From: Eduardo Valentin <eduval@amazon.com>
To: Dave Hansen <dave.hansen@linux.intel.com>
Cc: <linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>,
<moritz.lipp@iaik.tugraz.at>, <daniel.gruss@iaik.tugraz.at>,
<michael.schwarz@iaik.tugraz.at>,
<richard.fellner@student.tugraz.at>, <luto@kernel.org>,
<torvalds@linux-foundation.org>, <keescook@google.com>,
<hughd@google.com>, <x86@kernel.org>, <aliguori@amazon.com>
Subject: Re: [PATCH 20/23] x86, kaiser: add a function to check for KAISER being enabled
Date: Fri, 24 Nov 2017 17:23:02 -0800 [thread overview]
Message-ID: <20171125012302.GD2017@u40b0340c692b58f6553c.ant.amazon.com> (raw)
In-Reply-To: <20171123003518.B7D81B14@viggo.jf.intel.com>
On Wed, Nov 22, 2017 at 04:35:18PM -0800, Dave Hansen wrote:
>
> From: Dave Hansen <dave.hansen@linux.intel.com>
>
> Currently, all of the checks for KAISER are compile-time checks.
>
> Runtime checks are needed for turning it on/off at runtime.
>
> Add a function to do that.
>
> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
> Cc: Moritz Lipp <moritz.lipp@iaik.tugraz.at>
> Cc: Daniel Gruss <daniel.gruss@iaik.tugraz.at>
> Cc: Michael Schwarz <michael.schwarz@iaik.tugraz.at>
> Cc: Richard Fellner <richard.fellner@student.tugraz.at>
> Cc: Andy Lutomirski <luto@kernel.org>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: Kees Cook <keescook@google.com>
> Cc: Hugh Dickins <hughd@google.com>
> Cc: x86@kernel.org
> ---
>
> b/arch/x86/include/asm/kaiser.h | 5 +++++
> b/include/linux/kaiser.h | 5 +++++
> 2 files changed, 10 insertions(+)
>
> diff -puN arch/x86/include/asm/kaiser.h~kaiser-dynamic-check-func arch/x86/include/asm/kaiser.h
> --- a/arch/x86/include/asm/kaiser.h~kaiser-dynamic-check-func 2017-11-22 15:45:55.262619723 -0800
> +++ b/arch/x86/include/asm/kaiser.h 2017-11-22 15:45:55.267619723 -0800
> @@ -56,6 +56,11 @@ extern void kaiser_remove_mapping(unsign
> */
> extern void kaiser_init(void);
>
> +static inline bool kaiser_active(void)
> +{
> + extern int kaiser_enabled;
Should this really be extern ?
I am getting a compilation error while linking the bzImage with this series:
arch/x86/boot/compressed/pagetable.o: In function `kernel_ident_mapping_init':
pagetable.c:(.text+0x336): undefined reference to `kaiser_enabled'
arch/x86/boot/compressed/Makefile:109: recipe for target 'arch/x86/boot/compressed/vmlinux' failed
make[2]: *** [arch/x86/boot/compressed/vmlinux] Error 1
arch/x86/boot/Makefile:112: recipe for target 'arch/x86/boot/compressed/vmlinux' failed
make[1]: *** [arch/x86/boot/compressed/vmlinux] Error 2
arch/x86/Makefile:296: recipe for target 'bzImage' failed
make: *** [bzImage] Error 2
What I did was to remove the extern and EXPORT_SYMBOL(kaiser_enabled) and initialize kaiser_enabled as 0, after that I got a proper bzImage.
