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From: David Long <dave.long@linaro.org>
To: stable@vger.kernel.org,
	Russell King - ARM Linux <linux@armlinux.org.uk>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Julien Thierry <julien.thierry@arm.com>,
	Tony Lindgren <tony@atomide.com>,
	Marc Zyngier <marc.zyngier@arm.com>,
	Greg KH <gregkh@linuxfoundation.org>,
	Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>,
	Mark Brown <broonie@kernel.org>,
	linux-kernel@vger.kernel.org
Subject: [PATCH 4.19 16/17] ARM: ensure that processor vtables is not lost after boot
Date: Wed, 13 Feb 2019 16:32:22 -0500	[thread overview]
Message-ID: <20190213213223.916-17-dave.long@linaro.org> (raw)
In-Reply-To: <20190213213223.916-1-dave.long@linaro.org>

From: Russell King <rmk+kernel@armlinux.org.uk>

Commit 3a4d0c2172bcf15b7a3d9d498b2b355f9864286b upstream.

Marek Szyprowski reported problems with CPU hotplug in current kernels.
This was tracked down to the processor vtables being located in an
init section, and therefore discarded after kernel boot, despite being
required after boot to properly initialise the non-boot CPUs.

Arrange for these tables to end up in .rodata when required.

Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Krzysztof Kozlowski <krzk@kernel.org>
Fixes: 383fb3ee8024 ("ARM: spectre-v2: per-CPU vtables to work around big.Little systems")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David A. Long <dave.long@linaro.org>
---
 arch/arm/mm/proc-macros.S | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/arm/mm/proc-macros.S b/arch/arm/mm/proc-macros.S
index 81d0efb055c6..19516fbc2c55 100644
--- a/arch/arm/mm/proc-macros.S
+++ b/arch/arm/mm/proc-macros.S
@@ -274,6 +274,13 @@
 	.endm
 
 .macro define_processor_functions name:req, dabort:req, pabort:req, nommu=0, suspend=0, bugs=0
+/*
+ * If we are building for big.Little with branch predictor hardening,
+ * we need the processor function tables to remain available after boot.
+ */
+#if 1 // defined(CONFIG_BIG_LITTLE) && defined(CONFIG_HARDEN_BRANCH_PREDICTOR)
+	.section ".rodata"
+#endif
 	.type	\name\()_processor_functions, #object
 	.align 2
 ENTRY(\name\()_processor_functions)
@@ -309,6 +316,9 @@ ENTRY(\name\()_processor_functions)
 	.endif
 
 	.size	\name\()_processor_functions, . - \name\()_processor_functions
+#if 1 // defined(CONFIG_BIG_LITTLE) && defined(CONFIG_HARDEN_BRANCH_PREDICTOR)
+	.previous
+#endif
 .endm
 
 .macro define_cache_functions name:req
-- 
2.17.1


  parent reply	other threads:[~2019-02-13 21:33 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-13 21:32 [PATCH 4.19 00/17] V4.19 backport of more 32-bit arm spectre patches David Long
2019-02-13 21:32 ` [PATCH 4.19 01/17] ARM: 8789/1: signal: copy registers using __copy_to_user() David Long
2019-02-13 21:32 ` [PATCH 4.19 02/17] ARM: 8790/1: signal: always use __copy_to_user to save iwmmxt context David Long
2019-02-13 21:32 ` [PATCH 4.19 03/17] ARM: 8791/1: vfp: use __copy_to_user() when saving VFP state David Long
2019-02-13 21:32 ` [PATCH 4.19 04/17] ARM: 8792/1: oabi-compat: copy oabi events using __copy_to_user() David Long
2019-02-13 21:32 ` [PATCH 4.19 05/17] ARM: 8793/1: signal: replace __put_user_error with __put_user David Long
2019-02-13 21:32 ` [PATCH 4.19 06/17] ARM: 8794/1: uaccess: Prevent speculative use of the current addr_limit David Long
2019-02-13 21:32 ` [PATCH 4.19 07/17] ARM: 8795/1: spectre-v1.1: use put_user() for __put_user() David Long
2019-02-13 21:32 ` [PATCH 4.19 08/17] ARM: 8796/1: spectre-v1,v1.1: provide helpers for address sanitization David Long
2019-02-13 21:32 ` [PATCH 4.19 09/17] ARM: 8797/1: spectre-v1.1: harden __copy_to_user David Long
2019-02-13 21:32 ` [PATCH 4.19 10/17] ARM: 8810/1: vfp: Fix wrong assignement to ufp_exc David Long
2019-02-13 21:32 ` [PATCH 4.19 11/17] ARM: make lookup_processor_type() non-__init David Long
2019-02-13 21:32 ` [PATCH 4.19 12/17] ARM: split out processor lookup David Long
2019-02-13 21:32 ` [PATCH 4.19 13/17] ARM: clean up per-processor check_bugs method call David Long
2019-02-13 21:32 ` [PATCH 4.19 14/17] ARM: add PROC_VTABLE and PROC_TABLE macros David Long
2019-02-13 21:32 ` [PATCH 4.19 15/17] ARM: spectre-v2: per-CPU vtables to work around big.Little systems David Long
2019-02-13 21:32 ` David Long [this message]
2019-02-13 21:32 ` [PATCH 4.19 17/17] ARM: fix the cockup in the previous patch David Long
2019-02-14  8:50 ` [PATCH 4.19 00/17] V4.19 backport of more 32-bit arm spectre patches Julien Thierry
2019-02-17 19:20 ` Sasha Levin

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