On Fri, 16 Apr 2021 20:28:40 +0200 Eric Dumazet wrote: > On Fri, Apr 16, 2021 at 7:57 PM Jakub Kicinski <k...@kernel.org> wrote: > > > > On Thu, 15 Apr 2021 10:37:53 -0700 Eric Dumazet wrote: > > > From: Eric Dumazet <eduma...@google.com> > > > > > > Calling two copy_to_user() for very small regions has very high overhead. > > > > > > Switch to inlined unsafe_put_user() to save one stac/clac sequence, > > > and avoid copy_to_user(). > > > > > > Signed-off-by: Eric Dumazet <eduma...@google.com> > > > Cc: Soheil Hassas Yeganeh <soh...@google.com> > > > > Hi Eric! > > > > This appears to break boot on my systems. > > > > IDK how exactly, looks like systemd gets stuck waiting for nondescript > > services to start in initramfs. I have lots of debug enabled and didn't > > spot anything of note in kernel logs. > > > > I'll try to poke at this more, but LMK if you have any ideas. The > > commit looks "obviously correct" :S > > Oops, my rebase went wong, sorry for that
Ah, my eyes failed to spot that :) > Can you check this patch (on top of the buggy one) ? > > If that works, I'll submit a v2 It's already merged. Let me try the fix now... > diff --git a/net/core/scm.c b/net/core/scm.c > index > bd96c922041d22a2f3b7ee73e4b3183316f9b616..ae3085d9aae8adb81d3bb42c8a915a205476a0ee > 100644 > --- a/net/core/scm.c > +++ b/net/core/scm.c > @@ -232,7 +232,7 @@ int put_cmsg(struct msghdr * msg, int level, int > type, int len, void *data) > if (!user_write_access_begin(cm, cmlen)) > goto efault; > > - unsafe_put_user(len, &cm->cmsg_len, efault_end); > + unsafe_put_user(cmlen, &cm->cmsg_len, efault_end); > unsafe_put_user(level, &cm->cmsg_level, efault_end); > unsafe_put_user(type, &cm->cmsg_type, efault_end); > unsafe_copy_to_user(CMSG_USER_DATA(cm), data,
