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78be3706b2
We allow for the fact that the guest kernel may not run in ring 0. This requires some abstraction in a few places when setting %cs or checking privilege level (user vs kernel). This is Chris' [RFC PATCH 15/33] move segment checks to subarch, except rather than using #define USER_MODE_MASK which depends on a config option, we use Zach's more flexible approach of assuming ring 3 == userspace. I also used "get_kernel_rpl()" over "get_kernel_cs()" because I think it reads better in the code... 1) Remove the hardcoded 3 and introduce #define SEGMENT_RPL_MASK 3 2) Add a get_kernel_rpl() macro, and don't assume it's zero. And: Clean up of patch for letting kernel run other than ring 0: a. Add some comments about the SEGMENT_IS_*_CODE() macros. b. Add a USER_RPL macro. (Code was comparing a value to a mask in some places and to the magic number 3 in other places.) c. Add macros for table indicator field and use them. d. Change the entry.S tests for LDT stack segment to use the macros Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Andi Kleen <ak@suse.de>
88 lines
2.0 KiB
C
88 lines
2.0 KiB
C
#ifndef _I386_PTRACE_H
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#define _I386_PTRACE_H
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#define EBX 0
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#define ECX 1
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#define EDX 2
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#define ESI 3
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#define EDI 4
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#define EBP 5
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#define EAX 6
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#define DS 7
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#define ES 8
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#define FS 9
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#define GS 10
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#define ORIG_EAX 11
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#define EIP 12
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#define CS 13
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#define EFL 14
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#define UESP 15
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#define SS 16
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#define FRAME_SIZE 17
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/* this struct defines the way the registers are stored on the
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stack during a system call. */
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struct pt_regs {
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long ebx;
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long ecx;
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long edx;
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long esi;
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long edi;
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long ebp;
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long eax;
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int xds;
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int xes;
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long orig_eax;
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long eip;
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int xcs;
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long eflags;
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long esp;
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int xss;
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};
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/* Arbitrarily choose the same ptrace numbers as used by the Sparc code. */
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#define PTRACE_GETREGS 12
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#define PTRACE_SETREGS 13
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#define PTRACE_GETFPREGS 14
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#define PTRACE_SETFPREGS 15
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#define PTRACE_GETFPXREGS 18
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#define PTRACE_SETFPXREGS 19
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#define PTRACE_OLDSETOPTIONS 21
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#define PTRACE_GET_THREAD_AREA 25
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#define PTRACE_SET_THREAD_AREA 26
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#define PTRACE_SYSEMU 31
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#define PTRACE_SYSEMU_SINGLESTEP 32
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#ifdef __KERNEL__
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#include <asm/vm86.h>
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#include <asm/segment.h>
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struct task_struct;
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extern void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code);
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/*
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* user_mode_vm(regs) determines whether a register set came from user mode.
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* This is true if V8086 mode was enabled OR if the register set was from
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* protected mode with RPL-3 CS value. This tricky test checks that with
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* one comparison. Many places in the kernel can bypass this full check
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* if they have already ruled out V8086 mode, so user_mode(regs) can be used.
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*/
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static inline int user_mode(struct pt_regs *regs)
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{
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return (regs->xcs & SEGMENT_RPL_MASK) == USER_RPL;
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}
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static inline int user_mode_vm(struct pt_regs *regs)
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{
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return ((regs->xcs & SEGMENT_RPL_MASK) | (regs->eflags & VM_MASK)) >= USER_RPL;
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}
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#define instruction_pointer(regs) ((regs)->eip)
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extern unsigned long profile_pc(struct pt_regs *regs);
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#endif /* __KERNEL__ */
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#endif
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