From: Jason Gunthorpe Date: Thu, 4 Jun 2026 18:03:13 +0000 (-0300) Subject: RDMA: During rereg_mr ensure that REREG_ACCESS is compatible X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=badad6fad60def1b9805559dd81dbab3d97b82aa;p=thirdparty%2Fkernel%2Flinux.git RDMA: During rereg_mr ensure that REREG_ACCESS is compatible If IB_MR_REREG_ACCESS changes from RO to RW then the umem has to be re-evaluated to ensure it is properly pinned as RW. Since the umem is hidden inside each driver's mr struct add a ib_umem_check_rereg() function that each driver has to call before processing IB_MR_REREG_ACCESS. mlx4 has to retain its duplicate ib_access_writable check because it implements IB_MR_REREG_ACCESS | IB_MR_REREG_TRANS by changing both items in place sequentially while the MR is live, so it will continue to not support this combination. Cc: stable@vger.kernel.org Fixes: b40656aa7d55 ("RDMA/umem: remove FOLL_FORCE usage") Link: https://patch.msgid.link/r/0-v1-06fb1a2d6cf5+107-rereg_access_jgg@nvidia.com Reported-by: Philip Tsukerman Signed-off-by: Jason Gunthorpe --- diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index 786fa1aa8e552..4b055712b0d0d 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -332,3 +332,19 @@ int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset, return 0; } EXPORT_SYMBOL(ib_umem_copy_from); + +/* + * Called during rereg mr if the driver is able to re-use a umem for + * IB_MR_REREG_ACCESS. + */ +int ib_umem_check_rereg(struct ib_umem *umem, int flags, int new_access_flags) +{ + if (!umem) + return 0; + + if ((flags & IB_MR_REREG_ACCESS) && !(flags & IB_MR_REREG_TRANS)) + if (ib_access_writable(new_access_flags) && !umem->writable) + return -EACCES; + return 0; +} +EXPORT_SYMBOL(ib_umem_check_rereg); diff --git a/drivers/infiniband/hw/hns/hns_roce_mr.c b/drivers/infiniband/hw/hns/hns_roce_mr.c index 896af1828a38d..25bfd3970f5b6 100644 --- a/drivers/infiniband/hw/hns/hns_roce_mr.c +++ b/drivers/infiniband/hw/hns/hns_roce_mr.c @@ -300,6 +300,10 @@ struct ib_mr *hns_roce_rereg_user_mr(struct ib_mr *ibmr, int flags, u64 start, goto err_out; } + ret = ib_umem_check_rereg(mr->pbl_mtr.umem, flags, mr_access_flags); + if (ret) + goto err_out; + mailbox = hns_roce_alloc_cmd_mailbox(hr_dev); ret = PTR_ERR_OR_ZERO(mailbox); if (ret) diff --git a/drivers/infiniband/hw/irdma/verbs.c b/drivers/infiniband/hw/irdma/verbs.c index 17086048d2d7f..8cd4275328052 100644 --- a/drivers/infiniband/hw/irdma/verbs.c +++ b/drivers/infiniband/hw/irdma/verbs.c @@ -3803,6 +3803,10 @@ static struct ib_mr *irdma_rereg_user_mr(struct ib_mr *ib_mr, int flags, if (flags & ~(IB_MR_REREG_TRANS | IB_MR_REREG_PD | IB_MR_REREG_ACCESS)) return ERR_PTR(-EOPNOTSUPP); + ret = ib_umem_check_rereg(iwmr->region, flags, new_access); + if (ret) + return ERR_PTR(ret); + if (dmabuf_revocable) { umem_dmabuf = to_ib_umem_dmabuf(iwmr->region); diff --git