From d1af2ab36d80fcdc15dcaaead68f15352778aec7 Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Wed, 18 Sep 2019 22:03:27 +0000 Subject: MIPS: Disable pte_special() for MIPS32 with RiXi Commit 61cbfff4b1a7 ("MIPS: pte_special()/pte_mkspecial() support") added a _PAGE_SPECIAL bit to the pgprot bits of our PTEs. Unfortunately for MIPS32 configurations with RiXi support this pushed the number of pgprot bits to 13. Since the PFN field in EntryLo begins at bit 12 this results in us shifting the most significant bit of the physical address beyond the end of the PTE, leading any mapped access to a physical address above 2GB to incorrectly access an address 2GB lower than intended. For now, disable the pte_special() support for MIPS32 configurations that support RiXi. Fixes: 61cbfff4b1a7 ("MIPS: pte_special()/pte_mkspecial() support") Signed-off-by: Paul Burton Cc: Dmitry Korotin Cc: linux-mips@vger.kernel.org --- arch/mips/Kconfig | 2 +- arch/mips/include/asm/pgtable-bits.h | 14 +++++++++++++- 2 files changed, 14 insertions(+), 2 deletions(-) (limited to 'arch/mips') diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 3f18aa018a0c..2f7c050e8cde 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -84,7 +84,7 @@ config MIPS select RTC_LIB select SYSCTL_EXCEPTION_TRACE select VIRT_TO_BUS - select ARCH_HAS_PTE_SPECIAL + select ARCH_HAS_PTE_SPECIAL if !(32BIT && CPU_HAS_RIXI) menu "Machine selection" diff --git a/arch/mips/include/asm/pgtable-bits.h b/arch/mips/include/asm/pgtable-bits.h index 409ae01ed7be..4da79b85c179 100644 --- a/arch/mips/include/asm/pgtable-bits.h +++ b/arch/mips/include/asm/pgtable-bits.h @@ -52,7 +52,9 @@ enum pgtable_bits { _PAGE_WRITE_SHIFT, _PAGE_ACCESSED_SHIFT, _PAGE_MODIFIED_SHIFT, +#if defined(CONFIG_ARCH_HAS_PTE_SPECIAL) _PAGE_SPECIAL_SHIFT, +#endif }; /* @@ -79,7 +81,9 @@ enum pgtable_bits { _PAGE_WRITE_SHIFT, _PAGE_ACCESSED_SHIFT, _PAGE_MODIFIED_SHIFT, +#if defined(CONFIG_ARCH_HAS_PTE_SPECIAL) _PAGE_SPECIAL_SHIFT, +#endif }; #elif defined(CONFIG_CPU_R3K_TLB) @@ -92,7 +96,9 @@ enum pgtable_bits { _PAGE_WRITE_SHIFT, _PAGE_ACCESSED_SHIFT, _PAGE_MODIFIED_SHIFT, +#if defined(CONFIG_ARCH_HAS_PTE_SPECIAL) _PAGE_SPECIAL_SHIFT, +#endif /* Used by TLB hardware (placed in EntryLo) */ _PAGE_GLOBAL_SHIFT = 8, @@ -116,7 +122,9 @@ enum pgtable_bits { #if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) _PAGE_HUGE_SHIFT, #endif +#if defined(CONFIG_ARCH_HAS_PTE_SPECIAL) _PAGE_SPECIAL_SHIFT, +#endif /* Used by TLB hardware (placed in EntryLo*) */ #if defined(CONFIG_CPU_HAS_RIXI) @@ -139,7 +147,11 @@ enum pgtable_bits { #if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) # define _PAGE_HUGE (1 << _PAGE_HUGE_SHIFT) #endif -#define _PAGE_SPECIAL (1 << _PAGE_SPECIAL_SHIFT) +#if defined(CONFIG_ARCH_HAS_PTE_SPECIAL) +# define _PAGE_SPECIAL (1 << _PAGE_SPECIAL_SHIFT) +#else +# define _PAGE_SPECIAL 0 +#endif /* Used by TLB hardware (placed in EntryLo*) */ #if defined(CONFIG_XPA) -- cgit v1.2.3