Hello, I came along another function implementation where I got the impression that the function “memdup_user” could also be used there in a way which is similar to an existing source code transformation approach by a small script for the semantic patch language.
SmPL script: https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/tree/scripts/coccinelle/api/memdup_user.cocci?id=632571b1bee00494aef749512d9f3290dfba0ead#n1 @refactoring@ expression code, count, from, to, size; identifier label, log; @@ to = - kcalloc(count, size, GFP_KERNEL) + memdup_user(from, size * count) ; if ( - !to + IS_ERR(to) || ...) { - code = -ENOMEM; - goto label; -} -code = copy_from_user(to, from, (size) * (count)); -if (code) { ... log(..., - code + PTR_ERR(to) , ...); code = -ENOMEM; goto label; } Source file: https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/tree/drivers/infiniband/hw/hfi1/user_sdma.c?id=632571b1bee00494aef749512d9f3290dfba0ead#n718 int hfi1_user_sdma_process_request(struct file *fp, struct iovec *iovec, unsigned long dim, unsigned long *count) { /* * ... */ if (req_opcode(req->info.ctrl) == EXPECTED) { u16 ntids = iovec[idx].iov_len / sizeof(*req->tids); if (!ntids || ntids > MAX_TID_PAIR_ENTRIES) { ret = -EINVAL; goto free_req; } req->tids = kcalloc(ntids, sizeof(*req->tids), GFP_KERNEL); if (!req->tids) { ret = -ENOMEM; goto free_req; } /* * ... */ ret = copy_from_user(req->tids, iovec[idx].iov_base, ntids * sizeof(*req->tids)); if (ret) { SDMA_DBG(req, "Failed to copy %d TIDs (%d)", ntids, ret); ret = -EFAULT; goto free_req; } req->n_tids = ntids; idx++; } /* * ... */ return 0; free_req: user_sdma_free_request(req, true); if (req_queued) pq_update(pq); set_comp_state(pq, cq, info.comp_idx, ERROR, req->status); return ret; } elfring@Sonne:~/Projekte/Coccinelle/janitor> spatch.opt replace_kcalloc_by_memdup_user-draft1.cocci ../Probe/user_sdma-excerpt1.c … refactoring: position variables or mixed modifs interfere with comm_assoc iso bool (bool !to >>> IS_ERR(to) || ...) … The software combination “Coccinelle 1.0.6-00093-ge1776d7b (OCaml 4.03.0)” does not like this change attempt so far. Which details should I reconsider next? Regards, Markus _______________________________________________ Cocci mailing list Cocci@systeme.lip6.fr https://systeme.lip6.fr/mailman/listinfo/cocci
