @@ -1389,6 +1389,11 @@ static struct ib_mr *mlx5_ib_get_dm_mr(struct ib_pd *pd, u64 start_addr, kfree(in); set_mr_fields(dev, mr, length, acc); + mr->umem = ib_umem_get_dummy(&dev->ib_dev); + if (IS_ERR(mr->umem)) { + err = PTR_ERR(mr->umem); + goto err_free; + } return &mr->ibmr; diff --git a/include/rdma/ib_umem.h b/include/rdma/ib_umem.h index 5ae9dff74dac..fd20b1610050 100644 --- a/include/rdma/ib_umem.h +++ b/include/rdma/ib_umem.h @@ -98,6 +98,7 @@ static inline void __rdma_umem_block_iter_start(struct ib_block_iter *biter, struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr, size_t size, int access); +struct ib_umem *ib_umem_get_dummy(struct ib_device *device); void ib_umem_release(struct ib_umem *umem); int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset, size_t length); @@ -153,6 +154,10 @@ static inline struct ib_umem *ib_umem_get(struct ib_device *device, { return ERR_PTR(-EOPNOTSUPP); } +static struct ib_umem *ib_umem_get_dummy(struct ib_device *device) +{ + return ERR_PTR(-EOPNOTSUPP); +} static inline void ib_umem_release(struct ib_umem *umem) { } static inline int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset, size_t length) {