From: Joerg Roedel <jroedel@suse.de>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Guenter Roeck <linux@roeck-us.net>,
linux-kernel@vger.kernel.org,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Thomas Gleixner <tglx@linutronix.de>,
Michal Hocko <mhocko@suse.com>, Andi Kleen <ak@linux.intel.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Dave Hansen <dave.hansen@intel.com>, Pavel Machek <pavel@ucw.cz>,
linux-efi@vger.kernel.org, x86@kernel.org
Subject: Re: Random crashes with i386 and efi boots
Date: Tue, 11 Sep 2018 19:41:58 +0200 [thread overview]
Message-ID: <20180911174158.7qu6f4vfnfzqqrcf@suse.de> (raw)
In-Reply-To: <90A7FF2E-F186-49CF-A028-CDE317BE13E1@amacapital.net>
On Tue, Sep 11, 2018 at 09:36:51AM -0700, Andy Lutomirski wrote:
> > save_pgd = efi_call_phys_prolog();
> > local_irq_save(flags);
> > status = efi_call_phys(...);
> > local_irq_restore(flags);
> >
> > efi_call_phys_epilog(save_pgd);
> >
> > So, yes, interrupts are very much enabled.
>
> Does fixing that solve the problem? It seems more robust.
The problem is still that in efi_call_phys_prolog() we load the gdt with
its physical address, and when we reload the %cr3 in _epilog from
initial_page_table to swapper_pg_dir again the gdt is no longer mapped.
Blocking interrupts is more robust, but we can't block NMIs that way
that would also trigger the issue, no?
So I am in favor of changing the order in efi_call_phys_epilog() too.
Regards,
Joerg
next prev parent reply other threads:[~2018-09-11 17:42 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-10 21:56 Random crashes with i386 and efi boots Guenter Roeck
2018-09-11 11:52 ` Andy Lutomirski
2018-09-11 13:30 ` Guenter Roeck
2018-09-11 16:36 ` Andy Lutomirski
2018-09-11 17:41 ` Joerg Roedel [this message]
2018-09-11 17:59 ` Linus Torvalds
2018-09-11 17:59 ` Guenter Roeck
2018-09-11 18:05 ` Andy Lutomirski
2018-09-11 18:22 ` Guenter Roeck
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