From: Daniel Borkmann <daniel@iogearbox.net>
To: lkp@lists.01.org
Subject: Re: [net/bpf] 3051bf36c2 BUG: unable to handle kernel paging request at 0000a7cf
Date: Thu, 09 Mar 2017 19:31:03 +0100 [thread overview]
Message-ID: <58C19F67.3040509@iogearbox.net> (raw)
In-Reply-To: <CA+55aFyu-LHqMaZBaa7VNamxhUR99F4Xr+nL9esLDUBhotopVg@mail.gmail.com>
[-- Attachment #1: Type: text/plain, Size: 839 bytes --]
On 03/09/2017 07:15 PM, Linus Torvalds wrote:
> On Thu, Mar 9, 2017 at 10:10 AM, Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
>>
>> Very odd. We should always have PGE (0x0080) set in cr4 (if the CPU
>> supports it).
>
> Daniel, do you see the code in probe_page_size_mask() triggering?
>
> /* Enable PGE if available */
> if (boot_cpu_has(X86_FEATURE_PGE)) {
> cr4_set_bits_and_update_boot(X86_CR4_PGE);
> __supported_pte_mask |= _PAGE_GLOBAL;
We do have boot_cpu_has(X86_FEATURE_PGE) and go indeed into this
branch here. So it seems something must be clearing it later, hmm.
> } else
> __supported_pte_mask &= ~_PAGE_GLOBAL;
>
> but maybe there's something wrong with the percpu cr4 caching?
>
> Linus
>
WARNING: multiple messages have this Message-ID (diff)
From: Daniel Borkmann <daniel@iogearbox.net>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Kees Cook <keescook@chromium.org>,
Laura Abbott <labbott@redhat.com>, Ingo Molnar <mingo@kernel.org>,
Peter Anvin <hpa@zytor.com>,
Fengguang Wu <fengguang.wu@intel.com>,
Network Development <netdev@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>, LKP <lkp@01.org>,
ast@fb.com, the arch/x86 maintainers <x86@kernel.org>,
"David S. Miller" <davem@davemloft.net>
Subject: Re: [net/bpf] 3051bf36c2 BUG: unable to handle kernel paging request at 0000a7cf
Date: Thu, 09 Mar 2017 19:31:03 +0100 [thread overview]
Message-ID: <58C19F67.3040509@iogearbox.net> (raw)
In-Reply-To: <CA+55aFyu-LHqMaZBaa7VNamxhUR99F4Xr+nL9esLDUBhotopVg@mail.gmail.com>
On 03/09/2017 07:15 PM, Linus Torvalds wrote:
> On Thu, Mar 9, 2017 at 10:10 AM, Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
>>
>> Very odd. We should always have PGE (0x0080) set in cr4 (if the CPU
>> supports it).
>
> Daniel, do you see the code in probe_page_size_mask() triggering?
>
> /* Enable PGE if available */
> if (boot_cpu_has(X86_FEATURE_PGE)) {
> cr4_set_bits_and_update_boot(X86_CR4_PGE);
> __supported_pte_mask |= _PAGE_GLOBAL;
We do have boot_cpu_has(X86_FEATURE_PGE) and go indeed into this
branch here. So it seems something must be clearing it later, hmm.
> } else
> __supported_pte_mask &= ~_PAGE_GLOBAL;
>
> but maybe there's something wrong with the percpu cr4 caching?
>
> Linus
>
next prev parent reply other threads:[~2017-03-09 18:31 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-01 12:54 [net/bpf] 3051bf36c2 BUG: unable to handle kernel paging request at 0000a7cf Fengguang Wu
2017-03-01 12:54 ` Fengguang Wu
2017-03-02 20:23 ` Fengguang Wu
2017-03-02 20:23 ` Fengguang Wu
2017-03-02 20:40 ` Daniel Borkmann
2017-03-02 20:40 ` Daniel Borkmann
2017-03-08 19:25 ` Linus Torvalds
2017-03-08 19:25 ` Linus Torvalds
2017-03-08 22:27 ` Daniel Borkmann
2017-03-08 22:27 ` Daniel Borkmann
2017-03-08 22:36 ` Kees Cook
2017-03-08 22:36 ` Kees Cook
2017-03-08 22:51 ` Daniel Borkmann
2017-03-08 22:51 ` Daniel Borkmann
2017-03-08 23:55 ` Laura Abbott
2017-03-08 23:55 ` Laura Abbott
2017-03-09 5:36 ` Kees Cook
2017-03-09 5:36 ` Kees Cook
2017-03-09 13:04 ` Daniel Borkmann
2017-03-09 13:04 ` Daniel Borkmann
2017-03-09 13:10 ` Thomas Gleixner
2017-03-09 13:10 ` Thomas Gleixner
2017-03-09 13:25 ` Daniel Borkmann
2017-03-09 13:25 ` Daniel Borkmann
2017-03-09 14:49 ` Thomas Gleixner
2017-03-09 14:49 ` Thomas Gleixner
2017-03-09 17:51 ` Daniel Borkmann
2017-03-09 17:51 ` Daniel Borkmann
2017-03-09 18:08 ` David Miller
2017-03-09 18:08 ` David Miller
2017-03-09 18:10 ` Linus Torvalds
2017-03-09 18:10 ` Linus Torvalds
2017-03-09 18:15 ` Linus Torvalds
2017-03-09 18:15 ` Linus Torvalds
2017-03-09 18:31 ` Daniel Borkmann [this message]
2017-03-09 18:31 ` Daniel Borkmann
2017-03-09 21:32 ` Daniel Borkmann
2017-03-09 21:32 ` Daniel Borkmann
2017-03-09 21:32 ` Daniel Borkmann
2017-03-09 21:55 ` Borislav Petkov
2017-03-09 21:55 ` Borislav Petkov
2017-03-09 22:07 ` Borislav Petkov
2017-03-09 22:07 ` Borislav Petkov
2017-03-09 22:11 ` Daniel Borkmann
2017-03-09 22:11 ` Daniel Borkmann
2017-03-09 22:48 ` Borislav Petkov
2017-03-09 22:48 ` Borislav Petkov
2017-03-09 23:26 ` Linus Torvalds
2017-03-09 23:26 ` Linus Torvalds
2017-03-09 23:44 ` Borislav Petkov
2017-03-09 23:44 ` Borislav Petkov
2017-03-10 0:13 ` Daniel Borkmann
2017-03-10 0:13 ` Daniel Borkmann
2017-03-12 21:40 ` Borislav Petkov
2017-03-12 21:40 ` Borislav Petkov
2017-03-09 14:53 ` Daniel Borkmann
2017-03-09 14:53 ` Daniel Borkmann
2017-03-09 17:48 ` Linus Torvalds
2017-03-09 17:48 ` Linus Torvalds
2017-03-08 22:43 ` Linus Torvalds
2017-03-08 22:43 ` Linus Torvalds
2017-03-09 1:34 ` Fengguang Wu
2017-03-09 1:34 ` Fengguang Wu
2017-03-09 13:09 ` Thomas Gleixner
2017-03-09 13:09 ` Thomas Gleixner
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