> + return kaiser_enabled;
> +}
> #endif
>
> #endif /* __ASSEMBLY__ */
> diff -puN include/linux/kaiser.h~kaiser-dynamic-check-func include/linux/kaiser.h
> --- a/include/linux/kaiser.h~kaiser-dynamic-check-func 2017-11-22 15:45:55.264619723 -0800
> +++ b/include/linux/kaiser.h 2017-11-22 15:45:55.268619723 -0800
> @@ -28,5 +28,10 @@ static inline int kaiser_add_mapping(uns
> static inline void kaiser_add_mapping_cpu_entry(int cpu)
> {
> }
> +
> +static inline bool kaiser_active(void)
> +{
> + return 0;
> +}
> #endif /* !CONFIG_KAISER */
> #endif /* _INCLUDE_KAISER_H */
> _
>
--
All the best,
Eduardo Valentin
next prev parent reply other threads:[~2017-11-25 1:23 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-23 0:34 [PATCH 00/23] [v4] KAISER: unmap most of the kernel from userspace page tables Dave Hansen
2017-11-23 0:34 ` [PATCH 01/23] x86, kaiser: disable global pages by default with KAISER Dave Hansen
2017-11-23 0:34 ` [PATCH 02/23] x86, kaiser: prepare assembly for entry/exit CR3 switching Dave Hansen
2017-11-23 0:34 ` [PATCH 03/23] x86, kaiser: introduce user-mapped per-cpu areas Dave Hansen
2017-11-23 0:34 ` [PATCH 04/23] x86, kaiser: mark per-cpu data structures required for entry/exit Dave Hansen
2017-11-23 0:34 ` [PATCH 05/23] x86, kaiser: unmap kernel from userspace page tables (core patch) Dave Hansen
2017-11-23 4:07 ` Andy Lutomirski
2017-11-26 16:10 ` Andy Lutomirski
2017-11-26 16:24 ` Dave Hansen
2017-11-26 16:29 ` Andy Lutomirski
2018-01-05 4:16 ` Yisheng Xie
2018-01-05 5:18 ` Dave Hansen
2018-01-05 6:16 ` Yisheng Xie
2018-01-05 6:29 ` Dave Hansen
2018-01-05 11:49 ` Andrea Arcangeli
2018-01-05 18:19 ` Jiri Kosina
2018-01-05 19:00 ` Jiri Kosina
2018-01-05 19:03 ` Dave Hansen
2018-01-05 19:17 ` Jiri Kosina
2018-01-05 19:18 ` Jiri Kosina
2018-01-05 19:55 ` Andrea Arcangeli
2018-01-05 21:07 ` Dave Hansen
2018-01-05 21:14 ` Jiri Kosina
2018-01-05 21:29 ` Andy Lutomirski
2018-01-05 22:48 ` Hugh Dickins
2018-01-06 4:54 ` Hanjun Guo
2018-01-06 6:06 ` Dave Hansen
2018-01-06 6:28 ` Hanjun Guo
2018-01-06 6:53 ` Hanjun Guo
2018-01-06 7:55 ` Dave Hansen
2018-01-06 8:42 ` Hanjun Guo
2018-01-06 7:51 ` Dave Hansen
2018-01-06 17:22 ` Andrea Arcangeli
2017-11-23 0:34 ` [PATCH 06/23] x86, kaiser: allow NX poison to be set in p4d/pgd Dave Hansen
2017-11-23 0:34 ` [PATCH 07/23] x86, kaiser: make sure static PGDs are 8k in size Dave Hansen
2017-11-23 0:34 ` [PATCH 08/23] x86, kaiser: map cpu entry area Dave Hansen
2017-11-23 0:34 ` [PATCH 09/23] x86, kaiser: map dynamically-allocated LDTs Dave Hansen
2017-11-23 19:42 ` Eric Biggers
2017-11-23 20:12 ` Andy Lutomirski
2017-11-23 0:34 ` [PATCH 10/23] x86, kaiser: map espfix structures Dave Hansen
2017-11-23 0:34 ` [PATCH 11/23] x86, kaiser: map entry stack variables Dave Hansen
2017-11-23 3:31 ` Andy Lutomirski
2017-11-23 15:37 ` Dave Hansen
2017-11-23 15:55 ` Andy Lutomirski
2017-11-23 0:35 ` [PATCH 12/23] x86, kaiser: map virtually-addressed performance monitoring buffers Dave Hansen
2017-11-23 0:35 ` [PATCH 13/23] x86, mm: Move CR3 construction functions Dave Hansen
2017-11-23 0:35 ` [PATCH 14/23] x86, mm: remove hard-coded ASID limit checks Dave Hansen
2017-11-23 0:35 ` [PATCH 15/23] x86, mm: put mmu-to-h/w ASID translation in one place Dave Hansen
2017-11-23 0:35 ` [PATCH 16/23] x86, pcid, kaiser: allow flushing for future ASID switches Dave Hansen
2017-11-23 0:35 ` [PATCH 17/23] x86, kaiser: use PCID feature to make user and kernel switches faster Dave Hansen
2017-11-23 0:35 ` [PATCH 18/23] x86, kaiser: disable native VSYSCALL Dave Hansen
2017-11-23 0:35 ` [PATCH 19/23] x86, kaiser: add debugfs file to turn KAISER on/off at runtime Dave Hansen
2017-11-23 0:35 ` [PATCH 20/23] x86, kaiser: add a function to check for KAISER being enabled Dave Hansen
2017-11-25 1:23 ` Eduardo Valentin [this message]
2017-11-23 0:35 ` [PATCH 21/23] x86, kaiser: un-poison PGDs at runtime Dave Hansen
2017-11-25 1:17 ` Eduardo Valentin
2017-11-23 0:35 ` [PATCH 22/23] x86, kaiser: allow KAISER to be enabled/disabled " Dave Hansen
2017-11-23 0:35 ` [PATCH 23/23] x86, kaiser: add Kconfig Dave Hansen
2017-11-23 7:23 ` [PATCH 00/23] [v4] KAISER: unmap most of the kernel from userspace page tables Ingo Molnar
2017-11-23 7:27 ` Ingo Molnar
2017-11-23 7:32 ` Ingo Molnar
2017-11-23 15:02 ` Dave Hansen
2017-11-23 16:20 ` Dave Hansen
2017-11-24 6:35 ` Ingo Molnar
2017-11-24 6:41 ` Dave Hansen
2017-11-24 7:33 ` Ingo Molnar
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