[{"id":3683296,"web_url":"http://patchwork.ozlabs.org/comment/3683296/","msgid":"","date":"2026-04-28T09:25:11","subject":"Re: [RFC PATCH v1 4/9] uaccess: Introduce\n copy_{to/from}_user_partial()","submitter":{"id":703,"url":"http://patchwork.ozlabs.org/api/people/703/","name":"Geert Uytterhoeven","email":"geert@linux-m68k.org"},"content":"Hi Christophe,\n\nThanks for your patch!\n\nOn Mon, 27 Apr 2026 at 19:18, Christophe Leroy (CS GROUP)\n wrote:\n> Today there are approximately 3000 calls for copy_to_user() and\n> 3000 calls to copy_from_user().\n>\n> The majority of callers of copy_{to/from}_user() don't care about the\n> return value, they only check whether it is 0 or not, and when it is\n> not 0 they handle it as a -EACCES.\n\nI think the \"a\" can be dropped.\n\n> In order to allow better optimisation of copy_{to/from}_user() when\n> the size of the copy is known at build time, create new fonctions\n\nfunctions\n\n> named copy_{to/from}_user_partial() to be used by the few callers\n> that are interested in partial copies and need to now how many\n\nknow\n\n> bytes remain at the end of the copy.\n>\n> For the time being it is just the same as copy_{to/from}_user().\n>\n> Signed-off-by: Christophe Leroy (CS GROUP) \n\nGr{oetje,eeting}s,\n\n Geert","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linuxppc-dev@lists.ozlabs.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org\n (client-ip=2404:9400:21b9:f100::1; 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