ARM: ensure that processor vtables is not lost after boot (3a4d0c21) · Commits · 戴 / test

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: ("ARM: spectre-v2: per-CPU vtables to work around big.Little systems") Signed-off-by:

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

arch/arm/mm/proc-macros.S

+10 −0

Original line number	Diff line number	Diff line
		@@ -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

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