![Zachary Amsden](/assets/img/avatar_default.png)
Privilege checking cleanup. Originally, these diffs were much greater, but recent cleanups in Linux have already done much of the cleanup. I added some explanatory comments in places where the reasoning behind certain tests is rather subtle. Also, in traps.c, we can skip the user_mode check in handle_BUG(). The reason is, there are only two call chains - one via die_if_kernel() and one via do_page_fault(), both entering from die(). Both of these paths already ensure that a kernel mode failure has happened. Also, the original check here, if (user_mode(regs)) was insufficient anyways, since it would not rule out BUG faults from V8086 mode execution. Saving the %ss segment in show_regs() rather than assuming a fixed value also gives better information about the current kernel state in the register dump. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
88 lines
2 KiB
C
88 lines
2 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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#ifdef __KERNEL__
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#include <asm/vm86.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 & 3) != 0;
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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 & 3) | (regs->eflags & VM_MASK)) != 0;
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}
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#define instruction_pointer(regs) ((regs)->eip)
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#if defined(CONFIG_SMP) && defined(CONFIG_FRAME_POINTER)
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extern unsigned long profile_pc(struct pt_regs *regs);
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#else
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#define profile_pc(regs) instruction_pointer(regs)
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#endif
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#endif /* __KERNEL__ */
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#endif
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