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WTF: patch "[PATCH] arm64: mm: Remove arch_apei_flush_tlb_one()" was seriously submitted to be applied to the 4.14-stable tree?

PATCH [email protected] 1 participant 1 message Nov 27, 2017

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The patch below was submitted to be applied to the 4.14-stable tree.

I fail to see how this patch meets the stable kernel rules as found at Documentation/process/stable-kernel-rules.rst.

I could be totally wrong, and if so, please respond to <[email protected]> and let me know why this patch should be applied. Otherwise, it is now dropped from my patch queues, never to be seen again.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

Quoted 1 line

From 18b4b276b490a8b9f86c512de8a6054c27bb87c2 Mon Sep 17 00:00:00 2001

From: James Morse <[email protected]>
Date: Mon, 6 Nov 2017 18:44:26 +0000
Subject: [PATCH] arm64: mm: Remove arch_apei_flush_tlb_one()

Nothing calls arch_apei_flush_tlb_one() anymore, instead relying on __set_fixmap() to do the invalidation. Remove it.

Move the IPI-considered-harmful comment to __set_fixmap().

Signed-off-by James Morse <[email protected]>
Acked-by Will Deacon <[email protected]>
Tested-by Tyler Baicar <[email protected]>
Signed-off-by Rafael J. Wysocki <[email protected]>
Cc All applicable <[email protected]>
arch/arm64/include/asm/acpi.h +0 -12
index 59cca1d6ec54..32f465a80e4e 100644
@@ -126,18 +126,6 @@ static inline const char *acpi_get_enable_method(int cpu)
  */
 #define acpi_disable_cmcff 1
 pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr);
-
-/*
- * Despite its name, this function must still broadcast the TLB
- * invalidation in order to ensure other CPUs don't end up with junk
- * entries as a result of speculation. Unusually, its also called in
- * IRQ context (ghes_iounmap_irq) so if we ever need to use IPIs for
- * TLB broadcasting, then we're in trouble here.
- */
-static inline void arch_apei_flush_tlb_one(unsigned long addr)
-{
-	flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
-}
 #endif /* CONFIG_ACPI_APEI */
 
 #ifdef CONFIG_ACPI_NUMA
arch/arm64/mm/mmu.c +4 -0
index f1eb15e0e864..267d2b79d52d 100644
@@ -778,6 +778,10 @@ void __init early_fixmap_init(void)
 	}
 }
 
+/*
+ * Unusually, this is also called in IRQ context (ghes_iounmap_irq) so if we
+ * ever need to use IPIs for TLB broadcasting, then we're in trouble here.
+ */
 void __set_fixmap(enum fixed_addresses idx,
 			       phys_addr_t phys, pgprot_t flags)
 {