From e377cd8221ebbe0b517861aa3d823bb42f9abbd4 Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Sun, 15 Jan 2017 03:59:00 +0100 Subject: [PATCH] ARM: 8640/1: Add support for CONFIG_DEBUG_VIRTUAL x86 has an option: CONFIG_DEBUG_VIRTUAL to do additional checks on virt_to_phys calls. The goal is to catch users who are calling virt_to_phys on non-linear addresses immediately. This includes caller using __virt_to_phys() on image addresses instead of __pa_symbol(). This is a generally useful debug feature to spot bad code (particulary in drivers). Acked-by: Russell King Acked-by: Laura Abbott Signed-off-by: Florian Fainelli Signed-off-by: Russell King --- arch/arm/Kconfig | 1 + arch/arm/include/asm/memory.h | 15 +++++++-- arch/arm/mm/Makefile | 1 + arch/arm/mm/physaddr.c | 57 +++++++++++++++++++++++++++++++++++ 4 files changed, 72 insertions(+), 2 deletions(-) create mode 100644 arch/arm/mm/physaddr.c diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 5fab553fd03a..4700294f4e09 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -2,6 +2,7 @@ config ARM bool default y select ARCH_CLOCKSOURCE_DATA + select ARCH_HAS_DEBUG_VIRTUAL select ARCH_HAS_DEVMEM_IS_ALLOWED select ARCH_HAS_ELF_RANDOMIZE select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h index bee7511c5098..c30d0d82a105 100644 --- a/arch/arm/include/asm/memory.h +++ b/arch/arm/include/asm/memory.h @@ -213,7 +213,7 @@ extern const void *__pv_table_begin, *__pv_table_end; : "r" (x), "I" (__PV_BITS_31_24) \ : "cc") -static inline phys_addr_t __virt_to_phys(unsigned long x) +static inline phys_addr_t __virt_to_phys_nodebug(unsigned long x) { phys_addr_t t; @@ -245,7 +245,7 @@ static inline unsigned long __phys_to_virt(phys_addr_t x) #define PHYS_OFFSET PLAT_PHYS_OFFSET #define PHYS_PFN_OFFSET ((unsigned long)(PHYS_OFFSET >> PAGE_SHIFT)) -static inline phys_addr_t __virt_to_phys(unsigned long x) +static inline phys_addr_t __virt_to_phys_nodebug(unsigned long x) { return (phys_addr_t)x - PAGE_OFFSET + PHYS_OFFSET; } @@ -261,6 +261,16 @@ static inline unsigned long __phys_to_virt(phys_addr_t x) ((((unsigned long)(kaddr) - PAGE_OFFSET) >> PAGE_SHIFT) + \ PHYS_PFN_OFFSET) +#define __pa_symbol_nodebug(x) __virt_to_phys_nodebug((x)) + +#ifdef CONFIG_DEBUG_VIRTUAL +extern phys_addr_t __virt_to_phys(unsigned long x); +extern phys_addr_t __phys_addr_symbol(unsigned long x); +#else +#define __virt_to_phys(x) __virt_to_phys_nodebug(x) +#define __phys_addr_symbol(x) __pa_symbol_nodebug(x) +#endif + /* * These are *only* valid on the kernel direct mapped RAM memory. * Note: Drivers should NOT use these. They are the wrong @@ -283,6 +293,7 @@ static inline void *phys_to_virt(phys_addr_t x) * Drivers should NOT use these either. */ #define __pa(x) __virt_to_phys((unsigned long)(x)) +#define __pa_symbol(x) __phys_addr_symbol(RELOC_HIDE((unsigned long)(x), 0)) #define __va(x) ((void *)__phys_to_virt((phys_addr_t)(x))) #define pfn_to_kaddr(pfn) __va((phys_addr_t)(pfn) << PAGE_SHIFT) diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile index e8698241ece9..b3dea80715b4 100644 --- a/arch/arm/mm/Makefile +++ b/arch/arm/mm/Makefile @@ -14,6 +14,7 @@ endif obj-$(CONFIG_ARM_PTDUMP) += dump.o obj-$(CONFIG_MODULES) += proc-syms.o +obj-$(CONFIG_DEBUG_VIRTUAL) += physaddr.o obj-$(CONFIG_ALIGNMENT_TRAP) += alignment.o obj-$(CONFIG_HIGHMEM) += highmem.o diff --git a/arch/arm/mm/physaddr.c b/arch/arm/mm/physaddr.c new file mode 100644 index 000000000000..02e60f495608 --- /dev/null +++ b/arch/arm/mm/physaddr.c @@ -0,0 +1,57 @@ +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +#include "mm.h" + +static inline bool __virt_addr_valid(unsigned long x) +{ + /* + * high_memory does not get immediately defined, and there + * are early callers of __pa() against PAGE_OFFSET + */ + if (!high_memory && x >= PAGE_OFFSET) + return true; + + if (high_memory && x >= PAGE_OFFSET && x < (unsigned long)high_memory) + return true; + + /* + * MAX_DMA_ADDRESS is a virtual address that may not correspond to an + * actual physical address. Enough code relies on __pa(MAX_DMA_ADDRESS) + * that we just need to work around it and always return true. + */ + if (x == MAX_DMA_ADDRESS) + return true; + + return false; +} + +phys_addr_t __virt_to_phys(unsigned long x) +{ + WARN(!__virt_addr_valid(x), + "virt_to_phys used for non-linear address: %pK (%pS)\n", + (void *)x, (void *)x); + + return __virt_to_phys_nodebug(x); +} +EXPORT_SYMBOL(__virt_to_phys); + +phys_addr_t __phys_addr_symbol(unsigned long x) +{ + /* This is bounds checking against the kernel image only. + * __pa_symbol should only be used on kernel symbol addresses. + */ + VIRTUAL_BUG_ON(x < (unsigned long)KERNEL_START || + x > (unsigned long)KERNEL_END); + + return __pa_symbol_nodebug(x); +} +EXPORT_SYMBOL(__phys_addr_symbol); -- 2.30.2