From 90f92c631b210c1e97080b53a9d863783281a932 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Tue, 13 Sep 2016 12:31:17 +0100 Subject: ARM: 8613/1: Fix the uaccess crash on PB11MPCore The following patch was sketched by Russell in response to my crashes on the PB11MPCore after the patch for software-based priviledged no access support for ARMv8.1. See this thread: http://marc.info/?l=linux-arm-kernel&m=144051749807214&w=2 I am unsure what is going on, I suspect everyone involved in the discussion is. I just want to repost this to get the discussion restarted, as I still have to apply this patch with every kernel iteration to get my PB11MPCore Realview running. Testing by Neil Armstrong on the Oxnas NAS has revealed that this bug exist also on that widely deployed hardware, so we are probably currently regressing all ARM11MPCore systems. Cc: Russell King Cc: Will Deacon Fixes: a5e090acbf54 ("ARM: software-based priviledged-no-access support") Tested-by: Neil Armstrong Signed-off-by: Linus Walleij Signed-off-by: Russell King --- arch/arm/kernel/smp_tlb.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'arch/arm/kernel') diff --git a/arch/arm/kernel/smp_tlb.c b/arch/arm/kernel/smp_tlb.c index 22313cb53362..9af0701f7094 100644 --- a/arch/arm/kernel/smp_tlb.c +++ b/arch/arm/kernel/smp_tlb.c @@ -9,6 +9,7 @@ */ #include #include +#include #include #include @@ -40,8 +41,11 @@ static inline void ipi_flush_tlb_mm(void *arg) static inline void ipi_flush_tlb_page(void *arg) { struct tlb_args *ta = (struct tlb_args *)arg; + unsigned int __ua_flags = uaccess_save_and_enable(); local_flush_tlb_page(ta->ta_vma, ta->ta_start); + + uaccess_restore(__ua_flags); } static inline void ipi_flush_tlb_kernel_page(void *arg) @@ -54,8 +58,11 @@ static inline void ipi_flush_tlb_kernel_page(void *arg) static inline void ipi_flush_tlb_range(void *arg) { struct tlb_args *ta = (struct tlb_args *)arg; + unsigned int __ua_flags = uaccess_save_and_enable(); local_flush_tlb_range(ta->ta_vma, ta->ta_start, ta->ta_end); + + uaccess_restore(__ua_flags); } static inline void ipi_flush_tlb_kernel_range(void *arg) -- cgit v1.2.3