From: Al Viro <viro@zeniv.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Borislav Petkov <bp@alien8.de>,
LKML <linux-kernel@vger.kernel.org>,
the arch/x86 maintainers <x86@kernel.org>
Subject: Re: [patch 01/10] x86/fpu/signal: Clarify exception handling in restore_fpregs_from_user()
Date: Tue, 31 Aug 2021 00:06:39 +0000 [thread overview]
Message-ID: <YS1yj+mUtvnCab1g@zeniv-ca.linux.org.uk> (raw)
In-Reply-To: <CAHk-=wh57tMaJxcH=kWE4xdKLjayKSDEVvMwHG4fKZ5tUHF6mg@mail.gmail.com>
On Mon, Aug 30, 2021 at 03:00:06PM -0700, Linus Torvalds wrote:
> On Mon, Aug 30, 2021 at 2:33 PM Al Viro <viro@zeniv.linux.org.uk> wrote:
> >
> > There's a place where we care about #PF vs. #MC (see upthread)...
>
> Interestingly (or perhaps not), that case is a problem case in general
> for "fault_in_pages_readable()".
s/a/the one and only/
> I'm not sure what the right model here is. We might need to make
> fault_in_pages_readable() do things a cacheline at a time, at which
> point those repeat loops start working, and the error code thing
> becomes pointless.
We really don't want to do that to fault_in_pages_readable();
a separate primitive doing that - perhaps, but fault_in_pages_readable()
is used on fairly hot paths and all callers except this one don't need
anything of that sort.
Similar for fault_in_pages_writeable() - there's exactly one
caller that needs the same kind of warranties, only there it's in
arch-independent code and I'm fairly sure that it (btrfs ioctl) really
is broken on arm64...
next prev parent reply other threads:[~2021-08-31 0:06 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-30 16:27 [patch 00/10] x86/fpu: Clean up error handling in sigframe related code Thomas Gleixner
2021-08-30 16:27 ` [patch 01/10] x86/fpu/signal: Clarify exception handling in restore_fpregs_from_user() Thomas Gleixner
2021-08-30 19:33 ` Borislav Petkov
2021-08-30 20:07 ` Borislav Petkov
2021-08-30 20:09 ` Thomas Gleixner
2021-08-30 21:02 ` Al Viro
2021-08-30 21:26 ` Linus Torvalds
2021-08-30 21:30 ` Al Viro
2021-08-30 22:00 ` Linus Torvalds
2021-08-30 22:12 ` Thomas Gleixner
2021-08-30 22:26 ` Linus Torvalds
2021-08-31 0:06 ` Al Viro [this message]
2021-08-31 0:34 ` Thomas Gleixner
2021-08-31 7:39 ` Borislav Petkov
2021-08-31 18:39 ` Luck, Tony
2021-09-01 7:27 ` Borislav Petkov
2021-08-30 22:01 ` Thomas Gleixner
2021-08-30 22:11 ` Linus Torvalds
2021-09-01 12:00 ` Thomas Gleixner
2021-09-01 15:52 ` Thomas Gleixner
2021-09-01 16:47 ` Sean Christopherson
2021-09-01 19:22 ` Thomas Gleixner
2021-09-01 19:22 ` Dave Hansen
2021-09-02 13:08 ` Jarkko Sakkinen
2021-09-02 14:08 ` Thomas Gleixner
2021-09-03 6:00 ` Jarkko Sakkinen
2021-09-03 6:05 ` Jarkko Sakkinen
2021-08-30 16:27 ` [patch 02/10] x86/fpu/signal: Move header zeroing out of xsave_to_user_sigframe() Thomas Gleixner
2021-08-30 16:27 ` [patch 03/10] x86/fpu/signal: Move xstate clearing out of copy_fpregs_to_sigframe() Thomas Gleixner
2021-08-30 16:27 ` [patch 04/10] x86/fpu/signal: Change return type of copy_fpstate_to_sigframe() to boolean Thomas Gleixner
2021-08-30 16:27 ` [patch 05/10] x86/fpu/signal: Change return type of copy_fpregs_to_sigframe() helpers " Thomas Gleixner
2021-08-30 16:27 ` [patch 06/10] x86/signal: Change return type of restore_sigcontext() " Thomas Gleixner
2021-08-30 16:27 ` [patch 07/10] x86/fpu/signal: Change return type of fpu__restore_sig() " Thomas Gleixner
2021-08-30 16:27 ` [patch 08/10] x86/fpu/signal: Change return type of __fpu_restore_sig() " Thomas Gleixner
2021-08-30 16:27 ` [patch 09/10] x86/fpu/signal: Change return code of check_xstate_in_sigframe() " Thomas Gleixner
2021-08-30 16:27 ` [patch 10/10] x86/fpu/signal: Change return code of restore_fpregs_from_user() " Thomas Gleixner
2021-08-30 17:39 ` [patch 00/10] x86/fpu: Clean up error handling in sigframe related code Linus Torvalds
2021-08-30 18:51 ` Thomas Gleixner
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