On Wed, 15 Feb 2017, SF Markus Elfring wrote:
> > 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)
> > || ...)
> > …
>
> Would you like to explain this message a bit more while the following SmPL
> approach seems to work
> as expected?
The comm_assoc isomorphism allows A || ... to match any disjunction where
A appears at the top level, not just in the far left position. It also
matches the case where A is not present at all.
I don't know what the original semantic patch looks like, so I don't know
exactly what is preventing this isomorphism from applying.
julia
>
> @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) {
> ...
> + code = PTR_ERR(to);
> log(..., code, ...);
> - code = -EFAULT;
> goto label;
> }
>
>
> elfring@Sonne:~/Projekte/Coccinelle/janitor> spatch.opt
> replace_kcalloc_by_memdup_user-draft2.cocci ../Probe/user_sdma-excerpt1.c
> init_defs_builtins: /usr/local/lib64/coccinelle/standard.h
> HANDLING: ../Probe/user_sdma-excerpt1.c
> diff =
> --- ../Probe/user_sdma-excerpt1.c
> +++ /tmp/cocci-output-8749-f5da06-user_sdma-excerpt1.c
> @@ -11,20 +11,12 @@ int hfi1_user_sdma_process_request(struc
> 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) {
> + req->tids = memdup_user(iovec[idx].iov_base,
> + sizeof(*req->tids) * ntids);
> + if (IS_ERR(req->tids)) {
> + ret = PTR_ERR(req->tids);
> SDMA_DBG(req, "Failed to copy %d TIDs (%d)",
> ntids, ret);
> - ret = -EFAULT;
> goto free_req;
> }
> req->n_tids = ntids;
>
>
> Regards,
> Markus
> _______________________________________________
> Cocci mailing list
> Cocci@systeme.lip6.fr
> https://systeme.lip6.fr/mailman/listinfo/cocci
>_______________________________________________
Cocci mailing list
Cocci@systeme.lip6.fr
https://systeme.lip6.fr/mailman/listinfo/cocci
