x86/iopl: Remove legacy IOPL option (a24ca997) · Commits · 戴 / test

arch/x86/Kconfig

+3 −20

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		@@ -1254,12 +1254,9 @@ config X86_VSYSCALL_EMULATION
		Disabling this option saves about 7K of kernel size and
		possibly 4K of additional runtime pagetable memory.

		choice
		prompt "IOPL"
		default X86_IOPL_EMULATION

		config X86_IOPL_EMULATION
		bool "IOPL Emulation"
		default y
		---help---
		Legacy IOPL support is an overbroad mechanism which allows user
		space aside of accessing all 65536 I/O ports also to disable
		@@ -1269,22 +1266,8 @@ config X86_IOPL_EMULATION

		The emulation restricts the functionality of the syscall to
		only allowing the full range I/O port access, but prevents the
		ability to disable interrupts from user space.

		config X86_IOPL_LEGACY
		bool "IOPL Legacy"
		---help---
		Allow the full IOPL permissions, i.e. user space access to all
		65536 I/O ports and also the ability to disable interrupts, which
		is overbroad and can result in system lockups.

		config X86_IOPL_NONE
		bool "IOPL None"
		---help---
		Disable the IOPL permission syscall. That's the safest option as
		no sane application should depend on this functionality.

		endchoice
		ability to disable interrupts from user space which would be
		granted if the hardware IOPL mechanism would be used.

		config TOSHIBA
		tristate "Toshiba Laptop support"

+0 −4

Original line number	Diff line number	Diff line
		@@ -294,10 +294,6 @@ static inline void write_idt_entry(gate_desc dt, int entry, const gate_desc g)
		{
		PVOP_VCALL3(cpu.write_idt_entry, dt, entry, g);
		}
		static inline void set_iopl_mask(unsigned mask)
		{
		PVOP_VCALL1(cpu.set_iopl_mask, mask);
		}

		static inline void paravirt_activate_mm(struct mm_struct *prev,
		struct mm_struct *next)

+0 −2

Original line number	Diff line number	Diff line
		@@ -140,8 +140,6 @@ struct pv_cpu_ops {

		void (*load_sp0)(unsigned long sp0);

		void (*set_iopl_mask)(unsigned mask);

		void (*wbinvd)(void);

		/* cpuid emulation, mostly so that caps bits can be disabled */

+3 −23

Original line number	Diff line number	Diff line
		@@ -516,10 +516,10 @@ struct thread_struct {
		struct io_bitmap *io_bitmap;

		/*
		* IOPL. Priviledge level dependent I/O permission which includes
		* user space CLI/STI when granted.
		* 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;
		unsigned long iopl_emul;

		mm_segment_t addr_limit;
		@@ -552,25 +552,6 @@ 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)
		{
		@@ -610,7 +591,6 @@ 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. */

+0 −2

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		@@ -62,6 +62,4 @@ void xen_arch_register_cpu(int num);
		void xen_arch_unregister_cpu(int num);
		#endif

		extern void xen_set_iopl_mask(unsigned mask);

		#endif /* _ASM_X86_XEN_HYPERVISOR_H */