a/drivers/infiniband/hw/mlx4/mr.c b/drivers/infiniband/hw/mlx4/mr.c index 650b4a9121ff6..6747bca306777 100644 --- a/drivers/infiniband/hw/mlx4/mr.c +++ b/drivers/infiniband/hw/mlx4/mr.c @@ -209,6 +209,10 @@ struct ib_mr *mlx4_ib_rereg_user_mr(struct ib_mr *mr, int flags, u64 start, struct mlx4_mpt_entry **pmpt_entry = &mpt_entry; int err; + err = ib_umem_check_rereg(mmr->umem, flags, mr_access_flags); + if (err) + return ERR_PTR(err); + /* Since we synchronize this call and mlx4_ib_dereg_mr via uverbs, * we assume that the calls can't run concurrently. Otherwise, a * race exists. diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c index 3b6da45061a55..fb40b44496f47 100644 --- a/drivers/infiniband/hw/mlx5/mr.c +++ b/drivers/infiniband/hw/mlx5/mr.c @@ -1179,6 +1179,10 @@ struct ib_mr *mlx5_ib_rereg_user_mr(struct ib_mr *ib_mr, int flags, u64 start, if (flags & ~(IB_MR_REREG_TRANS | IB_MR_REREG_PD | IB_MR_REREG_ACCESS)) return ERR_PTR(-EOPNOTSUPP); + err = ib_umem_check_rereg(mr->umem, flags, new_access_flags); + if (err) + return ERR_PTR(err); + if (!(flags & IB_MR_REREG_ACCESS)) new_access_flags = mr->access_flags; if (!(flags & IB_MR_REREG_PD)) diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c index 4d4891dc28846..4cf04a44189c6 100644 --- a/drivers/infiniband/sw/rxe/rxe_verbs.c +++ b/drivers/infiniband/sw/rxe/rxe_verbs.c @@ -1319,6 +1319,7 @@ static struct ib_mr *rxe_rereg_user_mr(struct ib_mr *ibmr, int flags, struct rxe_mr *mr = to_rmr(ibmr); struct rxe_pd *old_pd = to_rpd(ibmr->pd); struct rxe_pd *pd = to_rpd(ibpd); + int err; /* for now only support the two easy cases: * rereg_pd and rereg_access @@ -1328,6 +1329,10 @@ static struct ib_mr *rxe_rereg_user_mr(struct ib_mr *ibmr, int flags, return ERR_PTR(-EOPNOTSUPP); } + err = ib_umem_check_rereg(mr->umem, flags, access); + if (err) + return ERR_PTR(err); + if (flags & IB_MR_REREG_PD) { rxe_put(old_pd); rxe_get(pd); diff --git a/include/rdma/ib_umem.h b/include/rdma/ib_umem.h index 2ad52cc1d52bd..49172098a8de1 100644 --- a/include/rdma/ib_umem.h +++ b/include/rdma/ib_umem.h @@ -156,6 +156,8 @@ void ib_umem_dmabuf_revoke_lock(struct ib_umem_dmabuf *umem_dmabuf); void ib_umem_dmabuf_revoke_unlock(struct ib_umem_dmabuf *umem_dmabuf); void ib_umem_dmabuf_revoke(struct ib_umem_dmabuf *umem_dmabuf); +int ib_umem_check_rereg(struct ib_umem *umem, int flags, int new_access_flags); + #else /* CONFIG_INFINIBAND_USER_MEM */ #include @@ -230,5 +232,11 @@ static inline void ib_umem_dmabuf_revoke_lock(struct ib_umem_dmabuf *umem_dmabuf static inline void ib_umem_dmabuf_revoke_unlock(struct ib_umem_dmabuf *umem_dmabuf) {} static inline void ib_umem_dmabuf_revoke(struct ib_umem_dmabuf *umem_dmabuf) {} +static inline int ib_umem_check_rereg(struct ib_umem *umem, int flags, + int new_access_flags) +{ + return -EOPNOTSUPP; +} + #endif /* CONFIG_INFINIBAND_USER_MEM */ #endif /* IB_UMEM_H */