diff options
| -rw-r--r-- | arch/x86/Kconfig | 7 | ||||
| -rw-r--r-- | arch/x86/include/asm/io_bitmap.h | 6 | ||||
| -rw-r--r-- | arch/x86/include/asm/processor.h | 9 | ||||
| -rw-r--r-- | arch/x86/include/asm/thread_info.h | 7 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 26 | ||||
| -rw-r--r-- | arch/x86/kernel/ioport.c | 26 | ||||
| -rw-r--r-- | arch/x86/kernel/process.c | 4 |
7 files changed, 65 insertions, 20 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 1f926e396ec1..b162ce1482fc 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1254,10 +1254,13 @@ config X86_VSYSCALL_EMULATION Disabling this option saves about 7K of kernel size and possibly 4K of additional runtime pagetable memory. -config X86_IOPL_EMULATION - bool "IOPL Emulation" +config X86_IOPL_IOPERM + bool "IOPERM and IOPL Emulation" default y ---help--- + This enables the ioperm() and iopl() syscalls which are necessary + for legacy applications. + Legacy IOPL support is an overbroad mechanism which allows user space aside of accessing all 65536 I/O ports also to disable interrupts. To gain this access the caller needs CAP_SYS_RAWIO diff --git a/arch/x86/include/asm/io_bitmap.h b/arch/x86/include/asm/io_bitmap.h index b664baadf736..02c6ef8f7667 100644 --- a/arch/x86/include/asm/io_bitmap.h +++ b/arch/x86/include/asm/io_bitmap.h @@ -15,9 +15,15 @@ struct io_bitmap { struct task_struct; +#ifdef CONFIG_X86_IOPL_IOPERM void io_bitmap_share(struct task_struct *tsk); void io_bitmap_exit(void); void tss_update_io_bitmap(void); +#else +static inline void io_bitmap_share(struct task_struct *tsk) { } +static inline void io_bitmap_exit(void) { } +static inline void tss_update_io_bitmap(void) { } +#endif #endif diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 1387d31c5e07..45f416a2c1f1 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -340,13 +340,18 @@ struct x86_hw_tss { (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 \ +# 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) @@ -398,7 +403,9 @@ struct tss_struct { */ 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); diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index 0accf44878a5..d779366ce3f8 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -156,8 +156,13 @@ struct thread_info { # define _TIF_WORK_CTXSW (_TIF_WORK_CTXSW_BASE) #endif -#define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW| _TIF_USER_RETURN_NOTIFY | \ +#ifdef CONFIG_X86_IOPL_IOPERM +# define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW| _TIF_USER_RETURN_NOTIFY | \ _TIF_IO_BITMAP) +#else +# define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW| _TIF_USER_RETURN_NOTIFY) +#endif + #define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW) #define STACK_WARN (THREAD_SIZE/8) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 7bf402be13bb..6f6ca6bd58d6 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1804,6 +1804,22 @@ static inline void gdt_setup_doublefault_tss(int cpu) } #endif /* !CONFIG_X86_64 */ +static inline void tss_setup_io_bitmap(struct tss_struct *tss) +{ + tss->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET_INVALID; + +#ifdef CONFIG_X86_IOPL_IOPERM + tss->io_bitmap.prev_max = 0; + tss->io_bitmap.prev_sequence = 0; + memset(tss->io_bitmap.bitmap, 0xff, sizeof(tss->io_bitmap.bitmap)); + /* + * Invalidate the extra array entry past the end of the all + * permission bitmap as required by the hardware. + */ + tss->io_bitmap.mapall[IO_BITMAP_LONGS] = ~0UL; +#endif +} + /* * cpu_init() initializes state that is per-CPU. Some data is already * initialized (naturally) in the bootstrap process, such as the GDT @@ -1860,15 +1876,7 @@ void cpu_init(void) /* Initialize the TSS. */ tss_setup_ist(tss); - tss->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET_INVALID; - tss->io_bitmap.prev_max = 0; - tss->io_bitmap.prev_sequence = 0; - memset(tss->io_bitmap.bitmap, 0xff, sizeof(tss->io_bitmap.bitmap)); - /* - * Invalidate the extra array entry past the end of the all - * permission bitmap as required by the hardware. - */ - tss->io_bitmap.mapall[IO_BITMAP_LONGS] = ~0UL; + tss_setup_io_bitmap(tss); set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss); load_TR_desc(); diff --git a/arch/x86/kernel/ioport.c b/arch/x86/kernel/ioport.c index d5dcde972c42..8abeee0dd7bf 100644 --- a/arch/x86/kernel/ioport.c +++ b/arch/x86/kernel/ioport.c @@ -14,6 +14,8 @@ #include <asm/io_bitmap.h> #include <asm/desc.h> +#ifdef CONFIG_X86_IOPL_IOPERM + static atomic64_t io_bitmap_sequence; void io_bitmap_share(struct task_struct *tsk) @@ -172,13 +174,6 @@ SYSCALL_DEFINE1(iopl, unsigned int, level) struct thread_struct *t = ¤t->thread; unsigned int old; - /* - * Careful: the IOPL bits in regs->flags are undefined under Xen PV - * and changing them has no effect. - */ - if (IS_ENABLED(CONFIG_X86_IOPL_NONE)) - return -ENOSYS; - if (level > 3) return -EINVAL; @@ -200,3 +195,20 @@ SYSCALL_DEFINE1(iopl, unsigned int, level) return 0; } + +#else /* CONFIG_X86_IOPL_IOPERM */ + +long ksys_ioperm(unsigned long from, unsigned long num, int turn_on) +{ + return -ENOSYS; +} +SYSCALL_DEFINE3(ioperm, unsigned long, from, unsigned long, num, int, turn_on) +{ + return -ENOSYS; +} + +SYSCALL_DEFINE1(iopl, unsigned int, level) +{ + return -ENOSYS; +} +#endif diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 8a844a5d5ae8..7964d7db9366 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -322,6 +322,7 @@ void arch_setup_new_exec(void) } } +#ifdef CONFIG_X86_IOPL_IOPERM static inline void tss_invalidate_io_bitmap(struct tss_struct *tss) { /* @@ -409,6 +410,9 @@ void tss_update_io_bitmap(void) tss_invalidate_io_bitmap(tss); } } +#else /* CONFIG_X86_IOPL_IOPERM */ +static inline void switch_to_bitmap(unsigned long tifp) { } +#endif #ifdef CONFIG_SMP |