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ARM: ensure that processor vtables is not lost after boot

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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: 383fb3ee80 ("ARM: spectre-v2: per-CPU vtables to work around big.Little systems")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
This commit is contained in:
Russell King 2018-12-06 16:36:38 +00:00
parent 383fb3ee80
commit 3a4d0c2172
1 changed files with 10 additions and 0 deletions
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10
arch/arm/mm/proc-macros.S
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@ -274,6 +274,13 @@
.endm .endm
.macro define_processor_functions name:req, dabort:req, pabort:req, nommu=0, suspend=0, bugs=0 .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 .type \name\()_processor_functions, #object
.align 2 .align 2
ENTRY(\name\()_processor_functions) ENTRY(\name\()_processor_functions)
@ -309,6 +316,9 @@ ENTRY(\name\()_processor_functions)
.endif .endif
.size \name\()_processor_functions, . - \name\()_processor_functions .size \name\()_processor_functions, . - \name\()_processor_functions
#if 1 // defined(CONFIG_BIG_LITTLE) && defined(CONFIG_HARDEN_BRANCH_PREDICTOR)
.previous
#endif
.endm .endm
.macro define_cache_functions name:req .macro define_cache_functions name:req