From: Dave Hansen <dave.hansen@intel.com>
To: ira.weiny@intel.com, Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>
Cc: x86@kernel.org, Dave Hansen <dave.hansen@linux.intel.com>,
Dan Williams <dan.j.williams@intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
Fenghua Yu <fenghua.yu@intel.com>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-nvdimm@lists.01.org, linux-fsdevel@vger.kernel.org,
linux-mm@kvack.org, linux-kselftest@vger.kernel.org
Subject: Re: [PATCH RFC V3 8/9] x86/fault: Report the PKRS state on fault
Date: Tue, 13 Oct 2020 11:56:53 -0700 [thread overview]
Message-ID: <d6546e84-2196-25fd-3d8d-5e65fe22a71c@intel.com> (raw)
In-Reply-To: <20201009194258.3207172-9-ira.weiny@intel.com>
> @@ -548,6 +549,11 @@ show_fault_oops(struct pt_regs *regs, unsigned long error_code, unsigned long ad
> (error_code & X86_PF_PK) ? "protection keys violation" :
> "permissions violation");
>
> +#ifdef CONFIG_ARCH_HAS_SUPERVISOR_PKEYS
> + if (irq_state && (error_code & X86_PF_PK))
> + pr_alert("PKRS: 0x%x\n", irq_state->pkrs);
> +#endif
This means everyone will see 'PKRS: 0x0', even if they're on non-PKS
hardware. I think I'd rather have this only show PKRS when we're on
cpu_feature_enabled(PKS) hardware.
...
> @@ -1148,14 +1156,15 @@ static int fault_in_kernel_space(unsigned long address)
> */
> static void
> do_kern_addr_fault(struct pt_regs *regs, unsigned long hw_error_code,
> - unsigned long address)
> + unsigned long address, irqentry_state_t *irq_state)
> {
> /*
> - * Protection keys exceptions only happen on user pages. We
> - * have no user pages in the kernel portion of the address
> - * space, so do not expect them here.
> + * If protection keys are not enabled for kernel space
> + * do not expect Pkey errors here.
> */
Let's fix the double-negative:
/*
* PF_PK is only expected on kernel addresses whenn
* supervisor pkeys are enabled:
*/
> - WARN_ON_ONCE(hw_error_code & X86_PF_PK);
> + if (!IS_ENABLED(CONFIG_ARCH_HAS_SUPERVISOR_PKEYS) ||
> + !cpu_feature_enabled(X86_FEATURE_PKS))
> + WARN_ON_ONCE(hw_error_code & X86_PF_PK);
Yeah, please stick X86_FEATURE_PKS in disabled-features so you can use
cpu_feature_enabled(X86_FEATURE_PKS) by itself here..
next prev parent reply other threads:[~2020-10-13 18:56 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-09 19:42 [PATCH RFC V3 0/9] PKS: Add Protection Keys Supervisor (PKS) support RFC v3 ira.weiny
2020-10-09 19:42 ` [PATCH RFC V3 1/9] x86/pkeys: Create pkeys_common.h ira.weiny
2020-10-13 17:46 ` Dave Hansen
2020-10-13 19:44 ` Ira Weiny
2020-10-09 19:42 ` [PATCH RFC V3 2/9] x86/fpu: Refactor arch_set_user_pkey_access() for PKS support ira.weiny
2020-10-13 17:50 ` Dave Hansen
2020-10-13 23:56 ` Ira Weiny
2020-10-16 10:57 ` Peter Zijlstra
2020-10-17 3:32 ` Ira Weiny
2020-10-19 9:35 ` Peter Zijlstra
2020-10-09 19:42 ` [PATCH RFC V3 3/9] x86/pks: Enable Protection Keys Supervisor (PKS) ira.weiny
2020-10-13 18:23 ` Dave Hansen
2020-10-14 2:08 ` Ira Weiny
2020-10-09 19:42 ` [PATCH RFC V3 4/9] x86/pks: Preserve the PKRS MSR on context switch ira.weiny
2020-10-13 18:31 ` Dave Hansen
2020-10-14 22:36 ` Ira Weiny
2020-10-16 11:12 ` Peter Zijlstra
2020-10-17 5:14 ` Ira Weiny
2020-10-19 9:37 ` Peter Zijlstra
2020-10-19 18:48 ` Ira Weiny
2020-10-16 11:06 ` Peter Zijlstra
2020-10-17 5:37 ` Ira Weiny
2020-10-09 19:42 ` [PATCH RFC V3 5/9] x86/pks: Add PKS kernel API ira.weiny
2020-10-13 18:43 ` Dave Hansen
2020-10-15 1:08 ` Ira Weiny
2020-10-16 11:07 ` Peter Zijlstra
2020-10-17 5:42 ` Ira Weiny
2020-10-09 19:42 ` [PATCH RFC V3 6/9] x86/entry: Pass irqentry_state_t by reference ira.weiny
2020-10-16 11:45 ` Peter Zijlstra
2020-10-16 12:55 ` Thomas Gleixner
2020-10-19 5:37 ` Ira Weiny
2020-10-19 9:32 ` Thomas Gleixner
2020-10-19 20:26 ` Ira Weiny
2020-10-19 21:12 ` Thomas Gleixner
2020-10-20 14:10 ` Ira Weiny
2020-10-09 19:42 ` [PATCH RFC V3 7/9] x86/entry: Preserve PKRS MSR across exceptions ira.weiny
2020-10-13 18:52 ` Dave Hansen
2020-10-15 3:46 ` Ira Weiny
2020-10-15 4:06 ` Dave Hansen
2020-10-15 4:18 ` Ira Weiny
2020-10-09 19:42 ` [PATCH RFC V3 8/9] x86/fault: Report the PKRS state on fault ira.weiny
2020-10-13 18:56 ` Dave Hansen [this message]
2020-10-15 4:13 ` Ira Weiny
2020-10-09 19:42 ` [PATCH RFC V3 9/9] x86/pks: Add PKS test code ira.weiny
2020-10-13 19:02 ` Dave Hansen
2020-10-15 4:46 ` Ira Weiny
2020-10-09 20:18 ` [PATCH RFC V3 0/9] PKS: Add Protection Keys Supervisor (PKS) support RFC v3 Ira Weiny
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=d6546e84-2196-25fd-3d8d-5e65fe22a71c@intel.com \
--to=dave.hansen@intel.com \
--cc=akpm@linux-foundation.org \
--cc=bp@alien8.de \
--cc=dan.j.williams@intel.com \
--cc=dave.hansen@linux.intel.com \
--cc=fenghua.yu@intel.com \
--cc=ira.weiny@intel.com \
--cc=linux-doc@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-nvdimm@lists.01.org \
--cc=luto@kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).