From: Mark Brown <broonie@kernel.org>
To: Russell King - ARM Linux <linux@armlinux.org.uk>
Cc: Marc Zyngier <marc.zyngier@arm.com>,
David Long <dave.long@linaro.org>,
stable@vger.kernel.org, Florian Fainelli <f.fainelli@gmail.com>,
Tony Lindgren <tony@atomide.com>,
Mark Rutland <mark.rutland@arm.com>,
Greg KH <gregkh@linuxfoundation.org>
Subject: Re: [PATCH 4.9 09/24] ARM: spectre-v2: add firmware based hardening
Date: Tue, 6 Nov 2018 16:53:29 +0000 [thread overview]
Message-ID: <20181106165329.GD31950@sirena.org.uk> (raw)
In-Reply-To: <20181106163044.GJ30658@n2100.armlinux.org.uk>
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On Tue, Nov 06, 2018 at 04:30:44PM +0000, Russell King - ARM Linux wrote:
> With any missing ENDPROC(), the only way to currently detect it is by
> trying to run the code path - building alone does not flag any warnings
> or errors. That's because the assembler has no idea whether what is
> being assembled is code or data, and the purpose of ENDPROC() is to
> mark it as code for the rest of the toolchain, so that it can apply the
> bit 0 "fixup" for Thumb2 code.
> So, in this case, the only way the error is detectable is to have a
> platform where we boot a kernel which makes use of the HVC fixup path.
> If that's too much to ask, then we're just going to have to accept that
> Thumb2 kernels are going to be more fragile than ARM kernels because
> there's no way to be certain that we have the correct annotations
> everywhere - so we're going to have to rely on users reporting these
> bugs _after_ the changes have hit mainline.
Oh, totally - but currently none of the automated stuff is even trying
to boot it so if we can do literally anything we'll be better off in
terms of coverage even though it doesn't address the fundemental
fragility.
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next prev parent reply other threads:[~2018-11-07 2:19 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-31 13:56 [PATCH 4.9 00/24] V4.9 backport of 32-bit arm spectre patches David Long
2018-10-31 13:56 ` [PATCH 4.9 01/24] ARM: add more CPU part numbers for Cortex and Brahma B15 CPUs David Long
2018-10-31 13:56 ` [PATCH 4.9 02/24] ARM: bugs: prepare processor bug infrastructure David Long
2018-10-31 13:56 ` [PATCH 4.9 03/24] ARM: bugs: hook processor bug checking into SMP and suspend paths David Long
2018-10-31 13:56 ` [PATCH 4.9 04/24] ARM: bugs: add support for per-processor bug checking David Long
2018-10-31 13:56 ` [PATCH 4.9 05/24] ARM: spectre: add Kconfig symbol for CPUs vulnerable to Spectre David Long
2018-10-31 13:56 ` [PATCH 4.9 06/24] ARM: spectre-v2: harden branch predictor on context switches David Long
2018-10-31 13:56 ` [PATCH 4.9 07/24] ARM: spectre-v2: add Cortex A8 and A15 validation of the IBE bit David Long
2018-10-31 13:56 ` [PATCH 4.9 08/24] ARM: spectre-v2: harden user aborts in kernel space David Long
2018-10-31 13:56 ` [PATCH 4.9 09/24] ARM: spectre-v2: add firmware based hardening David Long
2018-11-06 10:40 ` Marc Zyngier
2018-11-06 10:55 ` Russell King - ARM Linux
2018-11-06 16:19 ` Mark Brown
2018-11-06 16:30 ` Russell King - ARM Linux
2018-11-06 16:53 ` Mark Brown [this message]
2018-11-06 16:20 ` David Long
2018-11-06 16:23 ` Russell King - ARM Linux
2018-10-31 13:56 ` [PATCH 4.9 10/24] ARM: spectre-v2: warn about incorrect context switching functions David Long
2018-10-31 13:57 ` [PATCH 4.9 11/24] ARM: KVM: invalidate BTB on guest exit for Cortex-A12/A17 David Long
2018-11-05 9:13 ` Marc Zyngier
2018-11-07 2:22 ` David Long
2018-11-07 2:23 ` David Long
2018-10-31 13:57 ` [PATCH 4.9 12/24] ARM: KVM: invalidate icache on guest exit for Cortex-A15 David Long
2018-10-31 13:57 ` [PATCH 4.9 13/24] ARM: spectre-v2: KVM: invalidate icache on guest exit for Brahma B15 David Long
2018-10-31 13:57 ` [PATCH 4.9 14/24] ARM: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handling David Long
2018-10-31 13:57 ` [PATCH 4.9 15/24] ARM: KVM: report support for SMCCC_ARCH_WORKAROUND_1 David Long
2018-10-31 13:57 ` [PATCH 4.9 16/24] ARM: spectre-v1: add speculation barrier (csdb) macros David Long
2018-10-31 13:57 ` [PATCH 4.9 17/24] ARM: spectre-v1: add array_index_mask_nospec() implementation David Long
2018-10-31 13:57 ` [PATCH 4.9 18/24] ARM: spectre-v1: fix syscall entry David Long
2018-10-31 13:57 ` [PATCH 4.9 19/24] ARM: signal: copy registers using __copy_from_user() David Long
2018-10-31 13:57 ` [PATCH 4.9 20/24] ARM: vfp: use __copy_from_user() when restoring VFP state David Long
2018-10-31 13:57 ` [PATCH 4.9 21/24] ARM: oabi-compat: copy semops using __copy_from_user() David Long
2018-10-31 13:57 ` [PATCH 4.9 22/24] ARM: use __inttype() in get_user() David Long
2018-10-31 13:57 ` [PATCH 4.9 23/24] ARM: spectre-v1: use get_user() for __get_user() David Long
2018-10-31 13:57 ` [PATCH 4.9 24/24] ARM: spectre-v1: mitigate user accesses David Long
2018-10-31 21:23 ` [PATCH 4.9 00/24] V4.9 backport of 32-bit arm spectre patches Florian Fainelli
2018-11-02 1:18 ` David Long
2018-11-02 8:54 ` Marc Zyngier
2018-11-02 17:22 ` David Long
2018-11-02 11:28 ` Russell King - ARM Linux
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