From: Chen Yu <yu.c.c...@intel.com> This patch implements acpi_os_readable(). The function is used by ACPICA AML debugger to validate user specified pointers for dumping the memory as ACPICA descriptor objects.
Signed-off-by: Chen Yu <yu.c.c...@intel.com> Tested-by: Lv Zheng <lv.zh...@intel.com> Signed-off-by: Lv Zheng <lv.zh...@intel.com> --- arch/x86/Kconfig | 1 + arch/x86/include/asm/acenv.h | 1 + arch/x86/kernel/acpi/boot.c | 44 +++++++++++++++++++++++++++++++++++++ drivers/acpi/Kconfig | 3 +++ drivers/acpi/osl.c | 12 ++++++++++ include/acpi/platform/aclinux.h | 1 - include/acpi/platform/aclinuxex.h | 5 ----- 7 files changed, 61 insertions(+), 6 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index db3622f..6593b6a 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -19,6 +19,7 @@ config X86 def_bool y select ACPI_LEGACY_TABLES_LOOKUP if ACPI select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI + select ACPI_MEMORY_ACCESS_CHECK_SUPPORT if ACPI select ANON_INODES select ARCH_CLOCKSOURCE_DATA select ARCH_DISCARD_MEMBLOCK diff --git a/arch/x86/include/asm/acenv.h b/arch/x86/include/asm/acenv.h index 1b010a8..a2a2849 100644 --- a/arch/x86/include/asm/acenv.h +++ b/arch/x86/include/asm/acenv.h @@ -20,6 +20,7 @@ int __acpi_acquire_global_lock(unsigned int *lock); int __acpi_release_global_lock(unsigned int *lock); +bool __acpi_memory_readable(void *pointer, size_t length); #define ACPI_ACQUIRE_GLOBAL_LOCK(facs, Acq) \ ((Acq) = __acpi_acquire_global_lock(&facs->global_lock)) diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index e759076..4a5e22e 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -1699,6 +1699,50 @@ int __acpi_release_global_lock(unsigned int *lock) return old & 0x1; } +bool __acpi_memory_readable(void *pointer, size_t length) +{ + unsigned long obj_start, obj_end; + unsigned long start_pfn, end_pfn; + + /* + * All direct mapped PFNs should have been recorded by the mapped + * PFN ranges. But pfn_range_is_mapped() requires the following + * sanity checks to be performed before invoking. + */ + obj_start = ACPI_TO_INTEGER(pointer); + obj_end = obj_start + length; + + /* + * ACPICA core doesn't validate if the object is wrapped over, so + * we should. + */ + if (length && (obj_end - 1) < obj_start) + return false; + + /* + * None direct mapping ranges contain holes. For example, high + * kernel map holes (lower than _text or higher than _brk_end). + * Converting a virtual address that belongs to the high map hole + * results in a valid PFN because its low map has been recorded as + * a mapped range. + */ + if (obj_start < PAGE_OFFSET || + obj_start >= (unsigned long)high_memory || + (length && (obj_end - 1) >= (unsigned long)high_memory)) + return false; + + /* + * It is required to pass a range (end_pfn - start_pfn > 0) to + * pfn_range_is_mapped(). + */ + start_pfn = PFN_DOWN(__pa(obj_start)); + end_pfn = PFN_UP(__pa(obj_end)); + if (unlikely(end_pfn == start_pfn)) + end_pfn++; + + return pfn_range_is_mapped(start_pfn, end_pfn); +} + void __init arch_reserve_mem_area(acpi_physical_address addr, size_t size) { e820_add_region(addr, size, E820_ACPI); diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index 82b96ee..9422133 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -57,6 +57,9 @@ config ACPI_SYSTEM_POWER_STATES_SUPPORT config ACPI_CCA_REQUIRED bool +config ACPI_MEMORY_ACCESS_CHECK_SUPPORT + bool + config ACPI_DEBUGGER bool "AML debugger interface" select ACPI_DEBUG diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c index bb66093..14a3beb 100644 --- a/drivers/acpi/osl.c +++ b/drivers/acpi/osl.c @@ -1585,6 +1585,18 @@ acpi_status acpi_os_get_line(char *buffer, u32 buffer_length, u32 *bytes_read) } EXPORT_SYMBOL(acpi_os_get_line); +#ifdef CONFIG_ACPI_MEMORY_ACCESS_CHECK_SUPPORT +u8 acpi_os_readable(void *pointer, acpi_size length) +{ + return __acpi_memory_readable(pointer, length) ? TRUE : FALSE; +} +#else +u8 acpi_os_readable(void *pointer, acpi_size length) +{ + return TRUE; +} +#endif + acpi_status acpi_os_wait_command_ready(void) { int ret; diff --git a/include/acpi/platform/aclinux.h b/include/acpi/platform/aclinux.h index e21857d..b3c493e 100644 --- a/include/acpi/platform/aclinux.h +++ b/include/acpi/platform/aclinux.h @@ -148,7 +148,6 @@ /* * OSL interfaces used by debugger/disassembler */ -#define ACPI_USE_ALTERNATE_PROTOTYPE_acpi_os_readable #define ACPI_USE_ALTERNATE_PROTOTYPE_acpi_os_writable #define ACPI_USE_ALTERNATE_PROTOTYPE_acpi_os_initialize_command_signals #define ACPI_USE_ALTERNATE_PROTOTYPE_acpi_os_terminate_command_signals diff --git a/include/acpi/platform/aclinuxex.h b/include/acpi/platform/aclinuxex.h index ceea026..94bead6 100644 --- a/include/acpi/platform/aclinuxex.h +++ b/include/acpi/platform/aclinuxex.h @@ -124,11 +124,6 @@ static inline acpi_thread_id acpi_os_get_thread_id(void) lock ? AE_OK : AE_NO_MEMORY; \ }) -static inline u8 acpi_os_readable(void *pointer, acpi_size length) -{ - return TRUE; -} - static inline acpi_status acpi_os_initialize_command_signals(void) { return AE_OK; -- 1.7.10 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/