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Groups > linux.kernel > #1642875
| From | Dmitry Vyukov <dvyukov@google.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH] [iov_iter] use memmove() when copying to/from user page |
| Date | 2017-05-17 00:20 +0200 |
| Message-ID | <tHSYX-371-27@gated-at.bofh.it> (permalink) |
| References | (3 earlier) <tHQu6-1gw-17@gated-at.bofh.it> <tHR6O-1Me-21@gated-at.bofh.it> <tHRJv-23G-1@gated-at.bofh.it> <tHRTc-2nV-13@gated-at.bofh.it> <tHSme-2zE-21@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Tue, May 16, 2017 at 2:33 PM, Al Viro <viro@zeniv.linux.org.uk> wrote: > On Tue, May 16, 2017 at 02:01:51PM -0700, Dmitry Vyukov wrote: > >> > In that case your patch does not suffice. Overlapping move _forwards_ still >> > yields unexpected results, doesn't it? >> >> Why? memmove can move both ways. Do we need to change more memcpy's to >> memmove's? > > Because it's not going to be *one* call of memcpy() or memmove(). It's > one per page. I missed that. I assumed that in the case of sendfile from memfd to memfd data will be copied directly. But it goes through a pipe with multiple buffers. Does not look easily fixable.
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[PATCH] [iov_iter] use memmove() when copying to/from user page Alexander Potapenko <glider@google.com> - 2017-05-16 14:30 +0200
Re: [PATCH] [iov_iter] use memmove() when copying to/from user page Al Viro <viro@ZenIV.linux.org.uk> - 2017-05-16 20:50 +0200
Re: [PATCH] [iov_iter] use memmove() when copying to/from user page Dmitry Vyukov <dvyukov@google.com> - 2017-05-16 21:00 +0200
Re: [PATCH] [iov_iter] use memmove() when copying to/from user page Al Viro <viro@ZenIV.linux.org.uk> - 2017-05-16 21:40 +0200
Re: [PATCH] [iov_iter] use memmove() when copying to/from user page Dmitry Vyukov <dvyukov@google.com> - 2017-05-16 22:20 +0200
Re: [PATCH] [iov_iter] use memmove() when copying to/from user page Al Viro <viro@ZenIV.linux.org.uk> - 2017-05-16 23:00 +0200
Re: [PATCH] [iov_iter] use memmove() when copying to/from user page Dmitry Vyukov <dvyukov@google.com> - 2017-05-16 23:10 +0200
Re: [PATCH] [iov_iter] use memmove() when copying to/from user page Al Viro <viro@ZenIV.linux.org.uk> - 2017-05-16 23:40 +0200
Re: [PATCH] [iov_iter] use memmove() when copying to/from user page Dmitry Vyukov <dvyukov@google.com> - 2017-05-17 00:20 +0200
Re: [PATCH] [iov_iter] use memmove() when copying to/from user page Al Viro <viro@ZenIV.linux.org.uk> - 2017-05-17 00:50 +0200
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