From: Srikar Dronamraju <srikar-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
To: Matt Fleming <matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>
Cc: Ingo Molnar <mingo-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
Thomas Gleixner <tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>,
"H . Peter Anvin" <hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Raghavendra K T
<raghavendra.kt-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>,
Dave Young <dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
Linus Torvalds
<torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>,
Borislav Petkov <bp-Gina5bIWoIWzQB+pC5nmwQ@public.gmane.org>
Subject: Re: [PATCH] x86/efi: Setup separate EFI page tables in kexec paths
Date: Fri, 22 Jan 2016 01:03:32 +0530 [thread overview]
Message-ID: <20160121193332.GA17206@linux.vnet.ibm.com> (raw)
In-Reply-To: <1453385519-11477-1-git-send-email-matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>
* Matt Fleming <matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org> [2016-01-21 14:11:59]:
> The switch to using a new dedicated page table for EFI runtime calls
> in commit commit 67a9108ed431 ("x86/efi: Build our own page table
> structures") failed to take into account changes required for the
> kexec code paths, which are unfortunately duplicated in the EFI code.
>
> Call the allocation and setup functions in kexec_enter_virtual_mode()
> just like we do for __efi_enter_virtual_mode() to avoid hitting
> NULL-pointer dereferences when making EFI runtime calls.
>
> At the very least, the call to efi_setup_page_tables() should have
> existed for kexec before commit 67a9108ed431. Things just magically
> worked because we were actually using the kernel's page tables that
> contained the required mappings.
>
> Reported-by: Srikar Dronamraju <srikar-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
> Cc: Raghavendra K T <raghavendra.kt-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
> Cc: Dave Young <dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> Cc: Ingo Molnar <mingo-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> Cc: Linus Torvalds <torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
> Cc: Borislav Petkov <bp-Gina5bIWoIWzQB+pC5nmwQ@public.gmane.org>
> Signed-off-by: Matt Fleming <matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>
Applied this patch on top of tip/x86/efi and was able to build and boot
the kernel.
--
Thanks and Regards
Srikar Dronamraju
WARNING: multiple messages have this Message-ID (diff)
From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
To: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Ingo Molnar <mingo@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
"H . Peter Anvin" <hpa@zytor.com>,
linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org,
Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>,
Dave Young <dyoung@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Borislav Petkov <bp@alien8.de>
Subject: Re: [PATCH] x86/efi: Setup separate EFI page tables in kexec paths
Date: Fri, 22 Jan 2016 01:03:32 +0530 [thread overview]
Message-ID: <20160121193332.GA17206@linux.vnet.ibm.com> (raw)
In-Reply-To: <1453385519-11477-1-git-send-email-matt@codeblueprint.co.uk>
* Matt Fleming <matt@codeblueprint.co.uk> [2016-01-21 14:11:59]:
> The switch to using a new dedicated page table for EFI runtime calls
> in commit commit 67a9108ed431 ("x86/efi: Build our own page table
> structures") failed to take into account changes required for the
> kexec code paths, which are unfortunately duplicated in the EFI code.
>
> Call the allocation and setup functions in kexec_enter_virtual_mode()
> just like we do for __efi_enter_virtual_mode() to avoid hitting
> NULL-pointer dereferences when making EFI runtime calls.
>
> At the very least, the call to efi_setup_page_tables() should have
> existed for kexec before commit 67a9108ed431. Things just magically
> worked because we were actually using the kernel's page tables that
> contained the required mappings.
>
> Reported-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
> Cc: Dave Young <dyoung@redhat.com>
> Cc: Ingo Molnar <mingo@kernel.org>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: Borislav Petkov <bp@alien8.de>
> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Applied this patch on top of tip/x86/efi and was able to build and boot
the kernel.
--
Thanks and Regards
Srikar Dronamraju
next prev parent reply other threads:[~2016-01-21 19:33 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-21 14:11 [PATCH] x86/efi: Setup separate EFI page tables in kexec paths Matt Fleming
2016-01-21 14:11 ` Matt Fleming
[not found] ` <1453385519-11477-1-git-send-email-matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>
2016-01-21 19:33 ` Srikar Dronamraju [this message]
2016-01-21 19:33 ` Srikar Dronamraju
2016-01-21 20:58 ` Matt Fleming
[not found] ` <20160121205815.GI2510-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>
2016-01-25 9:42 ` Matt Fleming
2016-01-25 9:42 ` Matt Fleming
2016-01-22 12:54 ` [tip:efi/core] " tip-bot for Matt Fleming
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