arm64: 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 inclues callers
using virt_to_phys on image addresses instead of __pa_symbol. As features
such as CONFIG_VMAP_STACK get enabled for arm64, this becomes increasingly
important. Add checks to catch bad virt_to_phys usage.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Laura Abbott 2017-01-10 13:35:50 -08:00 коммит произвёл Will Deacon
Родитель 2077be6783
Коммит ec6d06efb0
4 изменённых файлов: 61 добавлений и 3 удалений

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@ -6,6 +6,7 @@ config ARM64
select ACPI_MCFG if ACPI
select ACPI_SPCR_TABLE if ACPI
select ARCH_CLOCKSOURCE_DATA
select ARCH_HAS_DEBUG_VIRTUAL
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
select ARCH_HAS_ELF_RANDOMIZE

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@ -172,10 +172,33 @@ static inline unsigned long kaslr_offset(void)
* private definitions which should NOT be used outside memory.h
* files. Use virt_to_phys/phys_to_virt/__pa/__va instead.
*/
#define __virt_to_phys(x) ({ \
/*
* The linear kernel range starts in the middle of the virtual adddress
* space. Testing the top bit for the start of the region is a
* sufficient check.
*/
#define __is_lm_address(addr) (!!((addr) & BIT(VA_BITS - 1)))
#define __lm_to_phys(addr) (((addr) & ~PAGE_OFFSET) + PHYS_OFFSET)
#define __kimg_to_phys(addr) ((addr) - kimage_voffset)
#define __virt_to_phys_nodebug(x) ({ \
phys_addr_t __x = (phys_addr_t)(x); \
__x & BIT(VA_BITS - 1) ? (__x & ~PAGE_OFFSET) + PHYS_OFFSET : \
(__x - kimage_voffset); })
__is_lm_address(__x) ? __lm_to_phys(__x) : \
__kimg_to_phys(__x); \
})
#define __pa_symbol_nodebug(x) __kimg_to_phys((phys_addr_t)(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
#define __phys_to_virt(x) ((unsigned long)((x) - PHYS_OFFSET) | PAGE_OFFSET)
#define __phys_to_kimg(x) ((unsigned long)((x) + kimage_voffset))
@ -207,6 +230,8 @@ 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 __pa_nodebug(x) __virt_to_phys_nodebug((unsigned long)(x))
#define __va(x) ((void *)__phys_to_virt((phys_addr_t)(x)))
#define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
#define virt_to_pfn(x) __phys_to_pfn(__virt_to_phys((unsigned long)(x)))

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@ -6,6 +6,8 @@ obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_ARM64_PTDUMP_CORE) += dump.o
obj-$(CONFIG_ARM64_PTDUMP_DEBUGFS) += ptdump_debugfs.o
obj-$(CONFIG_NUMA) += numa.o
obj-$(CONFIG_DEBUG_VIRTUAL) += physaddr.o
KASAN_SANITIZE_physaddr.o += n
obj-$(CONFIG_KASAN) += kasan_init.o
KASAN_SANITIZE_kasan_init.o := n

30
arch/arm64/mm/physaddr.c Normal file
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@ -0,0 +1,30 @@
#include <linux/bug.h>
#include <linux/export.h>
#include <linux/types.h>
#include <linux/mmdebug.h>
#include <linux/mm.h>
#include <asm/memory.h>
phys_addr_t __virt_to_phys(unsigned long x)
{
WARN(!__is_lm_address(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);