diff options
Diffstat (limited to 'arch/x86/include/asm/processor.h')
| -rw-r--r-- | arch/x86/include/asm/processor.h | 113 |
1 files changed, 68 insertions, 45 deletions
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 94227da69da1..b4e29d8b9e5a 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -7,6 +7,7 @@ /* Forward declaration, a strange C thing */ struct task_struct; struct mm_struct; +struct io_bitmap; struct vm86; #include <asm/math_emu.h> @@ -336,10 +337,32 @@ struct x86_hw_tss { * IO-bitmap sizes: */ #define IO_BITMAP_BITS 65536 -#define IO_BITMAP_BYTES (IO_BITMAP_BITS/8) -#define IO_BITMAP_LONGS (IO_BITMAP_BYTES/sizeof(long)) -#define IO_BITMAP_OFFSET (offsetof(struct tss_struct, io_bitmap) - offsetof(struct tss_struct, x86_tss)) -#define INVALID_IO_BITMAP_OFFSET 0x8000 +#define IO_BITMAP_BYTES (IO_BITMAP_BITS / BITS_PER_BYTE) +#define IO_BITMAP_LONGS (IO_BITMAP_BYTES / sizeof(long)) + +#define IO_BITMAP_OFFSET_VALID_MAP \ + (offsetof(struct tss_struct, io_bitmap.bitmap) - \ + offsetof(struct tss_struct, x86_tss)) + +#define IO_BITMAP_OFFSET_VALID_ALL \ + (offsetof(struct tss_struct, io_bitmap.mapall) - \ + offsetof(struct tss_struct, x86_tss)) + +#ifdef CONFIG_X86_IOPL_IOPERM +/* + * sizeof(unsigned long) coming from an extra "long" at the end of the + * iobitmap. The limit is inclusive, i.e. the last valid byte. + */ +# define __KERNEL_TSS_LIMIT \ + (IO_BITMAP_OFFSET_VALID_ALL + IO_BITMAP_BYTES + \ + sizeof(unsigned long) - 1) +#else +# define __KERNEL_TSS_LIMIT \ + (offsetof(struct tss_struct, x86_tss) + sizeof(struct x86_hw_tss) - 1) +#endif + +/* Base offset outside of TSS_LIMIT so unpriviledged IO causes #GP */ +#define IO_BITMAP_OFFSET_INVALID (__KERNEL_TSS_LIMIT + 1) struct entry_stack { unsigned long words[64]; @@ -349,13 +372,21 @@ struct entry_stack_page { struct entry_stack stack; } __aligned(PAGE_SIZE); -struct tss_struct { +/* + * All IO bitmap related data stored in the TSS: + */ +struct x86_io_bitmap { + /* The sequence number of the last active bitmap. */ + u64 prev_sequence; + /* - * The fixed hardware portion. This must not cross a page boundary - * at risk of violating the SDM's advice and potentially triggering - * errata. + * Store the dirty size of the last io bitmap offender. The next + * one will have to do the cleanup as the switch out to a non io + * bitmap user will just set x86_tss.io_bitmap_base to a value + * outside of the TSS limit. So for sane tasks there is no need to + * actually touch the io_bitmap at all. */ - struct x86_hw_tss x86_tss; + unsigned int prev_max; /* * The extra 1 is there because the CPU will access an @@ -363,21 +394,30 @@ struct tss_struct { * bitmap. The extra byte must be all 1 bits, and must * be within the limit. */ - unsigned long io_bitmap[IO_BITMAP_LONGS + 1]; + unsigned long bitmap[IO_BITMAP_LONGS + 1]; + + /* + * Special I/O bitmap to emulate IOPL(3). All bytes zero, + * except the additional byte at the end. + */ + unsigned long mapall[IO_BITMAP_LONGS + 1]; +}; + +struct tss_struct { + /* + * The fixed hardware portion. This must not cross a page boundary + * at risk of violating the SDM's advice and potentially triggering + * errata. + */ + struct x86_hw_tss x86_tss; + +#ifdef CONFIG_X86_IOPL_IOPERM + struct x86_io_bitmap io_bitmap; +#endif } __aligned(PAGE_SIZE); DECLARE_PER_CPU_PAGE_ALIGNED(struct tss_struct, cpu_tss_rw); -/* - * sizeof(unsigned long) coming from an extra "long" at the end - * of the iobitmap. - * - * -1? seg base+limit should be pointing to the address of the - * last valid byte - */ -#define __KERNEL_TSS_LIMIT \ - (IO_BITMAP_OFFSET + IO_BITMAP_BYTES + sizeof(unsigned long) - 1) - /* Per CPU interrupt stacks */ struct irq_stack { char stack[IRQ_STACK_SIZE]; @@ -488,10 +528,14 @@ struct thread_struct { struct vm86 *vm86; #endif /* IO permissions: */ - unsigned long *io_bitmap_ptr; - unsigned long iopl; - /* Max allowed port in the bitmap, in bytes: */ - unsigned io_bitmap_max; + struct io_bitmap *io_bitmap; + + /* + * IOPL. Priviledge level dependent I/O permission which is + * emulated via the I/O bitmap to prevent user space from disabling + * interrupts. + */ + unsigned long iopl_emul; mm_segment_t addr_limit; @@ -523,25 +567,6 @@ static inline void arch_thread_struct_whitelist(unsigned long *offset, */ #define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/ -/* - * Set IOPL bits in EFLAGS from given mask - */ -static inline void native_set_iopl_mask(unsigned mask) -{ -#ifdef CONFIG_X86_32 - unsigned int reg; - - asm volatile ("pushfl;" - "popl %0;" - "andl %1, %0;" - "orl %2, %0;" - "pushl %0;" - "popfl" - : "=&r" (reg) - : "i" (~X86_EFLAGS_IOPL), "r" (mask)); -#endif -} - static inline void native_load_sp0(unsigned long sp0) { @@ -581,7 +606,6 @@ static inline void load_sp0(unsigned long sp0) native_load_sp0(sp0); } -#define set_iopl_mask native_set_iopl_mask #endif /* CONFIG_PARAVIRT_XXL */ /* Free all resources held by a thread. */ @@ -849,7 +873,6 @@ static inline void spin_lock_prefetch(const void *x) #define INIT_THREAD { \ .sp0 = TOP_OF_INIT_STACK, \ .sysenter_cs = __KERNEL_CS, \ - .io_bitmap_ptr = NULL, \ .addr_limit = KERNEL_DS, \ } |